Macular Photocoagulation Study (MPS)

Launched by NATIONAL EYE INSTITUTE (NEI) · Sep 23, 1999

Keywords

ClinConnect Summary

In each randomized trial conducted by the MPS Group, focal laser photocoagulation was compared to observation without treatment. Patients were assigned to laser treatment or to observation with equal probability. The first set of MPS randomized trials, the Argon Study, focused on the effectiveness of photocoagulation with argon blue-green laser in eyes with discrete extrafoveal choroidal neovascularization. The study investigators, who began recruiting patients in 1979, estimated that 550 patients with AMD and 750 with POH would be required. Follow-up was to continue for 5 years to determin...

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Eligibility criteria

• Common Eligibility Criteria for the Argon, Krypton, and Foveal Studies:
• • To be eligible, men and women must have been experiencing visual symptoms attributable to the macular lesion, such as decreased visual acuity or Amsler grid distortion, at the time of entry into the study. They also must have had visible, well-demarcated hyperfluorescence characteristic of classic choroidal neovascularization on fluorescein angiography. AMD patients were 50 years of age or older and had drusen visible in the macula of at least one eye. POH patients were at least 18 years old and had at least one characteristic histo spot in one or both eyes. INVM patients were at least 18 years old and had no evidence of AMD, POH, angioid streaks, high myopia, diabetic retinopathy, or any other condition that could be the cause of the neovascularization. In particular, INVM patients had neither drusen greater than MPS Standard Photograph No. 1.1 nor histo spots in either eye.
• Additional Patient Eligibility Criteria for the Argon Study:
• • Each patient had a visible serous detachment of the sensory retina with a diffuse area of leakage, discrete choroidal neovascularization outside the fovea (200-2,500 microns from the center of the FAZ), and visual acuity of 20/100 or better in the study eye.
• Additional Patient Eligibility Criteria for the Krypton Study:
• • All patients had a neovascular lesion consisting of neovascularization and possibly blood and/or pigment that extended into the FAZ. The posterior border of CNV could extend as close as 1 micron to the FAZ center. Visual acuity of the study eye was 20/400 or better.
• Additional Patient Eligibility Criteria for the Foveal Study:
• • Only patients with AMD were eligible for this study. Fluorescein angiography of the eligible eye had to show evidence of a leaking choroidal neovascular membrane, some part of which extended under the center of the FAZ, or a neovascular lesion consisting of an old laser treatment scar and contiguous leaking neovascularization within 150 microns of the center of the FAZ. New, never-treated subfoveal lesions were less than four disc areas in size. Recurrent lesions were less than six disc areas in size, including the old treatment scar and new neovascularization. Best-corrected visual acuity was no better than 20/40 and no worse than 20/320.