Hassan Hashemi1, Mohammad Miraftab2, Kazem Amanzadeh1, Mohammad Amin Seyedian1, Riccardo Vinciguerra3, Renato Ambrósio4,5, Cynthia Roberts6, Ali Makateb1, Paolo Vinciguerra7,8, Soheila Asgari9. 1. Noor Ophthalmology Research Center, Noor Eye Hospital, No. 96 Esfandiar Blvd, Vali'asr Ave, Tehran, Iran. 2. Noor Research Center for Ophthalmic Epidemiology, Noor Eye Hospital, Tehran, Iran. 3. St Paul's Eye Unit, Royal Liverpool and Broadgreen University Hospital, Liverpool, UK. 4. Rio de Janeiro Corneal Tomography and Biomechanics Study Group, Rio de Janeiro, RJ, Brazil. 5. Federal University of the State of Rio de Janeiro (UNIRIO), Rio de Janeiro, RJ, Brazil. 6. Department of Ophthalmology and Visual Science, Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA. 7. Department of Biomedical Sciences, Humanitas University, Pieve Emanuele Milan, Italy. 8. Humanitas Clinical and Research, Rozzano, Italy. 9. Noor Ophthalmology Research Center, Noor Eye Hospital, No. 96 Esfandiar Blvd, Vali'asr Ave, Tehran, Iran. soheilaasgari@gmail.com.
Abstract
PURPOSE: To use novel indices to determine the prevalence of KC and its progression in patients aged 10-30 years with Down syndrome. STUDY DESIGN: Cohort population-based study. METHODS: Two hundred twenty-six of 250 invited Down syndrome patients were enrolled. The diagnostic criteria were confirmed by two independent expert examiners using slit-lamp examinations and topographic indices measured by Pentacam HR (Oculus Optikgeräte): maximum keratometry centered on the steepest point (zonal Kmax-3 mm), Ambrósio's relational thickness (ART), inferior-superior asymmetry (IS-value), Belin/Ambrósio deviation value (BAD-D), the Tomographic and Biomechanical Index (TBI), and a posterior elevation map. In the KC cases, Corvis ST (Oculus Optikgeräte) was done. All the KC cases completed the second phase in 2017. RESULTS: KC was identified in 28 patients (12.39%; 95% confidence interval: 8.2-17.9%): 20 bilateral and eight unilateral cases. Of these, 24 were in the ≤ 20-years age group, and four, in the > 20-years age group. The frequency of KC was not significantly correlated with age (P = 0.804) or gender (P = 0.322). In the KC cases, the mean zonal Kmax-3 mm, ART-max, IS-value, BAD-D, CBI, and TBI were 50.40 ± 5.88 D, 321.63 ± 111.94 μm, 1.99 ± 2.51, 3.73 ± 3.12, 0.54 ± 0.61, and 0.86 ± 0.20, respectively, and the minimum corneal thickness was 492.17 ± 42.67 μm. Of the 28 patients, 39.6% showed progression, and all were in the ≤ 20-years age group. CONCLUSION: The prevalence of KC in Down syndrome patients is significantly higher than that reported in non-Down syndrome individuals of the same age groups. The progression rate is approximately similar to that of the non-Down syndrome population. Screening programs should be applied to prohibit serious visual impairment in these populations.
PURPOSE: To use novel indices to determine the prevalence of KC and its progression in patients aged 10-30 years with Down syndrome. STUDY DESIGN: Cohort population-based study. METHODS: Two hundred twenty-six of 250 invited Down syndrome patients were enrolled. The diagnostic criteria were confirmed by two independent expert examiners using slit-lamp examinations and topographic indices measured by Pentacam HR (Oculus Optikgeräte): maximum keratometry centered on the steepest point (zonal Kmax-3 mm), Ambrósio's relational thickness (ART), inferior-superior asymmetry (IS-value), Belin/Ambrósio deviation value (BAD-D), the Tomographic and Biomechanical Index (TBI), and a posterior elevation map. In the KC cases, Corvis ST (Oculus Optikgeräte) was done. All the KC cases completed the second phase in 2017. RESULTS: KC was identified in 28 patients (12.39%; 95% confidence interval: 8.2-17.9%): 20 bilateral and eight unilateral cases. Of these, 24 were in the ≤ 20-years age group, and four, in the > 20-years age group. The frequency of KC was not significantly correlated with age (P = 0.804) or gender (P = 0.322). In the KC cases, the mean zonal Kmax-3 mm, ART-max, IS-value, BAD-D, CBI, and TBI were 50.40 ± 5.88 D, 321.63 ± 111.94 μm, 1.99 ± 2.51, 3.73 ± 3.12, 0.54 ± 0.61, and 0.86 ± 0.20, respectively, and the minimum corneal thickness was 492.17 ± 42.67 μm. Of the 28 patients, 39.6% showed progression, and all were in the ≤ 20-years age group. CONCLUSION: The prevalence of KC in Down syndrome patients is significantly higher than that reported in non-Down syndrome individuals of the same age groups. The progression rate is approximately similar to that of the non-Down syndrome population. Screening programs should be applied to prohibit serious visual impairment in these populations.
Entities:
Keywords:
Cornea biomechanics; Down syndrome; Keratoconus; Progressive keratoconus; Tomographic index
Authors: Dimitrios Karamichos; Paulina Escandon; Brenda Vasini; Sarah E Nicholas; Lyly Van; Deanna H Dang; Rebecca L Cunningham; Kamran M Riaz Journal: Prog Retin Eye Res Date: 2021-11-02 Impact factor: 19.704