Mean values and standard deviations for differences between first and second CCT measurements.

<p>Mean values and standard deviations for differences between first and second CCT measurements.</p

Tonographic effect from the first (GAT-IOP 1) to the second (GAT-IOP 2) GAT measurement for patients, probands and the overall sample (patients and probands combined), [mmHg].

<p>Tonographic effect from the first (GAT-IOP 1) to the second (GAT-IOP 2) GAT measurement for patients, probands and the overall sample (patients and probands combined), [mmHg].</p

Tonographic effect from the first (IOPg 1) to the second (IOPg 2) IOPg measurement for patients, probands and the overall sample (patients and probands combined), [mmHg].

<p>Tonographic effect from the first (IOPg 1) to the second (IOPg 2) IOPg measurement for patients, probands and the overall sample (patients and probands combined), [mmHg].</p

Mean values and standard deviations of central corneal thickness before and after IOP measurements for patients and probands.

<p>Mean values and standard deviations of central corneal thickness before and after IOP measurements for patients and probands.</p

Tonographic effect from the first (IOPcc 1) to the second (IOPcc 2) IOPcc measurement for patients, probands and the overall sample (patients and probands combined), [mmHg].

<p>Tonographic effect from the first (IOPcc 1) to the second (IOPcc 2) IOPcc measurement for patients, probands and the overall sample (patients and probands combined), [mmHg].</p

Flow-chart representing fixation and bleaching methods employed for frozen tissue samples.

<p>Flow-chart representing fixation and bleaching methods employed for frozen tissue samples.</p

Photomicrographs of frozen and paraffin-embedded mouse ocular tissues that were fixed in freshly prepared 4% PFA prior to sectioning showing the iris dilator muscles.

<p>Bleaching was performed by treatment with warm 10% H₂O₂ diluted in PBS at 65°C for 120 min. All tissues were stained with HE. (A and C) Unbleached control tissues from the frozen and paraffin-embedded specimens, respectively. Dense pigmentation that obscures the visualization of the muscle is shown. (B and D) Bleached tissues from the frozen and paraffin-embedded specimens, respectively. Complete removal of the melanin pigmentation can be seen in these tissues, with preserved cytological details. Magnification 200x.</p

Representative photomicrographs of paraffin-embedded mouse ocular tissues treated with KMnO4 and oxalic acid.

<p>All tissues were routinely stained with HE. The degree of tissue disintegration increases with bleaching time and is especially evident at 120 and 180(A) Retinal tissue bleached for 5 min. (B) Ciliary processes bleached for 5 min. (C) Retinal tissue bleached for 10 min. (D) Ciliary processes bleached for 10 min. (E) Retinal tissue bleached for 15 min. (F) Ciliary processes bleached for 15 min. (G) Retinal tissue bleached for 30 min. (H) Ciliary processes bleached for 30 min. (I) Retinal tissue bleached for 120 min. (J) Retinal tissue bleached for 180 min. Magnification 200x. C: Choroid; RPE: Retinal pigmented epithelium; RC: Rods and cones; ONL: Outer nuclear layer; OPL: Outer plexiform layer; INL: Inner nuclear layer; IPL: Inner plexiform layer; Arrows indicate retinal ganglion cells.</p

Influence of Corneal Opacity on Intraocular Pressure Assessment in Patients with Lysosomal Storage Diseases

<div><p>Aims</p><p>To investigate an influence of mucopolysaccharidosis (MPS)- and Morbus Fabry-associated corneal opacities on intraocular pressure (IOP) measurements and to evaluate the concordance of the different tonometry methods.</p><p>Methods</p><p>25 MPS patients with or without corneal clouding, 25 Fabry patients with cornea verticillata ≥ grade 2 and 25 healthy age matched controls were prospectively included into this study. Outcome measures: Goldmann applanation tonometry (GAT); palpatory assessment of IOP; Goldmann-correlated intraocular pressure (IOPg), corneal-compensated intraocular pressure (IOPcc), corneal resistance factor (CRF) and corneal hysteresis (CH) assessed by Ocular Response Analyzer (ORA); central corneal thickness (CCT) and density assessed with Pentacam. Statistical analysis was performed using linear mixed effect models and Spearman correlation coefficients. The concordance between tonometry methods was assessed using Bland-Altman analysis.</p><p>Results</p><p>There was no relevant difference between study groups regarding median GAT, IOPg, IOPcc and CCT measurements. The limits of agreement between GAT and IOPcc/IOPg/palpatory IOP in MPS were: [-11.7 to 12.1mmHg], [-8.6 to 15.5 mmHg] and [- 5.4 to 10.1 mmHg] respectively. Limits of agreement were less wide in healthy subjects and Fabry patients. Palpatory IOP was higher in MPS than in healthy controls and Fabry patients. Corneal opacity correlated more strongly with GAT, IOPg, CH, CRF, CCT and corneal density in MPS (r = 0.4, 0.5, 0.5, 0.7, 0.6, 0.6 respectively) than in Fabry patients (r = 0.3, 0.2, -0.03, 0.1, 0.3, -0.2 respectively). In contrast, IOPcc revealed less correlation with corneal opacity than GAT in MPS (r = 0.2 vs. 0.4).</p><p>Conclusions</p><p>ORA and GAT render less comparable IOP-values in patients suffering from MPS-associated corneal opacity in comparison to Fabry and healthy controls. The IOP seems to be overestimated in opaque MPS-affected corneas. GAT, IOPg and biomechanical parameters of the cornea correlate more strongly with the corneal clouding than IOPcc in MPS patients.</p><p>Trial Registration</p><p>ClinicalTrials.gov <a href="https://clinicaltrials.gov/ct2/show/NCT01695161" target="_blank">NCT01695161</a></p></div

Bland-Altmann Plot for agreement between Goldmann applanation tonometry (GAT) and palpatory assessed IOP (palp IOP).

<p>Bland-Altmann Plot for agreement between Goldmann applanation tonometry (GAT) and palpatory assessed IOP (palp IOP).</p