Temporary Keratoprosthesis and Primary Corneal Graft for Ocular Trauma: A Systematic Review and Meta-Analysis

When severe retinal and corneal injury occur together, a temporary keratoprosthesis (TKP) is often a last resort to allow posterior segment visualization to enable vitreoretinal surgery, followed by a penetrating keratoplasty (PKP) which can restore corneal clarity in a single operation. We aimed to assess visual outcomes following combined PKP and vitreoretinal surgery with the use of a TKP for cases of ocular trauma. A systematic literature review was performed following PRISMA guidelines (PROSPERO registration number: CRD42023423518). CENTRAL, MEDLINE, Embase, ISRCTN registry, and ClinicalTrials.gov were searched from inception to 27 April 2023. Randomized and nonrandomized studies assessing visual outcomes after combined vitreoretinal surgery and PKP with the use of a TKP after ocular trauma were eligible for inclusion. Outcomes included change in best corrected visual acuity, corneal graft survival and retinal reattachment at final follow up. Proportional meta-analysis was used to estimate the overall rate of the primary outcomes. Risk of bias for nonrandomized studies was assessed using the Joanna Briggs Institute (JBI) critical appraisal checklist for case series. A total of 19 studies met inclusion criteria reporting a total of 352 eyes. All studies were retrospective and nonrandomized with follow up times ranging from 6 to 91 months, with at least 79% of outcomes reported after 6 months. After combined surgery the rate of corneal graft survival was 52% (95% CI 0.41-0.62; I2 60%) successful retinal attachment was 79% (95% CI 0.73-0.84; I2 0%). and improved visual acuity, when compared to no change or decrease in visual acuity, was 45% (95% CI 0.32-0.59; I2 66%). Patients with severe injury affecting the anterior and posterior segments have very limited treatment options. This systematic review found that when combined vitreoretinal surgery and PKP with a TKP are performed, approximately half of corneal grafts survive, anatomically successful retinal reattachment is likely, and a similar proportion of patients benefit in terms of improved visual acuity, compared to their preoperative function. This systematic review of the available literature may help inform surgeons of the benefits of using a TKP for cases of ocular trauma.