Incidence of visual loss in the Ponza Eye Study, Italy

Aim To study the incidence of visual loss over a 12-year period in the survivors of an original cohort aged 40 years or older at baseline. Methods Visual acuity (VA) was measured by means of a standardized logMAR chart. World Health Organization definition of blindness and low vision was adopted ( respectively, best-corrected VA >1.3 logMAR or a visual field <10&DEG; around central fixation, and best-corrected VA >0.5 - 1.3 logMAR or a visual field <20&DEG; around central fixation). Moreover, binocular visual loss incidence (VA >0.5 logMAR) was calculated in a ` healthy' group who had uncorrected VA of 0.0 logMAR or better in both eyes at baseline and absence of eye diseases. Results Of the 584 eligible survivors, 411 (70.7%) had a 12-year follow-up visit. The overall incidence figures were as follows: best-corrected binocular blindness (0.7%), binocular low vision (3.9%), monocular blindness (2.7%), and monocular low vision (5.0%), respectively. The results for presenting VAs were 1.2, 9.5, 4.2, and 15.3%. Figures for uncorrected, best-corrected, and presenting binocular visual loss incidence in the ` healthy' group were respectively 12.7, 0.9, and 3.7%. Conclusion The discrepancy between the ideal and real situations that emerges from this study has important implications for health-care planning. Over a period of 12 years, a substantial percentage of ` healthy' subjects will have to seek medical care. Incident visual loss was caused mainly by untreated cataract, glaucoma, myopia, and age-related macular degeneration.