Table 3 Specification of secondary endpoints
Outcome | Specific measurement variable | Analysis metric (participant level) | Method of aggregation (summary measure for each study group) | Measurement time or time point |
|---|---|---|---|---|
Overall functional graft survival rate | Graft survival | Time from surgery to graft failure or to the last observation | Rate derived from survival curve | Within 24 months after transplantation |
Rejection-related graft failure rate | Rejection-related graft failure with endothelial graft rejection | Time from surgery to rejection-related graft failure or to last observation | Rate derived from survival curve | Within 24 months after transplantation |
Sufficient regression of CoNV after 1st CXL and only after 2nd CXL | Regression of CoNV > 50% (intervention arm only) | Value (yes/no) | Proportion | After 1st CXL and after 2nd CXL |
Recurrence of CoNV | Recurrence (after sufficient regression was reached; intervention arm only) | Value (yes/no) | Proportion | After CXL (until transplantation) and after transplantation (within 24 months) |
Visual acuity (BCVA) | ETDRS charts (transformed to logMAR) | Value | Mean | Prior to CXL, prior to transplantation, and 3, 6, 12, 18, and 24 months after transplantation |
Vision-related quality of life | Overall score of NEI-VFQ25 | Value | Mean | Prior to CXL, prior to transplantation, and 3, 6, 12, 18, and 24 months after transplantation |
Infections | Active infectious keratitis or corneal ulceration | Value (yes/no) | Proportion | Within 24 months |
Delayed wound healing | Delayed wound healing: corneal epithelium not closed (delay) or closed (no delay) | Value (yes/no) | Proportion | Within 24 months after transplantation |
Graft dehiscence | Graft dehiscence characterized by leakage of aqueous humor | Value (yes/no) | Proportion | Within 24 months after transplantation |