This is a retrospective, observational, cohort study held at Benha University Hospital, ophthalmology department. Benha University Hospital ethics review board approved the study (Approval number: RC 5-12-2021), and it adheres to the tenets of the Declaration of Helsinki. All patients enrolled in this study were recruited from the glaucoma outpatient clinic at the ophthalmology department, Benha University. The study targeted adult patients diagnosed with cataract plus primary open-angle glaucoma based on standard slit-lamp examination, best-corrected visual acuity test using the Snellen chart, IOP measurement (Goldman applanation tonometer), fundus examination with the 90 diopters Volk lens, and gonioscopy (4-mirror Volk contact lens). In addition, all patients had a 24-2 Humphrey visual field test (Zeiss Medical Technology, United States) and an Optical Coherence Tomography (OCT) for the optic disc, Retinal Nerve Fiber Layer (RNFL), and Ganglion Cell Complex (GCC) (Topcon SD-OCT, Topcon Corporation, Japan) when fundus view was achievable. In addition, both maximum and presenting IOP and the number of IOP lowering medications were recorded for each patient. Preoperative medicated IOP was also recorded for all patients in the study. We excluded patients younger than 18 years old, those who had other ocular or systemic diseases or had a previous ocular surgery that might affect the IOP, and patients with other types of glaucoma like angle-closure, congenital, and secondary glaucoma. We also excluded those who failed to complete the 24-month postoperative follow-up period and those unwilling to have the surgery. A written informed consent including the aim of surgery, detailed steps, and potential complications was signed by each patient before surgery.
Patients were allocated into two groups; Group (P), in which patients had phacoemulsification alone, and Group (PG), in which patients had combined phacoemulsification-goniotomy. Each group was further subdivided into moderate and severe glaucoma subtypes based on the degree of glaucoma damage. We depended on the American Glaucoma Society classification of glaucoma severity 14 where optic nerve abnormalities consistent with glaucoma and glaucomatous visual field abnormalities in one hemifield and not within 5 degrees of fixation were considered as moderate glaucoma (Sub-groups Pm and PGm, respectively). On the other hand, optic nerve abnormalities consistent with glaucoma and glaucomatous visual field abnormalities in both hemifields and/or loss within 5 degrees of fixation in at least one hemifield were considered severe glaucoma (Sub-groups Ps and PGs, respectively)
All surgeries were performed by the same surgeon (MAM) under local peri-bulbar anesthesia (2% lidocaine, 0.5% bupivacaine, and hyaluronidase). All patients had a temporal 2.4 mm clear corneal incision, Sodium Hyaluronate (Healon, Johnson & Johnson Vision Care, USA) into the anterior chamber, capsulorhexis, hydrodissection, phacoemulsification, and a foldable in-the-beg Intraocular lens IOL (Sensar, Johnson & Johnson Vision Care, USA). In the PG group, goniotomy was performed using an MVR blade and the gonioprism (Katena, Parsippany, New Jersey, USA) through the temporal corneal incision. The patient's head was turned nearly 45° away from the surgeon and the surgical microscope was tilted 45 ° toward the surgeon. The MVR blade was advanced toward the nasal angle through the anterior chamber. The trabecular meshwork was circumferentially incised at the level of the pigmented band of the trabecular meshwork for approximately 120°. The MVR was then withdrawn, the patient's head and the surgical microscope were returned to the primary position, and the Healon was washed-out from the anterior chamber.
All patients had postoperative topical Moxifloxacin (5mg/ml), and Prednisolone acetate 1% eye drops four times daily for two weeks. All IOP lowering drops were discontinued after surgery. However, they were reinstated once IOP started to exceed its target for each patient.
Complications, either pre-or postoperative, were recorded and managed accordingly. All patients were followed up for 24 months after surgery. Postoperative visits were scheduled into one week, one month, three months, six months, 12 months, and 24 months. Patients had their IOP checked in all visits, the number of IOP lowering drops used, best-corrected visual acuity, and any postoperative complications. Success criteria were defined as final IOP ≤21 mmHg, a 20% decrease from the preoperative non-medicated IOP, and no need for further IOP lowering surgery.
Data were analyzed using Graph Pad Prism 5 (GraphPad Software, Inc., La Jolla, CA, USA). All results are presented as mean values ± standard error of the mean. One-way analysis of variance (ANOVA) was used with Tukey-Kramer post-hoc-test. Differences were considered statistically significant at a P-value <0.05.