title: Risk factors for early-onset corneal haze after photorefractive keratectomy in an Asian population: Outcomes from the Singapore Armed Forces Corneal Refractive Surgery Programme 2006 to 2013.
abstract: To assess the incidence and risk factors for early corneal haze after myopic photorefractive keratectomy (PRK).
  
  
  
  Tertiary eye center, Singapore.
  
  
  
  Retrospective case series.
  
  
  
  The refractive results and corneal haze severity 3 months after PRK were analyzed. Eyes were categorized into 4 groups based on haze severity. Multivariate ordinal logistic regression analysis adjusting for age, ethnicity, sex, use of intraoperative mitomycin-C (MMC), preoperative sphere, and preoperative cylinder was performed.
  
  
  
  The study reviewed data from 177 patients (347 eyes) with a mean age of 22.6 years ± 4.1 (SD). The majority of the patients were Chinese (98.3%) and men (98.3%). The mean preoperative spherical equivalent (SE) was -3.34 ± 1.19 diopters (D). One hundred thirty-five eyes (38.9%) had PRK with MMC. Ten eyes (2.9%) had enhancement surgery. The overall efficacy index was 0.88 and the safety index was 1.07. At 3 months, 187 eyes (53.9%) had no haze, 76 eyes (21.9%) had a haze grade of more than 0 and less than 1, 76 eyes (21.9%) had a haze grade of 1 or more and less than 2, and 8 eyes (2.3%) had grade 2 haze. Higher degrees of myopia (odds ratio [OR], 1.36; 95% confidence interval [CI], 1.13-1.63; P = .001) and astigmatism (OR, 1.56; 95% CI, 1.09-2.24; P = .014) were associated with increased severity of corneal haze, whereas older age (OR, 0.94; 95% CI, 0.88-0.99; P = .023) had a protective effect.
  
  
  
  Myopia and astigmatism were associated with increased severity of haze, and older age was protective against early corneal haze development after PRK in an Asian population.
  
  
  
  None of the authors has a financial or proprietary interest in any material or method mentioned.
authors.affiliation: From the Vision Performance Centre (Ang, Lim, Nah, Tan, Zhao), the Military Medicine Institute, Singapore Armed Forces, National Healthcare Group Eye Institute (Ang), Tan Tock Seng Hospital, the Singapore National Eye Centre (Foo), the DSO National Laboratories (Tan), Defence Medical and Environmental Research Institute, the W Eye Clinic (Nah), the Department of Ophthalmology (Nah, Thean, Tan, Zhao), the National University Health System, and the Department of Ophthalmology (Thean), Jurong Health Services, Singapore.
authors.forename: Bryan Chin Hou
authors.initials: BC
authors.lastname: Ang
authors.affiliation: From the Vision Performance Centre (Ang, Lim, Nah, Tan, Zhao), the Military Medicine Institute, Singapore Armed Forces, National Healthcare Group Eye Institute (Ang), Tan Tock Seng Hospital, the Singapore National Eye Centre (Foo), the DSO National Laboratories (Tan), Defence Medical and Environmental Research Institute, the W Eye Clinic (Nah), the Department of Ophthalmology (Nah, Thean, Tan, Zhao), the National University Health System, and the Department of Ophthalmology (Thean), Jurong Health Services, Singapore.
authors.forename: Reuben Chao Ming
authors.initials: RC
authors.lastname: Foo
authors.affiliation: From the Vision Performance Centre (Ang, Lim, Nah, Tan, Zhao), the Military Medicine Institute, Singapore Armed Forces, National Healthcare Group Eye Institute (Ang), Tan Tock Seng Hospital, the Singapore National Eye Centre (Foo), the DSO National Laboratories (Tan), Defence Medical and Environmental Research Institute, the W Eye Clinic (Nah), the Department of Ophthalmology (Nah, Thean, Tan, Zhao), the National University Health System, and the Department of Ophthalmology (Thean), Jurong Health Services, Singapore.
authors.forename: Edmund Wei Long
authors.initials: EW
authors.lastname: Lim
authors.affiliation: From the Vision Performance Centre (Ang, Lim, Nah, Tan, Zhao), the Military Medicine Institute, Singapore Armed Forces, National Healthcare Group Eye Institute (Ang), Tan Tock Seng Hospital, the Singapore National Eye Centre (Foo), the DSO National Laboratories (Tan), Defence Medical and Environmental Research Institute, the W Eye Clinic (Nah), the Department of Ophthalmology (Nah, Thean, Tan, Zhao), the National University Health System, and the Department of Ophthalmology (Thean), Jurong Health Services, Singapore.
authors.forename: Mellisa Mei Hui
authors.initials: MM
authors.lastname: Tan
authors.affiliation: From the Vision Performance Centre (Ang, Lim, Nah, Tan, Zhao), the Military Medicine Institute, Singapore Armed Forces, National Healthcare Group Eye Institute (Ang), Tan Tock Seng Hospital, the Singapore National Eye Centre (Foo), the DSO National Laboratories (Tan), Defence Medical and Environmental Research Institute, the W Eye Clinic (Nah), the Department of Ophthalmology (Nah, Thean, Tan, Zhao), the National University Health System, and the Department of Ophthalmology (Thean), Jurong Health Services, Singapore.
authors.forename: Gerard Kwang Ming
authors.initials: GK
authors.lastname: Nah
authors.affiliation: From the Vision Performance Centre (Ang, Lim, Nah, Tan, Zhao), the Military Medicine Institute, Singapore Armed Forces, National Healthcare Group Eye Institute (Ang), Tan Tock Seng Hospital, the Singapore National Eye Centre (Foo), the DSO National Laboratories (Tan), Defence Medical and Environmental Research Institute, the W Eye Clinic (Nah), the Department of Ophthalmology (Nah, Thean, Tan, Zhao), the National University Health System, and the Department of Ophthalmology (Thean), Jurong Health Services, Singapore.
authors.forename: Lennard See Yin
authors.initials: LS
authors.lastname: Thean
authors.affiliation: From the Vision Performance Centre (Ang, Lim, Nah, Tan, Zhao), the Military Medicine Institute, Singapore Armed Forces, National Healthcare Group Eye Institute (Ang), Tan Tock Seng Hospital, the Singapore National Eye Centre (Foo), the DSO National Laboratories (Tan), Defence Medical and Environmental Research Institute, the W Eye Clinic (Nah), the Department of Ophthalmology (Nah, Thean, Tan, Zhao), the National University Health System, and the Department of Ophthalmology (Thean), Jurong Health Services, Singapore.
authors.forename: Clement Woon Teck
authors.initials: CW
authors.lastname: Tan
authors.affiliation: From the Vision Performance Centre (Ang, Lim, Nah, Tan, Zhao), the Military Medicine Institute, Singapore Armed Forces, National Healthcare Group Eye Institute (Ang), Tan Tock Seng Hospital, the Singapore National Eye Centre (Foo), the DSO National Laboratories (Tan), Defence Medical and Environmental Research Institute, the W Eye Clinic (Nah), the Department of Ophthalmology (Nah, Thean, Tan, Zhao), the National University Health System, and the Department of Ophthalmology (Thean), Jurong Health Services, Singapore. Electronic address: vpc@defence.gov.sg.
authors.forename: Paul Song Bo
authors.initials: PS
authors.lastname: Zhao
mesh_terms: D000293:Adolescent; D000328:Adult; D003315:Cornea / Q000473:pathology*; D005260:Female; D006801:Humans; D000074431:Keratectomy; D054018:Lasers, Excimer; D008297:Male; D009216:Myopia / Q000628:therapy*; D018903:Photorefractive Keratectomy / Q000009:adverse effects*; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome; D014792:Visual Acuity; D055815:Young Adult