Abstract
Purpose: :
There are some reports about optic nerve fiber layer changes after vitrectomy surgery, such as dissociated optic nerve fiber layer appearance, which is not associated with the loss of optic nerve fibers. We have investigated the course of changes in peripapillary retinal nerve fiber layer (RNFL) thickness after vitrectomy surgery for macular hole or epiretinal membrane.
Methods: :
We included 31 eyes which underwent vitrectomy surgery for idiopathic macular hole or epiretinal membrane in this observational study. The series comprised 13 males and 18 females. The ages ranged from 53 to 83 years, with an average of 68 ±7.1 years. Peripapillary RNFL thickness was measured by optical coherence tomography ( Stratus OCT, Carl Zeiss Meditec ) to acquire circular scans of 3.4 mm in diameter around the optic nerve. For each eye, RNFL thicknesses were evaluated in 4 quadrants ( superior, nasal, inferior, temporal ) before surgery, immediately after surgery, 1, 3, 6 and 12 months after surgery.
Results: :
Total RNFL thickness averaged 105.0 ± 16.9 μm before surgery, and increased significantly ( 113.9 ± 17.1 μm P<0.01 ) immediately after surgery. Total RNFL thickness at 1 month after surgery returned to the basal level ( 106.9 ± 15.3 μm ). However, the total RNFL thickness was 100.5 ± 14.3 μm at 3 months after surgery, 97.6 ± 14.8 μm at 6 months after surgery and 97.5 ± 14.1 μm at 12 months after surgery, all of which showed significant decreases compared with the preoperative measurement. After 3 months, temporal RNFL thickness was significantly thinner than before surgery ( before: 94.7 ± 30.7 μm, 3 months: 78.5 ± 23.7 μm P<0.01 ), and it became thinner continuously until 12 months after surgery. In the inferior and superior RNFL, the decreases were significant after 6 months ( before: 126.7 ± 23.0 μm, 6months: 119.8 ± 19.8 μm P<0.01 ) and 12 months ( before: 122.9 ± 27.2 μm, 12months: 115.2 ± 20.5 μm P<0.01 ) respectively. In the nasal RNFL, decreases were not statistically significant until 12 months after surgery.
Conclusions: :
Peripapillary RNFL thickness decreased continuously until 12 months after surgery. Vitrectomy surgery for macular hole or epiretinal membrane may have long term effects on peripapillary RNFL thickness.
Keywords: nerve fiber layer • imaging/image analysis: clinical • macular holes