Retinal nerve fibre layer thickness measurements in myopia by optical coherence tomography

Aim: Our study aimed to evaluate through OCT, in a homogeneous group of subjects with various degrees of myopia, the macular thickness and that of the RNFL with the purpose of highlighting the possible presence of a correlation between their impairment and the degree of myopia. Material and Methods : 83 students of the Faculty of Medicine were considered, distinguished into 4 groups, 3 of them according to the degree of myopia and the last group (control group) was made of emmetropic subjects. Each subject was submitted to a determination of visual acuity and refractive defect and evaluation of the thickness of the macular fibres and of the retinal nerve fibre layer (RNFL) through OCT (Stratus Oct 3000 - Carl Zeiss Meditec inc) Results: With a growth in axial length there was a reduction in the average macular thickness in all quadrants of the parafovea with the exception of the superior one. By contrast, in the foveola and fovea there was an increase in thickness with a rise in the refractive defect. The lowest thickness was found in the emmetropic subject Conclusion : Our data found therefore allow us to conclude, in agreement with others, that the progressive increase in axial length in myopic subjects involves reshaping of the arrangement of the nerve fibres which needs to be taken into account, especially in subjects with glaucoma that are also very myopic