Contrast sensitivity in diabetic retinopathy after panretinal photocoagulation

Area of Science:

• Ophthalmology
• Retinal Diseases
• Diabetic Retinopathy

Background:

• Panretinal photocoagulation (PRP) is a standard treatment for proliferative diabetic retinopathy (PDR).
• Previous studies on contrast sensitivity changes post-PRP have yielded conflicting short-term results.
• A comprehensive evaluation of visual function changes after PRP is needed.

Purpose of the Study:

• To evaluate changes in contrast sensitivity and other macular functions in PDR patients following PRP.
• To compare the impact of single-sitting versus two-sitting PRP on visual function.
• To determine the optimal method for monitoring foveal integrity post-PRP.

Main Methods:

• 30 eyes of 29 PDR patients underwent PRP, divided into single (Group A) or two-sitting (Group B) sessions.
• Macular function tests including best-corrected visual acuity, color vision, contrast sensitivity, and photostress were performed before and after PRP.
• Statistical analysis was used to assess changes in visual parameters.

Main Results:

• Contrast sensitivity and color vision-error scores were significantly affected immediately after PRP in both groups (P < .001).
• These visual functions stabilized to pre-laser levels by 3 months post-PRP.
• Best-corrected Snellen visual acuity remained stable throughout the study period.

Conclusions:

• Contrast sensitivity is significantly impacted by PRP but recovers within 3 months.
• Contrast sensitivity is a more sensitive indicator of foveal function than Snellen visual acuity in PDR patients undergoing PRP.
• PRP treatment requires careful monitoring of visual functions beyond simple visual acuity.