This is a retrospective study of 160 consecutive patients with Coat’s disease under the Shields classification, with Snellen visual acuity (VA) pre and post treatment. Affected eyes were categorised based on the Shields classification:
Stage 1: retinal telangiectasia only
Stage 2a: 1 plus extra fovealexudation
Stage 2b: 1 plus foveal exudation
Stage 3a1: subtotal exudative retinal detachment (ERD)
Stage 3a2: 3a1 plus foveal involvement
Stage 3b: total ERD
Stage 4: 3b plus secondary glaucoma
Stage 5: end-stage disease, phthisis bulbi
More advanced stages showed higher frequency of poor VA at presentation (<20/200) (0% vs. 0% vs. 50% vs. 35% vs. 38% vs. 83% vs. 100% vs. 100%, p<0.001.) and higher mean IOP. More advanced stage was less likely managed with laser photocoagulation and more likely with cryotherapy. More advanced stages were shown to have lower frequency of VA > or equal to 20/40 (100% vs. 71% vs. 5% vs. 42% vs. 23% vs. 5% vs. 0% vs. 0%, p< 0.001) and higher frequency of VA , 20/200 (0% vs. 12% vs. 36% vs. 31% vs. 45% vs. 88% vs. 0% vs. 100% p,0.001). The authors concluded that VA correlates well with the staging classification that more advanced disease shows poorer VA at presentation and final visit. The limitations of the study are the retrospective nature, potential selection bias of older cohort to perform Snellen VA, and fewer eyes in each group for statistical analysis.
