Structural and functional changes to the retina and optic nerve following panretinal photocoagulation over a 2-year time period

Abstract

PurposeTo evaluate long-term structural and functional changes to the retina and optic nerve following panretinal photocoagulation (PRP) in diabetic retinopathy (DR) patients.MethodsParticipants were patients with DR requiring PRP and control patients with DR not requiring PRP. The Heidelberg retinal tomography (HRT) and optical coherence tomography (OCT) were performed to analyze the optic nerve and macula. Best-corrected visual acuity (BCVA) and visual field (VF) testing were done to measure central and peripheral vision. Wide-field fluorescein angiogram was performed to monitor the progression of diabetic ischemia. The primary outcome measure was to determine the degree of retinal and optic nerve changes before and after PRP.ResultsThere was a non-significant thickening of the macula and retinal nerve fiber layer at 6 months post laser that recovered by 24 months. Mean perfused ratio was significantly increased (P=0.02) at 12 and 24 months post laser. Independently grading patient stereophotographs, grader 1 indicated there was a non-significant increase in cup to disk ratio post laser, while grader 2 indicated a significant increase at 6 (P=0.04), 12 (P=0.02), and 24 months (P=0.005). There was a significant VF decrease (P≤0.02) at 12 and 24 months post laser with BCVA showing a non-significant trend of deteriorating results.ConclusionDespite an improvement in peripheral perfusion, there was a significant progressive decline of peripheral VF over the study period. Clinical grading of the optic nerve was more unreliable following PRP, despite the absence of significant morphological changes as detected by the OCT and HRT.

Long-Term Retinal Neurovascular and Choroidal Changes After Panretinal Photocoagulation in Diabetic Retinopathy

“…Over the long-term followup, they gradually returned to the baseline level. Many of the previous studies using OCT obtained similar results (27,28). They considered that the retinal inflammation and edema caused by PRP at the early postoperative phase could damage the retinal neural cell and tissue and later recovery might be attributed to the absorption and healing of the edema and the laser-induced photoreceptors and ganglion cell damage.…”

Long-Term Visual Function Effects of Pan-Retinal Photocoagulation in Diabetic Retinopathy and Its Impact in Real Life

“…In a study with a small population (10 eyes), there were no negative effects of treatment regarding VF in the short term (6 months). 7 On the other hand, in a recent prospective 2-year study, Filek et al 17 described a significant loss in VF evaluation in 16 patients undergoing PRP. In the scientific literature, no studies comprising long-term results in a large sample were found, as in the present study.…”