Retinal nerve fibre layer and macular thickness analysis with Fourier domain optical coherence tomography in subjects with a positive family history for primary open angle glaucoma

Abstract

AIM: To detect early structural changes of retinal nerve fibre layer (RNFL) and macular ganglion cell complex (GCC) in subjects with a positive family history for primary open angle glaucoma (POAG) using Fourier domain optical coherence tomography (FD-OCT) (RTVue-100). METHODS: This was a cross-sectional observational study. First and second degree relatives of POAG patients, healthy subjects, and subjects with preperimetric glaucoma (PPG) without a family history for glaucoma, were enrolled. All participants underwent complete ophthalmic examination, visual field test and FD-OCT (RTVue-100) imaging. Average RNFL and GCC thicknesses were measured and a pattern analysis was applied to the GCC map. Analysis of variance (ANOVA), least significant difference post-hoc test, and multiple ANOVA were used. RESULTS: The final analysis included 271 eyes divided into several groups: 163 eyes of first and second degree relatives (85 healthy, 40 with ocular hypertension and 38 with PPG); and 108 eyes of subjects without a positive family history (60 healthy and 48 PPG). RNFL and GCC thickness values of these five groups were statistically different (p<0.001). RNFL superior, GCC average, GCC superior, and GCC inferior were found to be significantly thinner and the global loss volume was higher in normal relatives than in healthy subjects without a positive family history of POAG (p=0.04, p=0.001, p=0.005, p=0.004, p=0.009). RNFL and GCC thicknesses obtained by dividing the family members by the degree of consanguinity showed statistically significant thinning in siblings of glaucomatous subjects than in offspring. CONCLUSIONS: Our study shows that the eyes of subjects with a positive family history for POAG have significantly thinner RNFL and GCC than normal eyes and a more accurate follow-up has to be performed.