Diabetic retinopathy and the major causes of vision loss in Aboriginals from remote Western Australia.

PURPOSE: To report on diabetic retinopathy (DR) and the major causes of vision loss and blindness in Aboriginals in the Eastern Goldfields region of Western Australia between 1995 and 2007. METHODS: Aboriginals (>16 years old) diagnosed with diabetes or eye problems from 11 communities in the Eastern Goldfields region of Western Australia were examined annually from 1995 to 2007. Data collected from prospective clinical examination included; visual acuity (VA), causes of vision loss, and whether DR was present. Severity of DR was graded according to the Early Treatment of Diabetic Retinopathy Study modified Airlie House grading system. RESULTS: A total of 920 Aboriginals underwent 1331 examinations over the study period. There were 246 eyes with vision loss (best-corrected VA < 6/12) in 159 Aboriginals, of whom five were bilaterally blind. The four major known causes of vision loss were cataract (n = 53, 30.1%), DR (n = 44, 25.0%), uncorrected refractive error (n = 31, 17.6%) and trauma (n = 19, 10.8%). Aboriginals who had diabetes were far more likely to have vision loss (odds ratio = 8.5, 95% confidence interval 5.7-12.6, P < 0.0001). Of the 329 Aboriginals with diabetes, 82 (24.9%) had DR, and 32 (9.7%) had vision-threatening retinopathy. Of those with diabetes, 94 (42.5%) returned for follow-up examination on an average of 3.2 visits with a median time between visits of 2 years. CONCLUSION: The four major causes of vision loss in Aboriginals from the Eastern Goldfields are largely preventable and/or readily treated. DR and other diabetes-related eye conditions are a major cause of vision loss in Aboriginals, representing a significant health challenge for health services and clinicians into the future.

New observations concerning the nature of central retinal vein pulsation.

AIMS: Central retinal vein pulsation is affected by intracranial pressure (ICP), glaucoma and venous pathology. Its genesis is poorly understood with most models suggesting that intraocular pressure (IOP) fluctuation dominates the rhythm of venous pulsation; however, this has not been explored experimentally. This study planned to measure the timing of central retinal vein pulsation with respect to IOP pulse. METHODS: Video recording of the optic disc vessels and movement of Goldmann applanation mires while recording the cardiac cycle with a pulse oximeter probe was undertaken in 10 subjects from a general ophthalmic clinic. The timing of the variation in IOP and retinal vein diameter from the onset of the oximeter signal were expressed as a percentage of the cardiac cycle and also in degrees of the cycle. RESULTS: Minimum vein diameter occurred at a mean 40 ms (SD 47) after minimum IOP in 10 subjects with mean cardiac cycle length of 866 ms (SD 132), the delay representing 4% or 14 degrees (SD 5.1, 95% CI 0.3% to 8%) of the mean cardiac cycle. Maximum vein diameter occurred an average of 5 ms after maximum IOP (SD 57) representing 1% or 4 degrees (SD 6.9, 95% CI -4% to 6%) of the mean cardiac cycle. CONCLUSION: During venous pulsation, venous collapse occurred in time with ocular diastole and dilatation in time with systole. This is contrary to earlier conceptual understanding. The results suggest that the intracranial pulse pressure may be of equal importance to intraocular pulse pressure in producing venous pulsation.

Prevalence of trachoma in school children of remote Western Australian communities between 1992 and 2003.

PURPOSE: To measure the prevalence and trends in childhood trachoma within remote, largely Aboriginal communities. METHODS: Children from eight remote communities of the Goldfields region of Western Australia were examined annually over 12 years from 1992 to 2003. World Health Organization trachoma grading system was used, with the data collected prospectively. RESULTS: In this study 2975 of 3483 child ocular examinations were analysed, 72% of whom were Aboriginal. The mean age was 8 years 9 months with a range from 1 month to 17 years 11 months. The overall prevalence of active trachoma was volatile ranging from 44% in 1993 to 5% in 1997 and 2001. The prevalence of World Health Organization grade TI disease showed a significant decline from 5% to less than 1% (P = 0.001). CONCLUSION: The prevalence of active trachoma in children of these eight remote communities of the Goldfields region of Western Australia was volatile. The prevalence of intense inflammation has dropped to very low levels. A significant reservoir of less severe inflammation remains.