Undifferentiated connective tissue dysplasia as a risk factor of keratoconus development and pathological changes of optic nerve and retina

The article shows evidence of the undifferentiated connective tissue dysplasia influence on the development of keratoconus and pathological changes of the optic nerve and retina.

PURPOSE: Comparative study of morphometric parameters of the optic nerve and retina variations in patients with keratoconus, depending on the presence of undifferentiated connective tissue dysplasia.

METHODS: 186 patients with verified keratoconus diagnosis (186 eyes) underwent optical coherence tomography of the posterior segment of the eye. The results were used to subdivide the patients into 3 clinical groups. A comparative analysis of the morphometric indices of the optic nerve and retina was conducted in all groups. Group 1 included 40 patients (40 eyes) with expressed changes in morphometric parameters of the optic nerve and retina. Group 2 consisted of 50 patients (50 eyes) with insignificant deviations from the average values. The comparison group comprised 96 patients (96 eyes) without any morphological changes of the fundus, according to optical coherence tomography.

RESULTS: Group 1 patients showed a statistically significant decrease of the average thickness of retinal nerve fiber layer compared to patients of the other groups (80.15±1.29 vs. 91.70±1.09 and 95.50±0.81, respectively) (1-2 p≤0.0001; 1-3 p≤0.0001; 2-3 p=0.003). Retinal nerve fiber layer thickness in separate segments (SNIT) in group 1 patients also significantly thinner. The analysis also identified significant differences in the volume of optic disc cup and rim area. No significant differences in average and vertical cup/disk ratio between patients of different clinical groups have been identified. Group 1 patients on average had a smaller optic disc than Group 2 and comparison group patients, (1.712±0.059 µm against 1.825±0.047 and 1.966±0.036 µm, respectively) (1-2 p=0.04; 1-3 p=0.0001; 2-3 p=0.01).

CONCLUSIONS: Currently undifferentiated connective tissue dysplasia presents a widely overlooked risk factor of keratoconus development and pathological changes of optic disc and retina. Patients with keratoconus combined with connective tissue dysplasia, apart from the «gold» standard of treatment, require both neuroprotective and collagen stabilizing therapy as well as a close medical monitoring.

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