Unclear if Cryopreserved Amniotic Membranes Have A Role in Preoperative EMBD Treatment

Cryopreserved amniotic membrane shows no benefit over bandage contact lens in optimizing the ocular surface before cataract removal, according to a study.

The application of cryopreserved amniotic membranes (CAM) after corneal epithelium debridement in the treatment of epithelial basement membrane dystrophy (EBMD) remains speculative, according to research published in Clinical Ophthalmology. Investigators were not able to show that the devices accelerate healing.

Corneal epithelium debridement is used to treat EBMD prior to cataract surgery, as research shows the preoperative management of any ocular surface disorder can stabilize intraocular lens (IOL) calculations, and reduce the potential for any unexpected postoperative refractive issues.

The pilot study (ClinicalTrial.gov Identifier: NCT02766907) consisted of 2 treatment groups: a prospective study group with significant EBMD who received debridement followed by self-retained CAM, and a control group with EBMD who received bandage contact lenses (BCL) after debridement. Investigators utilized slit-lamp photography after fluorescein staining to monitor healing. They compared corneal topography and IOL calculation at baseline and 1 month after the procedure. The team also compared refraction and ocular surface stability following cataract surgery. 

The study group included 9 participants (average age: 74.0±7.5 years, 5 women, 4 men) and the control group included 10 participants (average age: 66.5±5.9 years, 7 women, 3 men). Corneal re-epithelialization after debridement occurred in 4.6±0.8 days in the study group and 6.8±0.6 days in the control group (P <.05), according to the report. Corneal topography revealed changes in curvature from 43.5±1.2D at baseline to 44.6±1.2 D at 1 month in the study group, and from 45.0±0.6D to 45.7±0.8 D in the control group; however, this difference was not statistically significant (P =.38).

The analysis also shows that the average change in IOL calculation was 1.56 D in the study group, compared with 0.95 D in the control group (P =.29), with no statistically significant difference (P =.29). One month after cataract surgery, the refractive error was within ±0.5 D of the anticipated measurement in both groups. For at least 1 year in both groups, the corneal surface remained stable without EBMD recurrence. 

“Although the concept of using self-retaining CAM after debridement holds great promise to accelerate the healing and optimize the ocular surface prior to cataract surgery, its use in cases of EBMD remains speculative,” according to the researchers. “CAM relatively accelerated healing after debridement; however, it was not better than BCL in stabilizing the ocular surface and improving visual outcome.”  

Study limitations include the limited sample size and the retrospective nature.

“Although CAM is prepared under complete aseptic conditions and passed all the required screening and microbial testing, it is non-sterile and carries the potential risk of transmitting unrecognized infectious diseases including COVID-19,” according to researchers. “Currently, there is no data on the survival of SARS-CoV-2 on CAM.”

Disclosure: One study author declared affiliations with biotech, pharmaceutical, and/or device companies. This research was supported by Tissuetech. Please see the original reference for a full list of disclosures. 

Reference

Yeu E, Hashem O, Sheha H. Treatment of epithelial basement membrane dystrophy to optimize the ocular surface prior to cataract surgery. Clin Ophthal. Published online March 15, 2022. doi:10.2147/OPTH.S356421