Outcomes of Descemet Stripping Only Without Postoperative Use of Topical Rho-associated Protein Kinase Inhibitors.

PURPOSE: Descemet Stripping Only (DSO) is a promising surgical option for select patients with Fuchs endothelial dystrophy (FED). There is growing support for the use of topical Rho-associated protein kinase inhibitors (ROCKi) to optimize DSO outcomes. However, in many settings, ROCKi are either unavailable or not approved to treat corneal diseases. This study sought to characterize patient outcomes after DSO in the absence of ROCKi and potentially broaden the settings where DSO can be offered to patients. METHODS: Single-center retrospective case series of 15 eyes/11 patients (66 years; 52-74) that underwent DSO, alone or combined with cataract surgery, by one surgeon between August 2020 and January 2023. Patients included in analyses had FED with central guttae, no clinical evidence of corneal edema, and a clinically healthy peripheral corneal endothelium. RESULTS: Mean follow-up time was 14 months (2-34). Fourteen of 15 eyes achieved corneal clearance (93.3%). Mean time to clearance was 8.5 weeks (3-23). Eleven eyes (73%) achieved corrected distance visual acuity of ≤0.2 with a significant postoperative improvement at 4 to 8 months (P < 0.05) and sustained improvements at >12 months. No significant astigmatism was introduced by the procedure. Two eyes developed cystoid macular edema postoperatively. A trend toward earlier clearance was observed in the <65 years old group. CONCLUSIONS: Despite a longer time to corneal clearance in this cohort compared with the few studies using ROCKi, the overall success rate and visual outcomes for the patients in our cohort supports the use of DSO in settings where ROCKi are not readily available.

A quantitative approach to the spread of variance in translational research using Monte Carlo simulation.

The translation of promising preclinical research into successful trials often fails. One contributing factor is the "Princess and the Pea" problem, which refers to how an initially significant effect size dissipates as research transitions to more complex systems. This work aimed to quantify the effects of spreading variability on sample size requirements. Sample size estimates were performed by Monte Carlo simulation. To simulate the process of progressing from preclinical to clinical studies, nested sigmoidal dose-response transformations with modifiable input parameter variability were used. The results demonstrated that adding variabilty to the dose-response parameters substantially increases sample size requirements compared to standared calculations. Increasing the number of consecutive studies further increases the sample size. These results quantitatively demonstrate how the spread of variability in translational research, which is not typically accounted for, can result in drastic increases in the sample size required to maintain a desired study power.