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September 1994

Evaluation of Argon Green vs Krypton Red Laser for Photocoagulation of Subfoveal Choroidal Neovascularization in the Macular Photocoagulation Study

Author Affiliations

Prepared for the MPS Group by Susan B. Bressler, MD; Joan L. Jefferys, ScM; Neil M. Bressler, MD; Judith Alexander; Mary Lou Lewis, MD; Lawrence J. Singerman, MD; James C. Folk, MD; Robert C. Watzke, MD; Suresh Chandra, MD; and Timothy Flood, MD. A complete membership listing for the MPS Group as of March 31, 1993, was published in the ARCHIVES (1994;112:482). No member of the MPS Group has any proprietary interest in development or marketing of any commercially available products used by these or any other MPS clinical trials.

Arch Ophthalmol. 1994;112(9):1176-1184. doi:10.1001/archopht.1994.01090210060017

Objective:  To evaluate the risks and benefits of argon-green compared with krypton red laser photocoagulation in the treatment of subfoveal choroidal neovascularization (CNV).

Design:  Prospective randomized clinical trial assessing efficacy of laser treatment vs no treatment in the course of subfoveal CNV. Patients randomly assigned to laser treatment were randomly allocated to either argon green or krypton red laser photocoagulation. Scheduled follow-up for periods up to 5 years was performed.

Setting:  Tertiary retinal referral centers.

Patients:  Individuals with age-related macular degeneration and new subfoveal CNV or recurrent subfoveal CNV enrolled in the Foveal Photocoagulation Studies of the Macular Photocoagulation Study.

Main Outcome Measures:  Visual acuity, contrast sensitivity, reading speed, persistent and/or recurrent CNV, and treatment complications.

Results:  There was no significant difference in average loss of visual acuity or contrast sensitivity from baseline levels in eyes treated with either wavelength. From baseline, eyes treated with argon green laser in the Subfoveal Recurrent CNV Study lost an average of 12 words per minute less than eyes treated with krypton red laser. Comparable rates of persistent and recurrent CNV were observed in the two laser treatment groups. Focal retinal vascular narrowing was more common in eyes treated with argon green laser.

Conclusions:  Small differences in outcomes favored argon-green treatment of subfoveal CNV, but the only statistically significant difference observed between green-and red-laser treatments was a smaller loss of reading speed among argon green-treated eyes in the Recurrent CNV Study. The multiple analyses performed in these two Macular Photocoagulation Study trials failed to identify any consistent clinically and statistically significant differences between green- or red-laser treatment in the management of eyes with subfoveal CNV.

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