An accurate diagnosis of<unk>  relies on the documentation of the progressive loss of photoreceptor cell function, confirmed by a combination of visual field and visual acuity tests, fundus and optical coherence imagery, and electroretinography (ERG). Visual field and acuity tests measure and compare the size of the patient's field of vision and the clarity of their visual perception with the standard visual measurements associated with healthy 20/20 vision. Clinical diagnostic features indicative of<unk>  include a substantially small and progressively decreasing visual area in the visual field test, and compromised levels of clarity measured during the visual acuity test. Additionally, optical tomography such as fundus and retinal (optical coherence) imagery provide further diagnostic tools when determining an<unk>  diagnosis. Photographing the back of the dilated eye allows the confirmation of bone spicule accumulation in the fundus, which presents during the later stages of<unk>  retinal degeneration. Combined with cross-sectional imagery of optical coherence tomography, which provides clues into photoreceptor thickness, retinal layer morphology, and retinal pigment epithelium physiology, fundus imagery can help determine the state of<unk>  progression. While visual field and acuity test results combined with retinal imagery support the diagnosis of<unk> , additional testing is necessary to confirm other pathological features of this disease. Electroretinography (ERG) confirms the<unk>  diagnosis by evaluating functional aspects associated with photoreceptor degeneration, and can detect physiological abnormalities before the initial manifestation of symptoms. An electrode lens is applied to the eye as photoreceptor response to varying degrees of quick light pulses is measured. Patients exhibiting the<unk>  phenotype would show decreased or delayed electrical response in the rod photoreceptors, as well as possibly compromised cone photoreceptor cell response. The patient's family history is also considered when determining a diagnosis due to the genetic mode of inheritance of<unk> . At least 35 different genes or loci are known to cause "nonsyndromic<unk> " <unk>  that is not the result of another disease or part of a wider syndrome). Indications of the<unk>  mutation type can be determine through DNA testing, which is available on a clinical basis for: * (autosomal recessive, Bothnia type<unk>  * (autosomal dominant,<unk> 1) * (autosomal dominant,<unk> 4) * (autosomal dominant,<unk> 7) * (autosomal dominant,<unk> 13) * (autosomal dominant,<unk> 18) * CRB1 (autosomal recessive,<unk> 12) * (autosomal recessive,<unk> 19) * (autosomal recessive,<unk> 20) For all other genes (e.g. DHDDS), molecular genetic testing is available on a research basis only.<unk>  can be inherited in an autosomal dominant, autosomal recessive, X-linked or Y-linked manner. X-linked<unk>  can be either recessive, affecting primarily only males, or dominant, affecting both males and females, although males are usually more mildly affected. Some digenic (controlled by two genes) and mitochondrial forms have also been described. Genetic counseling depends on an accurate diagnosis, determination of the mode of inheritance in each family, and results of molecular genetic testing.
Retinitis pigmentosa
Far-sightedness
Photic retinopathy
Chloroquine retinopathy
Corneal dystrophy
Sickle cell retinopathy
Ocular melanosis
Diabetic retinopathy