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Variability in the ocular phenotype in mucopolysaccharidosis
  1. Krishanthy Sornalingam1,2,
  2. Ahmed Javed1,
  3. Tariq Aslam1,2,
  4. Panagiotis Sergouniotis1,3,
  5. Simon Jones4,
  6. Arunabha Ghosh4,
  7. Jane Ashworth1,2
  1. 1 Manchester Academic Health Science Centre, Manchester Royal Eye Hospital, Manchester, UK
  2. 2 Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
  3. 3 Division of Evolution and Genetics, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
  4. 4 Willink Unit, Manchester Centre for Genomic Medicine, St Mary’s Hospital, Manchester, UK
  1. Correspondence to Jane Ashworth, Manchester Royal Eye Hospital, Manchester, M13 9WL, UK; jane.ashworth{at}


Purpose Mucopolysaccharidoses (MPSs) are a heterogeneous group of lysosomal storage disorders. Ocular complications (such as corneal clouding, retinopathy and optic neuropathy) are common. Notably, there is a paucity of data on the effect of genotype and systemic treatments (enzyme replacement therapy or haematopoietic stem cell transplantation) on the ocular phenotype in MPS. We prospectively studied the ocular features of patients with MPSI (Hurler/Hurler-Scheie/Scheie), MPSIV (Morquio) and MPSVI (Maroteaux-Lamy), to evaluate the effect of different therapeutic interventions and to correlate the findings with genetic and biomarker data.

Methods Prospective observational cohort study. Study participants underwent detailed ocular examination including visual acuity; assessment of corneal clouding (Iris camera Corneal Opacification Measure score and Pentacam densitometry) and retinal and optic nerve imaging (optical coherence tomography and wide-field fundus imaging). Data on genotype, biomarkers and delivered therapies (type and length of treatment) were also collected for each patient where available.

Results Overall, 21 patients with MPSI, 4 patients with MPSIV and 3 patients with MPSVI were recruited. Corneal clouding scores were higher in MPSI compared with MPSIV and MPSVI. Retinopathy was evident in patients with MPSI only. Association was observed between corneal clouding and biomarkers in MPSI, MPSIV and MPSVI. However, no clear association was seen between genotype or treatment type and ocular phenotype.

Conclusions The ocular phenotype in MPS is variable, with corneal clouding occurring in MPSI, MPSIV and MPSVI, and retinopathy in MPSI only. There was an association between corneal clouding and efficacy of systemic treatment as measured by biomarkers.

  • Cornea
  • genetics
  • imaging
  • vision
  • retina

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  • Contributors KS drafted the manuscript, performed analysis and interpretation of data and was responsible for making revisions to the manuscript. AJ was involved in acquisition of data and review of the manuscript. TA was involved in the design of this study, analysed data and critically revised the manuscript. PS was involved in data analysis and critically revising the manuscript. SJ was involved with the design of the study and revision of the manuscript. AG helped with data acquisition and review of the manuscript. JA designed this study, was involved with data analysis and interpretation, drafting and critically revising this work. All authors have approved this work and agree to be accountable for its content.

  • Funding This work was supported by BioMarin Pharmaceutical Inc. Grant number: Ashworth/Grant G00423. The organisation had no role in the design or conduct of this research.

  • Competing interests JA reports grants from Biomarin Ltd, during the conduct of the study; personal fees from Biomarin Ltd, personal fees from Inventiva, personal fees from AbbVie, outside the submitted work. TA reports grants from Biomarin, during the conduct of the study. SJ reports personal fees and non-financial support from Biomarin, outside the submitted work. AG reports personal fees from Alexion Pharmaceuticals, non-financial support from Biomarin Pharmaceuticals, non-financial support from Shire Pharmaceuticals, outside the submitted work. PS has nothing to disclose. AJ has nothing to disclose. KS reports grants from Biomarin, during the conduct of the study (research grant awarded to Jane Ashworth and paid to institution).

  • Patient consent Not required.

  • Ethics approval West of Scotland Research Ethics Service.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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