Spectral domain optical coherence tomography in patients after successful management of postoperative endophthalmitis following cataract surgery by pars plana vitrectomy

Abstract

Background: Acute severe postoperative endophthalmitis may lead to severe vision loss. The aim of this study was the analysis of macular microstructure imaged by spectral domain optical coherence tomography in patients after pars plana vitrectomy due to postcataract endophthalmitis.

Methods: A cross sectional study was carried out in 17 patients who had cataract surgery in both eyes and underwent unilateral pars plana vitrectomy due to postcataract endophthalmitis. Postoperative best corrected visual acuity was determined in both eyes. Evaluation of macular thickness, macular volume, peripapillary retinal nerve fiber layer thickness and choroidal thickness using enhanced depth imaging technique was performed by spectral domain optical coherence tomography. The measurements obtained in the operated eye were compared to the fellow eye by Wilcoxon matched pair test. Correlation test was performed by Spearman rank order.

Results: A mean postoperative best corrected visual acuity of 63 ± 30 ETDRS letters versus 75 ± 21 letters was achieved in the study and fellow eyes, respectively, after a mean of 5.3 ± 4.5 months (p = 0.1). The mean macular thickness was 320.6 ± 28.8 μm SD in the study eyes compared to 318.4 ± 18.8 μm in the fellow eyes (p = 0.767). No differences were noted in macular volume (p = 0.97) and in peripapillary retinal nerve fiber layer thickness (p = 0.31). Choroidal thickness was significantly lower in the study eyes compared to the fellow eyes (p = 0.018). Epiretinal membrane was found in 7 eyes after endophthalmitis, while in the fellow eyes only in 3 cases (p = 0.13, Fisher's exact test).

Conclusion: Choroidal thickness decreased significantly after endophthalmitis, but there was no functional correlation with the changes in choroidal microstructure. The development of epiretinal membranes may be associated with either vitrectomy or endophthalmitis in the history. Absence of other significant structural and morphological findings shows that successful treatment may guarantee good clinical results even in long term after this severe postoperative complication.

Figure 1

The blue dots on the infrared fundus image denote the measurement points used in the study. Each measurement point has a distance of 2000 um on the central horizontal and two vertical axes.

Figure 2

SD-OCT image in EDI mode in an eye after postoperative endophthalmitis. Choroidal thickness is measured between the outer border of the retinal pigment epithelium and the inner scleral border using the caliper tool of the software (red line).

Figure 3

Measurement of the peripapillary nerve fiber layer thickness in an eye after postcataract endophthalmitis. Note that the thickness curve is running mostly within normal limits, except for the temporal and superotemporal regions.

Figure 4

Choroidal thickness in the different measurement regions and mean choroidal thickness comparison between study eye and fellow eye. Significant changes of decreased thickness were found in the central, temporal superior, nasal superior and nasal macular areas in eyes after postoperative endophthalmitis. Compared to eyes after uncomplicated phacoemulsification (221.86 μm ± 28.47) mean choroidal thickness is significantly thinner in eyes after endophthalmitis (195.14 μm ± 23.19), (p = 0.018).

Figure 5

No correlation was seen between CRT and subfoveal choroidal thickness in the study and fellow eyes. (Spearman Rank Order Correlation, p > 0.05).