Comparison of intraocular pressure measurements with different contact tonometers in young healthy persons

AIM：To analyze the correlation of Goldmann applanation tonometer（GAT）,I-Care tonometer and Tono-Pen tonometer results in young healthy persons,and to investigate the influence of central corneal thickness（CCT）on intraocular pressure（IOP）measurements recorded with these tonometers.·M ETHODS：We conducted a pilot clinical study in 78eyes of 78 subjects aged 22-28 years old（44 women and34 men;mean age 23.8±1.19y）.IOP was measured using GAT,I-Care and Tono-Pen tonometers,followed by measurements of CCT.Statistical analysis was performed using SPSS 20.0.·RESULTS：The mean IOPs and standard deviation（±SD）for GAT,I-Care and Tono-Pen were 15.62±2.281 mm Hg,16.29±2.726 mm Hg and 16.32±2.393 mm Hg,respectively.The mean CCT was 555.15±29.648μm.Clear positive correlations between GAT and I-Care,GAT and TonoPen,and I-Care and Tono-Pen tonometers were found（=0.867,〈0.001;=0.861,〈0.001;=0.915,〈0.001,respectively）.In comparison between devices,BlandAltman analysis showed a significant mean difference（MD）in the measurements by GAT and I-Care of-0.679 mm Hg and by GAT and Tono-Pen of-0.705 mm Hg（〈0.001）,but there was no significant difference between I-Care and Tono-Pe（〉0.05）.Both non-gold standard tonometers were affected by CCT;that is,both I-Care and Tono-Pen tonometer values were significantly higher with higher CCT means（〉555μm;MD=-1.282,〈0.001;MD=-0.949,〈0.001,respectively）compared with GAT.·CONCLUSION：Both I-Care and Tono-Pen tonometers overestimated IOP compared with the GAT values.Either the I-Care or Tono-Pen tonometer could be used instead of GAT because there was no significant difference between their results.Higher CCT values（〉555μm）were associated with overestimated IOP values.

X-linked juvenile retinoschisis： phenotypic and genetic characterization

Juvenile X-linked retinoschisis（XLRS, MIM#312700） belongs to a group of the vitreoretinal dystrophies. We aimed to describe the phenotype-genotype correlation of three XLRS cases in juveniles with different novel mutations from the Lithuanian population. The patients demonstrated macular retinoschisis and typical cyst-like cavities on spectral-domain optical coherence tomography（SD-OCT） images. The mean central foveal thickness was 569.7 μm. Two patients presented with peripheral retinoschisis. Flash electroretinogram demonstrated a reduced b/a ratio（〈1.0） in all patients. RS1（NM_000330.3） gene coding exons Sanger sequencing was performed. RS1 c.599 G〉T（p.R200 L） mutation was detected in one case, showing to be pathogenic in silico analysis. c.（92_97） ins C（p.W33 fs） mutation was identified for another patient, indicating the variant is possibly damaging in silico analysis. The third case was identified with a pathogenic mutation c.422 C〉G（p.R141 H）, HGMD CM981753. These are the first cases of XLRS in the Lithuanian population confirmed by molecular genotyping. Presented patients had a different genotype but similar phenotypic traits.

Endothelial parameters in central and peripheral cornea in patients wearing contact lenses

AIM： To measure the parameters of endothelium in the central and peripheral parts of the cornea and evaluate the influence of wearing the hard and soft contact lenses on the mentioned parameters.METHODS： A specular microscope was used to measure the corneal endothelium parameters in both eyes of 139 Caucasians（a total of 278）. All participants were divided into three groups： soft lens wearers, hard lens wearers and a control group. Factors, such as age, smoking, types of lens material, duration of lens wear and lens air permeability were assessed to determine their impact on the morphometric parameters of the endothelium.RESULTS： A lower percentage of hexagon-like cells and higher cell variation than in other groups were determined in hard contact lens wearers. The difference in density of endotheliocytes between the groups was not observed. The measurements of the morphometric parameters in soft contact lens wearers did not depend neither on the duration of lens wear, nor on air permeability. The relation between the patients＇ age and the variation of endothelium parameters was determined in the group of hard contact lens wearers.CONCLUSION： Wearing hard contact lenses provokes pleomorphism and polymegethism of the corneal endothelium, while soft contact lenses do not impact any parameters of the endothelium, most likely due to higher air permeability.