Combined MIGS: Comparing Additive Effects of Phacoemulsification, Endocyclophotocoagulation, and Kahook Dual Blade

Abstract

Purpose

Combining two or more MIGS (cMIGS) promises to be more efficacious than single MIGS (sMIGS). This study compared the efficacy of PEcK, which combines Phacoemulsification (Phaco), Endocyclophotocoagulation (ECP), and Kahook dual blade (KDB), relative to both of its constituent sMIGS, Phaco/ECP (Endo Optiks, NJ) and Phaco/KDB (New World Medical, CA) for the first time.

Patients and methods

Data was collected retrospectively from 1833 visits of 271 patients who underwent PEcK, Phaco/ECP, or Phaco/KDB from 2016–2021 at Massachusetts Eye and Ear. Primary outcomes included Generalized Estimating Equations (GEE) of intraocular pressure (IOP) and medication burden, as well as survival models.

Results

Mean preoperative IOP was 17.6 ± 5.0 (SD) mmHg on 3.0 ± 1.4 medications in the PEcK group (n = 128), 17.9 ± 5.1 mmHg on 2.2 ± 1.5 medications in the Phaco/ECP group (n = 78), and 16.1 ± 4.3 mmHg on 0.4 ± 1.0 medications in the Phaco/KDB group (n = 65). For more than 36 months, all procedures resulted in significant patterns of IOP and medication reduction (all p < 0.001), before and after statistical adjustment. The reduction pattern in IOP was significantly different when comparing all groups over time and favored PEcK (p = 0.04), but the reduction pattern in medications was not significantly different (p = 0.11). Procedures did not differ in procedural time (p = 0.18) or in survival to maintain ≥20% IOP reduction (p = 0.43) without additional medication or procedure. There was a trend toward significant difference in maintaining IOP ≤ goal IOP that favored PEcK over Phaco/ECP after adjustment (p = 0.09).

Conclusion

PEcK may confer greater IOP reduction without added procedural time compared to Phaco/ECP and Phaco/KDB in predominantly mild or moderate glaucoma. Further research on cMIGS may benefit from adopting this comparative analysis to constituent MIGS.

Keywords:

• microinvasive glaucoma surgery
• cMIGS
• generalized estimating equations
• GEE
• comparative effectiveness
• combined efficacy
• glaucoma

Abbreviations

ALT, Argon Laser Trabeculoplasty; BCVA, Best corrected distance visual acuity; CME, Cystoid macular edema; cMIGS, Combined MIGS, denoting a procedure of two or more MIGS; Cox PH, Cox Proportional Hazards; GEE, Generalized Estimating Equations; ICE, cMIGS procedure combining iStent insertion, Cataract extraction, and ECP; IOP, Intraocular pressure; logMAR, Logarithm of the Minimum Angle of Resolution; LPI, Laser Peripheral Iridotomy; LTP, Laser trabeculoplasty; MIGS, Microinvasive glaucoma surgery; MPCPC, MicroPulse Trans-Scleral Cyclophotocoagulation; PEcK, cMIGS procedure combining Phacoemulsification, Endocyclophotocoagulation, and Kahook Dual Blade; Phaco, Phacoemulsification; Phaco/ECP, Phacoemulsification with endocyclophotocoagulation; Phaco/KDB, Phacoemulsification with Kahook Dual Blade; SC1, Survival Criteria 1; SC2, Survival Criteria 2; SLT, Selective Laser Trabeculoplasty; sMIGS, Single MIGS, denoting a procedure that included only one MIGS; TM, Trabecular meshwork.

Acknowledgments

Varshini Odayar, an undergraduate at Harvard University, contributed to data collection of less than 10 patients. The authors are grateful that this research was generously supported by donations from Mr. and Mrs. Charles and Anne Gifford (Concord, Massachusetts, USA), Mr. and Mrs. Joseph and Cathey S. Leitch (Charleston, South Carolina, USA), and Stephen Traynor. The article has been presented as an e-poster at the American Academy of Ophthalmology (AAO) 2022 Annual Conference, Chicago, USA, October 2022.

Author Contributions

All authors made a significant contribution to the work reported, whether that was in the conception, study design, execution, acquisition of data, analysis, and interpretation, or in all these areas. All authors have drafted or written, or substantially revised or critically reviewed the article. All authors have agreed on the journal to which the article will be submitted. All authors have reviewed and agreed on all versions of the article before submission, during revision, the final version accepted for publication, and any significant changes introduced at the proofing stage. All authors have agreed to take responsibility and accountability for the contents of the article.

Disclosure

Dr David Solá-Del Valle reports being a speaker for Allergan (an AbbVie company) in 2021 for two weeks. The authors report no other conflicts of interest in this work.