ASSESSMENT OF QUALITY AND ADEQUACY OF PANRETINAL PHOTOCOAGULATION IN PROLIFERATIVE DIABETIC RETINOPATHY USING ULTRA-WIDEFIELD IMAGING

Abstract Purpose: To assess the characteristics of completed PRP, using UWF in PDR. Methods: Quantitative assessment of UWF images of 133 patients with PDR with completed PRP was made using Image J software. The parameters assessed included distance of laser spots from the optic disc, foveal centre, superior and inferior arcade, extent of maximum width of laser. Areas assessed were total area of the image, area of the inner limit within which laser spots are restricted, minimum areas of unlasered patches, total area lasered, and ideal area to be covered by PRP. Results: 201 images were assessed for final analysis. The mean distance of laser spots from the optic disc (nasal) was 4.2 mm ± 2.4 mm, and from the foveal centre (temporal) was 6.6 mm ± 2.5 mm. The mean distance of laser spots from the superior arcade vessel was 3.2mm ± 1.9 mm, and 6.2mm ± 4.4 mm from the inferior arcade. The mean area of the retina that should have been ideally lasered was found to be 900 mm 2 ± 267 mm 2 , actual area lasered was found to be 681 mm 2 ± 254.4 mm 2 . Conclusion: About a quarter area of the retina continues to remain ischemic by the lack of inadequate coverage of PRP. Further longitudinal studies are recommended, using UWFI to objectively assess the adequacy of PRP and its role in modulating the course of progression of the retinopathy.