Central Corneal Thickness in Mucopolysaccharidosis II and VI

Abstract

To describe the ultrasonographically detected central corneal thickness (CCT) in patients with Type II and VI mucopolysaccharidosis (MPS) and its impact on applanation tonometry and glaucoma detection. Twenty-eight patients with MPS (19 MPS II, nine MPS VI) underwent pachymetric investigation of CCT. Additionally, ultrasound measurements of axial length of the globe, slit-lamp evaluation with semiquantitative grading of corneal clouding, applanation tonometry, and assessment of refractive error were performed. Median average corneal thickness was 534.5 microm (range, 491.5-579.0 microm) in the MPS II and 547.0 microm (range, 492.5-693.05 microm) in the MPS VI group. CCT depended on degree of corneal clouding and patients' age, but did not correlate with intraocular pressure, refractive error, axial length, or MPS type. There were no substantial differences in refractive error between MPS II and MPS VI. In our patients, CCT in MPS II and VI did not differ statistically significantly from age-related values found in healthy subjects. Thus, intraocular pressure readings detected by applanation tonometry in MPS II and VI in the majority of patients can be regarded as reliable. In the case of clinically marked corneal clouding, measurement of CCT is recommended to adequately assess intraocular pressure and possible coexistent glaucoma.