Purpose
Various qualitative visual disturbances are reported by patients with age-related macular degeneration (AMD). Here we characterize such visual phenomena, and estimate their prevalence and associations with clinical aspects of AMD.
Methods
Consecutive patients (n=100) with AMD in an out-patient clinic were presented a questionnaire to investigate aspects of transient visual phenomena (TVP), subjective day-to-day and intradiurnal variation in visual functioning, and formed visual hallucinations.
Results
TVP typically consisted of large central dark scotomas that resolve within several seconds to minutes after onset. TVP were reported by 35/100 of patients; these were bilateral in 25/30 (83%, “uncertain” in 5) and most often occurred with eye opening at night or upon awakening. Most patients had not previously discussed such symptoms with their physician, even though they were "emotionally concerning" in 28%, and disrupted daily activities in 6%, of subjects. TVP was reported by patients with mild to severe levels of visual impairment, and in patients with either atrophic or with exudative AMD. Day-to-day variation in vision (sufficient to preclude or enable visual activities) was present in 38% of patients, and visual variation across the day in 27% (most were either “worst in the morning” or “best in the morning”). Nearly all patients reported improved reading with brighter lighting. Formed visual hallucinations were noted in 3/100 patients. Assessment of associations of TVPs with medications or with physical findings such as visual acuity, choroidal neovascularization, drusen type and number, and geographic atrophy, requires further analysis.
Conclusions
Qualitative visual symptoms, in particular TVPs, are common among patients with AMD. These symptoms may be disturbing to patients, yet are often overlooked by their physicians. These symptoms likely relate to defective outer retinal visual processing and may provide insight into the pathophysiology of macular disease.
Keywords: 412 age-related macular degeneration •
463 clinical (human) or epidemiologic studies: prevalence/incidence