BACKGROUND

Visual acuity charts are commonly used to measure visual acuity because they are standardized and easy to use, and can be widely distributed. Testing of visual acuity typically involves asking a patient to identify optotypes—visual patterns of letters or objects—presented on a test slide (or series of slides). Each slide includes one or more optotypes, arranged in one or more lines at one time. The patient's ability to identify optotypes as a function of their size is registered and scored to yield an estimate of visual acuity. The estimate of visual acuity obtained, e.g., the smallest optotype size that the patient can reliably see, can depend fundamentally on the design of testing and scoring, which is based on pre-determined rules and heuristics specific to each chart.

SUMMARY OF THE INVENTION

Two approaches to visual acuity testing have come to dominate the current art: chart tests in which patients identify multiple lines of optotypes presented at one time, or computerized testing in which optotypes are presented one at a time. The computerized test has gained recent favor, because it provides the potential advantage of increased test resolution, via the flexible and precise sampling of optotype size on digital displays, and the application of adaptive and personalized test strategies that focus testing to the specific vision of the patient.

One important shortcoming in existing acuity testing is the difference in chart design between charts used for clinical trials and clinical practice. Therefore, acuity testing results collected in clinical practice are only imprecisely related to those collected on the “gold standard” chart used in clinical trials. Due to long testing times needed for clinical trials, this chart design and testing standard remains unfeasible for clinical testing by eye care specialists or general practitioners. Even allowing for the longer times allowable in clinical research, the acuity testing results obtained with pediatric charts (e.g., HOTV, Lea designs) exhibit systemic biases when compared to those obtained from charts designed for adults.

The testing of visual acuity with precision presents a challenge. For many charts currently used in the clinical setting, acuity testing provides only qualitative rather than quantitative results (e.g., 20/20 or 20/40). Furthermore, the variety of chart designs in circulation across clinical testing sites can make it difficult to compare and coordinate acuity testing obtained with different charts. Without precision and concordance between the charts used for clinical vision testing, it remains difficult to track how vision changes with disease or treatment.

The systems and methods disclosed herein for testing and analysis of visual acuity address existing problems in acuity testing. Advantages of the systems and methods disclosed herein include development of personalized acuity charts based on subject-specific (interchangeable as chart-invariant) information related to his/her visual acuity. In some embodiments, another advantage of the systems and methods disclosed herein includes the capability of analyzing visual acuity data collected with a wide spectrum of acuity charts including but not limited to legacy charts. In some embodiments, yet another advantage of the systems and methods disclosed herein includes generation of precise acuity parameters that are independent of the acuity chart design(s) used to collect the data.

In some embodiments, disclosed herein is a scoring algorithm (interchangeable as algorithm S herein) that enables the analysis of visual acuity data collected optionally on different acuity chart designs. In some cases, disclosed herein is an adaptive algorithm (interchangeable as algorithm A) that improves the quality of visual acuity data by generating or selecting personalized chart designs that focus precisely on the acuity of the test subject. In some cases, disclosed herein is a combination algorithm, which combines algorithms A and S in a re-iterative fashion: the evaluation of previously collected acuity data (from the subject or from a population) is used to personalize chart designs for the collection of acuity chart data using algorithm A. In turn, that data can be scored using algorithm S, which provides an updated estimate of the patient's visual acuity. This re-iterative process can provide estimates of visual acuity with high precision and reduced testing times. In some embodiments, disclosed herein is an acuity model for analyzing visual acuity, which predicts visual performance during testing with different acuity chart designs. In some cases, such acuity models provide the foundation for algorithms S and A. In some embodiments, the acuity models disclosed herein provide a powerful description of acuity chart performance, which generalizes to predict visual performance across different acuity charts, using model parameters specific to the subject, and/or model parameters specific to each chart design. These model parameters specific to the subject (interchangeably herein as chart-invariant parameters) can provide the valuable acuity parameters that can be used to track visual health over time.

For instances, in the acuity models disclosed herein, the distinction of chart-specific and chart-invariant metrics (interchangeable as parameters) provides flexibility and versatility to the estimates of visual acuity. Such two sets of acuity metrics can be important and complementary. The set of chart-specific metrics may describe visual acuity within the context of the specific acuity chart used during testing. An alternative set of chart-invariant metrics can describe visual acuity independently of the design features of acuity charts. These comprehensive parameters therefore may have the flexibility to deliver acuity metrics that are specific to, or independent of, the acuity chart used for testing. The chart-specific metrics can be important for research and development applications that use the same chart over time. The chart-invariant metric approach is important to evaluate and compare data across different clinical practices and populations. As shown inFIG. 3A, a flow chart of an exemplary embodiment of generating the chart-invariant acuity model may include an operation230using chart-invariant acuity parameters, which then may be transformed into chart-specific acuity parameters330, depending on the design factors of the acuity chart.

The acuity models disclosed herein can also provide a foundation for novel presentations of visual acuity data. The visualization tools may help patients and clinicians to understand the changes in acuity that are being measured.

Since the same chart can often be used to measure vision in different eyes, at different distances, or in situations that require repeated measure of visual acuity (e.g., tracking the progression of an eye disease or treatment effects), it is difficult to prevent contamination between conditions. The recommendations of the National Academy of Sciences-National Research Council (NAS-NRC) committee and ANSI (American National Standards Institute) standards dictate that acuity charts should comprise multiple lines of optotypes that are logarithmically-decreasing in size. In addition to other design recommendations (5-10 optotypes per line, sampled randomly without replacement), the standards recommend against the single letter presentation used by computerized adaptive acuity methods.

Unlike traditional adaptive acuity testing methods that optimize optotype selection for only one letter at one size, the system and method disclose herein can advantageously enable composite optimization of acuity charts that concurrently estimate chart-specific and chart-invariant acuity metrics. Additional advantages associated with the methods and systems disclosed herein includes but are not limited to: a precise personalized focus on each individual subject while adhering to chart design standards, rapid testing times, comparable precision to time-consuming single-letter acuity tests, and visual acuity metrics that described the subject's vision independently of optotype sizes, test charts, or testing procedures. Both sets of acuity parameters, whether chart-specific or chart-invariant are interchangeable and inter-translatable, given knowledge of acuity chart design.

In some embodiments, the systems and methods disclosed herein includes a chart-based adaptive acuity test, which provides the advantages of standardization provided by chart-based testing, with the advantages of flexibility and precision provided by single-letter testing. The systems and methods disclosed herein can apply Bayesian adaptive algorithms to personalize and precisely focus acuity charts to optimally test the vision of each subject, while adhering to design constraints or recommendations from ruling committees, or more generally, while maintaining any desired design constraints at all. In some embodiments, the development of design-constrained optimization methods for visual acuity testing optionally using Bayesian adaptive algorithms and a signal detection framework provides one or more of: the adherence to chart design standards; precise personalization by adaptive testing that focuses on the individual; the short testing time of charts; the precision of longer single-letter acuity tests; correction for guessing behavior with different optotype sets; and visual acuity estimates that are invariant with respect to practical issues of acuity testing, e.g., the design of the visual test or the optotypes used.

In one aspect, disclosed herein is a computer-implemented method for generating an acuity model for scoring visual acuity of a subject, the method comprising: a) obtaining one or more acuity chart design parameters; b) collecting acuity test data of the subject; c) selecting a first set of chart-specific acuity parameters from one or more sets of candidate acuity parameters; d) generating an acuity model comprising: i) generating a single-optotype psychometric function, the single-optotype psychometric function comprising the first set of chart-specific acuity parameters; ii) calculating a family of multiple-optotype psychometric functions using the single-optotype psychometric function; and iii) generating a chart-specific psychometric function using the family of multiple-optotype psychometric functions, the chart-specific psychometric function comprising a second set of chart-specific acuity parameters, wherein the acuity model is configurable to estimate possibility of obtaining the acuity test data of the subject based on the one or more acuity chart design parameters. In some embodiments, the method further comprising, subsequent to (c) and prior to (i), generating a sensitivity-based psychometric function comprising a first set of chart-invariant sensitivity parameters, and wherein the first set of chart-invariant sensitivity parameters comprises a sensitivity threshold and a sensitivity range, and wherein the first set of chart-invariant sensitivity parameters are generated based on the first set of chart-specific acuity parameters. In some embodiments, the sensitivity-based psychometric function is independent of the one or more acuity chart design parameters. In some embodiments, the sensitivity-based psychometric function is generated based on the one or more acuity chart design parameters and/or one or more additional parameters of the subject, the one or more additional parameters being chart-invariant. In some embodiments, the sensitivity-based psychometric function is generated based on signal detection theory. In some embodiments, the sensitivity-based psychometric function is configured to describe visual acuity performance of the subject as a d′ function of one or more optotype sizes and independent of the one or more chart design parameters. In some embodiments, the method further comprising translating the sensitivity-based psychometric function to the single-optotype psychometric function, prior to (i). In some embodiments, the first set of chart-specific acuity parameters comprises an acuity threshold and an acuity range. In some embodiments, the single-optotype psychometric function is chart-specific. In some embodiments, the second set of chart-specific acuity parameters comprises an acuity threshold and an acuity range. In some embodiments, the first set or the second set of chart-specific acuity parameters comprises an acuity threshold, an acuity range, an acuity slope, a change in the acuity threshold between two test conditions, the change in the acuity range between two test conditions, the change in the acuity slope between two test conditions, or a combination thereof. In some embodiments, the first set or the second set of chart-specific acuity parameters comprises one or more numerical values. In some embodiments, the first set or the second set of chart-specific acuity parameters comprises at least one posterior probability density function for a parameter thereof. In some embodiments, the acuity test data of the subject comprises data from at least two different test conditions. In some embodiments, the first set or the second set of chart-specific acuity parameters comprises posterior probability density functions for an acuity threshold from the at least two different test conditions. In some embodiments, the one or more acuity chart design parameters comprises: a total number of optotypes, a number of optotypes per line, a method of optotype sampling, an optotype size, a number of lines, and a response of the subject, or a combination thereof. In some embodiments, the single-optotype psychometric function is based on at least one optotype size. In some embodiments, each function of the family of multiple-optotype psychometric functions is based on two or more different optotype sizes. In some embodiments, the single-optotype psychometric function comprises an acuity threshold and an acuity range of the subject. In some embodiments, one or more functions in the family of multiple-optotype psychometric functions are based on a number of optotypes per line in an acuity chart or subchart. In some embodiments, (iii) further comprising using a weighted sum of the family of multiple-optotype psychometric functions. In some embodiments, the weighting of the family of psychometric functions is based on the acuity chart data of the subject. In some embodiments, the weighting is determined manually by a user or automatically by a computer program. In some embodiments, (b) further comprising displaying one or more acuity charts generated based on the one or more acuity chart design parameters to the subject. In some embodiments, each of the one or more acuity charts comprises at least one optotype, wherein the at least one optotype selected from a library of optotypes. In some embodiments, the one or more acuity charts are of a contrast that is about 25%, 2.5%, or 1.5% of a normal contrast in standard ETDRS charts or Sloane charts. In some embodiments, the at least one optotypes is a letter, a number, or a symbol. In some embodiments, the one or more sets of candidate acuity parameters are generated based on the one or more acuity chart design parameters, the acuity test data of the subject, or both.

In another aspect, disclosed herein is a computer-implemented method for scoring visual acuity of a subject, the method comprising: a) obtaining one or more acuity chart design parameters; b) collecting acuity test data of the subject; c) generating one or more sets of candidate acuity parameters based on the one or more acuity chart design parameters, the acuity test data of the subject, or both; d) generating an acuity model comprising generating one or more chart-specific psychometric functions, each chart-specific psychometric function comprising a set of chart-specific acuity parameters of the one or more sets of chart-specific acuity parameters; e) generating the probabilities of observing the acuity test data using the acuity model and the one or more sets of candidate acuity parameters; f) ranking the one or more sets of candidate acuity parameters for the subject based on the probabilities; and g) selecting one set from the one or more sets of candidate acuity parameters for the subject based on the rankings. In some embodiments, each set of the candidate acuity parameters comprises: an acuity threshold and an acuity range. In some embodiments, each set of the candidate acuity parameters comprises: an acuity threshold, an acuity range, an acuity slope, a change in the acuity threshold between two test conditions, the change in the acuity range between two test conditions, the change in the acuity slope between two test conditions, or a combination thereof. In some embodiments, each set of the candidate acuity parameters comprises a posterior probability density function for the one or more acuity parameters. In some embodiments, each set of the candidate acuity parameters comprises a posterior probability density function for each of the one or more acuity parameters. In some embodiments, (b) comprises summarizing acuity test data from the subject. In some embodiments, the method further comprises, subsequent to (g), displaying visual acuity test result to the subject or the user, the test result comprising the selected set of candidate acuity parameters. In some embodiments, the acuity test data of the subject comprises data from only a first test condition. In some embodiments, the acuity test data of the subject comprises data from a first and second test conditions. In some embodiments, the selected set of the candidate acuity parameters comprises a first posterior probability density function of an acuity threshold or an acuity range. In some embodiments, b) comprises selecting data with the first test condition. In some embodiments, the method further comprises, subsequent to g), selecting data with the second test condition from the acuity test data of the subject; and repeating c) to g). In some embodiments, the selected set of the candidate acuity parameters comprises a second posterior probability density function for the acuity threshold or the acuity range. In some embodiments, the method further comprises obtaining a difference distribution using the first and second posterior probability density functions. In some embodiments, the method comprises calculating a change in acuity threshold or acuity range between the first and the second test conditions based on the difference distribution. In some embodiments, the visual acuity test result is chart-invariant or chart-specific. In some embodiments, (e) is based on Bayes' theorem or maximum likelihood estimation. In some embodiments, the posterior probability density function is a Bayesian posterior probability density function. In some embodiments, the first or the second posterior probability density function is a Bayesian posterior probability density function. In some embodiments, (d) comprises: generating a single-optotype psychometric function, the single-optotype psychometric function comprising the first set of chart-specific acuity parameters; calculating a family of multiple-optotype psychometric functions using the single-optotype psychometric function; and generating a chart-specific psychometric function using the family of multiple-optotype psychometric functions, the chart-specific psychometric function comprising a second set of chart-specific acuity parameters. In some embodiments, the method further comprises, prior to generating the single-optotype psychometric function, generating a sensitivity-based psychometric function comprising a first set of chart-invariant sensitivity parameters. In some embodiments, the sensitivity-based psychometric function is independent of the one or more acuity chart design parameters. In some embodiments, the first set of chart-invariant sensitivity parameters comprises a sensitivity threshold and a sensitivity range, and wherein the first set of chart-invariant sensitivity parameters are generated based on the one or more sets of candidate acuity parameters. In some embodiments, the sensitivity-based psychometric function is generated based on the one or more acuity chart design parameters and/or one or more additional parameters of the subject, the one or more additional parameters being chart-invariant. In some embodiments, the sensitivity-based psychometric function is generated based on signal detection theory. In some embodiments, the sensitivity-based psychometric function is configured to describe visual acuity performance of the subject as a d′ function of one or more optotype sizes and independent of the one or more chart design parameters. In some embodiments, the method further comprises translating the sensitivity-based psychometric function to the single-optotype psychometric function. In some embodiments, the set of chart-specific acuity parameters comprises an acuity threshold and an acuity range. In some embodiments, the single-optotype psychometric function is chart-specific. In some embodiments, the set of chart-specific acuity parameters comprises an acuity threshold, an acuity range, an acuity slope, a change in the acuity threshold between two test conditions, the change in the acuity range between two test conditions, the change in the acuity slope between two test conditions, or a combination thereof. In some embodiments, the set of chart-specific acuity parameters comprises one or more numerical values. In some embodiments, the set of chart-specific acuity parameters comprises at least one posterior probability density function for a parameter thereof. In some embodiments, the acuity test data of the subject comprises data from at least two different test conditions. In some embodiments, the set of chart-specific acuity parameters comprises posterior probability density functions for an acuity threshold of the at least two different test conditions. In some embodiments, the one or more acuity chart design parameters comprises: a total number of optotypes, a number of optotypes per line, a method of optotype sampling, an optotype size, a number of lines, and a response of the subject, or a combination thereof. In some embodiments, the single-optotype psychometric function is based on at least one optotype size. In some embodiments, each function of the family of multiple-optotype psychometric functions is based on two or more different optotype sizes. In some embodiments, the single-optotype psychometric function comprises an acuity threshold and an acuity range of the subject. In some embodiments, one or more functions in the family of multiple-optotype psychometric functions are based on a number of optotypes per line in an acuity chart or subchart. In some embodiments, generating a chart-specific psychometric function further comprising using a weighted sum of the family of multiple-optotype psychometric functions. In some embodiments, the weighting of the family of psychometric functions is based on the acuity chart data of the subject. In some embodiments, the weighting is determined manually by a user or automatically by a computer program. In some embodiments, (b) further comprises displaying one or more acuity charts generated based on the one or more acuity chart design parameters to the subject. In some embodiments, each of the one or more acuity charts comprises at least one optotype, wherein the at least one optotype selected from a library of optotypes. In some embodiments, the one or more acuity charts are of a contrast that is about 25%, 2.5%, or 1.5% of a normal contrast in standard ETDRS charts or Sloane charts. In some embodiments, the at least one optotypes is a letter, a number, or a symbol. In some embodiments, the method further comprises: h) generating a plurality of candidate acuity charts based on the one or more chart design parameters; and i) selecting one or more of the plurality of candidate acuity charts for acuity testing of the subject based on the ranking of the plurality of candidate acuity charts, wherein the ranking is based on the selected set of candidate acuity parameters for the subjects. In some embodiments, the method further comprising, subsequent to (b); collecting data from the subject using the selected one or more candidate acuity charts; if a stopping criterion has not been met, repeating steps c) to g) and steps h) to i) in until the stopping criteria has been met.

In yet another aspect, disclosed herein is a computer-implemented method for adaptively evaluating visual acuity of a subject, the method comprising: a) obtaining one or more acuity chart design parameters; b) collecting acuity test data of the subject; c) generating one or more sets of candidate acuity parameters based on one or more acuity chart design parameters and the acuity test data of the subject, each of the one or more sets of candidate acuity parameters comprises a rank obtained by analyzing the acuity test data of the subject; d) generating a plurality of candidate acuity charts based on the one or more acuity chart design parameters; e) ranking the plurality of candidate acuity charts based on the rank of each of the one or more sets of candidate acuity parameters; and f) selecting one or more acuity charts from the plurality of candidate acuity charts based on ranks thereof to be presented to the subject for acuity testing. In some embodiments, the method further comprises, subsequent to f), presenting the one or more selected acuity charts to the subject. In some embodiments, the method further comprises, subsequent to f) updating the acuity test data with new data collected from the subject using the one or more selected acuity charts. In some embodiments, the method further comprises repeating: presenting the one or more selected acuity charts to the subject; updating the acuity test data with new data collected from the subject using the one or more selected acuity charts; and steps b) to f); until a stopping criterion has been met. In some embodiments, each set of the one or more sets of candidate acuity parameters comprises: an acuity threshold and an acuity range. In some embodiments, each set of the one or more sets of candidate acuity parameters comprises: an acuity threshold, an acuity range, an acuity slope, a change in the acuity threshold between two test conditions, the change in the acuity range between two test conditions, the change in the acuity slope between two test conditions, or a combination thereof. In some embodiments, each set of the one or more sets of candidate acuity parameters comprises a posterior probability density function for the one or more acuity parameters. In some embodiments, each set of the one or more sets of candidate acuity parameters comprises a posterior probability density function for each of the one or more acuity parameters. In some embodiments, (b) comprises summarizing acuity test data from the subject. In some embodiments, the acuity test data of the subject comprises data from only a first test condition. In some embodiments, the acuity test data of the subject comprises data from a first and second test conditions. In some embodiments, each set of the one or more sets of candidate acuity parameters comprises an acuity threshold, an acuity range, an acuity slope, a change in the acuity threshold between two test conditions, the change in the acuity range between two test conditions, the change in the acuity slope between two test conditions, or a combination thereof. In some embodiments, the acuity test data of the subject comprises data from at least two different test conditions. In some embodiments, each set of the one or more sets of candidate acuity parameters comprises posterior probability density function for an acuity threshold or an acuity range. In some embodiments, the one or more acuity chart design parameters comprises: a total number of optotypes, a number of optotypes per line, a method of optotype sampling, an optotype size, a number of lines, and a response of the subject, or a combination thereof. In some embodiments, each of the candidate acuity charts comprises at least one optotype, wherein the at least one optotype selected from a library of optotypes. In some embodiments, one or more of candidate acuity charts are of a contrast that is about 25%, 2.5%, or 1.5% of a normal contrast in standard ETDRS charts or Sloane charts. The method of claim90, wherein the at least one optotypes is a letter, a number, or a symbol.

In yet another aspect, disclosed herein is a computer-implemented system for generating an acuity model for scoring visual acuity of a subject, the system comprising: a digital processing device comprising an operating system configured to perform executable instructions and a memory; and a computer program including instructions executable by the digital processing device to create a scoring application comprising a software module configured to: a) obtain one or more acuity chart design parameters; b) collect acuity test data of the subject; c) select a first set of chart-specific acuity parameter from one or more sets of candidate acuity parameters; d) generate an acuity model comprising: i. generate a single-optotype psychometric function, the single-optotype psychometric function comprising the first set of chart-specific acuity parameters; ii. calculate a family of multiple-optotype psychometric functions using the single-optotype psychometric function; and iii. generate a chart-specific psychometric function using the family of multiple-optotype psychometric functions, the chart-specific psychometric function comprising a second set of chart-specific acuity parameters, wherein the acuity model is configurable to estimate possibility of obtaining the acuity test data of the subject based on the one or more acuity chart design parameters. In some embodiments, the system further comprises, subsequent to (c) and prior to (i), generate a sensitivity-based psychometric function comprising a first set of chart-invariant sensitivity parameters, and wherein the first set of chart-invariant sensitivity parameters comprises a sensitivity threshold and a sensitivity range, and wherein the first set of chart-invariant sensitivity parameters are generated based on the first set of chart-specific acuity parameters. In some embodiments, the sensitivity-based psychometric function is independent of the one or more acuity chart design parameters. In some embodiments, the sensitivity-based psychometric function is generated based on the one or more acuity chart design parameters and/or one or more additional parameters of the subject, the one or more additional parameters being chart-invariant. In some embodiments, the sensitivity-based psychometric function is generated based on signal detection theory. In some embodiments, the sensitivity-based psychometric function is configured to describe visual acuity performance of the subject as a d′ function of one or more optotype sizes and independent of the one or more chart design parameters. In some embodiments, the system further comprises translate the sensitivity-based psychometric function to the single-optotype psychometric function, prior to (i). In some embodiments, the first set of chart-specific acuity parameters comprises an acuity threshold and an acuity range. In some embodiments, the single-optotype psychometric function is chart-specific. In some embodiments, the second set of chart-specific acuity parameters comprises an acuity threshold and an acuity range. In some embodiments, the first set or the second set of chart-specific acuity parameters comprises an acuity threshold, an acuity range, an acuity slope, a change in the acuity threshold between two test conditions, the change in the acuity range between two test conditions, the change in the acuity slope between two test conditions, or a combination thereof. In some embodiments, the first set or the second set of chart-specific acuity parameters comprises one or more numerical values. In some embodiments, the first set or the second set of chart-specific acuity parameters comprises at least one posterior probability density function for a parameter thereof. In some embodiments, the acuity test data of the subject comprises data from at least two different test conditions. In some embodiments, the first set or the second set of chart-specific acuity parameters comprises posterior probability density functions for an acuity threshold from the at least two different test conditions. In some embodiments, the one or more acuity chart design parameters comprises: a total number of optotypes, a number of optotypes per line, a method of optotype sampling, an optotype size, a number of lines, and a response of the subject, or a combination thereof. In some embodiments, the single-optotype psychometric function is based on at least one optotype size. In some embodiments, each function of the family of multiple-optotype psychometric functions is based on two or more different optotype sizes. In some embodiments, the single-optotype psychometric function comprises an acuity threshold and an acuity range of the subject. In some embodiments, one or more functions in the family of multiple-optotype psychometric functions are based on a number of optotypes per line in an acuity chart or subchart. In some embodiments, (iii) further comprises using a weighted sum of the family of multiple-optotype psychometric functions. In some embodiments, the weighting of the family of psychometric functions is based on the acuity chart data of the subject. In some embodiments, the weighting is determined manually by a user or automatically by a computer program. In some embodiments, (b) further comprising use one or more acuity charts generated based on the one or more acuity chart design parameters. In some embodiments, each of the one or more acuity charts comprises at least one optotype, wherein the at least one optotype selected from a library of optotypes. In some embodiments, the one or more acuity charts are of a contrast that is about 25%, 2.5%, or 1.5% of a normal contrast in standard ETDRS charts or Sloane charts. In some embodiments, the at least one optotypes is a letter, a number, or a symbol. In some embodiments, the one or more sets of candidate acuity parameters are generated based on the one or more acuity chart design parameters, the acuity test data of the subject, or both.

In yet another aspect, disclosed herein is a computer system for generating an acuity model for scoring visual acuity of a subject, the system comprising: a digital processing device comprising an operating system configured to perform executable instructions and a memory; and a computer program including instructions executable by the digital processing device to create a scoring application comprising a software module configured to: a) obtain one or more acuity chart design parameters; b) collect acuity test data of the subject; c) generate one or more sets of candidate acuity parameters based on the one or more acuity chart design parameters, the acuity test data of the subject, or both; d) generate an acuity model comprising generating one or more chart-specific psychometric functions, each chart-specific psychometric function comprising a set of chart-specific acuity parameters of the one or more sets of chart-specific acuity parameters, e) generate the probabilities of observing the acuity test data using the acuity model and the one or more sets of candidate acuity parameters; f) rank the one or more sets of candidate acuity parameters for the subject based on the probabilities; and g) select one set from the one or more sets of candidate acuity parameters for the subject based on the rankings. In some embodiments, each set of the candidate acuity parameters comprises: an acuity threshold and an acuity range. In some embodiments, each set of the candidate acuity parameters comprises: an acuity threshold, an acuity range, an acuity slope, a change in the acuity threshold between two test conditions, the change in the acuity range between two test conditions, the change in the acuity slope between two test conditions, or a combination thereof. In some embodiments, each set of the candidate acuity parameters comprises a posterior probability density function for the one or more acuity parameters. In some embodiments, each set of the candidate acuity parameters comprises a posterior probability density function for each of the one or more acuity parameters. In some embodiments, (b) comprises summarize acuity test data from the subject. In some embodiments, the system further comprises, subsequent to (g), display visual acuity test result to the subject or the user, the result comprising the selected set of candidate acuity parameters. In some embodiments, the acuity test data of the subject comprises data from only a first test condition. In some embodiments, the acuity test data of the subject comprises data from a first and second test conditions. In some embodiments, the selected set of the candidate acuity parameters comprises a first posterior probability density function of an acuity threshold or an acuity range. In some embodiments, b) comprises select data with the first test condition. In some embodiments, the system further comprises, subsequent to g), select data with the second test condition from the acuity test data of the subject; and repeat c) to g). In some embodiments, the selected set of the candidate acuity parameters comprises a second posterior probability density function for the acuity threshold or the acuity range. In some embodiments, the system further comprises obtain a difference distribution using the first and second posterior probability density functions. In some embodiments, the system further comprises calculate a change in acuity threshold or acuity range between the first and the second test conditions based on the difference distribution. In some embodiments, the visual acuity test result is chart-invariant or chart-specific. In some embodiments, (e) is based on Bayes' theorem or maximum likelihood estimation. In some embodiments, the posterior probability density function is a Bayesian posterior probability density function. In some embodiments, the first or the second posterior probability density function is a Bayesian posterior probability density function. In some embodiments, (d) comprises: generating a single-optotype psychometric function, the single-optotype psychometric function comprising the first set of chart-specific acuity parameters; calculating a family of multiple-optotype psychometric functions using the single-optotype psychometric function; and generating a chart-specific psychometric function using the family of multiple-optotype psychometric functions, the chart-specific psychometric function comprising a second set of chart-specific acuity parameters. In some embodiments, the system further comprises prior to generating the single-optotype psychometric function, generate a sensitivity-based psychometric function comprising a first set of chart-invariant sensitivity parameters. In some embodiments, the sensitivity-based psychometric function is independent of the one or more acuity chart design parameters. In some embodiments, the first set of chart-invariant sensitivity parameters comprises a sensitivity threshold and a sensitivity range. In some embodiments, the sensitivity-based psychometric function is generated based on the one or more acuity chart design parameters and/or one or more additional parameters that are based on the subject, the one or more additional parameters being chart-invariant. In some embodiments, the sensitivity-based psychometric function is generated based on signal detection theory. In some embodiments, the sensitivity-based psychometric function is configured to describe visual acuity performance of the subject as a d′ function of one or more optotype sizes and independent of the one or more chart design parameters. In some embodiments, the system further comprises translate the sensitivity-based psychometric function to the single-optotype psychometric function. In some embodiments, the set of chart-specific acuity parameters comprises an acuity threshold and an acuity range. In some embodiments, the single-optotype psychometric function is chart-specific. In some embodiments, the set of chart-specific acuity parameters comprises an acuity threshold, an acuity range, an acuity slope, a change in the acuity threshold between two test conditions, the change in the acuity range between two test conditions, the change in the acuity slope between two test conditions, or a combination thereof. In some embodiments, the set of chart-specific acuity parameters comprises one or more numerical values. In some embodiments, the set of chart-specific acuity parameters comprises at least one posterior probability density function for a parameter thereof. In some embodiments, the acuity test data of the subject comprises data from at least two different test conditions. In some embodiments, the set of chart-specific acuity parameters comprises posterior probability density functions for an acuity threshold at the at least two different test conditions. In some embodiments, the one or more acuity chart design parameters comprises: a total number of optotypes, a number of optotypes per line, a method of optotype sampling, an optotype size, a number of lines, and a response of the subject, or a combination thereof. In some embodiments, the single-optotype psychometric function is based on at least one optotype size. In some embodiments, each function of the family of multiple-optotype psychometric functions is based on two or more different optotype sizes. In some embodiments, the single-optotype psychometric function comprises an acuity threshold and an acuity range of the subject. In some embodiments, one or more functions in the family of multiple-optotype psychometric functions are based on a number of optotypes per line in an acuity chart or subchart. In some embodiments, generating a chart-specific psychometric function further comprising using a weighted sum of the family of multiple-optotype psychometric functions. In some embodiments, the weighted sum of the family of psychometric functions is based on the acuity chart data of the subject. In some embodiments, the weighting is determined manually by a user or automatically by a computer program. In some embodiments, (b) further comprising displaying one or more acuity charts generated based on the one or more acuity chart design parameters to the subject. In some embodiments, each of the one or more acuity charts comprises at least one optotype, wherein the at least one optotype selected from a library of optotypes. In some embodiments, the one or more acuity charts are of a contrast that is about 25%, 2.5%, or 1.5% of a normal contrast in standard ETDRS charts or Sloane charts. In some embodiments, the at least one optotypes is a letter, a number, or a symbol. In some embodiments, the system further comprises: h) generate a plurality of candidate acuity charts based on the one or more chart design parameters; and i) select one or more of the plurality of candidate acuity charts for acuity testing of the subject based on the ranking of the plurality of candidate acuity charts, wherein the ranking is based on the selected set of candidate acuity parameters for the subjects. In some embodiments, the system further comprises, subsequent to (b); collecting data from the subject using the selected one or more candidate acuity charts; if a stopping criterion has not been met, repeating steps c) to g) and steps h) to i) until the stopping criteria has been met.

In still yet another aspect, disclosed herein is a computer-implemented system for adaptively evaluating visual acuity of a subject, the system comprising: a digital processing device comprising an operating system configured to perform executable instructions and a memory; and a computer program including instructions executable by the digital processing device to create a scoring application comprising a software module configured for: a) obtaining one or more acuity chart design parameters; b) collecting acuity test data of the subject; c) generating one or more sets of candidate acuity parameters based on one or more acuity chart design parameters and the acuity test data of the subject, each of the one or more sets of candidate acuity parameters comprises a rank obtained by analyzing the acuity test data of the subject; d) generating a plurality of candidate acuity charts based on the one or more acuity chart design parameters; e) ranking the plurality of candidate acuity charts based on the rank of each of the one or more sets of candidate acuity parameters; and f) selecting one or more acuity charts from the plurality of candidate acuity charts based on ranks thereof to be presented to the subject for acuity testing. In some embodiments, the system further comprises, subsequent to f), present the one or more selected acuity charts to the subject. In some embodiments, the system further comprising, subsequent to f), update the acuity test data with new data collected from the subject using the one or more selected acuity charts. In some embodiments, the system further comprises repeat: present the one or more selected acuity charts to the subject; update the acuity test data with new data collected from the subject using the one or more selected acuity charts, and steps b) to f); until a stopping criterion has been met. In some embodiments, each set of the one or more sets of candidate acuity parameters comprises: an acuity threshold and an acuity range. In some embodiments, each set of the one or more sets of candidate acuity parameters comprises: an acuity threshold, an acuity range, an acuity slope, a change in the acuity threshold between two test conditions, the change in the acuity range between two test conditions, the change in the acuity slope between two test conditions, or a combination thereof. In some embodiments, each set of the one or more sets of candidate acuity parameters comprises a posterior probability density function for the one or more acuity parameters. In some embodiments, each set of the one or more sets of candidate acuity parameters comprises a posterior probability density function for each of the one or more acuity parameters. In some embodiments, (b) comprises summarize acuity test data from the subject. In some embodiments, the acuity test data of the subject comprises data from only a first test condition. In some embodiments, the acuity test data of the subject comprises data from a first and second test conditions. In some embodiments, each set of the one or more sets of candidate acuity parameters comprises an acuity threshold, an acuity range, an acuity slope, a change in the acuity threshold between two test conditions, the change in the acuity range between two test conditions, the change in the acuity slope between two test conditions, or a combination thereof. In some embodiments, the acuity test data of the subject comprises data from at least two different test conditions. In some embodiments, each set of the one or more sets of candidate acuity parameters comprises posterior probability density function for an acuity threshold or an acuity range. In some embodiments, the one or more acuity chart design parameters comprises: a total number of optotypes, a number of optotypes per line, a method of optotype sampling, an optotype size, a number of lines, and a response of the subject, or a combination thereof. In some embodiments, each of the candidate acuity charts comprises at least one optotype, wherein the at least one optotype selected from a library of optotypes. In some embodiments, one or more of candidate acuity charts are of a contrast that is about 25%, 2.5%, or 1.5% of a normal contrast in standard ETDRS charts or Sloane charts. In some embodiments, the at least one optotypes is a letter, a number, or a symbol.

Consistent with other disclosed embodiments, non-transitory computer-readable storage media can store program instructions, which are executed by a processor to perform any of the methods described herein.

Additional aspects and advantages of the present disclosure will become readily apparent to those skilled in this art from the following detailed description, wherein only illustrative embodiments of the present disclosure are shown and described. As will be realized, the present disclosure is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the disclosure. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.

INCORPORATION BY REFERENCE

All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference. To the extent publications and patents or patent applications incorporated by reference contradict the disclosure contained in the specification, the specification is intended to supersede and/or take precedence over any such contradictory material.

