Evaluation of the lamina cribrosa curvature index in different types of glaucoma

The aim of this study is to evaluate the Lamina Cribrosa Curvature Index in different types of glaucoma. Patients older than 18 years of age, whose disease was under control for at least 1 year, had at least three reliable visual fields, had a refractive error between -6 and +5, and did not have any disease other than glaucoma that would affect the visual field were included in the study who followed up in the Glaucoma Unit, Fırat University Faculty of Medicine, Department of Ophthalmology. Age, gender, visual acuity, duration of glaucoma disease, intraocular pressure, number of topical drugs used, and central corneal thickness of the patients were recorded. The lamina cribrosa curvature index (LCCI) values measured over the lamina cribrosa from high definiton optic nerve head optical coherence tomography (OCT) imaging taken in enhanced depth image mode with visual field parameters such as mean deviation (MD), visual field index (VFI), pattern standard deviation (PSD) and retinal nerve fiber thickness (RNFL) measurement by OCT evaluated. Study patients were divided into six groups; according to the Hadoop classification, group 1 with early-stage primary open-angle glaucoma (POAG) patients and group 2 with moderate-to-advanced POAG patients, Group 3 patients with pseudoexfoliation glaucoma (PXG), and group 4 patients with normal tension glaucoma (NTG), group 5 patients with ocular hypertension (OHT) who subsequently develop POAG (OHTSOG), and 6th group which is the control group, healthy individuals of similar age and gender without glaucoma. Our study included 189 eyes of 101 patients. 47 (46.5%) were male and 54 (53.5%) were female. The mean age was 62.43 ± 1.49 years. In group 1: LCCI: 5.85 ± 1.21, MD: -2.83 ± 1.22, PSD: 2.58 ± 0.93, VFI: 96.12 ± 2.20, RNFL: 89.54 ± 8.10 µm, in group 2: LCCI : 9.71 ± 1.54, MD: -12.53 ± 5.91, PSD: 6.64 ± 2.60, VFI: 68.73 ± 19.87, RNFL : 68.46 ± 11.05, in group 3: 9.62 ± 2.55, MD: -12.50 ± 6.72, PSD: 6.27 ± 2.60, VFI: 68.67 ± 21 .78, RNFL: 70.82 ± 15.27 µm, in group 4: LCCI : 7.37 ± 1.87, MD: -5.95 ± 4.02, PSD: 4.89 ± 2.93, VFI: 87.33 ± 9.93, RNFL: 81.19 ± 10.95 µm, in group 5: LCCI: 5.33 ± 1.26, MD: -2.44 ± 1.92, PSD: 2.39 ± 1, 17, VFI: 96.89 ± 2.72, RNFL: 94.32 ± 7.05 µm, and in group 6 LCCI :4.94 ± 0.77, MD: -0.51 ± 0.96, PSD: 1,69 ± 0.64, VFI: 99.35 ± 0.85, RNFL: 97.35 ± 6.25 µm measured. With Pearson correlation analysis, PSD and RNFL values and LCCI values were statistically significantly correlated in all groups. (p<0.05) When the groups were compared with each other according to the Post Hoc Tamhane test, LCCI measurement showed similar statistically significant results with MD, VFI, PSD and RNFL values. In conclusion, our study shows that LCCI measurement is a powerful parameter that can be used in the diagnosis and follow-up of glaucoma.