[Correlation between neuroretinal rim and optic disc areas in normal melanoderm and glaucoma patients]

To evaluate optic disc size and its relationship with neuroretinal rim areas.

The study was prospective; 400 hundred patients with 292 glaucomatous and 108 non glaucomatous were enrolled in this study. Optic disc size quantification was assessed by the use of Goldmann 3 mirror contact lens; diameter reading were adjusted by the magnification factor of the lens, squares of the disc and the cupping were calculated using an ellipse formula, the neuroretinal rim area was then obtained by reducing the cupping area from the whole optic disc area.

The mean age of the sample was 36.80 years (sd: 15.68 years).The average value of the vertical disc diameter was 2.045 mm (sd: 0.254) for glaucoma patients and 1.966 mm (sd: 0.237) in the control group; p<0.001. Neuroretinal rim area was 1.886 mm(2) (sd: 0.675) in the glaucoma group; and 2.165 mm(2) (sd: 0.425) in the control one; p<0. 004. In the glaucoma group, 72.97% of large optic disc were found (vertical diameter over 1.90 mm); and 63.80% in the control one. In the control group, neuroretinal rim area was wider in the large optic discs compared to the small discs, p<0.001, Anova test. Neuroretinal rim area was thinner in the glaucoma large disc compared to the control, p<0.005, Student test. Meanwhile, there was no difference in the medium and the small discs in the glaucoma and control groups; p > 0.005, Student Newmann test.

Neuroretinal rim areas are thinner in the large glaucoma discs compared to the non glaucoma large discs. In Africa, this parameter could be helpful in the diagnosis and survey of glaucoma patients.