The gonio scratch study: methodology of a multicenter clinical trial establishing a new minimally invasive glaucoma surgery.

There are numerous surgical procedures for glaucoma. Minimally invasive glaucoma surgery is becoming popular; however, the disadvantage is the high incidence of anterior chamber hemorrhage. Heavy bleeding can also lead to increased intraocular pressure (IOP) postoperatively. Gonio scratch is a surgical procedure that improves aqueous humor outflow by rubbing off deposits on the trabecular meshwork with a Diamond Dusted Sweeper. As the conjunctiva and trabecular meshwork are not incised, no postoperative bleeding is expected, and the IOP spike will be minimal. We designed this study to determine the efficacy and safety of gonio scratch. This is an on-going multicenter, prospective, clinical trial. Patients who are scheduled for glaucoma surgery with or without cataract surgery are being enrolled. A total of 80 eyes will be recruited in the Hiroshima University Hospital, Miyoshi Eye Clinic, Yokoyama Retina Clinic, and Kusatsu Eye Clinic. All patients will undergo gonio scratch. When combined with cataract surgery, gonio scratch is performed after the intraocular lens is inserted. The primary study endpoint is the change in IOP from baseline to 1 year after surgery. The secondary endpoints are complications, number of glaucoma medications, surgical time, and changes in visual acuity and the visual field. This study protocol was approved by the institutional review board of Hiroshima University. The trial results will be shared with the scientific community at international conferences and by publication in a peer-reviewed journal. Trial registration number is jRCTs062200003.

Surgical Outcomes of Ab Interno Trabeculotomy Without Phacoemulsification.

Purpose: The aim of this study was to evaluate ab interno trabeculotomy outcomes without phacoemulsification. Methods: This retrospective study evaluated 118 eyes of patients aged 18 and above who underwent ab interno trabeculotomy between December 2017 and August 2022. When surgeries were performed in both eyes, only the eye undergoing the initial surgery was evaluated. Prior to and after surgery, the intraocular pressure (IOP) and mean number of IOP-lowering medications were compared. An IOP of ≤21 mmHg (A) and ≤18 mmHg (B) along with a ≥20% reduction in the preoperative IOP was defined as survival. Cases that required reoperation for glaucoma were defined as surgical failure. The Kaplan-Meier method was used to evaluate the survival rates. A Cox proportional hazards model was used to analyze the preoperative factors that influenced survival rates. Results: At 36 months postoperatively, the 13.4 ± 2.8 mmHg average IOP was significantly decreased from the preoperative 23.5 ± 9.8 mmHg value (P < 0.0001). Moreover, a significant decrease in the mean number of the IOP-lowering medications to 2.3 ± 1.4 at 36 months was found versus the initial 3.9 ± 1.1 preoperative value (P < 0.0001). The survival rates for criteria A and B at 36 months postoperatively were 28% and 25%, respectively. Only the preoperative IOP was identified by multivariate analysis as a factor influencing survival rates (P < 0.0001). Hyphema in 36 eyes (30.5%) and an IOP spike in 20 eyes (16.9%) were the only observed complications. Additional glaucoma surgery was required in 27 eyes (22.9%) during the follow-up period. Conclusion: Utilization of ab interno trabeculotomy effectively lowered the IOP and reduced the number of IOP-lowering medications. Patients with higher preoperative IOP exhibited better postoperative outcomes.

Which is More Effective and Safer? Comparison of Propensity Score-Matched Microhook Ab Interno Trabeculotomy and iStent Inject.

INTRODUCTION: The purpose of this study was to compare the surgical outcomes between ab interno trabeculotomy (LOT) and iStent inject W implantation (iStent) both combined with cataract surgery, matching the background factors including age, intraocular pressure (IOP), medication score, central corneal thickness (CCT), and axial length. METHODS: A total of 100 eyes from 75/79 patients with primary open-angle glaucoma were included in the LOT/iStent groups. The background factors were matched between the two groups using the propensity score. RESULTS: There were no significant differences in age, IOP, medication score, CCT, and axial length, preoperatively. The postoperative medication scores were 1.3 ± 1.2 and 1.2 ± 1.2 in the LOT and iStent groups. The postoperative IOPs were 12.8 ± 2.8 and 13.1 ± 2.4 mmHg in the LOT and iStent groups, respectively. The changes in the medication score were - 0.64 ± 1.4 and - 0.44 ± 1.6 in the LOT and iStent groups, respectively. The changes in the IOP were - 2.1 ± 3.3 and - 1.5 ± 3.0 mmHg in the LOT and iStent groups, respectively. These values were not significantly different between the two groups. The postoperative IOP and changes in the IOP were significantly associated with preoperative IOP and CCT. There was no significant difference in the occurrence of postoperative complications (hyphema, 11.0% and 6.0%, and transient ocular hypertension, 8.0% and 5.0%, in the LOT and iStent groups, respectively). CONCLUSION: LOT and iStent have similar surgical outcomes with sufficient safety. Postoperative IOP was significantly associated with preoperative IOP and CCT in both groups.

Effect of Topical Pilocarpine Instilled Before Laser Peripheral Iridotomy on Regional Iris Thickness in Primary Angle Closure Disease: A Swept-Source Anterior Segment Optical Coherence Tomography Pilot Study.

PURPOSE: To determine whether the temporal-superior or the nasal-superior iris area becomes thinner (more optimal) for laser peripheral iridotomy (LPI) after pilocarpine instillation in primary angle closure disease (PACD); and to identify an angle for optimal penetration of the laser beam. PATIENTS AND METHODS: Iris thickness at 2 mm from the iris root in the preset scanning axes was measured using swept-source anterior segment optical coherence tomography before and 60 minutes after the instillation of pilocarpine 2% in one eye of 30 consecutive Japanese PACD patients with thick, dark brown iris. Iris thickness at 1:30 and 10:30 clock hour positions were evaluated in sagittal and oblique directions, resulting sagittal iris thickness (SIT) and minimum iris thickness (MIT) parameters, respectively. RESULTS: Compared to the baseline values, iris thickness decreased significantly (P < .001) in both locations after pilocarpine instillation. Both before and after pilocarpine instillation the temporal-superior iris thickness was significantly smaller than the nasal-superior thickness (P ≤ .001). After pilocarpine instillation, the temporal-superior iris was significantly thinner in an approximately 13° angle direction temporal to the sagittal direction than in the sagittal direction (MIT: 0.322 mm; SIT: 0.346 mm, P < .001). CONCLUSIONS: After pilocarpine instillation, the temporal-superior iris and an approximately 13° angle temporal to the sagittal direction may provide an optimal location and laser beam angle for LPI in PACD eyes.