Structural And Angiography Imaging Of Benign Conjunctival Proliferative Diseases Using Optical Coherence Tomography

Objective:To describe the structural and angiography imaging of conjunctival benign proliferative diseases using optical coherence tomography(OCT).Methods:Nasal and temporal bulbar conjunctiva of 25 cases(30 eyes)that included pinguecula(10 eyes of 8 cases),pterygium(10 eyes of 9 cases),and normal(10 eyes of 8 cases)eyes were scanned by optical coherence tomography angiography(OCTA)in a corneal adapter module(CAM).The thickness of the bulbar conjunctiva epithelium and propria tissues at sites that with a distance of 0.0mm,0,5mm,1.0mm,1.5mm,2.0mm and 2.5mm from the scleral process,were measured,compared and further analyzed.Vessel density of nasal and temporal bulbar conjunctiva with 3mm×3mm in 28 cases(30 eyes)were measured by OCTA in an angiographic module.The data were described by means of mean1 standard deviation.Variance analysis were used to compare the data between groups.Paired t test was used to compared the data between nasal and temporal bulbar conjunctiva in one eye.Statistical significance was accepted at ap level of<0.05.Results:Thirty eyes from 25 patients,that with 10 normal eyes,10pinguecula eyes and 10 pterygium eyes were scanned by structural OCT.Including 11 males and 14 females with a mean age of 50.04±10.01 years.Thirty eyes from 28 patients,that with 10 normal eyes,10pinguecula eyes and 10 pterygium eyes were scanned by OCTA.Including 14 males and 14 females with a mean age of 49.82±9.31 years.There was no statistical difference in subjective symptoms between the two groups of pinguecula eyes and pterygium eyes(p>0.05).In the 2.5mm range of the nasal side,compared with normal eye tissue,the pterygium and pinguecula demonstrated thickened epithelium and sub epithelium tissue(p<0.05),especially for pterygium.The thickness of conjunctival epithelium and propria tissues of the normal eyes was uniform(p>0.05),while those of pterygium and pinguecula were uneven in thickness(p<0.05).Compared between nasal and temporal conjunctival thickness,the thickness of conjunctival epithelium of the normal eyes was uniform(p>0.05),but the thickness of propria tissues in temporal conjunctiva of the normal eyes was demonstrated thickened(p<0.05).The thickness of conjunctival epithelium of the pinguecula eyes was uniform(p>0.05).Tempera propria tissues of the pinguecula eyes at two sites(0.5mm and 1.0mm)were more thicker(p<0.05).Tempera conjunctival epithelium of the pterygium eyes at two sites(1.0mm and 1.5mm)were more thicker(p<0.05).the thickness of propria tissues in Nasal propria tissues of the pinguecula eyes were more thicker(p<0.05).The vessel density between nasal and temporal conjunctiva had no difference(p>0.05)both in normal eyes and in pinguecula eyes,however,the vessel density in the nasal was higher than that in temporal in pterygium eyes(p<0.0001).The vessel density of nasal conjunctiva had no difference(p>0.05)between normal eyes and pinguecula eyes,and was lower than that of the pterygium eyes(p<0.0001).The vessel density of temporal conjunctiva had no difference(p>0.05)among normal eyes,pinguecula eyes and pterygium eyes(p>0.05).Conclusion:Micro-scaled topography and blood vessel of conjunctiva could be imaged clearly by OCT and OCTA in normal eyes,pinguecula eyes and pterygium eyes.Each layer of conjunctiva was thicker in pterygium eyes and in pinguecula eyes than that in normal eyes.The vessel density of pterygium was significantly higher than that of normal conjunctiva and pinguecula.