Change in choroidal thickness and the relationship with accommodation following myopic excimer laser surgery

Abstract

PurposeTo investigate early changes in choroidal thickness (CT) and the relationship with accommodation after myopic excimer laser surgery.MethodsWe enrolled the right eye of 70 patients with myopia and without other ophthalmic or systemic diseases who were suitable for myopic excimer laser surgery. The CT was measured at the fovea and at distances of 0.5 and 2.5 mm for the following: nasal; temporal; superior; and inferior to the fovea preoperatively and at 1 month postoperatively. Other data collected included demographic information (age, sex, and refractive error), the amplitude of accommodation (AA), intraocular pressure, axial length, corneal thickness, and surgical parameters. The data were analyzed with a paired Student's t-test, stepwise linear regression, and correlation analysis.ResultsThe CT was significantly thicker postoperatively compared with the preoperative CT. The AA significantly decreased postoperatively. The change in the AA was the most significant factor associated with the change in the CT at the fovea. Except for 2.5 mm inferior to the fovea, the increase in the CT at other locations was positively correlated with the decrease in the AA.ConclusionsThe CT increased following myopic excimer laser surgery and the change was most obvious when accompanied by a decrease in the AA early after the surgery.

Figures

Figure 1

Choroidal measurements in myopic eyes by SD-OCT. Numbers are in μm units. (a) Five lines scanning at horizontal azimuth by SD-OCT with EDI. (b) Preoperative. (c) Postoperative. (d) Five lines scanning at vertical azimuth by SD-OCT with EDI. (e) Preoperative. (f) Postoperative. The OCT images for our study were selected in the location of the red line.

Figure 2

Choroidal thickness measured by SD-OCT before surgery and 1 month after surgery. T1 is the location 0.5 mm temporal to the fovea. T2 is the location 2.5 mm temporal to the fovea. N1 is the location 0.5 mm nasal to the fovea. N2 is the location 2.5 mm nasal to the fovea. S1 is the location 0.5 mm superior to the fovea. S2 is the location 2.5 mm superior to the fovea. I1 is the location 0.5 mm inferior to the fovea. I2 is the location 2.5 mm inferior to the fovea.

Figure 3

Correlation between ΔCT (μm) and ΔAA(D). (a) The fovea. (b) The location 0.5 mm temporal to the fovea. (c) The location 2.5 mm temporal to the fovea. (d) The location 0.5 mm nasal to the fovea. (e) The location 2.5 mm nasal to the fovea. (f) The location 0.5 mm superior to the fovea. (g) The location 2.5 mm superior to the fovea. (h) The location 0.5 mm inferior to the fovea. (i) The location 2.5 mm inferior to the fovea. ΔAA=AA before surgery−AA after surgery, ΔCT=CT after surgery−CT before surgery.