(d)  

In vivo confocal microscopy (IVCM)
Study	Location	Year	Study design	Number of eyes	Major findings
Parrozzani et al. [24]	Italy	2011	Prospective case series	Conjunctival intraepithelial neoplasia (2) Corneoconjunctival intraepithelial neoplasia (8)	IVCM findings of OSSN lesions were described. Structural findings included large areas of superficial cell debris and/or keratin debris accompanied by syncytial-like groupings, loss of the normal structure of the conjunctival epithelium and/or the corneal basal epithelium layer, papillomatous organization, large fibrovascular structures, and fine vessels perpendicular to the tumor surface. Marginal findings included subepithelial (pre-Bowman) space involvement in 4 cases, irregular healthy tissue infiltration at the lateral edge of the lesion in 2 cases, and abrupt demarcation between neoplastic cells and normal epithelium in 8 cases. In vivo cytomorphologic findings included cellular anisocytosis, pleocytosis, and anisonucleosis, enlarged nuclei with high nuclear to cytoplasmic ratio, high reflective cytoplasm, and indistinct cytoplasmic borders.
Alomar et al. [12]	United Kingdom and Italy	2011	Observational case series	Corneal/conjunctival intraepithelial neoplasia (CCIN) (4) Control (4; 2 with limbal stem cell deficiency, 1 with suspicious limbal lesion, 1 with diffuse keratoconjunctival proliferation)	This study defined IVCM features of CCIN, which included (1) hyperreflective pleomorphic cells of varying shapes and sizes, (2) the edge of hyperreflective CCIN lesion contrasting with the darker and smaller normal cells, (3) “starry night sky” pattern of the basal layer produced by prominent nucleoli, and (4) absence of subbasal corneal nerves within areas involved by CCIN compared to nonaffected regions. These IVCM findings were found to be highly correlated with histologic features.
Xu et al. [25]	China	2012	Retrospective case series	Conjunctival intraepithelial neoplasia (3) Carcinoma in situ (1) Ocular surface squamous carcinoma (1)	IVCM demonstrated cellular anisocytosis and enlarged nuclei with high nuclear to cytoplasmic ratio in conjunctival intraepithelial neoplasia while nests were partially formed by isolated keratinized, binucleated, and actively mitotic dysmorphic epithelial cells in carcinoma in situ and ocular surface squamous carcinoma. The IVCM characteristics were similar to histopathologic findings.
Nguena et al. [10]	Tanzania	2014	Case-control	OSSN (26) Benign conjunctival lesions (18) Age matched controls with normal conjunctiva (57)	IVCM was able to reliably distinguish normal conjunctiva from conjunctival lesions. However, IVCM was unable to reliably differentiate OSSN from benign conjunctival lesions due to an overlap in IVCM features between the two conditions (kappa = 0.44, 95% CI 0.32–0.57). IVCM has a low sensitivity (38.5%) and moderate specificity (66.7%) for distinguishing OSSN from benign conjunctival lesions.