Keratoconus in Down syndrome: Prevalence, risk factors, severity and corneal tomographic characteristics.

BACKGROUND: This study investigated the prevalence, risk factors and severity of corneal tomographic features of keratoconus in Down syndrome (DS). Additionally, previous studies indicate anomalous corneal features in DS, without keratoconus, this study characterised corneal features in DS without keratoconus. METHODS: This prospective observational study included participants with DS ≥10 years old. Keratoconus diagnosis, risk factors and corneal tomographic characteristics were recorded. Participants underwent slit-lamp biomicroscopy, Scheimpflug corneal tomography, corneal topography and autorefraction. A diagnosis of keratoconus (DS-KC), suspect keratoconus (DS-SK) and non-keratoconus (DS-NK) was made based on expert review of scans by three fellowship trained anterior segment ophthalmologists. Corneal tomography parameters from one eye of each participant were analysed. RESULTS: Keratoconus affected 50 (26.3%) of 190 participants, diagnosed by corneal tomography, topography or slit-lamp signs. Corneal hydrops affected 14.0% of DS-KC participants. Eye rubbing was a significant risk factor for keratoconus (p = 0.036). 175 (92%) participants could undertake corneal tomography of which tomography assessment alone identified 47 (26.9%) DS-KC participants, 64 (36.6%) DS-SK participants and 64 (36.6%) DS-NK participants. Significant differences (p < 0.001) were identified when the DS-KC, DS-SK and DS-NK groups were compared in maximum keratometry and posterior elevation at the thinnest point respectively: median (interquartile range) 50.20 (10.30D), 47.60 (1.95D), 46.50 (2.40D); 24.0 (38.00 µm), 10.00 (13.75 µm), 8.00 (6.00 µm). The DS-SK and DS-NK cohorts had similar minimum pachymetry, however, had several significantly different parameters among which included greater maximum keratometry, posterior elevation at the thinnest point in the DS-SK group. CONCLUSIONS: Keratoconus is common in DS. Keratoconus screening with corneal tomography is recommended for early detection.

Topographic screening reveals keratoconus to be extremely common in Down syndrome.

IMPORTANCE: Keratoconus disproportionately affects people with Down syndrome (DS). This is the first study of its kind in Australasia. BACKGROUND: To investigate the prevalence of keratoconus in DS. DESIGN: Cross-sectional study. PARTICIPANTS: Athletes with DS attending 2017 New Zealand Special Olympics National Summer Games. METHODS: Keratoconus was identified using corneal topography (TMS-4N, Tomey). Topography from both eyes was required to be included. Two independent quantitative criteria were used to indicate keratoconus. The first was keratoconus severity index ≥ 30%. The second, adapted from the literature, required at least four of eight topographic parameters to be abnormal. Data from the worse eye were analysed. Diagnosis in each group was subsequently confirmed qualitatively by three corneal fellowship-trained ophthalmologists. Those with a definitive diagnosis were grouped into Keratoconus Confirmed Group 1 (KCC1) and Keratoconus Confirmed Group 2 (KCC2), respectively. MAIN OUTCOME MEASURES: Keratoconus prevalence, severity, demographics. RESULTS: Of 110 athletes screened, N = 98 were included, mean age 30.0 ± 9.7 years. Using only topographic data, keratoconus was identified in 39 (39.8%) athletes by quantitative topographic criteria 1, and in 63 (64.3%) athletes by criteria 2. Keratoconus was confirmed by qualitative sub-specialist review in 30 (30.6%) (KCC1) and 38 (38.8%) (KCC2) athletes, respectively. Mean keratometry in groups KCC1 and KCC2 were 48.4 ± 3.2D and 48.2 ± 2.9D, respectively. Most were male (KCC1 63.3%, KCC2 76.3%) and of European ethnicity (KCC1 80%, KCC2 78.9%). CONCLUSIONS AND RELEVANCE: We report keratoconus in 30.6% to 38.8% of athletes with DS; therefore, we believe keratoconus screening is indicated in DS for early management.

The effect of flavonoids on visual function in patients with glaucoma or ocular hypertension: a systematic review and meta-analysis.

BACKGROUND: Glaucoma is a leading cause of irreversible blindness worldwide. A major symptom of this pathology is the loss to the visual field in a peripheral to central pattern. Flavonoids are polyphenol compounds sourced from plants, commonly found in green tea, red wine and cocoa, and they have neuroprotective and antioxidant characteristics proposed to be advantageous within the context of glaucoma. Currently, the literature presents conflicting evidence regarding the effect of flavonoids on patients with glaucoma and ocular hypertension; hence a systematic review and meta-analysis was conducted. METHOD: Databases included in our literature search were EMBASE (1980-present), MEDLINE Ovid, Alternative and Complementary Medicine Database (AMED), Cumulative Index to Nursing and Allied Health Literature (CINAHL) and Cochrane Central Register of Controlled Trials (CENTRAL). Meta-analysis was performed using RevMan 5 (Review Manager) 5 software, version 5.3 (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen). The primary outcomes were visual field mean deviation (MD) and intraocular pressure (IOP). Secondary outcomes were ocular blood flow and blood pressure (BP). CONCLUSION: Meta-analyses showed that flavonoids have a promising role in improving visual function in patients with glaucoma and ocular hypertension (OHT), and appear to play a part in both improving and slowing the progression of visual field loss.