Transcorneal freezing does not affect ultrastructural composition of Descemet’s membrane in Fuchs’ endothelial corneal dystrophy but does not preclude subsequent Descemet membrane endothelial keratoplasty (DMEK), according to a correspondence published in Eye.
Currently, no conclusive evidence suggests which surgical approach — removal of Descemet’s membrane without endothelial keratoplasty or removal of only the diseased corneal endothelial cells — is best when combined with Rho kinase (ROCK) inhibitor treatment to enhance the regeneration of corneal endothelial cells.
Researchers reported their findings from 3 patients with moderate Fuchs’ endothelial corneal dystrophy using the Erbokryo® AE cryosurgical system (Erbe Elektromedizin). Erbokryo was applied at -60° Celsius for 15 seconds to the central 3 mm of the cornea to remove corneal endothelial cells, followed by ripasudil eye drops (Glantec® ophthalmic solution 0.4%; Kowa Company, Ltd.) 6 times daily for 1 week.
The first patient, a 48-year-old woman) presented with corrected distance visual acuity (CDVA) of 0.3 logMAR, which increased to 0.1 logMAR after 1 month of cryotherapy/ripasudil treatment. At the 2-year posttreatment mark, CDVA dropped to 0.2 logMAR. Three and a half years after treatment, DMEK was performed. At the time of treatment, CDVA was 0.5 logMAR; this increased to 0.0 logMAR within 2 months of the DMEK.
The second patient, a 62-year-old woman, also presented with a CDVA of 0.3 logMAR, which remained the same at 1 month after treatment. DMEK was performed 14 months later, with a CDVA of 0.5 logMAR. Three months post-DMEK, CDVA increased to 0.1 logMAR.
The third patient, a 64-year-old man, presented with a CDVA of 1.0, which improved to 0.2 logMAR after 6 months of treatment. At 18 months, CDVA dropped by 1 line due to herpes simplex keratitis, which prompted a penetrating keratoplasty with CDVA of 0.8 logMAR.
Corneal tissue samples were obtained from patients 2 and 3 during surgery, and transmission electron microscopy studies were performed on these samples. Descemet’s membrane ultrastructure demonstrated alterations typical to Fuchs’ endothelial corneal dystrophy, but “no sequelae of transcorneal freezing and/or ripasudil” were noted.
According to the researchers, these observations “suggest that transcorneal freezing does not affect the ultrastructural composition of Descemet’s membrane in Fuchs’ endothelial corneal dystrophy.”
“The persistence of guttae may explain why this procedure yields improvement in CDVA only transiently, despite the application of ripasudil,” according to the publication. “However, the intervention does not preclude subsequent DMEK surgery with excellent visual outcomes. It may therefore provide a viable option in patients who benefit from postponing intraocular surgery.”
Further studies are required to determine the mean duration of improved visual acuity as well as whether patients with endothelial disease “not characterized by corneal guttae may have a more sustained effect.”
Menzel-Severing J, Schrader S, Schlötzer-Schrehardt U, Geerling G. Transcorneal freezing and topical Rho-kinase inhibitor treatment in Fuchs endothelial corneal dystrophy. Eye. Published online April 12, 2021. doi:10.1038/s41433-021-01520-2