Clinical Investigation Of Corneal Nerve Changes In Primary Glaucoma

Aim:To investigate the change features of corneal subepithelial nerve fibers(SBN)in primary glaucoma.Methods:Retrospective study.From January 1,2020 to December 31,2022,27 patients with primary glaucoma who were diagnosed with monocular disease and untreated in the Affiliated Eye Hospital of Nanchang University were included,with the affected eye as the observation group and the contralateral healthy eye as the control group.CCM was performed on the corneas(central,superior,inferior,nasal and temporal)of both eyes of the patients,and Image J software was used for measurement,and the average value of five directions was taken for analysis.Observation indexes included corneal subepithelial nerve fiber length(CNFL),corneal subepithelial nerve fiber density(CNFD),corneal subepithelial nerve fiber branch number(CNBN),corneal subepithelial nerve fiber curvature(CNFT),dendritic cells(DC),and number of beaded structures(BN).At the same time,the optical coherence tomography(OCT)scanner was used to measure the retinal nerve fiber layer(RNFL)thickness of the optic disc.The correlations between the percentage changes in corneal SBN parameters(ΔSBN parameter %)and the percentage changes in the RNFL thickness of the optic disc(ΔRNFL%),the percentage changes in dendritic cells(ΔDC%),and the percentage changes in beaded numbers(ΔBN%)were analyzed.All data were analyzed using SPSS25.0 statistical software.All data were analyzed using spss25.0.Results:1.Compared with the control group,the CNFL of the observation group(1034.65±440.77 μm,1527.89±523.08 μm,P<0.001),CNFD(30.51±13.74/mm 2,43.82±14.49 /mm2,P<0.001)and CNBN(2.03±1.40,3.41±1.56,P<0.001)were significantly decreased,while CNFT(2.26±0.22,2.07±0.38,P<0.05)was significantly increased.2.Compared with the control group,the DC(0.72±0.48 grades,0.41±0.27 grades,P < 0.05)and the BN(1.27±0.44 beads/100μm,1.09±0.50 beads/100μm,P< 0.05)were all significantly higher.3.There was no significant correlation between ΔCNFL%(rs=0.039、-0.023、0.275),ΔCNFD%(rs=-0.105、0.188、0.064),ΔCNBN%(rs=-0.067、0.167、0.174),and ΔCNFT%(rs=-0.208、0.313、-0.059),andΔRNFL%,ΔDC%,and ΔBN%,respectively,in the observation group.Conclusion:Corneal nerve fibers in primary glaucoma are more slender and sparse,consideration may be associated with mechanical compression of corneal nerves under prolonged high intraocular pressure,decreased blood supply to the limbus,and corneal neurotrophic disorders due to mild inflammatory states of the cornea.