Abstract
Purpose: :
To present the 4-year incidence of visual impairment (VI) and blindness in a population based study of adult Latinos (primarily Mexican-Americans) age 40 and older who did not have VI at the baseline examination.
Methods: :
Participants underwent a detailed ophthalmologic examination including measurement of best-corrected distance visual acuity (BCVA) using a standard ETDRS protocol. 4-year binocular VI or blindness was defined as 1) baseline presenting visual acuity (PVA)>20/40 and a follow-up PVA<20/40, or 2) baseline PVA>20/200 and a follow-up PVA≤20/200. The US-modified criterion for 4-year monocular VI or blindness in either eye was defined as: 1) a baseline BCVA≥20/40 and a follow-up BCVA< 20/40 but ≥20/200, or 2) baseline BCVA>20/200 and a follow-up BCVA≤20/200. The WHO-modified criterion for 4-year monocular VI or blindness in either eye was defined as: 1) a baseline BCVA≥20/63 and a follow-up BCVA<20/63 but ≥20/400, or 2) baseline BCVA>20/400 and a follow-up BCVA<20/400.
Results: :
Of the 4520 participants who underwent a follow-up eye examination, 4.6% had binocular visual impairment, 2.7%, 12.6% and 3.2% (US-modified) vs. 1.5%, 7.4% and 1.7% (WHO-modified) had monocular VI in the 1st eye, 2nd eye and 1st or 2nd eye, respectively. In addition, 1.2%, 8.8% and 1.3% (US-modified) vs. 0.9%, 10.2% and 1.0% (WHO-modified) had blindness in the 1st eye, 2nd eye and 1st or 2nd eye, respectively.
Conclusions: :
Age-specific incidence rates of VI and blindness in LALES-II are the highest reported in the U.S. Overall, the incidence of VI was considerably higher than that reported in the Beaver Dam Eye Study, which included primarily non-Hispanic white participants. Screening and intervention programs should primarily focus on the older Latino population.
Keywords: visual acuity • aging • clinical (human) or epidemiologic studies: natural history