Contact lenses for the treatment of ocular surface diseases.

Contact lens wear is useful in ocular conditions such as high refractive errors, irregular astigmatism, corneal ectasias, corneal dystrophies, post-keratoplasty, post-refractive surgeries, trauma, and ocular surface diseases. The new innovations of highly oxygen-permeable contact lens materials have broadened the applications of contact lens suitability. Therapeutic contact lenses are medically used in the management of a wide variety of corneal conditions and ocular surface diseases. These lenses aid in pain relief, enhance corneal healing, maintain ocular homeostasis, and act as a drug delivery system. Drug delivery applications of contact lenses hold promise for improving topical therapy. The modern rigid gas permeable scleral contact lens provides symptomatic relief in painful corneal diseases such as bullous keratopathy, corneal epithelial abrasions, and erosions. It has been useful in therapeutic management as well as visual rehabilitation by enhancing the ocular surface and protecting the cornea from adverse environmental conditions. This review provides a summary of contact lenses used for the treatment of ocular surface diseases based on the current evidence available in the literature. This can help enhance the understanding and management of ocular surface diseases with respect to contact lens use in our day-to-day ophthalmology practice.

Impact of Taping The Upper Mask Edge On Ocular Surface Stability and Dry Eye Symptoms.

PURPOSE: To evaluate the impact of taping the upper mask edge on ocular surface stability, dry eye symptomology, and tear osmolarity in N95 mask users. DESIGN: Prospective interventional before-and-after study. METHODS: Fifty eyes of 50 health care workers regularly using N95 masks were included. Preintervention, ocular surface parameters, subjective dry eye score, and visual acuity were assessed at the end of an 8-hour shift when the subjects used an N95 face mask without taping the upper edge. Next day, the upper edge of the N95 mask was taped to the nasal bridge in all subjects at the beginning of the 8-hour shift, and postintervention assessment was performed after the shift. The primary outcome measure was change in noninvasive tear break-up time (NIBUT). Secondary outcome measures were change in the symptom score, tear lipid layer thickness (LLT), tear break-up time (TBUT), Schirmer I test, tear meniscus height (TMH), osmolarity, and visual acuity. RESULTS: Mean age of the cohort was 26.7 ± 3.67 years. Post-taping, significantly better ocular surface stability was observed in terms of NIBUT (P < .001), TBUT (P < .001), LLT (P < .001), TMH (P = .01), corneal staining score (P = .001), and tear osmolarity (P = .04). There was no significant change in visual acuity, Schirmer I, and Ocular Surface Disease Index score (P > .05). Symptom improvement was reported by 68% patients (SANDE version 2), which correlated well with change in NIBUT (r = 0.38; P = .005), TMH (r = 0.37; P = .007), LLT (r = 0.35; P = .01), and TBUT (r = 0.28; P = .04). CONCLUSION: Taping of the upper mask edge resulted in significantly better ocular surface stability, which correlated well with decrease in dry eye symptoms.

TETology: Epigenetic Mastermind in Action.

Cytosine methylation is a well-explored epigenetic modification mediated by DNA methyltransferases (DNMTs) which are considered "methylation writers"; cytosine methylation is a reversible process. The process of removal of methyl groups from DNA remained unelucidated until the discovery of ten-eleven translocation (TET) proteins which are now considered "methylation editors." TET proteins are a family of Fe(II) and alpha-ketoglutarate-dependent 5-methyl cytosine dioxygenases-they convert 5-methyl cytosine to 5-hydroxymethyl cytosine, and to further oxidized derivatives. In humans, there are three TET paralogs with tissue-specific expression, namely TET1, TET2, and TET3. Among the TETs, TET2 is highly expressed in hematopoietic stem cells where it plays a pleiotropic role. The paralogs also differ in their structure and DNA binding. TET2 lacks the CXXC domain which mediates DNA binding in the other paralogs; thus, TET2 requires interactions with other proteins containing DNA-binding domains for effectively binding to DNA to bring about the catalysis. In addition to its role as methylation editor of DNA, TET2 also serves as methylation editor of RNA. Thus, TET2 is involved in epigenetics as well as epitranscriptomics. TET2 mutations have been found in various malignant hematological disorders like acute myeloid leukemia, and non-malignant hematological disorders like myelodysplastic syndromes. Increasing evidence shows that TET2 plays an important role in the non-hematopoietic system as well. Hepatocellular carcinoma, gastric cancer, prostate cancer, and melanoma are some non-hematological malignancies in which a role of TET2 has been implicated. Loss of TET2 is also associated with atherosclerotic vascular lesions and endometriosis. The current review elaborates on the role of structure, catalysis, physiological functions, pathological alterations, and methods to study TET2, with specific emphasis on epigenomics and epitranscriptomics.

Exploring the Role of Gut Microbiome in Colon Cancer.

Dysbiosis of the gut microbiome has been associated with the development of colorectal cancer (CRC). Gut microbiota is involved in the metabolic transformations of dietary components into oncometabolites and tumor-suppressive metabolites that in turn affect CRC development. In a healthy colon, the major of microbial metabolism is saccharolytic fermentation pathways. The alpha-bug hypothesis suggested that oncogenic bacteria such as enterotoxigenic Bacteroides fragilis (ETBF) induce the development of CRC through direct interactions with colonic epithelial cells and alterations of microbiota composition at the colorectal site. Escherichia coli, E. faecalis, F. nucleatum, and Streptococcus gallolyticus showed higher abundance whereas Bifidobacterium, Clostridium, Faecalibacterium, and Roseburia showed reduced abundance in CRC patients. The alterations of gut microbiota may be used as potential therapeutic approaches to prevent or treat CRC. Probiotics such as Lactobacillus and Bifidobacterium inhibit the growth of CRC through inhibiting inflammation and angiogenesis and enhancing the function of the intestinal barrier through the secretion of short-chain fatty acids (SCFAs). Crosstalk between lifestyle, host genetics, and gut microbiota is well documented in the prevention and treatment of CRC. Future studies are required to understand the interaction between gut microbiota and host to the influence and prevention of CRC. However, a better understanding of bacterial dysbiosis in the heterogeneity of CRC tumors should also be considered. Metatranscriptomic and metaproteomic studies are considered a powerful omic tool to understand the anti-cancer properties of certain bacterial strains. The clinical benefits of probiotics in the CRC context remain to be determined. Metagenomic approaches along with metabolomics and immunology will open a new avenue for the treatment of CRC shortly. Dietary interventions may be suitable to modulate the growth of beneficial microbiota in the gut.

Efficacy and Safety of Topical Chloroquine in Mild to Moderate Dry Eye Disease.

Purpose: To evaluate the role of topical chloroquine (CHQ) as an adjunct to topical lubricants in the management of mild-moderate dry eye disease (DED)Methods: Prospective comparative pilot study allocated 150 patients with symptoms of mild to moderate DED to receive topical CMC 0.5% three times a day (group I, n = 75) or topical CHQ 0.03% twice a day with carboxymethylcellulose (CMC) 0.5% three times a day (group II, n = 75), for three months. Primary outcome measures were ocular surface disease index (OSDI) score and conjunctival impression cytology at 3 months. Secondary outcome measures were TBUT, Schirmer's test, ocular surface staining and any adverse effects at 3 months. Follow up was performed at 1 and 3 months.Results: At three months, the OSDI score was significantly better in the CHQ group as compared with the CMC group (CMC-18.36 ± 4.03 (SD), CHQ group- 15.9 ± 5.18 (SD); p = .002). Nelson's score was 0.92 ± 0.69 (SD) in the CHQ group as compared with 1.60 ± 0.77 (SD) in the CMC group (p < .001). Abnormal impression cytology was observed in 20% cases in the CHQ group as compared with 61.3% cases in CMC group (p < .001). A significant correlation was observed between Nelson's score and OSDI (Spearman's rho correlation coefficient 0.414, p < .001). TBUT, Schirmer test and ocular surface staining were significantly better in the CHQ group (p < .001). No adverse effects were observed in any group.Conclusion: Topical chloroquine is a useful adjunct to topical lubricants in the management of DED as it decreases the underlying chronic inflammation and helps maintain ocular surface stability.