Abstract
Purpose :
To construct an objective analysis system of corneal nerve tortuosity and detect the changes of corneal subbasal nerve tortuosity in patients with dry eye disease (DED) and diabetes.
Methods :
Grade I to IV nerve tortuosity were evaluated and 80 photos of each grade were randomly chosen from the in vivo confocal microscopy library. Nerve fibers were extracted, segmented and then analyzed by 6 tortuosity related parameters including L_C, Seg_L_C_mean, Cur_mean, Specific_p, ICM and SCC_mean. After verifying the validaty of parameters above, a cross-sectional study was conducted. Subjects were divided into four groups: control group, DED without diabetes group, diabetes without DED group, diabetes with DED group. 23 to 28 persons in each group. Basic and DED information includes sex, age, OSDI,TBUT, SIt and CFS score. FPG and HbA1c were detected in diabetic patients. C-BE was detected to evaluate corneal sensation and 2 corneal subbasal nerve photos of each eye were selected for effective tortuosity and density related parameters analysis. Data was analyzed by SPSS 20.0. This study followed the Declaration of Helsinki and was approved by Ethic Committee of Peking University Third Hospita. Informed consents were obtained.
Results :
L_C, Seg_L_C_mean, Cur_mean, Specific_p, ICM and SCC_mean increased as the nerve tortuosity increased from Grade I to Grade IV (Fig. 1A/1B). Among the above 6 parameters, Cur_mean and L_C of any two groups were of significant difference (all at P<0.01). Sex and age were comparable among 4 groups. Diagnostic criteria were met in dry eye disease(DED) and diabetes (Fig. 1C). Corneal sensation(C-BE) decreased in diabetes without DED group and diabetes with DED group compared with control group(all at AdjP<0.05), other than in DED without diabetes group(AdjP≥0.05). Nerve density of diabetes without DED group and diabetes with DED group was lower compared with control group(all at P<0.001), while no significant difference between DED without diabetes group and control group(P≥0.05). Among the effective parameters of tortuosity, L_C, Cur_mean, Seg_L_C_mean and SCC_mean of last 3 groups were higher compared with control group(all at P<0.05) (Fig. 1D).
Conclusions :
L_C and Cur_mean are most suitable parameters to analyze corneal nerve tortuosity. Compared with volunteers, patients of DED or diabetes showed higher corneal subbasal nerve tortuosity.
This is a 2021 ARVO Annual Meeting abstract.