Risk factors for early and late retinal detachment after boston type I keratoprosthesis surgery

To determine the differential risk factors for retinal detachment (RD) after Boston Type 1 Keratoprosthesis (B1KPro) during the first year after surgery (early RD; ERD) and afterwards (late RD; LRD).

Retrospective cohort study of 94 eyes (90 patients) undergoing B1KPro implantation at Centro de Oftalmología Barraquer from June 2006 to July 2022 with a minimum follow-up of one year.

The incidence of RD in the whole sample after B1KPro implantation was 29% (27/94), occurring in 21% of eyes (ERD; 20/94) the first year, and in 7% afterwards (LRD; 7/94). Hypotony was revealed as a significant risk factor for ERD (16/19 = 84%; OR = 14.5, P < 0.0001), together with aphakia (16/20 = 80%; OR = 5.9, P = 0.004), intraocular lens (IOL) removal (4/8 = 50%; OR = 6.2, P = 0.03), previous choroidal detachment (CD; 7/20 = 35%; OR = 35.5, P = 0.001) and previous pars plana vitrectomy (PPV; 15/20 = 75%; OR = 6.6, P = 0.006). Multivariate analysis included hypotony and PPV at any time as variables significantly associated with ERD occurrence. The occurrence of LRD was significantly related to peripheral retinal changes, detected few days before (4/6 = 66%; OR = 65, P < 0.0001).

Hypotony emerged as one of the main factors influencing ERD occurrence after B1KPro implantation. Additionally, previous CD, PPV, aphakia, and IOL removal should be considered to estimate the risk of postoperative retinal detachment. In contrast, peripheral retinal changes after B1KPro seem to be significantly related to LRD occurrence. This study reinforces the need for frequent intraocular pressure evaluation, and comprehensive periodic retinal assessment over time.

What is known Retinal detachment (RD) is a severe complication after Boston Type 1 Keratoprosthesis (B1KPro) implantation, resulting in a permanent reduction of visual acuity in a clinically relevant percentage of eyes. The time of RD occurrence after B1KPro implantation differs in the literature but is reported to be more common within the first year. Previous aphakia, choroidal detachment, or RD repair, intraocular lens removal, vitritis, or history of Nd-YAG laser have been described as risk factors for RD after B1KPro surgery in samples with varying follow-ups.

Multivariate analysis in the first year after B1KPro surgery showed hypotony and pars plana vitrectomy at any time as significant risk factors for early RD. Late RD cases, occurring after one year following the B1KPro surgery, seem to be significantly related to peripheral retinal changes suffered a few days before loss of visual acuity and RD diagnosis. It is plausible to think that risk factors for RD after B1KPro differ in short and long postoperative times.