Table 1

Proportions with keratoconus in persons with Down syndrome (studies identified by literature review)

n DSn (%) KCLocationCTPatient group and age
Walsh18917 (8%)SwedenNoInstitutionalised mentally retarded persons (5–60 years).
Wong and Ho191400 (0%)Hong KongNoChildren (3 months–13 years) in hospital.
Van Allen et al29386 (15.8%)USANoAdults (30–68 years old) in residential centre.
Haugen et al15475 (10.6%)NorwayYesCase–control study (all ages)
Kim et al251230 (0%)KoreaNoChildren (6 months–14 years), non-institutionalised.
Van Splunder et al3040936 (9%)NetherlandsNoCross-sectional survey. Adults (≥18 years)
Liza-Sharmini et al26600 (0%)MalaysiaNo*Children (1 month–17 years) in hospital.
Fimiani et al201570 (0%)ItalyNoChildren (1 month–18 years) in hospital.
Karlica et al241532 (1.3%)Split-DalmatiaNoChildren (0–18 years).
Fong et al21911 (1%)Hong KongNo†Cross-sectional survey. Adults (≥18 years)
Aslan et al162721.1% (11 eyes)HelsinkiYesChildren (5–12 years). Clinical trial. Identified early subclinical keratoconus.
Li et al332036.3% (12 eyes)Hong KongYes‡Adult patients scheduled for cataract surgery (tertiary eye hospital)
Real de Asua et al2814410 (7%)SpainUnknownRetrospective review of medical records. Adults (17–65 years)
Alio et al1359§42 (71.3%)Spain and EgyptYesMulticentre case–control study. Age 3 months–60 years.
Marsack et al2714011.8%–20.8%¶ (26–46 eyes)USAYesCase–control study. Age 8–55 years
Hashemi et al2222628 (12.4%)IranYesPopulation-based cohort study. Age 10–30 years.
Imbornoni et al233110 (32%)USAYesChildren/young adults (4–24 years) in hospital.
Mathan et al329830 (30.6%) **New ZealandYesScreening of paralympics athletes (age 15–53 years)
Bermudez et al311207331 (27.2%)BrazilYes‡Retrospective review of medical records. Adults (all ages)
Kristianslund and Drolsum344342238 (5.5%)NorwayYes††Population-based register study. All ages.
  • *Placido disc used to detect keratoconus.

  • †Corneal thickness measured.

  • ‡when KC suspected and the patient cooperated.

  • §Number of patients that cooperated with eye examination.

  • ¶Proportion above threshold on detection metric (two types used).

  • **Presents several numbers.

  • ††Performed in many cases when indicated and the patient cooperated, however, proportion unknown.

  • CT, corneal topography/tomography; DS, Down Syndrome; KC, keratoconus; n, number.