Postoperative Posterior Segment Complications After Boston Type 1 Keratoprosthesis

Abstract

Purpose: To identify the incidence of, risk factors for, and outcomes of posterior segment complications (PSC) after Boston type 1 keratoprosthesis (KPro) implantation.Methods: Retrospective, consecutive case series of KPro procedures at the Stein Eye Institute. Data regarding ocular history, intraoperative details, postoperative management, and outcomes were collected. Eyes with at least one PSC (PSC group) were compared with eyes without PSC (No PSC group), and risk factors for PSC were determined.Results: Ninety-five PSC occurred in 69/169 eyes (40.8%), at a mean of 20.1 months after KPro implantation (0.01 complications/eye month). The median follow-up after KPro implantation was 44.0 months (range 3.0-174.4). The most common PSC were epiretinal membrane (16.6%), cystoid macular edema (12.4%), vitritis (11.2%), and retinal detachment (9.5%). Previous retinal detachment repair, concomitant intraocular lens removal, postoperative aphakia, and vitritis were risk factors for retinal detachment. Postoperative infectious keratitis was a risk factor for epiretinal membrane, cystoid macular edema, and vitritis. The posterior segment complication group had a significantly higher rate of eyes failing to maintain visual acuity $20/200 (HR = 2.28; 95% CI = 1.35-3.85) and KPro retention failure rate (HR = 1.66; 95% CI = 0.95-2.91).Conclusion: Posterior segment complications occur in approximately 40% of eyes after KPro implantation, resulting in reduced visual outcomes and KPro retention.

Retinal Detachment in Eyes With Boston Type 1 Keratoprosthesis

“…4,21,22 Idiopathic vitritis occurred frequently in our series, but detailed risk factor analysis was not performed because of the small cohort size and is reported elsewhere. 4 It has also been shown that a chronic low grade of inflammation from the KPro device itself can promote a strong inflammatory response within the retina, leading to an aggressive PVR response following RD. 7 This may have contributed to the high rate of severe PVR we noted and may result in underestimation of the rate of rhegmatogenous etiology, given that anterior tears or holes can be difficult to detect in these eyes.…”

“…[3][4][5] Retinal detachment (RD) is a known complication after KPro implantation and has been reported to occur in 2.0% to 17.6% of cases. 1,3,4 Its treatment with 20gauge pars plana vitrectomy (PPV) is reported with acceptable anatomical outcomes but limited visual outcomes. 5,6 Reports focusing on minimally invasive, smaller-gauge vitrectomy instrumentation techniques have described better but still low functional outcomes, at a mean follow-up of 28 months.…”

“…Management of postoperative posterior segment complications highlights the need for multidisciplinary expertise. 3–5…”

Ultra-wide field imaging to assess the optic nerve and retina in Boston type I and II keratoprosthesis patients

“…Visualization of posterior segment structures in Kpro patients is often difficult with indirect ophthalmoscopy and with standard fundus photography due to patient-specific ocular comorbidities, post-surgical complications, and the small aperture of the Kpro implant [ 6 , 7 , 14 – 16 ]. The results of this study support existing data suggesting UWF imaging provides meaningful clinical utility in the diagnosis and follow-up of posterior segment disease in Kpro patients.…”

“…A recent report of 169 type I Kpro implanted eyes found posterior segment complications using a combination of clinical examination, B-scan ultrasonography, and optical coherence tomography in approximately 40% of eyes, with the highest incidence complications being ERM (16.6%), CME (12.4%), vitreitis (11.2%), retinal detachment (9.5%), and endophthalmitis (4.1%) [ 16 ]. Chew et al reported preexisting glaucoma in 73% of Kpro patients with increased intraocular pressure (38%) and glaucoma progression (14%) being two common postoperative complications after Kpro implantation [ 8 ].…”