Panretinal Photocoagulation During Vitrectomy for Diabetic Vitreous Hemorrhage

Inclusion Criteria: * The subject has type I or II diabetes mellitus * The age of the subject is \> 18 years old * Snellen best-corrected visual acuity ranges from 20/40 to hand motions at one foot in the research eye * Proliferative diabetic retinopathy with a vitreous hemorrhage is present in the research eye, and the vitreous hemorrhage is considered to be the primary cause for the subject's reduced vision * The subject is panretinal photocoagulation-naïve * The vitreoretinal adhesion is Grade 0 or 1 according to the classification system published by Ahn et al in the research eye Exclusion Criteria: * The research eye had formerly undergone anterior or posterior vitrectomy. * An opacity of the anterior segment (cornea or lens) is thought to be responsible for two or more lines of decreased visual acuity in the research eye (cataract, corneal scar, ectasia, etc.) * Optic nerve or retina disease unconnected to diabetes mellitus is thought to be responsible for two or more lines of decreased visual acuity in the research eye (optic neuritis, macular degeneration, glaucoma, etc.) * Amblyopia or a non-ocular source (i.e., cerebrovascular accident) is considered to be responsible for two or more lines of decreased visual acuity in the research eye * Neovascular glaucoma with an elevated intraocular pressure (\> 30 mm Hg) is present in the research eye * Uncontrolled systemic hypertension (systolic \> 200 mmHg or diastolic \> 120 mmHg) is present