Application frequency - key indicator for the efficiency of severe dry eye disease treatment - evidence for the importance of molecular weight of hyaluronan in lubricating agents.

PURPOSE: Lubricant eye drops are the main therapeutic resource for dry eye disease (DED), with each drop representing the equivalent of ocular surface disease treatment. Thus, any reduction in the frequency of eye drop application reflects a degree of therapeutic success. Considering also the socioeconomic burden of DED, we investigated eye drop application frequency (DF) as a parameter to potentially track the success of therapy in severe DED. Hyaluronan (HA)-containing eye drops have become the first choice for tear substitution in many countries, and recent data indicate that the average molecular weight (Mw) of HA determines the therapeutic efficacy of such eye drops. This post-hoc subgroup analysis of a previously published multicentre prospective randomized open-label study, HYLAN M, is set out to compare the effects of very high Mw HA (hylan A) eye drops to comparator eye drops, containing lower Mw HA (control). METHODS: Patients with severe DED (n = 47), recruited as part of the larger HYLAN M prospective, multicentre, open-label study, were randomized into two groups: hylan A and control group. In the hylan A group, 24 patients replaced their HA-containing eye drops with eye drops containing 0.15% hylan A, whereas the 23 control patients continued to use comparator HA eye drops. The DF was recorded daily by all participants over 8 weeks, and other subjective and objective parameters of DED were assessed at the time of inclusion (baseline), as well as at week 4 and 8. RESULTS: There was a significant decrease in DF in the hylan A users between the baseline and week 4 (p = 0.004), remaining stable until week 8. Indeed, in contrast to the baseline, the hylan A group had a significantly lower DF than the control group at weeks 4 (p = 0.018) and 8 (p = 0.008). Likewise, the ocular surface disease index (OSDI) improved significantly between the time of inclusion and week 4 (p < 0.001) in hylan A users, remaining stable until week 8. The OSDI was similar in both groups at the baseline but it was significantly lower in the hylan A group than in the control group at week 4 (p = 0.002), remaining lower at week 8. Such a decrease in the DF and OSDI was not witnessed in the control group at any time point. The objective parameters assessed did not differ significantly within or between the two groups. CONCLUSION: When treating severe DED, the DF can be significantly reduced by using very high Mw HA (3 MDa) lubricant eye drops, which better alleviate DED symptoms and decrease the OSDI scores. These drops not only provide an attractive and comfortable alternative for patients with severe DED but also offer the possibility of reducing the disease's socioeconomic burden, both for affected individuals and society as a whole.

Heme oxygenase-1 gene rs2071746 polymorphism in retinal vein occlusion.

BACKGROUND: Heme oxygenase-1 (HO-1) is an important cytoprotective enzyme due to its ability to degrade pro-inflammatory heme. The common single nucleotide polymorphism (SNP) rs2071746 on the HMOX1 gene has been associated with HO-1 activity and a variety of cardiovascular diseases. This study was performed to investigate the association between the rs2071746 SNP and retinal vein occlusion (RVO). METHODS: We included 496 RVO patients and 297 control subjects in this case-control study. Genotypes of the rs2071746 polymorphism were determined by TaqMan assays. RESULTS: There was no association between the rs2071746 genotype and the presence of RVO (p = .443). The lack of association was found in all three logistic regression models, namely the dominant (p = .560), the recessive (p = .373) and the co-dominant model (p = .444). The distribution of the rs2071746 genotype was 30% (AA), 51% (AT), and 19% (TT). Baseline characteristics were similar between these genotypes, except for diabetes mellitus, which was less prevalent in the AA genotype (p < .001). CONCLUSION: The rs2071746 polymorphism does not seem to be a major risk factor for the presence of RVO.

Demodex Mite Infestation and its Associations with Tear Film and Ocular Surface Parameters in Patients with Ocular Discomfort.

PURPOSE: The presence of Demodex species can be associated with blepharitis. Their pathogenic potential in meibomian gland dysfunction is discussed herein. The purpose of this study was to determine the prevalence of Demodex mites in eyelashes of Austrian patients with ocular discomfort and to evaluate associated changes of the lid margins and meibomian glands. DESIGN: This is a case-control study. METHODS: Two hundred twenty-nine consecutive patients with ocular discomfort from an Austrian dry eye clinic were investigated for the presence of Demodex mites on sampled eyelashes. Associations of a mite infestation with individual dry eye and lid parameters were assessed. Lid margins were evaluated for scales, vascularization, Marx line, expressibility and quality of meibum, and drop-out of meibomian glands. RESULTS: Demodex mites were identified in 40.2% of patients suffering from ocular discomfort (mean mite count 3.3 ± 2.9 per patient). Infestation with mites was associated with the presence of significantly more cylindrical scales (sleeves), a higher Marx line score, and a lower quality of meibum compared with mite-free patients. There were no significant associations with the expressibility and the drop-out of meibomian glands. CONCLUSION: The prevalence of Demodex mites in patients with ocular discomfort is high. The mean mite count per patient in this Austrian dry eye unit population is lower compared with previously published data from Asian regions. The infestation of the eyelids with Demodex species is associated with changes of the anterior and posterior lid margin, suggesting a pathogenic role in blepharitis and meibomian gland dysfunction.