Clinical Observation About The Corneal Nerve And Tear Film Function After Pterygium Excision

【Objective】To observe the corneal nerve and tear film function after pterygium excision and discuss their correlation.【Methods】Data were collected from 18 randomly selected patients who after pterygium excision combined with autologous conjunctival flap transplantation in the Department of Ophthalmology,the First Affiliated Hospital of Jinan University from April 2017 to July 2018,including 6 males and 12 females,average age 65.33 ±7.65 years,the average time of follow-up was 11.60 ± 5.49 months.The mainly Ophthalmic examinations are: Ocular surface disease index(OSDI)questionnaire,Fluorescent(FL),and Oculus Keratograph examination for tear meniscus height(TMH),non-invasive tear burst time(NIBUT),corneal topography.The corneal subepithelial plexus was observed by the HRT Ⅲ confocal microscope.Three-dimensional scanning was randomly selected in the central and nasal regions of the cornea,and the most abundant and clear images of the three nerves were selected in the two regions.and the number of the nerves and morphological parameter of the image was counted by Image J software and take the average.Specific neurological parameters include: corneal nerve fibre density(CNFD),corneal nerve branch density(CNBD),corneal nerve fibre length(CNFL),corneal nerve fibre tortuosity(CNFT)and Langerhans cell density(LCD).Also,we compared the indicators of the large pterygium group and the small pterygium group after surgery,and the differences in corneal nerve and tear film function between the post-operative eye and the contralateral normal eye.In addition,the correlation between the neural parameters and the dry eye index of the post-operative eye was analyzed.【Results】 1.There were no significant differences in OSDI scores,objective indicators of dry eye,corneal topography and corneal nerve parameters between the large pterygium group and the small pterygium group(P>0.05).2.For the dry eye index,the OSDI score of the contralateral normal eye was smaller than that of the post-operative eye(Z=-2.077,P<0.05),but there was no significant difference in FL,TMH,NIBUT and dry eye grade between the two groups(P>0.05).In corneal topography,there were no significant differences in Km and astigmatism between the two groups(P>0.05).For corneal nerve parameters,the nasal corneal CNFD value of the contralateral normal eye was significantly larger than that of the post-operative eye(Z=-2.618,P<0.01);the central corneal CNFL value of the contralateral normal eye was significantly larger than that of the post-operative eye(t=4.048,P<0.01);The total values of CNFD and CNFL of the contralateral normal eye were significantly higher than those of the post-operative eye(t=2.417,4.641,P<0.05);there were no significant differences in the other neurological parameters(P>0.05).3.In the post-operative eye,the total CNFD values in the nasal and central regions of the cornea were negatively correlated with NIBUT(r=-0.52,P<0.05),and positively correlated with dry eye grade(rs=0.51,P<0.05).There were no correlations between the remaining neural parameters and dry eye indicators(P>0.05).【Conclusions】 1.The change of the dry eye index and nerve parameters after operation were not associated with the size of pterygium.2.The post-operative eye was less comfortable than the contralateral normal eye.The corneal nerve fibre density and the corneal nerve fibre length were decreased.3.The stability of the post-operative eye tear film was negatively correlated with the corneal nerve fibre density.