Corneal Morphologic Characteristics in Patients With Down Syndrome

Abstract

IMPORTANCE Literature suggests corneal morphologic characteristics compatible with keratoconus are present in a high percentage of patients with Down syndrome (DS), suggesting the need to perform a detailed examination of the anterior segment to try to avoid serious visual impairment in this group of patients. OBJECTIVE To characterize the abnormal features of the cornea in patients with DS and compare these with a control group. DESIGN, SETTING, AND PARTICIPANTSMulticenter case-control study at Vissum Alicante, . The study included 321 eyes of 217 participants from 2 groups: 112 participants in the DS group and 105 healthy participants in the control group.INTERVENTIONS Patients were evaluated using Placido disc/Scheimpflug camera topographer (Sirius, CSO). Visual, refractive and anterior, and posterior corneal characteristics were assessed and compared in both groups.MAIN OUTCOMES AND MEASURES Keratoconus diagnosis. Incidence of corneal morphologic irregularities similar to keratoconus in patients with DS. RESULTSIn the DS group, mean (SD) age was 14.88 (15.76) years, 54 (48%) were women, 66 (59%) were white, and 46 (41%) were Arab. In the control group, mean (SD) age was 40.29 (14.66) years, 54 (51%) were women, and all were white. Clinical assessment of corneal topography showed that 71.3% (95% CI, 45.2-97.4) of patients in the DS group showed characteristics compatible with keratoconus. Differences were found in steepest keratometry of 47.35 diopters (D) in patients with DS vs 43.70 D in control individuals (difference, 3.65 D; 95% CI, 3.23-4.35 D; P <.001) and in corneal pachymetry of 503 μm in patients with DS vs 545 μm in control individuals (difference, 42 μm; 95% CI, 38.8-56.7 μm; P <.001).CONCLUSIONS AND RELEVANCE Patients with DS have steeper and thinner corneas and more corneal aberrations than those without genetic alterations and normal corneas. The findings suggest a detailed corneal study should be considered in such patients to detect keratoconus and implement treatment as appropriate to try to avoid serious visual impairment in this group of patients. JAMA Ophthalmol. 2018;136(9):971-978.

Tomography-based definition of keratoconus for Down syndrome patients

“…Several studies have reported variable rates for the prevalence and incidence of KC in DS patients, which may be due to the lack of standard criteria for KC diagnosis in DS [ 11 ]. As demonstrated in this study (Tables 1 and 4 ), the DS-C group differed from the age- and gender-matched non-DS NC group.…”

“…This difference, in addition to age and genetic predisposition, can be due to diagnostic criteria. Given these uncertainties in the diagnosis, the term KC-compatible has been used to describe findings, and it has been shown that 71.3% of DS patients may have findings suggestive of KC [ 11 ]. Given the lack of literature on this topic, this study was designed in an attempt to define diagnostic criteria for differentiating KC and KCS from non-ectatic corneas in DS patients.…”

Assessment of the mechanical forces applied during eye rubbing

“…6 ORASIS Eye Clinic, Swiss Eye Research Foundation, Reinach, Switzerland. 7 Department of Physics, Faculty of Sciences, University of Novi Sad, Novi Sad, Serbia. 8 Faculty of Medicine of the Military Medical academy, University of Defense, Belgrade, Serbia.…”

“…Patients who intensely rub their eyes (e.g. those with Down Syndrome and atopic patients are at higher risk of developing keratoconus [ 4 , 7 – 9 ]. The reasons to rub their eyes are manifold: itchiness in atopic conjunctivitis represents one of the most common causes of eye rubbing [ 10 ].…”

In vivo evaluation of corneal biomechanical properties by optical coherence elastography at different cross-linking irradiances

“…2 The widely used standard Dresden solution requires a 30-min infiltration of riboflavin solutions followed by 30 min of UV irradiation (3 mW∕cm 2 , 5.4 J∕cm 2 ). 3 However, it is difficult for some patients, for example, children and patients with Down syndrome (a disease highly associated with keratoconus), 4 to keep themselves focused on the target over a 30-min treatment. According to the Bunsen-Roscoe law, the same effect can be achieved theoretically with an equal radiant energy provided by less intense UV radiation over a longer period of time or a more intense UV radiation over a shorter period of time.…”