Transient increase of retinal nerve fiber layer thickness after macular hole surgery

We studied the changes in the thickness of the retinal nerve fiber layer (RNFL) after surgery for idiopathic macular hole (MH) using spectral-domain optical coherence tomography (SD-OCT). Twenty eyes of 20 consecutive patients who underwent vitrectomy to close a MH were studied. The peripapillary RNFL thickness was measured by SD-OCT before and at 1, 3, and 6 months after surgery. The mean overall thickness, the thickness of the four quadrants, and the thickness of each of the 12 clock hours of the RNFL were analyzed. The mean overall RNFL thickness before surgery was 93.3 ± 9.6 μm, and it increased significantly to 98.7 ± 7.4 μm at 1 month after surgery (P < 0.05). The mean overall thickness then returned to the pre-surgery level at three and 6 months. The transient increase of RNFL thickness at 1 month after surgery was statistically significant in the superior, nasal, and inferior quadrants. The increase in the thickness of the nasal quadrants was maintained for up to 6 months. When the thickness of the individual 12 clock hours were analyzed, the transient increase of RNFL thickness at 1 month after surgery was significant at each of the 0–5 o’clock positions. The transient increase in the RNFL thickness after MH surgery may be caused by mild edema of the inner retinal layers caused by the MH surgery.