Analysis of the trabecular pigmentation in patients with primary open-angle glaucoma using the colorimetric scale

    

    Abstract

    Analysis of the trabecular pigmentation in patients with primary open-angle glaucoma using the colorimetric scale

    Sarkisyan A.S., Balalin S.V., Balalin A.S., Dzhashe B.G.

    Federal State Autonomous Institution “S.N. Fedorov National Medical Research Center „MNTK „Eye Microsurgery“ of Healthсare of the Russian Federation, Volgograd branch

    Purpose. Development of a photocolorimetric scale to assess the extent of trabecula pigmentation along its circumference in patients with primary open-angle glaucoma.

    Material and methods. Study of 36 patients (62 eyes) with primary open-angle glaucoma was performed. Average age: 61.5 ± 9.8 years (48–75 years). Men – 24 (40 eyes), women – 12 (22 eyes). All patients underwent a comprehensive ophthalmic examination, as well as photoregistration of the iridocorneal angle along the circumference. Using the Pixelmator Pro (Pixelmator Team, USA) and the photographic images, we performed colorimetric estimation of the degree of the iridocorneal angle pigmentation at 360°. RGB values for weak, moderate, pronounced, and sharply pronounced trabecular pigmentation were determined. Using color model HSL (Hue, Saturation, Lightness) derived percentages (range) corresponding to a certain degree of trabecular pigmentation.

    Results. Basing on the results, a colorimetric scale was developed for quantifying the trabecular pigmentation degree in patients with primary open-angle glaucoma.

    Conclusion. Photocolorimetric analysis of trabecular pigmentation along the circumference of the iridocorneal angle in patients with primary open angle glaucoma was possible with using Nidek GS-1 gonioscope. The application of RGB- and HSL-color models allows to estimate with high reliability the differences between the levels of trabecular pigmentation in patients with glaucoma. Using a photocolorimetric scale allows to estimate objectively the efficacy of laser operations aimed at reducing the degree of trabecular pigmentation along the entire circumference of the iridocorneal angle.

    Keywords: primary open-angle glaucoma, gonioscopy, photocolorimetric assessment of the pigmentation degree, colorimetric scale.