title: Clinical Presentation of Ocular Surface Squamous Neoplasia in Kenya.
abstract: OBJECTIVE
  There is a trend toward treating conjunctival lesions suspected to be ocular surface squamous neoplasia (OSSN) based on the clinical impression.
  
  
  OBJECTIVE
  To describe the presentation of OSSN and identify clinical features that distinguish it from benign lesions and subsequently evaluate their recognizability.
  
  
  METHODS
  Prospective multicenter study in Kenya from July 2012 through July 2014 of 496 adults presenting with conjunctival lesions. One histopathologist examined all specimens. Six additional masked ophthalmologists independently examined photographs from 100 participants and assessed clinical features.
  
  
  METHODS
  Comprehensive history, slitlamp examination, and photography before excision biopsy.
  
  
  METHODS
  Frequency of clinical features in OSSN and benign lesions were recorded. Proportions and means were compared using χ2, Fisher exact test, or t test as appropriate. Interobserver agreement was estimated using the κ statistic. Examiners' assessments were compared with a reference.
  
  
  RESULTS
  Among 496 participants, OSSN was the most common (38%) histological diagnosis, followed by pterygium (36%) and actinic keratosis (19%). Patients with OSSN were slightly older (mean [SD] age, 41 [11.6] vs 38 [10.9] years; P = .002) and tended to have lower levels of education than patients with benign lesions (P = .001). Females predominated (67% of OSSN vs 64% of benign lesions; P = .65). Human immunodeficiency virus infection was common among patients with OSSN (74%). The most common 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 (6.7% vs 0.3%; P < .001), severe inflammation (6.7% vs 0.3%; P < .001), and larger mean (SD) diameter (6.8 [3.2] vs 4.8 [2.8] mm; P < .001). All OSSN signs were also observed in benign lesions. There was slight to fair interobserver agreement in assessment of most signs and diagnosis (κ, 0.1-0.4). The positive predictive value of clinical appearance in identifying OSSN was 54% (interquartile range, 51%-56%) from photographs in which prevalence was 32%.
  
  
  CONCLUSIONS
  With overlapping phenotypes and modest interobserver agreement, OSSN and benign conjunctival lesions are not reliably distinguished clinically. Point-of-care diagnostic tools may help.
authors.affiliation: London School of Hygiene and Tropical Medicine, London, England2Department of Ophthalmology, University of Nairobi, Nairobi, Kenya.
authors.forename: Stephen
authors.initials: S
authors.lastname: Gichuhi
authors.affiliation: PCEA Kikuyu Eye Unit, Kikuyu, Kenya.
authors.forename: Ephantus
authors.initials: E
authors.lastname: Macharia
authors.affiliation: PCEA Kikuyu Eye Unit, Kikuyu, Kenya.
authors.forename: Joy
authors.initials: J
authors.lastname: Kabiru
authors.affiliation: PCEA Kikuyu Eye Unit, Kikuyu, Kenya.
authors.forename: Alain M'bongo
authors.initials: AM
authors.lastname: Zindamoyen
authors.affiliation: Eye Department, Kitale District Hospital, Kitale, Kenya.
authors.forename: Hilary
authors.initials: H
authors.lastname: Rono
authors.affiliation: Sabatia Eye Hospital, Wodanga, Kenya.
authors.forename: Ernest
authors.initials: E
authors.lastname: Ollando
authors.affiliation: Sabatia Eye Hospital, Wodanga, Kenya.
authors.forename: Leonard
authors.initials: L
authors.lastname: Wanyonyi
authors.affiliation: Ophthalmology Department, Kenyatta National Hospital, Nairobi, Kenya.
authors.forename: Joseph
authors.initials: J
authors.lastname: Wachira
authors.affiliation: Ophthalmology Department, Kenyatta National Hospital, Nairobi, Kenya.
authors.forename: Rhoda
authors.initials: R
authors.lastname: Munene
authors.affiliation: Department of Pathology, MP Shah Hospital, Nairobi, Kenya.
authors.forename: Timothy
authors.initials: T
authors.lastname: Onyuma
authors.affiliation: UCL Institute of Ophthalmology, London, England9Moorfields Eye Hospital, London, England10St Bartholomew's Hospital, London, England.
authors.forename: Mandeep S
authors.initials: MS
authors.lastname: Sagoo
authors.affiliation: London School of Hygiene and Tropical Medicine, London, England.
authors.forename: Helen A
authors.initials: HA
authors.lastname: Weiss
authors.affiliation: London School of Hygiene and Tropical Medicine, London, England9Moorfields Eye Hospital, London, England.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Burton
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D002278:Carcinoma in Situ / Q000175:diagnosis / Q000453:epidemiology* / Q000601:surgery; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000453:epidemiology* / Q000601:surgery; D003230:Conjunctival Neoplasms / Q000175:diagnosis / Q000453:epidemiology* / Q000601:surgery; D005260:Female; D006801:Humans; D007630:Kenya / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011446:Prospective Studies