The Relationship of Age-Related Maculopathy, Cataract, and Glaucoma to Visual Acuity Ronald Klein, Qin Wang, Barbara E. K. Klein, Scot E. Moss, and Stacy M. Meuer Purpose. To investigate the relationship of age-related maculopathy, cataract, and glaucoma to visual acuity in the population-based Beaver Dam Eye Study. Methods. A cross-sectional, population-based study was performed in people 43 through 86 years of age residing in Beaver Dam, Wisconsin, who were identified between 1987 and 1988 and examined (n = 4926) between 1988 and 1990. Of those who participated, 99.4% were white. Visual acuity was measured (n = 4886) using a modification of the Early Treatment Diabetic Retinopathy Study protocol. Stereoscopic color fundus photographs and slit lamp and retroillumination photographs of the lens were graded in a masked fashion using standardized protocols to determine the presence of age-related maculopathy and central cataract. Results. Fifty-seven percent of those who were legally blind had late age-related maculopathy in both eyes. The frequency of visual acuity of 20/200 or worse was not significantly different in eyes with exudative maciilar degeneration (48%) than in eyes with pure geographic atrophy (42%). While controlling for other factors (age, central cataract, and glaucoma) in partici- pants with both gradable age-related maculopathy and visual acuity measurable in at least one eye (n = 4716), investigators found that each of the early age-related maculopathy lesions was associated with a decrease in visual acuity of approximately two letters or fewer when compared to eyes without these lesions. Late age-related maculopathy was associated with a decrease of approximately seven lines of letters read correctly. Conclusion. These data demonstrate that exudative macular degeneration and pure geographic atrophy are the most important causes of legal blindness in this population and that early age-related maculopathy, central cataract, and glaucoma had a small effect on visual acuity. Invest Ophthalmol Vis Sci. 1995;36:182-191. .Late age-related maculopathy (exudative macular de- tion) is associated widi less severe loss of vision.8'9 Cata- generation and geographic atrophy) and cataract are ract, especially in rural areas5 or among black Americans important causes of decreased vision as people grow living in urban areas,4 is another important cause of age- older. '~5 Data from the Macular Photocoagulation Study related loss of vision. There are few population-based show that eyes with untreated exudative macular degen- data describing the relationship of age-related eye dis- eration with extrafoveal choroidal neovascularization eases to blindness and visual acuity.2"589 The purposes have approximately a 50% increased risk of losing six of this report are to examine the relationship of age- or more lines of vision in a 5-year period compared to related maculopathy, central cataract, and glaucoma to eyes that were treated.6'7 Data from other studies suggest monocular severe vision impairment (visual acuity of that "dry" macular degeneration (geographic atrophy 20/200 or worse) and legal blindness (20/200 or worse or nonatrophic retinal pigment epithelial depigmenta- in the better eye) in the entire Beaver Dam population and to examine the relationships of these three age- related eye diseases to visual acuity after excluding other From the Department of Ophthalmology and Visual Sciences, University of causes of decreased vision. Wisconsin Medical School, Madison, Wisconsin. Supported by the National Institutes of Health/National Eye Institute grant U10- EYO6594 (RK, BEKK) and, in part, by Research to Prevent Blindness (RK). RK i METHODS AND MATERIALS a Research to Prevent Blindness Senior Scientific. Investigator. Submitted for publication March 22, 1994; revised August 15, 1994; accepted The Population August 17, 1994. The Beaver Dam Eye Study population has been de- Proprietary interest category: N. 10 No reprints available. scribed in detail in previous reports. " In brief, a Investigative Ophthalmology & Vis•al Science, January 1995, Vol. 36, No. 1 182 Copyright © Association for Resea ch in Vision and Ophthalmology Downloaded from iovs.arvojournals.org on 09/29/2021 Age-Related Eye Disease and Visual Acuity 183 private census of the population of Beaver Dam, Wis- 4,926 Participants consin was performed from September 15, 1987 to Examined May 4, 1988. All residents (n = 5924) 43 to 84 years of age at the time of the census were invited to partici- pate. Of these, 4926 (83.2%) were seen for the study 40 participants visual examination. Two hundred twenty-six (3.8%) people acuity unmeasurable or 20/200 or worse and died before the examination, 100 (1.7%) moved out unreliable in both eyes. of the area, and 18 (0.3%) could not be located. Two hundred seventy-six (4.6%) permitted an interview only, and 378 (6.4%) refused to participate. Compari- Included* sons between participants and nonparticipants have 4,886 participants with been presented elsewhere" Of those who partici- reliable visual acuity in pated, 99.4% were white. at least one eye. To examine late age-related maculopathy, cata- ract, and glaucoma as causes of blindness in the popu- lation, we excluded 29 people in whom visual acuity 11 participants visual acuity 20/40 to 20/160 could not be determined in both eyes and 11 people and unreliable in both eyes in whom visual acuity was less than 20/200 and unreli- 138 participants age-related maculopathy able because of organic mental syndrome, stroke, or ungradable in both eyes. Excluded some other condition. This left us with 4886 partici- 8 participants with age-related maculopathy pants in whom visual acuity was measurable (Fig. 1). availalble in one eye, visual To evaluate the relationships of early and late age- acuity available in the other. 13 participants related maculopathy, cataract, and glaucoma to visual with other ocular conditions in acuity, we excluded an additional 11 people in whom both eyes. visual acuity was better than 20/200 and worse than Included! 20/40 and was judged to be unreliable in both eyes, 4,716 eligible people 138 people in whom the location and the severity of 4262 people with both age- related maculopathy age-related maculopathy lesions were not gradable in and visual acuity both eyes, 8 people in whom visual acuity could not be both eyes. determined in one eye and age-related maculopathy 220 people with both age-related maculopathy could not be graded in the other, and 13 people who and visual acuity had bilateral conditions other than cataract, age-re- right eye only. lated maculopathy, or glaucoma that significantly af- 234 people with both age- related maculopathy fected visual acuity. This resulted in 4262 persons in and visual acuity measurable in left whom the relationships between the age-related macu- eye only. lopathy and visual acuity could be determined in both eyes, 220 in whom these relationships could be exam- FIGURE 1. Description of population. ined only in the right eye, and 234 in whom these relationships could only be examined in the left eye the Early Treatment Diabetic Retinopathy Study (Fig. 1). Exclusions were based on a review of exami- (ETDRS) protocol with a modified chart R at a 2- nation findings, history, and fundus photographs. Per- meter distance.12 If the best corrected visual acuity was sons who were excluded (n = 210) were older (72.3 20/40 or worse, an ETDRS refraction was performed versus 61.6 years of age, P < .0001) and had higher and the visual acuity was remeasured. For each eye, serum glucose levels (118.6 mg/dl versus 106.2 mg/ the visual acuity was recorded as the number of letters dl, P= .001). (range, 0 [<20/200] to 70 [20/10]) correctly identi- fied. Impaired vision was defined as best corrected Procedures and Definitions visual acuity of 20/40 or worse and included eyes that Tenets of the Declaration of Helsinki were followed. were blind (a visual acuity of 20/200 or worse). Legal Informed consent was signed, and institutional human blindness was defined as best corrected visual acuity experimentation committee approval was granted. of 20/200 or worse in the better eye. Monocular severe The parts of the examination pertinent to this vision impairment was defined as best corrected visual article consisted of a standardized refraction and mea- acuity of 20/200 or worse in one eye, with visual acuity surement of the visual acuity using the Humphrey 530 better than 20/200 in the other. refractor (Allegan Humphrey, San Leandro, CA)." During the examination, the pupils were dilated. The refraction was placed in a trial lens frame, and Stereoscopic 30° color fundus photographs centered the best-corrected visual acuity was remeasured using on the disk (Diabetic Retinopathy Study Standard Downloaded from iovs.arvojournals.org on 09/29/2021 184 Investigative Ophthalmology & Visual Science, January 1995, Vol. 36, No. 1 early or late age-related maculopathy had to be pres- ent in the specific subfield involved. For example, early age-related maculopathy in the central circle sub- field of the grid was defined as present when either soft indistinct drusen were found in the central sub- field or when increased retinal pigment or retinal pig- ment epithelial degeneration and hard or soft drusen were present in the central subfield in the absence of signs of late age-related macular degeneration. For purposes of analyses, two categories were used—ab- sent (includes questionable) and present in that spe- cific area. The procedures for grading of both slit-lamp and retroilluminated photographs of the lens are detailed elsewhere.16"18 For the purposes of this article, nuclear sclerotic cataract was defined as present if the photo- graph of the lens was graded as more opaque than standard 3 (levels 4 or 5 in a five-step scale of severity).