Conventional glaucoma implants and the new MIGS devices: a comprehensive review of current options and future directions

Glaucoma is a progressive optic neuropathy that is the second leading cause of preventable blindness worldwide, after cataract formation. A rise in the intraocular pressure (IOP) is considered to be a major risk factor for glaucoma and is associated with an abnormal increase of resistance to aqueous humour outflow from the anterior chamber. Glaucoma drainage devices have been developed to provide an alternative pathway through which aqueous humour can effectively exit the anterior chamber, thereby reducing IOP. These devices include the traditional aqueous shunts with tube-plate design, as well as more recent implants, such as the trabeculectomy-modifying EX-PRESS® implant and the new minimally invasive glaucoma surgery (MIGS) devices. In this review, we will describe each implant in detail, focusing on their efficacy in reducing IOP and safety profile. Additionally, a critical and evidence-based comparison between these implants will be provided. Finally, we will propose potential developments that may help to improve the performance of current devices.

Comparison of complications after Ahmed versus Baerveldt implant in glaucoma patients: one year follow-up

AIM: To compare surgical results of the Ahmed and Baerveldt implant procedures in glaucoma patients at 1y follow-up at Jakarta Eye Center (JEC) Eye Hospitals. METHODS: This cohort retrospective study was conducted on glaucoma patients aged ≥18y who had undergone Ahmed and Baerveldt implant surgery. Intraocular pressure (IOP), visual acuity, glaucoma medication, success rate, early and late postoperative complications, and the number of resurgeries were analyzed. RESULTS: A total of 351 eyes in the Ahmed group and 94 eyes in the Baerveldt group were included in this study. At 1y follow-up, the mean IOP was found to be significantly lower in the Baerveldt group (13±4.47 mm Hg) compared to the Ahmed group (15.02±5.73 mm Hg; P=0.025). Glaucoma medication was required in both the Ahmed and Baerveldt groups (58.92% vs 71.67%). Comparable success rate was found in both groups. The Ahmed group revealed a complete and qualified success of 86.82%, and failure of 13.17%. Similarly, the Baerveldt group showed complete and qualified success in 87.75% and failure in 12.25% cases. In the Ahmed group, 11.97% early complications, 26.06% late complications and 9.97% resurgeries were observed. In comparison, in the Baerveldt group, 23.40% early complications, 30.95% late complications and 11.70% resurgeries were observed. CONCLUSION: Both groups of glaucoma implants show significant IOP reduction, however, the Baerveldt implant group demonstrates greater IOP reduction with more failure rates and complications than the Ahmed implant group.

Ahmed Glaucoma Valves versus EX-PRESS Devices in Glaucoma Secondary to Silicone Oil Emulsification

Objective. To evaluate and compare the clinical effects of Ahmed glaucoma valves (AGVs) and EX-PRESS implants on glaucoma secondary to silicone oil (SO) emulsification. Methods. A retrospective case-series study was designed. A total of 23 eyes with late intraocular pressure (IOP) elevation secondary to SO emulsification were included in the study. Antiglaucoma surgery with implantation of AGVs or EX-PRESS devices was performed. Pre- and postoperative ocular parameters were recorded at each visit during a 1-year follow-up period. The rates of complete success (IOP < 21 mmHg without medication) and qualified success (IOP < 21 mmHg with ≤3 glaucoma medications) were analyzed. Results. A total of 14 eyes underwent AGV implantation, and 9 underwent EX-PRESS implantation. The mean IOP and number of medications used at the last follow-up decreased significantly compared with that before surgery (P<0.001). The total success rate for all eyes including complete success (7/23) and qualified success (7/23) was 60.9% (14/23) at 1 year. The total success rate in the AGV group was 78.6% (11/14), whereas it was 33.3% (3/9) in the EX-PRESS group; the difference between the 2 groups was significant (P<0.05). Conclusion. For glaucoma secondary to SO emulsification, glaucoma implants could be effective at lowering IOP, and AGVs might produce better outcomes than EX-PRESS devices.