The Effect of Panretinal Photocoagulation (PRP) versus Intravitreal Bevacizumab (IVB) Plus PRP on Peripapillary Retinal Nerve Fiber Layer (RNFL) Thickness Analyzed by Optical Coherence Tomography in Patients with Proliferative Diabetic Retinopathy.

ABSTRACT

PURPOSE: The current study aimed to evaluate changes in peripapillary retinal nerve fiber layer (RNFL) thickness in diabetic patients with bilateral proliferative diabetic retinopathy (PDR) after receiving panretinal photocoagulation (PRP) or intravitreal bevacizumab (IVB) with PRP. METHODS: Ocular examination and peripapillary optical coherent tomography (OCT) were performed for each patient at baseline, 1, 3, 6, and 10 months after treatment. Both eyes of each patient were randomized into either PRP or PRP + IVB group. RESULTS: Sixty-four eyes (32 patients) were enrolled in this randomized clinical trial. In the PRP group, global RNFL thickness initially increased and reached statistical significance in the third month (from 105.9 ± 21.4µm at baseline to 119 ± 41.6µm at 3 months, P = 0.03). Subsequent decline was observed with no significant difference from baseline at 10 months (106 ± 19.3µm, P = 0.914). There were no statistically significant changes in the PRP + IVB group (from 101.7 ± 22.2µm at baseline to 109.3 ± 26.9µm at 3 months, P = 0.996 and 101.9 ± 16.5µm at 10 months, P = 0.999). In the latter group, slight increase in RNFL thickness was observed in the first month (107.7 ± 21.1µm). RNFL thickness was similar to baseline in the two groups at month 10, with the exception of significant increase in superior-temporal sector in the PRP group (145.3 ± 13.4µm vs. 127.2 ± 17.3µm, P = 0.045). CONCLUSION: Compared to eyes treated with PRP, eyes treated with adjunctive IVB showed less significant post-treatment changes in RNFL thickness.