Importance There is a trend towards treating conjunctival lesions suspected to be ocular surface squamous neoplasia (OSSN) based on the clinical impression. Objectives To describe the presentation of OSSN and identify clinical features which distinguish it from benign lesions and subsequently evaluate their recognisability. Design, Setting and Participants Prospective multi-centre study in Kenya from July 2012 through July 2014 of 496 adults presenting with conjunctival lesions. Exposures Comprehensive history, slit lamp examination and photography before excision biopsy. Frequency of clinical features in OSSN and benign lesions recorded. One histopathologist examined all specimens. Six additional masked ophthalmologists independently examined photographs from 100 participants and assessed clinical features. Main Outcomes and Measures Proportions and means were compared using Chi-square, Fisher’s exact test or t-test as appropriate. Inter-observer agreement was estimated using Kappa statistic. Examiners’ assessments were compared to a reference. Results Among 496 participants, OSSN was the most common (38%) histological diagnosis, followed by pterygium (36%) and actinic keratosis (19%). OSSN cases were slightly older and tended to have lower levels of education than benign ones. Females predominated (67% of OSSN vs 64% of benign lesions; P = .65). HIV-infection was common among OSSN cases (74%). The commonest location was the nasal limbus (61% OSSN vs 78% benign lesions; P < .001). Signs more frequent in OSSN included; feeder vessels, odds ratio [OR], 5.8 [95%CI, 3.2-10.5]; moderate inflammation, OR, 3.5 [95%CI,1.8-6.8]; corneal involvement, OR, 2.7 [95%CI,1.8-4.0]; leukoplakia, OR, 2.6 [95%CI,1.7-3.9]; papilliform surface, OR, 2.1 [95%CI,1.3-3.5]; pigmentation, OR, 1.5 [95%CI, 1.0-2.2]; temporal location, OR, 2.0 [95%cI, 1.2-3.2]; circumlimbal location, (7.0% vs 0.3%; P<.001); severe inflammation (6.0% vs 0.3%; P <.001) and larger mean [SD] diameter (6.8 [3.2]mm vs 4.8[2.8]mm; P < .001). All OSSN signs were also observed in benign lesions. There was slight to fair inter-observer agreement in assessment of most signs and diagnosis (Kappa, 0.1-0.4). The positive predictive value of clinical appearance in identifying OSSN was 54% (interquartile range, 51-56) from photographs where prevalence was 32%. Conclusions and Relevance With overlapping phenotypes and modest inter-observer agreement, OSSN and benign conjunctival lesions are not reliably distinguished clinically. Point-of-care diagnostic tools may help.
ObjectiveTo determine modifiable risk factors of ocular surface squamous neoplasia (OSSN) in Kenya using disease‐free controls.MethodsAdults with conjunctival lesions were recruited at four eye care centres in Kenya and underwent excision biopsy. An equal number of controls having surgery for conditions not affecting the conjunctiva and unrelated to ultraviolet light were group‐matched to cases by age group, sex and eye care centre. Associations of risk factors with OSSN were evaluated using multivariable logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs). Continuous variables were compared using the t‐test or the Wilcoxon–Mann–Whitney U‐test depending on their distribution.ResultsA total of 131 cases and 131 controls were recruited. About two‐thirds of participants were female, and the mean age of cases and controls was 42.1 years and 43.3 years, respectively. Risk factors for OSSN were HIV infection without antiretroviral therapy (ART) use (OR = 48.42; 95% CI: 7.73–303.31) and with ART use (OR = 19.16; 95% CI: 6.60–55.57), longer duration of exposure to the sun in the main occupation (6.9 h/day vs. 4.6 h/day, OR = 1.24; 95% CI: 1.10–1.40) and a history of allergic conjunctivitis (OR = 74.61; 95% CI: 8.08–688.91). Wearing hats was protective (OR = 0.22; 95% CI: 0.07–0.63).ConclusionMeasures to prevent and control HIV, reduce sun exposure such as wearing hats and control allergic conjunctivitis are recommended.
Importance Clinical features are unreliable for distinguishing Ocular Surface Squamous Neoplasia (OSSN) from benign conjunctival lesions. Objective To evaluate the adverse effects, accuracy and inter-observer variation of Toluidine Blue 0.05% vital staining in distinguishing OSSN, confirmed by histopathology, from other conjunctival lesions. Design, Setting and Participants Cross-sectional study in Kenya from July 2012 through July 2014 of 418 adults with suspicious conjunctival lesions. Pregnant and breastfeeding women were excluded. Exposures Comprehensive ophthalmic slit-lamp examination was conducted. Vital staining with Toluidine Blue 0.05% aqueous solution was performed before surgery. Initial safety testing was conducted on large tumours scheduled for exenteration looking for corneal toxicity on histology before testing smaller tumours. We asked about pain or discomfort after staining and evaluated the cornea at the slit lamp for epithelial defects. Lesions were photographed before and after staining. Diagnosis was confirmed by histopathology. Six examiners assessed photographs from a sub-set of 100 consecutive participants for staining and made a diagnosis of OSSN vs Non-OSSN. Main Outcomes and Measures Staining was compared with histopathology to estimate sensitivity, specificity and predictive values. Adverse effects were enumerated. Inter-observer agreement was estimated using the kappa statistic (k). Results 143/419 (34%) participants had OSSN by histopathology. The median (interquartile range) age of the 419 was 37 (32-45) years and 278 (66%) were female. 322/419 participants had positive staining while 2/419 were equivocal. There was no histological evidence of corneal toxicity. Mild discomfort was reported by 88 (21%) and mild superficial punctate keratopathy seen in 7 (1.7%).For detecting OSSN, Toluidine blue had a sensitivity of 92% (95%CI, 87%-96%), specificity 31% (95%CI, 25%-36%), positive predictive value 41% (95%CI, 35%-46%), and negative predictive value 88% (95%CI, 80%-94%). Inter-observer agreement was substantial for staining (k=0.8) and moderate for diagnosis (k=0.4). Conclusion and Relevance With the high sensitivity and low specificity for OSSN compared with histopathology among patients with conjunctival lesions, Toluidine Blue 0.05% vital staining is a good screening tool, but not a good diagnostic tool due to a high frequency of false positives. The high negative predictive value suggests that a negative staining result indicates that OSSN is relatively unlikely.
SummaryBackgroundOcular surface squamous neoplasia (OSSN) is an aggressive eye tumour particularly affecting people with HIV in Africa. Primary treatment is surgical excision; however, tumour recurrence is common. We assessed the effect of fluorouracil 1% eye drops after surgery on recurrence.MethodsWe did this multicentre, randomised, placebo-controlled trial in four centres in Kenya. We enrolled patients with histologically proven OSSN aged at least 18 years. After standard surgical excision, participants were randomly allocated to receive either topical fluorouracil 1% or placebo four times a day for 4 weeks. Randomisation was stratified by surgeon, and participants and trial personnel were masked to assignment. Patients were followed up at 1 month, 3 months, 6 months, and 12 months. The primary outcome was clinical recurrence (supported by histological assessment where available) by 1 year, and analysed by intention to treat. The sample size was recalculated because events were more common than anticipated, and trial enrolment was stopped early. The trial was registered with Pan-African Clinical Trials Registry (PACTR201207000396219).FindingsBetween August, 2012, and July, 2014, we assigned 49 participants to fluorouracil and 49 to placebo. Four participants were lost to follow-up. Recurrences occurred in five (11%) of 47 patients in the fluorouracil group and 17 (36%) of 47 in the placebo group (odds ratio 0·21, 95% CI 0·07–0·63; p=0·01). Adjusting for passive smoking and antiretroviral therapy had little effect (odds ratio 0·23; 95% CI 0·07–0·75; p=0·02). Adverse effects occurred more commonly in the fluorouracil group, although they were transient and mild. Ocular discomfort occurred in 43 of 49 patients in the fluorouracil group versus 36 of 49 in the placebo group, epiphora occurred in 24 versus five, and eyelid skin inflammation occurred in seven versus none.InterpretationTopical fluorouracil after surgery substantially reduced recurrence of OSSN, was well-tolerated, and its use recommended.FundingBritish Council for Prevention of Blindness and the Wellcome Trust.
BackgroundOcular rhinosporidiosis is a chronic granulomatous infection caused by a newly classified organism that is neither a fungus nor bacterium. It often presents as a benign conjunctival tumour but may mimic other ocular conditions. It is most often described in India. In Africa cases have been reported from South Africa, Kenya, Tanzania, Malawi, Uganda, Congo and Ivory Coast.Case presentationA 54 year old man was seen in Kenya with a lesion that resembled a conjunctival papilloma. We report resemblance to conjunctival papilloma and the result of vital staining with 0.05% Toluidine Blue.ConclusionOcular rhinosporidiosis occurs in East Africa. It may resemble conjunctival squamous papilloma. Vital staining with 0.05% Toluidine blue dye did not distinguish the two lesions well.
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