Contrast sensitivity and visual recovery time in diabetic patients treatedwith panretinal photocoagulation

Purpose: To study patients treated with panretinal photocoagulation regardi ng contrast sensitivity and visual recovery time after exposure to glare. Methods: To compare contrast sensitivity and visual recovery-time after exp osure to glare in eyes (n=20) from 20 type 1 diabetic patients treated with panretinal photocoagulation for proliferative retinopathy with eyes (n=19) from 19 un-treated type I diabetic patients. Contrast sensitivity was test ed with a low contrast acuity chart, before and during exposure to either a uniform background illumination or a spotlight, Visual recovery time was d efined as the time required to regain baseline visual acuity during light e xposure. Results: Contrast thresholds values were higher in eyes treated with panret inal photocoagulation compared to un-treated eyes before illumination 4.2+/ -1.2% vs, 3.1+/-1.7% (p=0.006), during background illumination 5.8+/-5.1% v s. 3.9+/-4.8% (p=0.001), and during spotlight exposure 5.6+/-2.2% vs. 3.2+/ -1.8% (p<0.001), Furthermore, recovery time was longer both during backgrou nd illumination, 20; 5-50 sec vs. 2; 2-80 sec. (md;range), (p<0.001) and du ring spotlight illumination 27; 5-70 sec vs. 2;1-60 sec. (md;range) (p<0.00 1), Conclusion: Eyes treated with panretinal photocoagulation had higher contra st threshold levels at baseline and during glare, as well as a prolonged vi sual recovery time compared to un-treated eyes with mild background retinop athy.