Trial of Yellow 577 nm Laser Versus Green 532 nm Laser for Proliferative Diabetic Retinopathy

A Randomised Control Trial Comparing the Effectiveness of Yellow 577 nm Laser to Conventional Green 532 nm Laser for Proliferative Diabetic Retinopathy

The purpose of this study is to measure effectiveness of yellow 577 nm laser compared to conventional green laser 532 nm for diabetic retinopathy in terms of number of treatment sessions required and visual acuity outcome.

The study also compares pain score of patients receiving laser treatment and side effects of laser treatment.

Diabetes mellitus (DM) is a major medical problem throughout the world. The most common and potentially most blinding of these complications is proliferative diabetic retinopathy (PDR).

Panretinal photocoagulation is established as the gold standard of treatment, supported by the data of the Diabetic Retinopathy Study (DRS).This study found that laser treatment reduced the rate of severe visual loss by 50%. Currently the green 532nm laser is the most common wavelength used. However, this conventional green laser has some complications such as pain, vitreous haemorrhage, choroidal effusion and visual field loss.

Due to the complication of conventional lasers, the yellow laser (577 nm)with peak absorption of oxyhemoglobin and good absorption of melanin is postulated to be more effective at producing retinal laser burns with a lower power and less pain compared to the green laser.

Inclusion Criteria:

• Patient more than 18 year of age
• Eyes with proliferative diabetic retinopathy requiring laser PRP
• Newly diagnosed patient
• Patients with no other intervention/surgeries done before the study

Exclusion Criteria:

• Eyes with media opacity not allowing adequate laser photocoagulation
• Patients who have had previous laser photocoagulation
• Patients who have had previous vitreoretinal surgery