Outcomes of Zone 3 Open Globe Injuries by Wound Extent: Subcategorization of Zone 3 Injuries Segregates Visual and Anatomic Outcomes

Abstract

Purpose: Open globe injuries (OGIs) are categorized by zone, with zone 3 (Z3) comprising wounds > 5 mm beyond the limbus. Outcomes of Z3 OGIs are highly heterogeneous. Open globe injuries with far posterior Z3 (pZ3) wounds were hypothesized to have worse visual and anatomic outcomes.

Design: Single-center retrospective cohort study.

Participants: A total of 258 eyes with Z3 OGIs.

Methods: A retrospective review of Z3 OGIs treated at a tertiary center over 12 years. Wounds ≥ 10 mm posterior to the limbus were defined as pZ3. Outcomes were compared between pZ3 and anterior Z3 (aZ3) eyes.

Main outcome measures: Visual acuity on a logarithm of the minimum angle of resolution (logMAR) scale. Secondary outcomes included anatomic outcomes, development of retinal detachment and proliferative vitreoretinopathy, and the number of secondary surgeries.

Results: A total of 258 Z3 OGI eyes with > 30 days follow-up were assessed; 161 (62%) were pZ3. At 3-month follow-up, pZ3 OGIs were more likely to exhibit no light perception (pZ3: 38%; aZ3: 17%; P < 0.003), lack count fingers vision (pZ3: 72%; aZ3: 43%; P < 0.002), and fail to read a letter on the eye chart (pZ3: 83%; aZ3: 64%; P < 0.001). The visual acuity distribution at 3 months was significantly worse for pZ3 compared with aZ3 injuries (P < 0.004). Similar results were found at final follow-up. Multiple linear regression showed that pZ3 location was independently associated with worse visual acuity (β = 0.29, 95% confidence interval [CI], 0.09-0.50, P < 0.006) in addition to presenting acuity, age, vitreous hemorrhage, uveal prolapse, and afferent pupillary defect. Far posterior wounds injuries were more likely to develop retinal detachments (pZ3: 87%; aZ3: 71%; P < 0.01) and proliferative vitreoretinopathy (pZ3 66%; aZ3 47%; P < 0.03). Patients with pZ3 OGIs were significantly more likely to reach poor anatomic outcome (phthisis, enucleation, need for keratoprosthesis) compared with patients with aZ3 OGI (pZ3: 56%; aZ3: 40%; P < 0.03).

Conclusions: Posterior OGI extension independently portends worse visual and anatomic outcomes. The effect on visual outcome was durable and clinically relevant compared with established predictors of OGI outcomes. Application of these findings improves the prognostic precision and will guide future research efforts to optimize surgical decision-making in severe OGI cases.

Financial disclosure(s): Proprietary or commercial disclosure may be found after the references.

Keywords: Injury; Ocular trauma; Open globe injury; Open globe repair; Prognostic factors; Trauma.

Figure 1.

Consort figure demonstrating the case review and exclusion process. Of 300 consecutive Zone 3 OGIs over a 12 year period, 258 were included for analysis. 97 were classified as anterior Zone 3 (aZ3) and 161 were classified as posterior Zone 3 (pZ3).

Figure 2.

Box plots demonstrating the distribution of visual acuity on a logMAR scale at presentation, 3 month follow-up and final follow-up. Box plots are stratified based on pZ3 and aZ3 categories. The presenting acuity distribution was not significantly different between pZ3 and aZ3 categories but the 3 month follow-up and final follow-up acuity distributions were significantly different.

Figure 3.

Multiple linear regression on final visual acuity. Posterior zone 3 injury was found to be an independent predictor of final visual acuity. Other significant predictors included presenting visual acuity, age, uveal prolapse, vitreous hemorrhage and the presence of an afferent pupillary defect.