Observation of the curative effect of full macular coverage micropulse laser in the treatment of refractory macular edema secondary to Irvine-Gass syndrome / 中华眼底病杂志

ABSTRACT

Objective:To observe the clinical efficacy and safety of full macular coverage micropulse laser in the treatment of refractory macular edema secondary to Irvine-Gass syndrome.Methods:A retrospective case study. From April 2018 to November 2019, 21 cases of Irvine-Gass syndrome patients with 24 eyes were included in the study. Among them, there were 11 females with 12 eyes and 10 males with 12 eyes; the average age was 54.5±10.1 years. All the affected eyes underwent best corrected visual acuity (BCVA) and optical coherence tomography (OCT) examination. BCVA was performed using a standard logarithmic visual acuity chart, and the results were converted into the logarithmic minimum angle of resolution (logMAR) visual acuity when recording. The frequency domain OCT instrument was used to measure the foveal retinal thickness (CMT) and the retinal volume (MRV) of the macular area with a diameter of 1, 6 mm. All the affected eyes were treated with a micropulse laser under the threshold of 577 nm, with a spot diameter of 200 μm, an exposure time of 200 ms, a power of 400 mW, and a 5% duty cycle. The treatment scope was in the upper and lower vascular arches of the macula, covering the entire macula (including the fovea). One or 3 months after treatment, the eyes with macular edema were treated twice with micropulse laser, the method was the same as before. 1, 3, and 6 months after the treatment, the same equipment and methods as before the treatment were used for related inspections. The changes of BCVA, CMT, MRV and the occurrence of complications in the affected eye were observed.Results:The average logMAR BCVA of the eyes before treatment and 1, 3, and 6 months after treatment were 0.440±0.320, 0.333±0.286, 0.250±0.245, 0.166±0.184, and the average CMT were 395.88±79.21, 349.17±78.07, 317.67±53.72, 285.29±37.03 μm, respectively; the average MRV of diameter 1, 6 mm were 0.310±0.063, 0.275±0.060, 0.245±0.035, 0.221±0.219 mm 3 and 9.866±0.846, 9.494±1.002, 9.005±0.885, 8.190±0.850 mm 3. Compared with before treatment, the BCVA of the eyes at 1, 3, and 6 months after treatment was significantly increased ( t=5.060, 5.564, 6.466), and CMT was significantly decreased ( t=4.854, 5.777, 7.349), and the differences were statistically significant ( P<0.01); the average MRV of diameters 1, 6 mm decreased significantly, and the difference was statistically significant (1 mm diameter t=4.527, 5.394, 7.380; P<0.01; diameter 6 mm t=4.577, 7.980, 11.209; P<0.01). The average number of micropulse laser treatments for the affected eye was 1.25 times. Conclusion:Full macular coverage micropulse laser can safely and effectively treat refractory macular edema secondary to Irvine-Gass syndrome and can be used as an alternative treatment.