Optical biopsy – Optical coherence tomography guided excision of ocular surface squamous neoplasia

Abstract

: To report the role of optical biopsy where the preoperative spectral domain optical coherence tomography (SD OCT) features were used for surgical margin clearance in ocular surface squamous neoplasia (OSSN) excision.In this prospectiveinterventional studypatients with clinically diagnosed OSSNundergopreoperative SD OCT and mass was excised with 3mm clearance with respect to the extent on OCT. Corneal, conjunctival margins and lamellar sclera was evaluated histopathologically. Twelve eyes of 11 patients with mean age of 59.2 ± 12.2 were studied. Hyper reflective epithelium, increased thickness, abrupt transition of corneal epithelium and increase back shadow were the features of OSSN noted. The mean functional epithelial thickness and epithelial thickness were 137.5± 60.6µm and 58.5±10.8 µm respectively. The histopathology confirmed as squamous cell carcinoma (SCC) (n=4, 33.3%), carcinoma in situ (CIN) (n=8, 66.6%). In CIN 2 eyes were severe dysplasia and 6 were moderate dysplasia. Corneal clearance was noted as 100 %. Of 36 conjunctival margins, the positive margin noted in 6 eyes (50%). Nasal margin (n=3) and temporal (n=3) were the common margins. There was no difference in clearance between CIN (50%) or SCC (50%) on conjunctival side. Two eyes with recurrence required and revision excision subsequent topical chemotherapyOptical biopsy by SD OCT though is an effective method for OSSN removal. Corneal margins showed better margin clearance than conjunctival.