Corneal Effects of Tea Tree Oil.

PURPOSE: The purpose of this study is to report a case of corneal epithelial defects resulting from topical treatment of blepharitis with tea tree oil (TTO). METHODS: A 44-year-old man with a 1 year history of blepharitis non-responsive to eyelid hygiene was found to have signs of Demodex infestation. He was treated with a topical, off-label 50% TTO solution. Shortly afterward, the patient complained of bilateral ocular discomfort. RESULTS: Slit-lamp examination revealed conjunctival injection and a corneal epithelial defect in both eyes. Treatment with lubricant, antibiotic, and steroid eye drops as well as bandage contact lenses was required to facilitate corneal healing. CONCLUSIONS: Topical use of off-label, 50% concentration TTO can result in corneal epithelial defects. Eye care professionals should remain aware of this risk and only use approved, low-concentration TTO products when treating Demodex-related blepharitis.

PLGA nanoparticles containing Lingzhi extracts rescue corneal epithelial cells from oxidative damage.

Oxidative stress-related ocular surface epithelial damage can be initiated by ambient oxygen, UV radiation, and chemical burns. The oxidative damage to cornea can lead to inflammation and even vision loss. Lingzhi (Ganoderma lucidum) is a Chinese herbal drug and has been shown to prevent chronic diseases in clinical practices and has been proven to possess anti-oxidative and anti-inflammatory properties. In the study, we prepared poly (lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) as a sustained drug release system of Lingzhi (LZH) to improve bioavailability. The particle size of developed NPs containing LZH (LZH-NPs) was ~184 nm with narrow size distribution. The results of cellular uptake revealed that using NPs as a drug delivery system could significantly increases the intracellular retention time. The results of the cell viability and chemiluminescence assay revealed that 5 µg/ml of LZH-NPs might be the threshold concentration for cultivation of corneal epithelial cells. After treating LZH-NPs in oxidative damaged cells, the results showed that the inflammation-related gene expression and DNA fragmentation level were both significantly decreased. Post-treatment of LZH-NPs in damaged corneal epithelial cells could increase the cell survival rate. In the rabbit corneal alkali burn model, topical instillation of LZH-NPs could promote corneal wound healing and decrease the inflammation. These results suggest that LZH-NPs may have the potential to treat ocular surface diseases caused by oxidative stress.

Topical cell-free conditioned media harvested from adipose tissue-derived stem cells promote recovery from corneal epithelial defects caused by chemical burns.

Corneal chemical burns can lead to blindness following serious complications. As most of these complications are caused by failure of reepithelization during the acute phase, treatment at this stage is critical. Although there have been some studies on corneal injury recovery using adipose tissue-derived stem cells (ADSCs), none has reported the effect of topical cell-free conditioned culture media (CM) derived from ADSCs on corneal epithelial regeneration. Here, the best conditions for CM were selected and used for in vitro and in vivo experiments. Corneal burn in rats was induced using 100% alcohol. The chosen CM was administered to corneal burn rats (CM-treated [CT] group) four times a day for three days and this group was compared with the normal control and corneal burn (CB) groups. Biomicroscopic fluorescence images and the actual physical corneas were taken over time and used for analysis. mRNA levels of hepatocyte growth factor and epidermal growth factor (EGF) were significantly increased, whereas those of vascular endothelial growth factor, interleukin (IL)-1ß, IL-6, IL-10, and matrix metalloproteinase-9 were significantly decreased in the CT group compared with those in the CB group. The numbers of proliferating cell nuclear antigen- and zonular occludens-1-positive cells in the CT group were significantly higher than those in the CB group. The macrophage-infiltrating corneas in the CT group expressed significantly more of the M2 marker arginase than corneas in the CB group. Optimal CM (× 0.5 concentration) treatment significantly accelerated the migration of corneal epithelial cells and induced upregulation of the expression of IL-6, EGF, and C-X-C chemokine receptor type 4 mRNAs. Overall, in this study, topical administration of cell-free CM promoted regeneration of the corneal epithelium after induction of chemical burns.

Effects of Vitamin D Receptor Knockout and Vitamin D Deficiency on Corneal Epithelial Wound Healing and Nerve Density in Diabetic Mice.

Diabetic keratopathy occurs in ∼70% of all people with diabetes. This study was designed to examine the effects of vitamin D receptor knockout (VDR-/-) and vitamin D deficiency (VDD) on corneal epithelial wound healing and nerve density in diabetic mice. Diabetes was induced using the low-dose streptozotocin method. Corneal epithelial wounds were created using an Algerbrush, and wound healing was monitored over time. Corneal nerve density was measured in unwounded mice. VDR-/- and VDD diabetic mice (diabetic for 8 and 20 weeks, respectively) had slower healing ratios than wild-type diabetic mice. VDR-/- and VDD diabetic mice also showed significantly decreased nerve density. Reduced wound healing ratios and nerve densities were not fully rescued by a supplemental diet rich in calcium, lactose, and phosphate. We conclude that VDR-/- and VDD significantly reduce both corneal epithelial wound healing and nerve density in diabetic mice. Because the supplemental diet did not rescue wound healing or nerve density, these effects are likely not specifically related to hypocalcemia. This work supports the hypothesis that low vitamin D levels can exacerbate preexisting ophthalmic conditions, such as diabetes.

Successful management of epithelial ingrowth after sequential intracameral 5-fluorouracil and Descemet-stripping automated endothelial keratoplasty.

To describe the successful treatment of epithelial ingrowth using combined surgical excision with intracameral adjuvant 5-fluorouracil (5-FU) followed by Descemet-stripping automated endothelial keratoplasty (DSAEK). A 71-year-old man presented with epithelial ingrowth after clear corneal phacoemulsification. He underwent surgical excision of the membrane together with pars plana vitrectomy, air fluid exchange, and intracameral 5-FU. This treatment resulted in corneal decompensation for which DSAEK was performed 6 months later. Despite interface haze, the postoperative corrected distance visual acuity returned to 20/40 three months after DSAEK. There was no clinical evidence of recurrence of the epithelial ingrowth 9 months after the surgical removal. Intracameral 5-FU can be used in conjunction with surgical excision and subsequent DSAEK to successfully treat epithelial ingrowth.

Thermosensitive chitosan-gelatin-based hydrogel containing curcumin-loaded nanoparticles and latanoprost as a dual-drug delivery system for glaucoma treatment.

Elevated intraocular pressure (IOP) in glaucoma is due to impairment of aqueous humor drainage via the uveoscleral or trabecular outflow pathway. Latanoprost reduces IOP by increasing the uveoscleral outflow. Despite its potency, long-term daily application of it may cause undesirable side effects and many require more than one medication for IOP control. Recent studies have suggested that oxidative stress in the trabecular meshwork (TM) play an important role in the pathogenesis of impaired trabecular outflow facility. Curcumin, a natural phenolic compound, possesses anti-oxidant and anti-inflammation properties. In this study, we developed a thermosensitive hydrogel containing latanoprost and curcumin-loaded nanoparticles (CUR-NPs), and evaluated its possible therapeutic effects with cultured human TM cells under oxidative stress. The results demonstrated that 20 µM of CUR-NPs might be the optimal concentration to treat TM cells without causing cytotoxicity. Using the newly developed system, both latanoprost and CUR-NPs displayed a sustained-release profile. Treatment with this hydrogel containing CUR-NPs effectively decreased the oxidative stress-mediated damage in TM cells via decreasing inflammation-related gene expression, mitochondrial reactive oxygen stress (ROS) production and apoptosis level. The in vivo biocompatibility revealed no signs of inflammation or damage after topical application of developed hydrogel in rabbits. These results suggest that this dual-drug delivery system might enhance both trabecular and uveoscleral outflow and is promising to develop into a novel treatment for glaucoma.

Aucuba japonica Extract and Aucubin Prevent Desiccating Stress-Induced Corneal Epithelial Cell Injury and Improve Tear Secretion in a Mouse Model of Dry Eye Disease.

Dry eye disease is affected by a broad range of causes such as age, lifestyle, environment, medication and autoimmune diseases. These causes induce tear instability that activates immune cells and promotes expression of inflammatory molecules. In this study, we investigated the therapeutic effects of an ethanolic extract of Aucuba japonica (AJE) and its bioactive compound, aucubin, on dry eye disease. The human corneal cells were exposed to desiccation stress induced by exposing cells to air, so that viability was decreased. On the other hand, pre-treatment of AJE and aucubin restored cell survival rate depending on the dose under the dry condition. This result was confirmed again by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. The mRNA expression of inflammatory molecules was reduced by the pretreatment of AJE and aucubin under the dry state. The therapeutic effects of AJE and aucubin were examined in the animal model for dry eye induced by unilateral excision of the exorbital lacrimal gland. Declined tear volumes and corneal irregularity in the dry eye group were fully recovered by the administration of AJE and aucubin. The apoptotic cells on the cornea were also decreased by AJE and aucubin. Therefore, this study suggests that administration of AJE can be a novel therapeutic for dry eye disease and that the pharmacological activities of AJE may be in part due to its bioactive compound, aucubin.

Anti-Inflammatory and Anti-Apoptotic Effects of Acer Palmatum Thumb. Extract, KIOM-2015EW, in a Hyperosmolar-Stress-Induced In Vitro Dry Eye Model.

The aim of this study was to assess the anti-inflammatory and anti-apoptotic effects of KIOM-2015EW, the hot-water extract of maple leaves in hyperosmolar stress (HOS)-induced human corneal epithelial cells (HCECs). HCECs were exposed to hyperosmolar medium and exposed to KIOM-2015EW with or without the hyperosmolar media. Tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-6 production and apoptosis were observed, and the activation of mitogen-activated protein kinases (MAPKs) including extracellular signal regulated kinase (ERK), p38 and c-JUN N-terminal kinase (JNK) signaling and nuclear factor (NF)-κB was confirmed. Compared to isomolar medium, the induction of cell cytotoxicity significantly increased in HCECs exposed to hyperosmolar medium in a time-dependent manner. KIOM-2015EW-treatment significantly reduced the mRNA and protein expression of pro-inflammatory mediators and apoptosis. KIOM-2015EW-treatment inhibited HOS-induced MAPK signaling activation. Additionally, the HOS-induced increase in NF-κB phosphorylation was attenuated by KIOM-2015EW. The results demonstrated that KIOM-2015EW protects the ocular surface by suppressing inflammation in dry eye disease, and suggest that KIOM-2015EW may be used to treat several ocular surface diseases where inflammation plays a key role.

Use of Copaifera multijuga for acute corneal repair after chemical injury: A clinical, histopathological and toxicogenetic study.

Copaiba oil is widely used in medicine, but there are no reports regarding its application in ophthalmology. Therefore, the objective of this study was to evaluate the clinical, histopathological and toxicogenetic effects of eye drops containing 0.1 and 0.5% of Copaifera multijuga Hayne oil on superficial corneal ulcers induced with alkali in the left eye of rats. For histological analysis, the percent reduction in ulcers and thickness of the corneal epithelium and stroma were evaluated 48 and 72 h after ulcer induction. Additionally, neovascularization and polymorphonuclear infiltration were classified in the stroma. The bone marrow micronucleus test was used for toxicogenetic assessment. None of the animals exhibited clinical signs of immediate ocular discomfort after instillation and the eye drops were harmless to the ocular surface. There was a significant difference in percent ulcer reduction and corneal stroma thickness between animals treated with the C. multijuga eye drops and untreated animals with corneal injury and the negative control, respectively, suggesting a healing effect of the oleoresin. Analysis of the thickness of the corneal epithelium at the two time points showed that the eye drops formulated did not significantly reduce the damage caused by alkali. The same was observed for the treatments with the reference drugs. No difference in stromal neovascularization or inflammatory infiltration was observed between the treated groups. The toxicogenetic results revealed the absence of cytotoxicity and genotoxicity of the treatments. In conclusion, the C. multijuga eye drops did not cause damage to the ocular surface under the present experimental conditions and corneal epithelization was similar to the conventional treatments. These results indicate that eye drops containing C. multijuga oleoresin are a promising option for the treatment of superficial keratitis.

Efficacy of 2-Month Treatment With Cord Blood Serum Eye Drops in Ocular Surface Disease: An In Vivo Confocal Microscopy Study.

PURPOSE: To investigate the morphological changes of corneal epithelium and subbasal nerves by in vivo confocal microscopy in patients with ocular surface disease (OSD) treated with cord blood serum (CBS) eye drops. METHODS: Twenty patients with OSD (mean age 61.1 ± 12.6 years) were included in this prospective 1-arm study and treated with CBS eye drops for 2 months. Corneal sensitivity, Schirmer test score, breakup time, subjective symptoms [Ocular Surface Disease Index (OSDI) and Visual Analogue Scale (VAS)], and corneal staining were evaluated before (T0) and after (T1) treatment. In vivo confocal microscopy analyzed giant epithelial cells, subbasal nerve number and tortuosity, neuromas, beading, and dendritic cells (DCs) in the central cornea. RESULTS: OSDI, Visual Analogue Scale, and Oxford grading values significantly decreased at T1 versus T0 (respectively, 44.1 ± 18.9 vs. 74.2 ± 13.9; 3.7 ± 1.5 vs. 8.9 ± 0.9; and 2.4 ± 1.1 vs. 3.3 ± 1.3; P < 0.0001), whereas corneal sensitivity, Schirmer test score, and breakup time significantly increased (respectively, 49.5 ± 2.6 vs. 47.9 ± 2.9; 3.2 ± 2.0 vs. 2.4 ± 2.2; 4.6 ± 3.1 vs. 3.8 ± 2.1; P < 0.0001). Corneal nerve morphology improved at T1 versus T0 with a higher total nerve number (3.4 ± 1.6 vs. 2.5 ± 1.6 per frame) and lower tortuosity (3.0 ± 0.7 vs. 3.5 ± 0.6) (P < 0.01). The number of patients presenting with giant epithelial cells, beading, and neuromas decreased at T1. DC density did not change after treatment. The detection of neuromas and higher DC density at T0 were associated with greater OSDI reduction at T1 (P < 0.001). CONCLUSIONS: CBS eye drops significantly improved corneal nerve morphology and subjective symptoms in patients with severe OSD. The presence of neuromas and higher dendritic cell density at baseline were associated with greater reduction of discomfort symptoms after treatment.

Effects of histatin-1 peptide on human corneal epithelial cells.

PURPOSE: Ocular surface and corneal epithelial wounds are common and potentially debilitating problems. Ideal treatments for these injuries would promote epithelial healing without inflammation, infection and scarring. In addition the best treatments would be cost-efficient, effective, non-toxic and easily applied. Histatin-1 peptides have been shown to be safe and effective enhancers of epithelial wound healing in other model systems. We sought to determine whether histatin-1 peptides could enhance human corneal epithelial wound healing in vitro. METHODS: Histatin-1 peptides were applied to human corneal epithelial cells and compared over useful dose ranges in scratch assays using time-lapse microscopy. In addition, path finding analysis, cell spreading assays, toxicity and proliferation assays were performed to further characterize the effects of histatin-1 peptide on human corneal limbal epithelial (HCLE). RESULTS: Histatin-1 enhanced human corneal epithelial wound healing in typical wound healing models. There was minimal toxicity and no significant enhancement of proliferation of corneal epithelium in response to histatin-1 application. Corneal epithelial spreading and pathfinding appeared to be enhanced by the application of histatin-1 peptides. CONCLUSIONS: Histatin -1 peptide may enhance migration of HCLE cells and wound healing in vitro. These peptides may have benefit in corneal epithelial wounds and need to be investigated further.

Omega-3 supplementation is neuroprotective to corneal nerves in dry eye disease: a pilot study.

PURPOSE: To investigate whether oral, long-chain omega-3 (ω-3) essential fatty acid (EFA) supplementation, for 3 months, induces changes to the central corneal sub-basal nerve plexus in dry eye disease and whether nerve alterations correlate with clinical findings. METHODS: This prospective, comparative study involved the final 12 participants enrolled in a randomised, double-masked, placebo-controlled clinical trial of 60 participants with moderate dry eye disease. Participants received either placebo (olive oil 1500 mg/day; n = 4) or ω-3 EFA supplements (~1000 mg/day eicosapentaenoic acid + ~500 mg/day docosahexaenoic acid; n = 8) for 90 days. The main outcome measure was the mean change in central corneal sub-basal plexus nerve parameters between days one and 90, quantified using in vivo confocal microscopy. Secondary outcomes included mean change in tear osmolarity, corneal dendritic cell density and basal epithelial cell density. RESULTS: Compared with baseline, the reduction in OSDI score and tear osmolarity at day 90 were greater in the ω-3 EFA group than the placebo group (OSDI: ω-3 EFA, mean ± SEM: -15.6 ± 2.8 vs placebo: -2.8 ± 4.1 units, t5 = 2.6, p = 0.04; tearosmolarity: ω-3 EFA: -22.63 ± 5.7 vs placebo: -8 ± 2.7 mOsmol/L, t9 = 2.3, p = 0.04). At day 90, corneal total nerve branch density (CTBD: 91.1 ± 8.6 vs 45.1 ± 13.4 branches/mm2 , F1,10 = 14, p = 0.004) and corneal nerve branch density on the main fibre (CNBD: 63.4 ± 6.5 vs 27.9 ± 11.5 branches/mm2 , F1,10 = 6, p = 0.03) were higher in the ω-3 EFA group compared with placebo. Relative to day 1, CNBD (branches/mm2 ) increased at day 90 in the ω-3 EFA group (+20.0 ± 9.2, t8 = 3.2 p = 0.01) compared with placebo (-10.8 ± 3.2). Similar changes were evident for corneal nerve fibre length (CNFL, mm/mm2 ), which increased from baseline at day 90 in the omega-3 EFA group (+2.9 ± 1.6, t8 = 3.4 p = 0.01) compared with placebo (-2.7 ± 0.5). There was a negative correlation between CTBD and tear osmolarity (r10 = -0.70, p = 0.01). No significant changes were observed for basal epithelial cell or corneal dendritic cell density. CONCLUSION: These pilot study findings suggest that ω-3 EFA supplementation imparts neuroprotective effects in the corneal sub-basal plexus that correlate with the extent of tear osmolarity normalisation.

Therapeutic outcomes of combined topical autologous serum eye drops with silicone-hydrogel soft contact lenses in the treatment of corneal persistent epithelial defects: A preliminary study.

PURPOSE: To evaluate the efficacy of the combination of topical 20% autologous serum eye drops (ASEs) and silicone-hydrogel soft contact lenses (SCLs) for the treatment of corneal persistent epithelial defects (PEDs), and to compare the recurrence of epithelial breakdown with or without continuous use of ASEs after silicone-hydrogel SCLs removal. METHODS: We conducted a prospective interventional study of 21 eyes of 21 patients with PEDs treated with combined ASEs and silicone-hydrogel SCLs from September 2014 to August 2015. SCLs were removed after total re-epithelialization and patients were subsequently randomized divided into two groups: (1) with and (2) without continuous use of ASEs for an additional 2 weeks. PEDs healing rate and epithelial defect recurrence were evaluated. RESULTS: PEDs healed in all eyes within 3 weeks. Recurrence was noted in five eyes (50%) in patients without continued use of ASEs for 2weeks after total re-epithelialization and SCLs removal during a 3-month follow-up (odds ratio: 23.0; P<0.05). Recurrent epithelial defects were successfully treated with secondary SCLs application combined with autologous serum use. No adverse events were noted during the entire treatment period. CONCLUSIONS: The combined use of ASEs and silicone-hydrogel SCLs can successfully treat recalcitrant PEDs. Prolonged use of ASEs after total re-epithelialization can decrease recurrence rates.

Evaluation of treatment for dry eye with 2-hydroxyestradiol using a dry eye rat model.

PURPOSE: 2-hydroxy estradiol (2-OHE2) is a catechol derivative of 17ß -Estradiol (E2) and it is synthesized from E2 catalyzed by cytochrome P4501A1. Previous studies reported that 2-OHE2 is a physiologic antioxidant in lipoproteins, liver microsomes, and the brain. Catechol derivatives show an anti-inflammatory effect through the inhibition of prostaglandin endoperoxide synthase (PGS) activity. Corneal erosion caused by dry eye is related to an increase in oxidative stress and inflammation in ocular surface cells. We investigated the therapeutic effects of 2-OHE2 on corneal damage caused by dry eye. METHODS: Steroidal radical scavenging activity was confirmed through the electron spin resonance (ESR) method. PGS activity was measured using the COX Fluorescent Activity Assay Kit. To evaluate the effect of 2-OHE2 on the treatment for dry eye, 2-OHE2 was applied as an eye drop experiment using dry eye model rats. RESULTS: 2-OHE2 scavenged tyrosyl radical and possibly suppressed oxidative stress in corneal epithelial cells. In addition, 2-OHE2 inhibited PGS activity, and 2-OHE2 is probably a competitive inhibitor of PGS. Corneal PGS activity was upregulated in the dry eye group. Therefore, 2-OHE2 eye drops improved corneal erosion in dry eye model rats. CONCLUSIONS: 2-OHE2 is a candidate for the treatment of dry eye through the suppression of inflammation and oxidative stress in the cornea.

Lychee flower extract inhibits proliferation and viral replication of HSV-1-infected corneal epithelial cells.

PURPOSE: Herpes simplex virus type I (HSV-1) is capable of causing a wide array of human ocular diseases. Herpes simplex virus keratitis (HSK)-induced cytopathogenicity together with the chronic immune-inflammatory reaction can trigger stromal scarring, thinning, and neovascularization which may lead to permanent vision impairment. Lychee flower extract (LFE) is known for its antioxidant and anti-inflammatory effects. Therefore, in this study, we investigated the mechanism of the Statens Seruminstitut rabbit corneal (SIRC) epithelial cells infected by HSV-1 and examined the antiviral capabilities of LFE. METHODS: SIRC cells were pretreated with different concentrations of LFE (0.2, 0.1, and 0.05 µg/ml) and then infected with 1 MOI of HSV-1 for 24 h. The cell viability or morphology was evaluated in this study. In addition, the supernatants and cell extracts were collected for Cell Counting Kit-8 (CCK), plaque assay, and western blotting. RESULTS: We found that HSV-1-induced cell proliferation is regulated through inhibition of the mammalian target of rapamycin (mTOR) and p70s6k phosphorylation in response to the LFE. In addition, the LFE enhanced the autophagy protein expression (Beclin-1 and light chain 3, LC3) and decreased the viral titers. CONCLUSIONS: These results showed the antiviral capabilities and the protective effects of LFE. Taken together, our data indicate that LFE has potential as an anti-HSK (herpes simplex keratitis) for HSV-1 infection.

Determination of cytotoxicity of traditional Chinese medicine herbs, Rhizoma coptidis, Radix scutellariae, and Cortex phellodendri, by three methods.

BACKGROUND: Many herbs are used in traditional Chinese medicine TCM) for treatment of infections but their properties, in particular, their effects on normal cells have received little attention. This study investigated the cytotoxic properties of three TCM herbs with potential use in prevention and treatment of ocular infections, including Acanthamoeba keratitis. METHOD: The study investigated cytotoxic effects of the herbal extracts of Rhizoma coptidis, Radix scutellariae, and Cortex phellodendri on human corneal epithelial cells using trypan blue staining, MTT production, and flow cytometry. Differences between herbs were determined using repeated measures one-way analysis of variance, followed by paired t-tests where appropriate. RESULTS: These three herbs appeared to lack cytotoxicity when tested with trypan blue and MTT, but flow cytometry revealed that R. coptidis led to cell membrane damage. CONCLUSION: Lack of cytotoxicity of R. scutellariae and C. phellodendri extracts suggest that these are potentially suitable for use in ocular preparations. Only flow cytometry was able to accurately predict cytotoxic effects of extracts of TCM herbs on HCEC, demonstrating the importance of using a sensitive method of detection of cytotoxicity.

Protective Effects of L-Carnitine Against Oxidative Injury by Hyperosmolarity in Human Corneal Epithelial Cells.

PURPOSE: L-carnitine suppresses inflammatory responses in human corneal epithelial cells (HCECs) exposed to hyperosmotic stress. In this study, we determined if L-carnitine induces this protective effect through suppression of reactive oxygen species (ROS)-induced oxidative damage in HCECs. METHODS: Primary HCECs were established from donor limbal explants. A hyperosmolarity dry-eye model was used in which HCECs are cultured in 450 mOsM medium with or without L-carnitine for up to 48 hours. Production of reactive oxygen species (ROS), oxidative damage markers, oxygenases and antioxidative enzymes were analyzed by 2',7'-dichlorofluorescein diacetate (DCFDA) kit, semiquantitative PCR, immunofluorescence, and/or Western blotting. RESULTS: Reactive oxygen species production increased in HCECs upon substitution of the isotonic medium with the hypertonic medium. L-carnitine supplementation partially suppressed this response. Hyperosmolarity increased cytotoxic membrane lipid peroxidation levels; namely, malondialdehyde (MDA) and hydroxynonenal (HNE), as well as mitochondria DNA release along with an increase in 8-OHdG and aconitase-2. Interestingly, these oxidative markers were significantly decreased by coculture with L-carnitine. Hyperosmotic stress also increased the mRNA expression and/or protein production of heme oxygenase-1 (HMOX1) and cyclooxygenase-2 (COX2), but inhibited the levels of antioxidant enzymes, superoxide dismutase-1 (SOD1), glutathione peroxidase-1 (GPX1), and peroxiredoxin-4 (PRDX4). However, L-carnitine partially reversed this altered imbalance between oxygenases and antioxidant enzymes induced by hyperosmolarity. CONCLUSIONS: Our findings demonstrate for the first time that L-carnitine protects HCECs from oxidative stress by lessening the declines in antioxidant enzymes and suppressing ROS production. Such suppression reduces membrane lipid oxidative damage markers and mitochondrial DNA damage.

Corneal epitheliopathy in congenital methemoglobinemia.

PURPOSE: The aim of this study was to describe a previously unreported characteristic corneal epitheliopathy in congenital methemoglobinemia (type 1). METHODS: This was an observational case series of ocular findings in congenital methemoglobinemia. RESULTS: Siblings of 2 different affected families (age range, 12-14 years; 3 girls, 1 boy) affected with congenital methemoglobinemia had similar ocular complaints and clinical presentation. All of them had recurrent episodes of irritation and tearing in both eyes. Slit lamp biomicroscopy examination in all of them revealed the presence of dark colored corkscrew conjunctival vessels (prominently seen on the tarsal and forniceal region) and grayish-white raised corneal epithelial lesions. Diagnostic corneal scrapings in 2 of the patients showed the presence of epithelial cells with nonspecific inflammatory cells, and the results were negative for microbes. None of the patients had any abnormality in the lid adnexa, blink response, corneal sensation, or in the tear film. The corneal lesions resolved in 2 to 3 weeks time while on supportive therapy alone and on vitamin C supplements. CONCLUSIONS: Dark colored conjunctival vessels and recurrent corneal epitheliopathy causing irritation and tearing may be ocular features associated with congenital methemoglobinemia. It is pertinent for ophthalmologists, hematologists, and pediatricians to be aware of this association.

Mitomycin C versus 5-fluorouracil as an adjunctive treatment for trabeculectomy: a meta-analysis of randomized clinical trials.

Mitomycin C (MMC) and 5-fluorouracil (5-FU) are the most frequently utilized adjuvant therapies in trabeculectomy (TRAB), but there is no general consensus as to the direct comparative efficacy and safety of these two adjuvants. In this study, the authors conducted a meta-analysis to compare the efficacy and safety of augmenting TRAB with MMC or 5-FU. A systematic review with meta-analysis was conducted and five randomized controlled clinical trials comparing MMC versus 5-FU as adjunctive therapies were identified, totaling 416 participants. A lower pooled mean IOP and higher complete and qualified success rates were observed in the MMC arm than in the 5-FU arm. Epithelial corneal defects were the unique complication reported more frequently with 5-FU compared to MMC treatment. Compared to TRAB with 5-FU, TRAB with MMC was associated with higher rates of complete and qualified surgical success and was not associated with increased incidences of postoperative complications.

Selenium compound protects corneal epithelium against oxidative stress.

The ocular surface is strongly affected by oxidative stress, and anti-oxidative systems are maintained in corneal epithelial cells and tear fluid. Dry eye is recognized as an oxidative stress-induced disease. Selenium compound eye drops are expected to be a candidate for the treatment of dry eye. We estimated the efficacy of several selenium compounds in the treatment of dry eye using a dry eye rat model. All of the studied selenium compounds were uptaken into corneal epithelial cells in vitro. However, when the selenium compounds were administered as eye drops in the dry eye rat model, most of the selenium compounds did not show effectiveness except for Se-lactoferrin. Se-lactoferrin is a lactoferrin that we prepared that binds selenium instead of iron. Se-lactoferrin eye drops suppressed the up-regulated expression of heme oxygenase-1, cyclooxygenase-2, matrix metallopeptidase-9, and interleukin-6 and also suppressed 8-OHdG production in the cornea induced by surgical removal of the lacrimal glands. Compared with Se-lactoferrin, apolactoferrin eye drops weakly improved dry eye in high dose. The effect of Se-lactoferrin eye drops on dry eye is possibly due to the effect of selenium and also the effect of apolactoferrin. Se-lactoferrin is a candidate for the treatment of dry eye via regulation of oxidative stress in the corneal epithelium.