Abstract
Purpose :
We evaluated the short-term changes in retinal thickness around the fovea using optical coherence tomography (OCT) after pars plana vitrectomy (PPV) for epiretinal membrane (ERM). We investigated the quadrant of the macula with the greatest retinal thickness change.
Methods :
A retrospective chart review was performed on patients with idiopathic ERM who underwent PPV with membrane stripping and had OCT data at baseline and one or two months following PPV. Additional data were gathered when longer follow-up OCT was available. The retinal thickness around the macula was derived from the 9 quadrants (Q) from the OCT map such that the central 1 mm region was surrounded by 3 mm and 6 mm circles, which were further divided into superior, nasal, inferior, and temporal quadrants (Figure 1). The time points were grouped as follows: preoperative, 1-2 months postoperative, 3-4 months postoperative, and 5-8 months postoperative periods. Average retinal thickness of all eyes at these time points at each of the 9 quadrants was compared. In addition, changes at each quadrant at each time point compared to the baseline was calculated for each eye, and the values for the all the eyes that had OCT at these time points were averaged for comparison (Table 1).
Results :
OCT from 39 eyes of 37 patients with a mean age of 65.7 ± 9.1 years (range, 44-80) were analyzed. Compared to the preoperative retinal thickness, the retina thinned statistically significantly at all 9 quadrants at all timepoints assessed. An average change from baseline to 3-4 months for Q1 through Q9 was as follows: 101.3 ± 79.2 µm in Q1, 76.9 ± 58.7 µm in Q2, 80.2 ± 74.3 µm in Q3, 80.8 ± 67.5 µm in Q4, 92.1 ± 61.5 µm in Q5, 38 ± 33.3 µm in Q6, 47.7 ± 44.5 µm in Q7, 48.7 ± 46.8 µm in Q8, and 46.9 ± 40.4 µm in Q9. At 1-2 months after surgery, Q5 displayed the greatest decrease in retinal thickness with a change of 74.8 ± 48.9 µm. However, Q1 thinned the most by 3-4 month and 5-8 month postoperative follow up with changes of 101.3 ± 79.2 µm and 86.6 ± 53.3 µm, respectively.
Conclusions :
PPV with ERM stripping resulted in a decrease in retinal thickness at and around the fovea. Retinal thinning stabilized sometime between 3 to 4 month and 5 to 8 month postoperative period. Furthermore, central 1 mm at the fovea (Q1) and temporal to the fovea (Q5) displayed the greatest amount of retinal thinning from the baseline.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.