Evaluation of changes in the corneal thickness, anterior chamber depth and iridocorneal angle following silicone oil removal using anterior segment optical coherence tomography

Purpose: To evaluate the changes in the corneal thickness, anterior chamber depth and iridocorneal angle following silicone oil removal with anterior segment optical coherence tomography (AS-OCT). Methods: Thirty-two eyes of 32 patients who underwent silicone oil removal were included in this prospective study and fellow eyes comprised the control group. Changes in corneal thickness, anterior chamber depth and iridocorneal angle were evaluated with anterior segment optical coherence tomography and the axial length were measured with partial coherence interferometry before surgery and one day, one week, one month and three months after the surgery. Patients with recurrent detachments, patients with only eye, patients requiring additional surgery and patients with coexisting anterior segment pathology were excluded. Results: No significant difference was present between the study and control group with regard to corneal thickness, anterior chamber depth and iridocorneal angle preoperatively. Preoperative axial length and spherical equivalent in the study group were statistically significantly higher than the control group (p=0.005 and p=0.000, respectively). There was a significant increase in the central corneal thickness at the first postoperative day and week (p=0.001 and p=0.014, respectively). Corneal thickness began to decrease after the first postoperative day and was close to the preoperative value at the postoperative third month. The increase in the anterior chamber depth at the postoperative first day, first week and first month were statistically significant (p=0.034, p=0.001 and p=0.001, respectively). There was also a slight but statistically insignificant increase at the third month. The decrease in the axial length at the postoperative first day, first week, first month and third month were statistically significant (all p=0.000). The increase in the iridocorneal angle 0º and 180˚ values at the postoperative first day, first week, first month and third month were statistically significant (all p=0.000 for iridocorneal angle 0º; p=0.000, p=0.000, p=0.000 and p=0.001 for iridocorneal angle 180º, respectively). The myopic shift in the spherical equivalent at the postoperative first day, first week, first month and third month were also statistically significant (all p=0.000). Conclusion: The changes in the central corneal thickness and anterior chamber depth after silicone oil removal were mild and temporary and almost returned to preoperative levels within three months. However, the decreases in the axial length, myopic shift and increase in iridocorneal angle persisted and did not return to preoperative values even after three months.