Six patients with OSSN-like AS-OCT features had benign lesions. The control group consisted of seven OSSN patients. The mean age of patients with benign pathology and with OSSN was 68.5±15.4 and 65.6±18.0 years, respectively. For detailed demographic data, see Table 1.
The source of pathology specimen and the diagnosis of the 13 cases are included in Table 1. The six benign cases are described in detail below; their AS-OCT images are presented in Fig. 1.
Case B1: The patient suffered from long-term inflammation of the right eye refractory to topical antibiotic therapy. By slit-lamp examination, a papilliform limbal mass was found in the superior nasal quadrant (Fig. 1a). On AS-OCT (Fig. 1b) inside the thickened hyperreflective epithelium, some vessels were observed. The excisional biopsy specimen was histologically a conjunctival papilloma.
Case B2: The patient was referred for a limbal conjunctival mass on the right eye. He had phacoemulsification 3 years before and vitrectomy 17 years before in this eye and multiple intravitreal bevacizumab injections for macular degeneration in the contralateral eye. By biomicroscopy, a 2 clock hour limbal papilliform, partly vascularised mass was detected in the temporal inferior quadrant. The eye was quiet. Pathological examination (Fig. 1c) of the excisional biopsy showed parakeratotic, slightly hyperplastic epithelium without signs of atypia. There was an extensive solar elastosis of collagen fibres in the stroma. The diagnosis was solar elastosis with parakeratosis.
Case B3: The patient presented with a limbal lesion of her left eye. The lesion that has been growing for two months and which occupied the 3 to 5 o’clock position was 3 mm wide. The nodular mass was localised mostly on the surface of the cornea (Fig. 1e). Microscopy of the excisional biopsy disclosed a hyper- and parakeratotic, markedly hyperplastic epithelium, with an abrupt transition to the normal epithelium. The epithelium was acanthotic, with slight spongiosis. Dyskeratotic cells, numerous apoptotic cells and several mitoses could be observed. The epithelial basement membrane was intact, and severe solar elastosis was found in the stroma. The diagnosis was keratotic plaque with signs of moderate epithelial dysplasia.
Case B4: The patient was referred because of a white limbal deposit on the left eye which could be wiped off but regrew every time. We saw a leukoplakic lesion over the limbal area with sharp edges beside a yellowish thickening of the conjunctiva (Fig. 1g). Pathological examination (Fig. 1i) revealed hyperkeratotic hyperplastic epithelium with mild dysplasia in some foci. Severe solar elastosis was found in the subconjunctival collagen fibres. The diagnosis was pinguecula with mild epithelial dysplasia on the surface.
Case B5: The patient was treated for chronic keratouveitis with secondary open-angle glaucoma of the right eye for 2 months. His treatment was ganciclovir gel and fluorometholone eye drops. At slit-lamp, mild cilio-conjunctival injection was found with a flat vascularised tissue overgrowth on the surface of the cornea between the 8 and 9 o’clock positions (Fig. 1j). On the corneal surface, this spread centrally in a subepithelial linear haze. The stroma was otherwise clear, but there were precipitates on the posterior corneal surface. No cells were seen in the anterior chamber. Corneal sensitivity was decreased. As the clinical presentation and the AS-OCT images (Fig. 1k) suggested OSSN, impression cytology (Fig. 1l) was performed. No malignant cells were detected. The treatment was continued and one month later the inflammatory signs faded, and the overgrowth on the cornea became much thinner and vascularisation decreased.
Case B6: The patient presented with chronic pingueculitis in the nasal side of the left eye that lasted for half a year. As the limbal area had a pronounced gelatinous appearance (Fig. 1m), AS-OCT was performed (Fig. 1n). Pathological examination revealed parakeratotic epithelium over degenerated stromal structure consistent with a pingueculum.
Out of the seven OSSN patients, conjunctival intraepithelial neoplasia (CIN) occurred in five, one further patient had carcinoma in situ (Fig. 2) and one had invasive squamous cell carcinoma with a scleral invasion at the limbus.
Maximal epithelial thickness
The mean maximal epithelial thickness was 461 ± 241 μm and 434 ± 121 μm in the benign group and OSSN group, respectively. The range spread from 250 μm to 859 μm in the benign group and from 252 μm to 596 μm in the OSSN group