VISUAL IMPAIRMENT IN AUSTRALIA - DISTANCE VISUAL-ACUITY, NEAR VISION,AND VISUAL-FIELD FINDINGS OF THE MELBOURNE VISUAL IMPAIRMENT PROJECT

PURPOSE: To describe the age-specific and gender-specific rates of bli ndness and visual impairment in urban adults aged 40 years and older. METHODS: A population-based sample of residents was recruited. Present ing and best-corrected distance visual acuities were assessed. Functio nal near vision was measured at each participant's preferred distance. Visual field examination was performed with a Humphrey Field Analyzer (HFA); those unable to perform the field analyzer test attempted a Bj errum screen or confrontation field. RESULTS: The study population com prised 3,271 residents (83% of eligible) from ages 40 to 98 years; 54% were women. Overall, 56% of the study population wore distance correc tion; this was significantly lower in men bur higher in the older age groups. Age adjusted rates of blindness were 0.066% in men and 0.170% in women. Vision with current correction improved after refraction by gender and age. Direct age-standardized rates of functional near visio n did not vary significantly by gender. Forty six people had significa nt visual field loss in their better eye. The proportion of participan ts with constriction of the visual field to within 20 degrees of fixat ion was similar for men and women when controlled for age (odds ratio, 0.81; 95% confidence interval, 0.44 to 1.49) but increased significan tly with age controlled for gender. Visual field abnormalities were de tected in 548 right eyes (17%) and 533 left eyes (16%). CONCLUSIONS: A lthough overall rates of blind ness because of visual acuity loss were relatively low, nearly three times more people had visual impairment because of visual field loss than visual acuity loss. These results hi ghlight the need to target blindness prevention programs to the aging population, with a special emphasis on women.