To evaluate the relationship between the size of internal limiting membrane (ILM) peeling and the elongation of foveal tissue after macular hole (MH) surgery.

The medical records of 29 patients (29 eyes) who developed elongation of foveal tissue on spectral domain optical coherence tomography (OCT) after vitrectomy with ILM peeling and gas tamponade for idiopathic MH were retrospectively reviewed. These eyes were classified into 3 subgroups by the size of ILM peeling: group A (9 eyes), smaller than 2 disc diameter (DD); group B (12 eyes), larger than 2 DD and within the major temporal vascular arcade, and group C (8 eyes), till the edge of the major temporal vascular arcade. Inter-outer plexiform layer (OPL) distance, representing elongation of foveal tissue, was measured 1, 3, and 6-8 months (only 18 eyes) postoperatively. 'Asymmetric elongation' was defined as non-uniform elongation of the foveal tissue in certain directions.

Horizontal/vertical inter-OPL distances 1 month postoperative, in descending order, were: group B, 436.58 ± 88.54 / 404.92 ± 78.55 µm; group A, 421.33 ± 109.97 / 404.14 ± 120.9 µm; and C group, 389.25 ± 48.75 / 400 ± 52.23 µm. Variations in the horizontal/vertical inter-OPL distance 3 months after MH surgery were: group B, 136.83 ± 65.64 / 103.92 ± 73.37 µm; group A, 88.11 ± 41.57 / 75.89 ± 53.18 µm; and group C, 140.25 ± 68.51 / 83.63 ± 56.62 µm. There were no significant differences in inter-OPL distance, variation in inter-OPL distance, or percent asymmetry in both horizontal and vertical directions among these groups.

Elongation of the foveal tissue and asymmetric elongation after MH surgery were not associated with the size of ILM peeling.