Femtosecond Laser-Assisted Versus Manual Descemet Membrane Endothelial Keratoplasty: A Systematic Review And Meta-Analysis

Published 2022 - 40th Congress of the ESCRS

Reference: FPT06.03 | Type: Free paper | DOI: 10.82333/xxhd-0211

Authors: Siddharth Nath* ¹ , Harrish Nithianandan ¹ , Arjan Dhoot ² , Carl Shen ³ , Daniel Peretz ¹ , Alex Koziarz ² , Nishaant Bhambra ⁴ , William Hodge ⁵ , Johanna Choremis ¹ , Mahshad Darvish-Zargar ¹

¹Department of Ophthalmology and Visual Sciences,McGill University,Montreal,Canada, ²University of Toronto,Toronto,Canada, ³Department of Ophthalmology and Visual Sciences,University of Alberta,Edmonton,Canada, ⁴McGill University,Montreal,Canada, ⁵Ivey Eye Institute and Department of Epidemiology and Biostatistics, Schulich School of Medicine and Dentistry,Western University,London,Canada

Purpose

Descemet membrane endothelial keratoplasty (DMEK) is a minimally invasive corneal lamellar transplant procedure involving removal/replacement of Descemet’s membrane and the corneal endothelium. DMEK is technically complex and creation of the descemetorhexis is crucial to determining graft success and visual outcome. The standard DMEK protocol requires manual scoring of a central section of Descemet’s membrane and removal, with or without a scraping device, of the endothelial disc. To standardize descemetorhexis size, improve graft adherence, and optimize vision, some surgeons have piloted femtosecond laser-assisted descemetorhexis during DMEK. The purpose of this meta-analysis is to compare laser-assisted DMEK with the manual approach.

Setting

The setting of this study is a systematic review and meta-analysis. Our study was performed in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 consensus statement and the Cochrane Collaboration's Handbook for Systematic Reviews of Interventions. All work was conducted in an academic health sciences centre with appropriate bibliographic and statistical support.

Methods

We searched 16 electronic databases, including MEDLINE, Embase, and Web of Science, from inception until March 2, 2022, for studies comparing femtosecond laser-assisted DMEK with manual DMEK, and supplemented with hand searching. We included both randomized trials and observational studies in our search criteria. Our primary outcome was the best-corrected visual acuity (BCVA) following DMEK. Secondary outcomes included the rate of endothelial cell loss, rate of graft detachment, and rate of re-bubbling across protocols. We summarized our analyses by calculating the weighted mean difference (MD) with associated 95% confidence interval (CI) for continuous outcomes and the odds ratio (OR) with 95% CI for dichotomous outcomes.

Results

Three observational studies (totalling 167 eyes) fulfilled our inclusion criteria. BCVA (MD -0.06, 95% CI: -0.18–0.05, p=0.29) and rate of endothelial cell loss (MD -1.39, 95% CI: -7.46–4.67, p=0.65) were comparable between laser-assisted and manual DMEK groups. Notably, laser-assisted DMEK was associated with a significantly lower incidence of graft detachment (OR 0.11, 95% CI 0.03–0.47, p<0.01) and need for re-bubbling (OR 0.14, 95% CI: 0.03–0.56, p<0.01).

Conclusions

Our work suggests that laser-assisted DMEK may be superior to the manual approach as it is associated with significantly lower rates of graft detachment and requirement for re-bubbling. Notably, however, the visual outcomes between the two protocols remain comparable. Given the paucity of literature on this topic, further research, especially rigorous randomized trials, will allow clinicians to better understand the safety and efficacy of laser-assisted DMEK in comparison to the manual approach.