There are several types of<unk> s: Hertel and Luedde<unk> s measure the distance of the corneal apex from the level of the lateral orbital rim, while Naugle<unk> s measure the relative difference between each eye. * Hertel<unk> s take a measurement from the lateral orbital rim to the corneal apex. If a patient presents with an orbital fracture or after lateral orbitotomy, the use of a Hertel<unk>  may be complicated because the lateral orbital rim serves as a reference point for this instrument. Consideration should be given to the use of the Naugle<unk>  in these cases. * Naugle<unk> s use fixation points slightly above and below the superior and inferior orbital rims (cheek bones and forehead). Naugle<unk> s measure the difference in proptosis between the two eyes, in contrast to the absolute measure obtained with the Hertel method. * Luedde<unk> s fix on the lateral orbital wall and use a transparent ruler to measure the amount of protrusion.
Exophthalmometer
Urinometer
Dosimetry
Pupilometer
Scanning laser ophthalmoscopy
Corneal topography
Scanning laser polarimetry
Ocular tonometry