PurposeTo compare the effects on tolerability, tear osmolarity, and intraocular pressure (IOP)-lowering effect of switching from benzalkonium chloride (BAK) containing prostaglandin analog (PGA) latanoprost to preservative-free tafluprost.Patients and methodsThirty patients with open-angle glaucoma (N = 60 eyes), 26 women (87%) and four men (13%) aged 64.1 (SD 14.1) years, showing abnormal values of tear osmolarity, corneal fluorescein staining, tear film break-up time (TBUT), or subjective discomfort with current latanoprost treatment were included. After tear osmolarity (TearLab™ Osmolarity System), TBUT, corneal fluorescein staining, and baseline IOP (Goldmann tonometer) measurements and the completion of Ocular Surface Disease Index and Ocular Surface Symptoms in Glaucoma Scale questionnaires, patients were assigned to preservative-free tafluprost treatment. Measurements were repeated 2, 6 and 12 weeks after change of medication.ResultsNo statistically significant differences in IOP were observed 2, 6, and 12 weeks after switching to preservative-free tafluprost. Mean IOP at baseline was 16.4 mmHg (SD 2.9), after 2 weeks 16.2 mmHg (2.8), after 6 weeks 16.2 (2.6), and after 12 weeks 16.3 mmHg (2.3). Mean tear osmolarity decreased significantly from 315.7 mOsm/L (SD 15.1) at baseline to 308.0 ± 14.4 mOsm/L (P = 0.002), 301.7 ± 14.5 mOsm/L (P < 0.001), and 302.0 ± 9.9 mOsm/L (P < 0.001) 2, 6, and 12 weeks after changing medication to preservative-free tafluprost, respectively. Tear osmolarity was lower in 37 eyes (61.7%) after 2 weeks, in 46 eyes (76.7%) after 6 weeks, and in 49 eyes (81.7%) after 12 weeks (P < 0.005; t-test). At baseline corneal fluorescein staining was observed in 43 eyes (71.7%), after 2 weeks in 34 eyes (56.7%), after 6 weeks in 12 eyes (20.0%), and after 12 weeks in 7 eyes (11.7%) (P < 0.005; McNemar test). Mean TBUT increased from 3.7 seconds (SD 1.1) at baseline to 4.1 seconds (SD 1.0) at week 2, 5.2 seconds (SD 1.5) at week 6, and 6.5 seconds (SD 1.5) at week 12 (P < 0.001; t-test). The number of patients expressing discomfort with latanoprost diminished from 30 (100%) at baseline, to 19 (63.3%) after week 2, and to 11 (36.6%) (P < 0.05; McNemar test) after 12 weeks.ConclusionPreservative-free tafluprost is better tolerated than BAK-containing latanoprost, showing lower tear osmolarity levels while maintaining effective IOP control.

BackgroundDiabetic retinopathy has a varied prevalence, severity, and rate of progression. The aim of this study was to determine whether the single nucleotide polymorphisms (SNPs) of the gene encoding a 135-kD centrosomal protein CEP135 rs4865047 and the gene encoding the type 2 NPY protein NPY2R rs1902491 were associated with the development of rapidly progressive proliferative diabetic retinopathy in patients with type 1 diabetes mellitus.Material/MethodsPatients with rapidly progressive proliferative diabetic retinopathy (n=48) were included in the study group. The control group (n=84) consisted of diabetes mellitus patients who had no proliferative diabetic retinopathy up to 15 years of diabetes duration. The reference group (n=90) included non-diabetic individuals who matched the study group by age and gender. The SNPs in the three groups were analyzed using real-time polymerase chain reaction (PCR) amplification.ResultsThe analysis of the distribution of genotypes in CEP135 rs4865047 and NPY2R rs1902491 detected significant differences only in the single nucleotide polymorphism rs4865047 genotype between the case and control group in comparison to the reference group. The co-dominant model showed that CEP135 rs4865047 was significantly associated with patients with rapidly progressive proliferative diabetic retinopathy (OR 7.2, 95% CI, 2.28–22.74, p=0.001). No significant association was found for the NPY2R SNP rs1902491 genotype.ConclusionsOur study reports a significant association of the CEP135 single nucleotide polymorphism rs4865047 genotype with rapidly progressive proliferative diabetic retinopathy and the control group. No significant association was found of the NPY2R single nucleotide polymorphism rs1902491 genotype.

Aim/purpose: It is believed that small nerve bundles are damaged in the earliest stages of neuropathy caused by diabetes mellitus (DM). Our goal was to evaluate and compare anatomical characteristics of corneal nerve fibers and corneal sensitivity in type-1 DM patients and in healthy control subjects.Design: A prospective, masked, controlled cross-sectional clinical study.Method: Thirty patients with type-1 DM and ten non-diabetic healthy subjects underwent a corneal confocal microscopy to evaluate the corneal sub-basal nerve fibers (density, number of nerves and branches, total nerve length) and contact corneal esthesiometry.Results: Diabetic patients had significantly lower corneal nerve fiber density density (14.32 ± 5.87 vs. 19.71 ± 5.59 mm/mm2; p = 0.023 ) nerve branches number (4.57 ± 3,91 vs. 9.90 ± 5.8 n°/image; p = 0.006) , nerve fiber length (2.28 ± 0.94 vs. 3.13 ± 0.89 mm; p = 0.032) and corneal sensitivity (1.13 ± 0.29 vs. 0.98 ± 0.058 gr/mm2 p = 0.02), as compared with controls. A negative correlation was found between corneal nerve fiber length, corneal nerve number, corneal nerve fiber density and disease duration (p < 0.05).Conclusion: Corneal confocal microscopy and corneal sensitivity evaluation are noninvasive techniques helping to detect early changes in the sub-basal nerve plexus characteristic for diabetic neuropathy (DN) in patients with type-1 DM. Further studies are required to investigate the role of corneal neuropathy assessment using these novel techniques as a toll to detect early DN.

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