Patient Comfort Using Green vs. Yellow Pan Retinal Photocoagulation

Inclusion Criteria: * patient of Wills Eye Hospital Retina Service and/or Mid Atlantic Retina * volunteer patients age 18 years and older. * healthy enough to participate in the study. * willing and able to consent to participation in the study. * diagnosis of PDR with HRC based on clinical criteria outlined by the DRS. Exclusion Criteria: * patient less than 18 years of age * institutionalized patient * prisoner * significant media opacity obscuring a view of the superior retina * history of intra-ocular surgery except cataract surgery * history of PRP laser within the last 30 days