Signalling pathways involved in ribonuclease-7 expression.

Antimicrobial peptides are host defence molecules that play a potential role in preventing infection at the epithelial surfaces. Ribonuclease (RNase)-7 has been shown to possess a broad spectrum of microbicidal activity against various pathogens. Here, we demonstrate that RNase-7 protein is localised to the superficial layers of ocular surface cells and increased in response to interleukin (IL)-1ß, suggesting an active role during inflammation related to ocular surface infection. Signal transduction pathways involved in RNase-7 expression are unknown. Involvement of transforming growth factor ß-activated kinase-1 (TAK-1) activated nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) pathway molecules [c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK) and p38] were studied because of their importance in infection and inflammation. Blocking the MAPKs resulted in inhibition of RNase-7 expression in response to IL-1ß. However, RNase-7 induction by IL-1ß was not affected by inhibiting the NF-κB signalling pathway. In conclusion, our results indicate that RNase-7 expression is specifically mediated via MAPKs but not NF-κB signalling pathways.

Monocular trial of intraocular pressure-lowering medication: a prospective study.

OBJECTIVE: To investigate the validity of the monocular therapeutic trial of therapy in patients commencing topical glaucoma treatment. DESIGN: Prospective intention-to-treat cohort study of untreated patients presenting with open-angle glaucoma or ocular hypertension. PARTICIPANTS: We included 30 treatment-naïve subjects. INTERVENTION: All subjects had 8 visits at which intraocular pressure (IOP) was measured by masked Goldmann tonometry. After the recruitment visit, IOP was measured in both eyes at 11 am for 7 consecutive weeks. At week 3, travaprost (0.001%) was commenced in the eye with the higher IOP and at week 4 travaprost was also commenced in the fellow eye. MAIN OUTCOME MEASURES: Three IOP outcomes were measured for the trial eye: (1) Unadjusted IOP-lowering effect (difference between recruitment IOP and first IOP on treatment); (2) adjusted IOP-lowering effect (unadjusted effect - [difference between IOPs at the same visits in the fellow eye]); and (3) true therapeutic effect (mean difference between 3 baseline pretreatment IOPs and 3 IOPs on treatment). RESULTS: Mean recruitment IOPs were 28.2 and 26.0 mmHg in the trial and fellow eyes, respectively. The mean baseline IOPs were 25.8 and 22.7 mmHg in the trial and fellow eyes, respectively, indicating that regression to the mean was responsible for 2.4 and 3.3 mmHg, respectively, in the trial and fellow eyes. The unadjusted treatment effect (11.7 mmHg) overestimated the true effect (8.6 mmHg) by a mean of 3.1 mmHg, whereas the mean adjusted IOP was almost identical to the true effect. The correlation between the unadjusted effect of treatment and the true effect was 0.55, whereas the effect when adjusted by the monocular trial was 0.72. CONCLUSIONS: In our cohort of patients with bilateral IOPs >21 mmHg at baseline, the monocular trial provides a significantly more accurate estimate of the therapeutic response when initiating prostaglandin monotherapy in untreated eyes. It is particularly helpful in avoiding overestimation of effectiveness and so reducing the number of patients on inadequate treatment. FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any of the materials discussed in this article.

A novel antimicrobial peptide on the ocular surface shows decreased expression in inflammation and infection.

PURPOSE: Antimicrobial peptides (AMPs) are cationic host defense peptides with microbicidal and cell-signaling properties. They show promise as potential therapeutic agents. In the present study, a beta-defensin AMP gene was isolated from the ocular surface for the first time, and its expression was characterized in the presence of ocular inflammation and/or infection. METHODS: Total RNA was obtained from impression cytology samples of the conjunctiva and cornea of normal patients and of those with bacterial, viral, acanthamoeba, or dry eye disease. The expression of the beta-defensin AMP DEFB-109 was determined by using reverse transcription-polymerase chain reaction (RT-PCR). Relative quantification of the gene in the various groups was performed by means of real-time PCR. RESULTS: DEFB-109 was constitutively expressed in all samples. The gene showed significantly decreased expression in the presence of all types of inflammation/infection. Reduced expression featured most prominently in acanthamoeba infection; the least change from normal was in dry eye. CONCLUSIONS: The discovery of DEFB-109 on the ocular surface enhances our knowledge of the profile of AMPs at this important mucosal surface. The fact that its expression is significantly reduced in both inflammatory and infective ocular surface disease reflects not only an intimate balance between this host defense gene and microbes but indicates a role other than purely microbicidal. This discovery will enable the mechanisms behind the intriguing phenomenon of reduced gene expression of an AMP in disease states to be uncovered.

Alcohol delamination of the corneal epithelium for recalcitrant recurrent corneal erosion syndrome: a prospective study of efficacy and safety.

AIM: To investigate the safety and efficacy of alcohol delamination of the corneal epithelium for recalcitrant recurrent corneal erosion syndrome (RCE) in a prospective non-comparative interventional case series. METHODS: Patients with RCE who remained symptomatic despite topical lubrication and 3-month use of an extended wear (bandage) contact lens were included. The intensity of pain on a scale of 1 to 10, and duration and frequency of attacks were recorded. Patients were treated with alcohol delamination and followed up at 1 week, 1 month and then at 12 months, which was the minimum follow up time. Success was defined as a resolution of symptoms after 1 month of treatment, and partial success as a significant reduction in symptoms manageable with topical lubricants, and failure where symptoms were unchanged or worsened. RESULTS: 20 eyes of 20 patients with RCE caused by trauma (n = 14), anterior basement membrane dystrophy (n = 5) or idiopathic (1) were studied. The mean age of patients was 44 years and mean follow-up 24 months. Two eyes were lost to follow-up. 15 (83%) eyes were qualified as successes, 3 as partial successes and no failures were seen. No intraoperative complications were observed. 1 patient developed transient subepithelial haze that resolved with topical steroid, 1 had a change in refraction and 1 developed herpetic stromal keratitis 2 months postoperatively, which was successfully treated. No loss of vision was observed in any of the patients. CONCLUSION: Alcohol delamination of the corneal epithelium is a safe and effective method for treating patients with recalcitrant RCE.

Predictive value of early IOP in mitomycin-C augmented trabeculectomy.

PURPOSE: To determine whether early intraocular pressure (IOP) after mitomycin-C (MMC) augmented trabeculectomy has any predictive value for intermediate IOP outcome. METHODS: Retrospective case note review. All cases of trabeculectomy using MMC augmentation and at least 1-year follow-up during the study period were included. Cases where a bleb leak occurred were excluded from the analysis. Only first eyes operated upon during the study period were included. Patient demographics and postoperative course were documented and analyzed. Early IOP measurements at day 1, day 7, and month 1 postoperatively were correlated to IOP at 1 year or final follow-up. RESULTS: One hundred nineteen trabeculectomies were identified. Of these 27 (22.7%) had an early bleb leak and were excluded. Further analysis was carried out on the remaining 92 cases. Mean age of cases was 70.8 years. Nine cases (9.8%) were repeat trabeculectomies. Mean follow-up time was 18.5 months (range 12 to 60 mo). Patients with a final IOP of < or =16 mm Hg (without drops or further surgery) (unqualified successes) had a mean day 1 IOP of 12.5 mm Hg compared with 17.4 mm Hg in those with an IOP more than 16 mm Hg at final follow-up (P=0.02). Patients with a final IOP of < or =16 mm Hg (with or without drops) (qualified successes) had mean day 1 IOP of 13.3 mm Hg compared with 17.1 mm Hg in those with an IOP of >16 mm Hg at final follow-up (P=0.06). At 1 month the mean IOPs were 10.7 mm Hg and 19.5 mm Hg, respectively (P<0.001). By logistic regression analysis at final recorded visit those cases in the lowest IOP quartile at 1 month were 14 times more likely to have an IOP < or =16 mm Hg without treatment than those in the highest quartile at 1 month. CONCLUSIONS: Our data suggests that a low early postoperative IOP measurement is a predictive factor for IOP value and success after intermediate length follow-up in patients undergoing trabeculectomy surgery augmented with MMC.

Increased expression of hepcidin and toll-like receptors 8 and 10 in viral keratitis.

PURPOSE: Antimicrobial peptides (AMPs) and toll-like receptors (TLRs) form part of the "chemical barrier" of the ocular surface to microbes. Evidence suggests that pathogen recognition by TLR releases AMPs, altering AMP-TLR profiles in pathological states. This study investigated ocular surface expression of AMP-TLRs in health and disease. METHODS: Complementary DNA from conjunctival and corneal impression cytology samples was used for semiquantitative and quantitative polymerase chain reactions, to determine gene expression of 6 AMPs and TLRs-1-10, in healthy subjects and patients with bacterial (n = 6), viral (n = 6), Acanthamoeba (n = 3), or dry eye (n = 7) diseases. RESULTS: Semiquantitative polymerase chain reaction showed variable AMP expression within groups and some expression patterns between groups, increased levels of LEAP (liver-expressed antimicrobial peptide)-1/hepcidin in viral disease, LEAP-2 in dry eye, and human beta defensin 3 in bacterial disease. There was no significant variability in TLR expression. Quantitative polymerase chain reaction showed significantly higher expression of LEAP-1 (P = 0.002) and TLR-8 (P = 0.023) and TLR-10 (P = 0.014) in viral keratitis and LEAP-2 (P = 0.034) in dry eye, versus controls. CONCLUSIONS: Increased expression of LEAP-1 and TLRs 8 and 10 in viral keratitis is novel; TLR-10 has not previously had a documented ligand. LEAP-2 may have a role in dry eye. Further studies will help to improve the understanding of these diseases and yield novel therapeutic interventions.