Since, in most eyes with retinal diseases quality of vision is greatly affected by visual field defects including paracentral scotoma and inferior field defects, visual function should be assessed by central 30- or 10-degrree automated static perimetry as well as visual acuity testing.
The reduction of light sensitivity, demonstrated in the results of Humphrey central 10-2 perimetry, is more apparent than visual acuity loss in eyes with central serous chorioretinopathy (CSC), in which patients complain of dimness in the visual field of the affected eye. While reduced light sensitivity in eyes with acute CSC is well correlated with the height of subretinal fluid, marked and irreversible light sensitivity loss is demonstrated in the absence of subretinal fluid in eyes with chronic CSC due to structural damage in the photoreceptors.
Various degrees of light sensitivity loss are seen in eyes with age-related macular degeneration corresponding to intraretinal or subretinal pathology including intra- or subretinal fluid, fibrous scarring containing choroidal neovascularization and atrophic changes. The mean deviation (MD) of Humphrey central 10-2 perimetry is useful in predicting the visual outcome in eyes with exudative AMD after photodynamic therapy or intravitreal injection of anti-vascular endothelial growth factor.
The progression of retinitis pigmentosa is well assessed with MD of Humphrey central 10-2 perimetry, which decreases linearly in the stage of residual visual field of 10 degrees or less. The age of patients with visual loss below 0.5 is delayed in eyes showing pencil-like configuration of "Traquair's island of visual field", in which a small area of normal light sensitivity around the fixation point is surrounded by absolute scotoma.
With less visual acuity loss compared with that seen in eyes with central retinal artery occlusion; eyes with branch retinal artery occlusion show marked visual field defects, which are permanent and profound simulating the nasal-step pattern seen in eyes with glaucoma. Non-perfusion areas in fluorescein angiograms of eyes with branch retinal vein occlusion generally demonstrate reduced light sensitivity in the results of Humphrey central 30-2 perimetry, the degree of which tends to correlate with severity of non-perfusion. The light sensitivity in the area of detached retina in eyes with rhegmatogenous retinal detachment is generally reduced to show absolute scotoma, yet these eyes recover greatly after successful surgical repair.
Nippon Ganka Gakkai Zasshi (J Jpn Ophthalmol Soc) 120: 190-209, 2016.