Efficacy of new two-stage methods of surgical and laser treatment for primary open-angle glaucoma combined with cataract

Background. Lowering the intraocular pressure (IOP) is the only proven method to slow the progression of glaucomatous optic neuropathy. Successful conservative treatment or surgery do not guarantee the preservation of visual fields throughout life. Despite the current advances in conservative treatment of primary open-angle glaucoma, about 5.3 % of patients still require surgical or combined treatment. There is no consensus yet on approaches to the treatment of patients with glaucoma and cataract. The objective was to evaluate the effectiveness of new two-stage methods for surgical and laser treatment of patients with primary open-angle glaucoma associated with cataract. Materials and methods. Seventy patients (70 eyes) with primary open-angle glaucoma stages I–IV complicated by cataract were included in this study. There were two observation groups. All patients received a two-stage treatment — micropulse transscleral cyclophotocoagulation (MP-TSCPC) and phacoemulsification with a monofocal intraocular lens (IOL) implantation. The first group (n = 34) included participants who underwent phacoemulsification with IOL implantation (stage 1) one month prior to MP-TSCPC (stage 2). The second group (n = 36) consisted of patients who underwent MP-TSCPC (stage 1) and phacoemulsification with IOL implantation a month after (stage 2). These groups did not statistically differ in terms of age, gender, baseline IOP, and stage of primary open-angle glaucoma. The primary outcome measure was the normalization of IOP with or without the use of antiglaucoma medications and without a need for further laser and incisional procedures in 1, 3 and 6 months. The secondary outcome was stabilization or expansion of visual fields when evalua­ting 1, 3, and 6 months after stage 2. Results. The average IOP level with antihypertensive medications before the treatment in group 1 was 27.5 ± 1.3 mmHg, in group 2 — 27.0 ± 1.1 mmHg. One month after the treatment, patients of group 1 had normal IOP in 94.2 % of eyes and in 5.8 % of eyes with local antihypertensive medications; in group 2, IOP was normal in 100 % of eyes without antiglaucoma medications (p < 0.05). In 3 and 6 months, better hypotensive results were in group 2, but outcomes were not statistically significant. The visual fields were preserved at the preoperative level or expan­ded in patients from groups 1 and 2 one month after the treatment in 91.2 and 97.2 % of the eyes, respectively, 3 months after — in 91.2 and 97.2 %, 6 months after — in 88.2 and 94.4 % of the eyes, respectively. In group 2, better functional results were obtained at all time points, but it was not statistically significant. Conclusions. The studies have established a high efficacy and safety of new two-stage methods for surgical and laser treatment of patients with primary open-angle glaucoma and cataract with a follow-up period of 6 months. There was a tendency to greater efficacy of the method, where MP-TSCPC as stage 1 was followed by phacoemulsification with IOL implantation as stage 2. The nature and frequency of surgical and postoperative complications in both groups did not differ.