Foveal Morphology of Normal Fellow Eyes of Patients with Unilateral Macular Hole.

PURPOSE: To determine the morphology of the fovea in the ophthalmoscopically and tomographically normal fellow eyes of patients with a unilateral idiopathic macular hole (MH) and determine the association between foveal morphological parameters and foveal outer nuclear layer (ONL) thickness. DESIGN: Retrospective observational study. PARTICIPANTS: Two hundred three normal fellow eyes of patients with a unilateral MH and 216 normal eyes of 216 healthy subjects. METHODS: All the eyes were examined using swept-source OCT. A built-in software was used to measure the average retinal and choroidal thickness in the center and in the inner 4 subfields defined in ETDRS. The total retinal thickness, thickness of 3 retinal layers at the fovea and parafovea (0.25 and 0.5 mm nasal and temporal from the fovea), and foveal floor width (FFW) were measured on a scan image of a horizontal line passing through the center of the fovea. We defined the thickness between the internal limiting membrane and outer plexiform layer as inner retinal thickness and the thickness between the external limiting membrane and retinal pigment epithelium as outer retinal thickness. Multiple regression analyses were performed with age, sex, axial length, and the presence of a posterior vitreous detachment as the dependent variables. MAIN OUTCOME MEASURES: OCT measurements and correlations between foveal parameters and foveal ONL thickness. RESULTS: The fellow eyes had a thinner central retinal subfield, thinner fovea, thinner ONL at all points except at 0.5 mm nasal, significantly thicker outer retina at all points, and a wider FFW (P = 0.040 to P < 0.0001). The foveal ONL thickness was significantly and positively correlated with the central subfield retinal thickness and foveal thickness and negatively correlated with the FFW (all P < 0.0001). CONCLUSIONS: The thinner and deeper fovea and the thinner ONL of the fellow eyes of patients with a unilateral MH make these eyes more susceptible to the formation of an MH.

The Association between Foveal Floor Measurements and Macular Hole Size.

PURPOSE: Determining which factors influence idiopathic macular hole (MH) size is important because it is a major prognostic indicator of treatment success. Foveal pit morphologic features are highly symmetrical within individuals and may influence idiopathic MH size. Using a series of patients with unilateral idiopathic MHs, we examined the foveal floor size of the fellow eye to evaluate its relationship with idiopathic MH size and postoperative outcomes. DESIGN: Retrospective observational study. PARTICIPANTS: Two hundred forty-one participants with a unilateral idiopathic MH treated with surgery and a fellow eye with no ocular pathologic features. METHODS: Both eyes underwent spectral-domain (SD) OCT imaging at the time of surgery. Minimum linear diameter (MLD) and base diameter (BD) defined idiopathic MH size. Foveal floor width (FFW) and minimal foveal thickness defined foveal pit morphologic features of the fellow eye. MAIN OUTCOME MEASURES: Baseline characteristics, SD OCT measurements, and preoperative variables were compared to determine their relationship with idiopathic MH size and postoperative visual acuity (VA) in logarithm of the minimum angle of resolution units. RESULTS: Foveal floor width was correlated with MLD (r = 0.36; P ≤ 0.001) and BD (r = 0.30; P ≤ 0.001), but not postoperative VA. Minimum linear diameter correlated with preoperative VA (r = 0.49; P ≤ 0.0001) and postoperative VA (r = 0.54; P ≤ 0.0001). A 2-stage regression model was developed to predict postoperative VA (r2 = 0.28): preoperative VA (ß = 0.36; P = 0.002) explained 13% of variability and MLD (ß = 0.29; P = 0.002), and idiopathic MH duration (ß = 0.23; P = 0.004) explained a further 16%. CONCLUSIONS: Foveal floor width of the fellow eye in patients with a unilateral idiopathic MH was correlated significantly with idiopathic MH size and may explain some of the variability in idiopathic MH size observed between individuals. However, FFW could not predict postoperative vision.