The large prospective clinical glaucoma trials and other studies have demonstrated that over longtime periods visual field defects progress in a large proportion of glaucoma patients. New imaging techniques of the optic disc and retinal nerve fibre are widely used in some clinical practices and provide complementary information. However, they cannot substitute perimetry as a surrogate measure of visual field change.

The purpose of the present work was to evaluate hypotensive effect of endotrabeculoectomy and influence of the operation for stabilization of glaucoma progression.

Material and methods. Investigation was done in two groups. The first group (22 patients, 23 eyes) with open-angle glaucoma who underwent endotrabeculoectomy (trabecula ablation through chamber anterior – ab interno – with the help of forceps) as a single procedure, and the second group (95 patients, 107 eyes) with open-angle glaucoma and cataract who underwent combined phacoemulsification of cataract with IOL implantation and endotrabeculoectomy. Aplanation tonometry by Maklakov, standard automated perimetry with 24-2 Swedish Interactive Threshold Algorithm (SITA), optical coherent tomography of optic nerve head and measurement of retinal nerve fiber layer thickness were done. Mean follow-up period was 27,8±2,4 months.

Results. In the first group on 7-th day after operation tonometric IOP decreased by 7,8±0,7 mm Hg and was 18,6±1,1 mm Hg without application of drugs. In the second group IOP decreased by 5,2±0,6 mm Hg and was 18,9±1,2 mm Hg one week after operation without application of drugs. In 6 months, IOP remained compensated (18,6±1,1 mmHg in the first group and 18,8±1,1 mm Hg – in the second group) and stable. The number of drops used by the patients to achieve the targeted pressure was 0,7±0,3 in the first group and 0,5±0,1 – in the second group. Absolute efficiency of the surgery was achieved in 13 cases out of 23 (56,5%) in the first group and in 63 cases out of 107 (58,9%) – in the second group. Relative efficiency of the surgery was registered in 8 cases out of 23 (34,8%) in the first group and in 38 cases out of 107 (35,5%) – in the second group.

Mean deviation in patients with IOP≤22 mm Hg decreased by 0,3±0,2 dB per year, and in patients with IOP over 22 mm Hg – by 0,6±0,4 dB per year. Pattern standart deviation in patients with IOP≤22 mm Hg increased by 0,1±0,1 dB, and in patients with IOP over 22 mm Hg – by 0,4±0,3 dB per year. Morphometric dates of the optic nerve head during two years after operation did not change significantly in the patients of both groups. Cup area before operation was 0,65±0,20, one year after operation – 0,65±0,17, and two years after operation – 0,66±0,20. Neuroretinal rim area before operation was 0,94±0,33 mm2, one year after operation – 0,93±0,32 mm2, and two years after operation – 0,92±0,28 mm2. Thickness of retinal nerve fiber layer decreased insignificantly (64,5±16,3 nm before operation, 63,1±16,1 nm one year after operation, and 62,6±15,6 nm – two years after operation).

Conclusion. Endotrabeculoectomy has an evident hypotensive effect. Results of standard automated perimetry, optical coherent tomography of optic nerve head, and measurement of retinal nerve fiber layer thickness confirmed stabilization of glaucoma progression after the operation.

Keywords: glaucoma, intraocular pressure, endotrabeculoectomy, glaucoma progression, visual field, optic nerve head, retinal nerve fiber layer thickness

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