Ocular surface squamous neoplasia with 360° limbal involvement: a study of 130 patients.

Purpose: To describe the risk factors, clinical features and management outcomes of ocular surface squamous neoplasia (OSSN) with 360° of limbal involvement (360-OSSN) and compare with segmental limbal involvement (SL-OSSN).

Methods: Retrospective comparative study of 360-OSSN vs SL-OSSN. All 360-OSSN and every 10th patient with SL-OSSN during the study period (2012-2020) were included. Lesions with uncertain diagnosis were excluded.

Results: Of 1250 patients diagnosed with OSSN during the study period, 30 (2%) had 360-OSSN. A total of 100 patients of OSSN with SL-OSSN were included for comparison. 360-OSSN patients more often had longer duration of symptoms (mean, 17 vs 8 months; p, 0.003), prior misdiagnosis (17% vs 6%, p, 0.13) and prior intervention (47% vs 13%; p, 0.0002) than patients with SL-OSSN. 360-OSSN had higher incidence of scleral fixity (57% vs 16%; p < 0.0001), corneal/scleral melt (17% vs 0%; p, 0.0005), intraocular tumor extension (17% vs 0%; p, 0.003), orbital tumor extension (33% vs 1%; p < 0.0001), and advanced T stage at presentation (Tis: 37% vs 76%, T1: 0% vs 15%; T2: 7% vs 4%; T3: 27% vs 4%; T4: 30% vs 1%; p < 0.001). Over a mean follow-up of 14 months, lymph node metastasis (8% vs 0%; p, 0.05) and distant metastasis (4% vs 0%; p, 0.23) were more common in 360-OSSN group compared to SL-OSSN group.

Conclusion: Risk factors of 360-OSSN include prolonged symptoms, prior misdiagnosis and prior intervention. It represents an advanced form of disease with propensity for corneo-scleral melt and invasive disease which requires aggressive management.