Electroretinogram Changes Following Sequential Panretinal Photocoagulation for Proliferative Diabetic Retinopathy

Area of Science:

• Ophthalmology
• Retinal Diseases
• Electrophysiology

Background:

• Proliferative diabetic retinopathy (PDR) is a severe complication of diabetes.
• Panretinal photocoagulation (PRP) is a standard treatment for PDR to prevent vision loss.
• The impact of multiple PRP sessions on retinal function, as measured by electroretinogram (ERG), requires detailed evaluation.

Purpose of the Study:

• To assess electroretinogram (ERG) response changes during and after multiple panretinal photocoagulation (PRP) sessions.
• To quantify the functional impact of PRP on retinal electrical activity in patients with proliferative diabetic retinopathy (PDR).

Main Methods:

• A prospective cohort study involving 11 patients with PDR undergoing three PRP sessions.
• Electroretinograms (ERGs) were recorded at baseline, after each session, and 6 weeks post-treatment.
• Standard ERG tests included dark-adapted (0.01, 3, 10) and light-adapted (3, 30 Hz flicker) responses, analyzing a- and b-wave amplitudes and implicit times.

Main Results:

• Significant reductions in a- and b-wave amplitudes and delayed latencies were observed across all ERG responses post-PRP (p<0.05).
• Scotopic b-waves showed greater amplitude reduction and latency delay. ERG parameters deteriorated similarly across all three PRP sessions.
• Partial recovery of ERG amplitude and latency was noted 6 weeks after the final PRP session, though not reaching baseline levels.

Conclusions:

• Panretinal photocoagulation (PRP) leads to a measurable decline in retinal function, evidenced by ERG changes, after each treatment session.
• Retinal function demonstrates partial recovery within six weeks of completing PRP therapy.
• Clinicians should consider these transient ERG alterations when managing PDR treatment plans.