advertisement
Abstract #15342 Published in IGR 1-3
Proportion of those with Open-angle glaucoma who become blind (letter to the editor).
Quigley HAOphthalmology 1999; Ophthalmology 1999;
This author comments on a paper by Hattenhauer et al. in Ophthalmology 1998; 105: 2099-2104. The article deals with the proportion of patients with open angle glaucoma who become blind. The original authors started the medical records retrospectively. The writer of the letter has the following comments: first of all 50% of patients with glaucoma are undiagnosed. Cases with diagnosed glaucoma are more severely affected that cases with undiagnosed glaucoma. This may lead to an overestimation of the prevalence of blindness among all those with glaucoma. The second point offered by the present author the meantime to initial field loss to death is estimated to be less than 13 years and fewer than 5% would have the disease for longer than 15 years. The original authors presented Kaplan-Meijer analyses with 20 year estimates for onset of blindness. This also may lead to an overestimation. Blindness was calculated from visual acuity and visual field blindness data. Many of the visual field data used Goldmann perimetry or tangent screen tests. In other studies it was suggested that those bilaterally blind from field testing increased the blindness estimates from acuity criteria by only 25%. Than there is the issue of blindness resulting from causes other than glaucoma. The corresponding authors are also amazed by the low percentage of pseudoexfoliation syndrome in this group of Minnesota patients with a dominant ancestry from Scandinavia. Finally the corresponding author corrects the impressions that he himself has stated that bilateral blindness is rare in open angle glaucoma. The exact figures of his study are that 4% of white persons and 8% of black persons become bilaterally blind. The point is not that glaucoma blindness is rare. The point is that the majority of those with open angle glaucoma do not go blind in their lifetime. These two facts are not contradictory.
Baltimore, Maryland
Classification:
1.5 Glaucomas as cause of blindness (Part of: 1 General aspects)
