The anti-scarring role of Lycium barbarum polysaccharide on cornea epithelial-stromal injury.

PURPOSE: Cornea epithelial-stromal scarring is related to the differentiation of fibroblasts into opaque myofibroblasts. Our study aims to assess the effectiveness of Lycium barbarum polysaccharide (LBP) solution as a pre-treatment in minimizing corneal scarring. METHODS: Human corneal fibroblasts were cultured in a three-dimensional collagen type I-based hydrogel in an eye-on-a-chip model. Fibroblasts were pre-treated with 2 mg/mL LBP for 24 h, followed by another 24-h incubation with 10 ng/mL transforming growth factor-beta 1 (TGF-ß1) to induce relevant physiological events after stromal injury. Intracellular pro-fibrotic proteins, extracellular matrix proteins, and pro-inflammatory cytokines that involved in fibrosis, were assessed using immunocytochemistry and enzyme-linked immunosorbent assays. RESULTS: Compared to the positive control TGF-ß1 group, LBP pre-treated cells had a significantly lower expression of alpha-smooth muscle actin, marker of myofibroblasts, vimentin (p < 0.05), and also extracellular matrix proteins both collagen type II and type III (p < 0.05) that can be found in scar tissues. Moreover, LBP pre-treated cells had a significantly lower secretion of pro-inflammatory cytokines interleukin-6 and interleukin-8 (p < 0.05). The cell-laden hydrogel contraction and stiffness showed no significant difference between LBP pre-treatment and control groups. Fibroblasts pretreated with LBP as well had reduced angiogenic factors expression and suppression of undesired proliferation (p < 0.05). CONCLUSION: Our results showed that LBP reduced both pro-fibrotic proteins and pro-inflammatory cytokines on corneal injury in vitro. We suggest that LBP, as a natural Traditional Chinese Medicine, may potentially be a novel topical pre-treatment option prior to corneal refractive surgeries with an improved prognosis.

Diffuse Lamellar Keratitis in a Patient Undergoing Collagen Corneal Cross-Linking 18 Years After Laser In Situ Keratomileusis Surgery.

PURPOSE: To report a case of diffuse lamellar keratitis (DLK) after corneal collagen cross-linking in an eye with a remote history of laser in situ keratomileusis (LASIK) surgery. METHODS: This is a case report and literature review. RESULTS: This report describes the development of unilateral stage IV DLK in a patient who underwent bilateral corneal cross-linking for corneal ectasia 18 years after LASIK surgery. The patient was treated with high-dose topical steroids that were tapered over 1 month and multiple flap lifts. The ultimate best-corrected visual outcome was 20/60. CONCLUSIONS: DLK is a potential sight-threatening complication of refractive surgery that can occur at any time in the postoperative period, even years after the procedure. Undergoing a subsequent corneal procedure that may disrupt or promote inflammation within the surgical flap-stromal interface, such as corneal collagen cross-linking, is a recognized risk factor for the development of DLK. This case suggests that patients with any history of LASIK surgery undergoing corneal cross-linking or other lamellar corneal surgeries may benefit from closer follow-up (eg, daily) than patients with no history of LASIK.

L-carnitine suppresses transient receptor potential vanilloid type 1 activity and myofibroblast transdifferentiation in human corneal keratocytes.

Corneal stromal wound healing is a well-balanced process promoted by overlapping phases including keratocyte proliferation, inflammatory-related events, and tissue remodeling. L-carnitine as a natural antioxidant has shown potential to reduce stromal fibrosis, yet the underlying pathway is still unknown. Since transient receptor potential vanilloid 1 (TRPV1) is a potential drug target for improving the outcome of inflammatory/fibrogenic wound healing, we investigated if L-carnitine can mediate inhibition of the fibrotic response through suppression of TRPV1 activation in human corneal keratocytes (HCK). We determined TRPV1-induced intracellular calcium transients using fluorescence calcium imaging, channel currents by planar patch-clamping, and cell migration by scratch assay for wound healing. The potential L-carnitine effect on TRPV1-induced myofibroblast transdifferentiation was evaluated by immunocytochemical detection of alpha smooth muscle actin. RT-PCR analysis confirmed TRPV1 mRNA expression in HCK. L-carnitine (1 mmol/l) inhibited either capsaicin (CAP) (10 µmol/l), hypertonic stress (450 mOsmol/l), or thermal increase (>43 °C) induced Ca2+ transients and corresponding increases in TRPV1-induced inward and outward whole-cell currents. This was accompanied by suppression of injury-induced increases in myofibroblast transdifferentiation and cell migration. In conclusion, L-carnitine contributes to inhibit stromal scarring through suppressing an injury-induced intrinsic TRPV1 activity that is linked with induction of myofibroblast transdifferentiation in HCK cells.

Therapeutic Effect of Corneal Crosslinking on Fungal Keratitis: Efficacy of Corneal Collagen Crosslinking as an Adjuvant Therapy for Fungal Keratitis in a Tertiary Eye Hospital in South India.

PURPOSE: To evaluate the efficacy of CXL in treating fungal keratitis as an adjuvant therapy. METHODS: Detailed clinical examination microbiological investigation was performed. Twenty fungal keratitis patients were recruited and randomized into two groups: group 1 (n= 11, standard antifungal), group 2 (n=9, corneal collagen crosslinking with standard antifungal). Corneal scraping and tear samples collected were subjected to real-time PCR targeting ITS, TLR analysis and cytokine analysis. RESULTS: The mean time for complete resolution of ulcer for group 2 was significantly shorter compared to group 1 and the final mean BCVA was better for group 2. Expression of IL-1ß, IL-8, IFN-γ significantly decreased immediately post CXL in group 2 patients. Significant downregulation of TLR 6, TLR-3, TLR-4 was observed 3-days post CXL compared to group 1 patients. CONCLUSION: Adjuvant effect of CXL was significant in treating fungal keratitis compared to standalone antifungal treatment.

Cross-Linking Assisted Infection Reduction (CLAIR): A Randomized Clinical Trial Evaluating the Effect of Adjuvant Cross-Linking on Bacterial Keratitis.

PURPOSE: To determine whether there is a benefit to adjuvant corneal cross-linking (CXL) for bacterial keratitis. METHODS: This is an outcome-masked, randomized controlled clinical trial. Consecutive patients presenting with a smear-positive bacterial ulcer at Aravind Eye Hospitals at Madurai, Pondicherry, and Coimbatore in India were enrolled. Study eyes were randomized to topical moxifloxacin 0.5% or topical moxifloxacin 0.5% plus CXL. The primary outcome of the trial was microbiological cure at 24 hours on repeat culture. Secondary outcomes included best spectacle corrected visual acuity at 3 weeks and 3 months, percentage of study participants with epithelial healing at 3 weeks and 3 months, infiltrate and/or scar size at 3 weeks and 3 months, 3-day smear and culture, and adverse events. RESULTS: Those randomized to CXL had 0.60 decreased odds of culture positivity at 24 hours (95% confidence interval [CI]: 0.10-3.50; P = 0.65), 0.9 logarithm of the minimum angle of resolution lines worse visual acuity (95% CI: -2.8 to 4.6; P = 0.63), and 0.41-mm larger scar size (95% CI: -0.48 to 1.30; P = 0.38) at 3 months. We note fewer corneal perforations or need for therapeutic penetrating keratoplasty in the CXL group. CONCLUSIONS: We were unable to confirm a benefit to adjuvant CXL in the primary treatment of moderate bacterial keratitis. However, CXL may reduce culture positivity and complication rates; therefore, a larger trial to fully evaluate this is warranted. TRIAL REGISTRATION: NCT02570321.

Cellular and molecular assessment of rose bengal photodynamic antimicrobial therapy on keratocytes, corneal endothelium and limbal stem cell niche.

Rose Bengal Photodynamic Antimicrobial Therapy (RB-PDAT) is a novel potential treatment for progressive infectious keratitis. The principle behind this therapy is using Rose Bengal as a photosensitizer that can be activated by green light and results in the production of oxygen free radicals which in turn eradicate the microorganism. Given RB-PDAT's mechanism of action and the potential cytotoxic effects, concerns regarding the safety of this technique have arisen. The purpose of this study was to evaluate the effect of RB-PDAT on keratocytes, while focusing on the safety profile that the photo-chemical reaction has on the limbal stem cell (LSC) niche and endothelial cell layer of the treated cornea. To perform RB-PDAT, Rose Bengal solution (0.1% RB in BSS) was applied to the right cornea of rabbits for 30 min and then irradiated by a custom-made green LED light source (525 nm, 6 mW/cm2) for 15 min (5.4 J/cm2). Three rabbits were sacrificed and enucleated after 24 h for evaluation. TUNEL assay and immunohistochemistry for endothelium and limbal stem cell viability were performed on whole mounts and frozen sections in treated and control eyes. LSC of both eyes were isolated and cultured to perform MTT viability and proliferation, and scratch wound healing assays under time-lapse microscopy. Interestingly, while Rose Bengal dye penetration was superficial, yet associated cellular apoptosis was evidenced in up to 1/3 of the stromal thickness on frozen sections. TUNEL assay on whole mounts showed no endothelial cell death following treatment. Immunohistochemistry on frozen sections of LSC displayed no structural difference between treated and non-treated eyes. There was no difference in LSC proliferation rates and scratch wound healing assay demonstrated adequate cell migration from treated and non-treated eyes. The current study suggests that even though penetration of the RB dye has been shown to be limited, oxidative stress produced by RB-PDAT can reach deeper into the corneal stroma. Nevertheless, our results show that performing RB-PDAT is safe on the corneal endothelium and has no effect on LSC viability or function.

Ocular chemical burns from accidental exposure to topical dermatological medicinal agent.

We report a case of accidental ocular chemical injury by self-medication with a single application of a topical ayurvedic medication containing salicylic acid, phenol, and tincture iodine, which is being used in developing countries for treatment of various dermatological conditions.

Interface Bonding With Corneal Crosslinking (CXL) After LASIK Ex Vivo.

Purpose: Interface bonding with corneal crosslinking (CXL) after LASIK using two different photosensitizers was studied ex vivo. Methods: A LASIK flap was created in enucleated rabbit eyes using a femtosecond laser. After the dissection, CXL was performed to seal the interface. In one group interface CXL was performed using rose bengal and green light, whereas in a second group riboflavin and UV-A light was used. In both groups irradiance, radiant exposure, dye concentration, and imbibition time was varied. In a control group, LASIK only was performed. After the procedures, the maximal shear-force required to separate the flap from the stroma was measured. Additionally, corneal transmission spectra were recorded. Results: Optimized parameters for rose bengal/green-light bonding lead to a 2.1-fold increase in shear-force compared with untreated control eyes (P < 0.01). The optimal parameter combination was: irradiance of 180 mW/cm2 for 14 minutes (total radiant exposure 150 J/cm2), rose bengal concentration 0.1%, and an imbibition time of 2 minutes. Optimized riboflavin/UV-A light parameters were 0.5% for 2 minutes with a radiant exposure of 8.1 J/cm2 obtained by an irradiance of 30 mW/cm2 for 4.5 minutes. These optimized parameters lead to a 2-fold increase compared with untreated control eyes (P < 0.01). Optical transmission experiments suggest safety for more posterior structures. Conclusions: Based on ex-vivo results, interface bonding after LASIK using crosslinking with either rose bengal or riboflavin increases the adhesion between flap and stromal bed. In vivo trials are needed to evaluate the temporal evolution of the effect.

The Effect of Ascorbic Acid (Vitamin C) on Transepithelial Corneal Cross-Linking in Rabbits.

PURPOSE: To evaluate the effects of ascorbic acid (vitamin C), the main antioxidant agent in the cornea on transepithelial corneal cross-linking (CXL) where the main mechanism is oxidation. METHODS: Twenty eyes of 20 rabbits were divided into 3 groups: Group 1 (7 eyes) had transepithelial corneal CXL after being fed with normal diet; Group 2 (7 eyes) had corneal CXL after once-daily subcutaneous injections of 200 mg of ascorbic acid in addition to normal diet; and the control group (6 eyes) was fed with normal diet but did not have corneal CXL performed. Ascorbic acid levels were measured in aqueous humor and plasma, and biomechanical measurements were applied to the cornea. RESULTS: There was a significant difference in ascorbic acid levels of plasma (P = 0.008) and aqueous humor (P = 0.006) between group 1 and 2. The Young's modulus values of group 1 and 2 were similar (P = 0.741) and were significantly higher than the control group (P = 0.02 and P = 0.01). The increase rate in Young's modulus values was 37.3% in group 1 and 43.9% in group 2 compared to control group. The ultimate strain values in group 1 and 2 were similar (P = 0.632) and were significantly higher than control group (P = 0.04, P = 0.03). The ultimate stress values in group 1 and 2 were similar (P = 0.836) and were significantly lower than control group (P = 0.001, P = 0.001). CONCLUSIONS: Systemic vitamin C does not appear to decrease effectiveness of transepithelial corneal CXL. Therefore, there is no reason to stop or reduce vitamin C supplementation before corneal CXL therapy.

Antiviral Activity of a Cloned Peptide RC28 Isolated from the Higher Basidiomycetes Mushroom Rozites caperata in a Mouse Model of HSV-1 Keratitis.

An Escherichia coli-expressed peptide with a molecular weight of 28.26, derived from the complementary DNA of antiviral protein RC28 isolated from the mushroom Rozites caperata (=Cortinarius caperatus), demonstrated potent antiviral activity against herpes simplex virus-1 in Vero cells and in a herpes simplex virus-1 mouse keratitis model. Plaque assays in Vero cells showed that the peptide reduced viral yields by at least 1.2 logs; in the animal model the cloned peptide delayed the occurrence of stromal keratitis and alleviated the severity of the disease. We believe this is the first report of a cloned mushroom peptide with antiviral activity for the prevention and treatment of a viral disease.

Beneficial effect of the antioxidant riboflavin on gene expression of extracellular matrix elements, antioxidants and oxidases in keratoconic stromal cells.

BACKGROUND: Keratoconus manifests as a conical protrusion of the cornea and is characterised by stromal thinning. This causes debilitating visual impairment which may necessitate corneal transplantation. Therapeutic targets related to disease mechanisms are currently lacking, as the pathobiology remains unclear. Many pathological features may be manifestations of defects in wound healing and reactive oxygen species (ROS)-associated functions. In a wide range of tissue and cell types, antioxidant exposure has beneficial effects on both of these pathways. This study investigated the effect of treatment with the antioxidant riboflavin on wound healing and ROS-associated functions in keratoconus. METHODS: Stromal cells were isolated from human central keratoconic (n = 3) and normal (n = 3) corneas. Total RNA was extracted and reverse-transcribed into complementary DNA. The gene expression of 22 genes involved in repair (eight normal and four repair-type extracellular matrix constituents) and ROS-associated processes (eight antioxidants and two ROS-synthesising oxidases) was quantified using quantitative polymerase chain reaction. This was also performed on keratoconic stromal cells treated in vitro with riboflavin (n = 3). RESULTS: In stromal cells from untreated keratoconic corneas (compared with untreated normal corneas), there was an up-regulation of 7/12 extracellular matrix elements. Four of eight antioxidants and two of two oxidases were also increased. In treated keratoconic corneas (compared with untreated keratoconic corneas), six out of eight normal extracellular matrix constituents were up-regulated and two of four repair-type molecules were reduced. An increase was also observed in seven out of eight antioxidants and there was a diminution in two out of two oxidases. CONCLUSION: Riboflavin encourages the synthesis of a normal extracellular matrix and reduces reactive oxygen species levels in keratoconus. This supports the occurrence of wound healing and ROS-associated abnormalities in keratoconus. By targeting the causative disease mechanisms, riboflavin may have therapeutic potential in the clinical management of keratoconus.

The effects of retinoic acid on human corneal stromal keratocytes cultured in vitro under serum-free conditions.

PURPOSE: Retinoic acid (RA) is a metabolite of vitamin A that plays a fundamental role in the development and function of the human eye. The purpose of this study was to investigate the effects of RA on the phenotype of corneal stromal keratocytes maintained in vitro for extended periods under serum-free conditions. METHODS: Keratocytes isolated from human corneas were cultured up to 21 days in serum-free media supplemented with RA or DMSO vehicle. The effects of RA and of its removal after treatment on cell proliferation and morphology were evaluated. In addition, the expression of keratocyte markers was quantified at the transcriptional and protein levels by quantitative PCR and immunoblotting or ELISA, respectively. Furthermore, the effects of RA on keratocyte migration were tested using scratch assays. RESULTS: Keratocytes cultured with RA up to 10 × 10(-6) M showed enhanced proliferation and stratification, and reduced mobility. RA also promoted the expression of keratocyte-characteristic proteoglycans, such as keratocan, lumican, and decorin, and increased the amounts of collagen type-I in culture while significantly reducing the expression of matrix metalloproteases 1, 3, and 9. RA effects were reversible, and cell phenotype reverted to that of control after removal of RA from media. CONCLUSIONS: Retinoic acid was shown to control the phenotype of human corneal keratocytes cultured in vitro by regulating cell behavior and extracellular matrix composition. These findings contribute to our understanding of corneal stromal biology in health and disease, and may prove useful in optimizing keratocyte cultures for applications in tissue engineering, cell biology, and medicine.

Stiffening of rabbit corneas by the bacteriochlorophyll derivative WST11 using near infrared light.

PURPOSE: We evaluated the efficacy and safety of photochemical corneal stiffening by palladium bacteriochlorin 13'-(2-sulfoethyl)amide dipotassium salt (WST11) and near infrared (NIR) illumination, using ex vivo and in vivo rabbit eye models. METHODS: Corneas of post mortem rabbits and living rabbits were pretreated topically with 2.5 mg/mL WST11 in saline or in 20% dextran T-500 (WST-D), washed and illuminated with an NIR diode laser (755 nm, 10 mW/cm(2). Studies with corneas of untreated fellow eyes served as controls. Tensile strength measurements, histopathology, electron spin resonance, and optical spectroscopy and fluorescence microscopy were used to assess treatment effects. Comparative studies were performed with standard riboflavin/ultraviolet-A light (UVA) treatment. RESULTS: WST11/NIR treatment significantly increased corneal stiffness following ex vivo or in vivo treatment, compared to untreated contralateral eyes. The incremental ultimate stress and Young's modulus of treated corneas increased by 45, 113, 115%, and 10, 79, and 174% following 10, 20, and 30 minutes of incubation with WST11, respectively. WST-D/NIR had a similar stiffening effect, but markedly reduced post-treatment edema and shorter time of epithelial healing. WST11/NIR and WST-D/NIR generate hydroxyl and superoxide radicals, but no singlet oxygen in the cornea. Histology demonstrated a reduction in the keratocyte population in the anterior half of the corneal stroma, without damage to the endothelium. CONCLUSIONS: Treatment of rabbit corneas, with either WST11/NIR or WST-D/NIR, increases their biomechanical strength through a mechanism that does not involve singlet oxygen. The WST-D/NIR treatment showed less adverse effects, demonstrating a new potential for clinical use in keratoconus and corneal ectasia after refractive surgery.

Yellow corneal ring associated with vitamin supplementation for age-related macular degeneration.

PURPOSE: To report the first described cases of peripheral yellow corneal rings secondary to vitamin supplementation for age-related macular degeneration (ARMD). DESIGN: Retrospective single-center case series. PARTICIPANTS: The eyes of 4 patients taking vitamin supplementation for ARMD were examined at the University of Pittsburgh Medical Center Department of Ophthalmology between January 2010 and April 2011. METHODS: We reviewed the medical records of 4 patients with peripheral corneal rings receiving vitamin supplementation for ARMD. MAIN OUTCOME MEASURES: The presence of peripheral yellow corneal rings, skin findings, and serum carotene levels. RESULTS: Each patient had circumferential, yellow, peripheral corneal rings and exhibited subtle yellowing of the skin most notable on the palms. Serum carotene levels were normal in 2 of the 3 patients and markedly elevated in the last patient in whom it was measured. CONCLUSIONS: It is unclear at this time how to counsel patients with this ocular finding. We suspect that these rings are more common than generally appreciated because they may have a subtle appearance or be misdiagnosed as arcus senilis. We suggest that a formal study be performed on a cohort of patients taking vitamin supplementation for macular degeneration that specifically screens for yellow rings and measures serum carotene levels when they are identified.

Inadvertent intracorneal injection of local anesthetic during lid surgery.

PURPOSE: To report a case of inadvertent intracorneal injection of anesthetic agents during lid anesthesia and corneal penetration without full-thickness perforation. METHOD: Case report. RESULTS: Corneal edema with acute loss of vision was noted. The patient was treated with topical, antibiotic, cycloplegic, hyperosmotic agent and lubricant. While the edema slowly subsided, a loss in endothelial cell count was noted. CONCLUSIONS: The effects of intracorneal injection of lignocaine, bupivacaine, and its preservatives have not previously been reported in the literature. A lower postinjection endothelial cell count and associated clinical features in our case indicate that endothelial toxicity occurred. This potential complication should be kept in mind with necessary precautions taken during injection of the eyelid, particularly in cases with preexisting lid laxity.

Ultra B2 - Promoção de ligações covalentes do colágeno corneal (Corneal cross-linking) no tratamento de ceratocone: resultados preliminares / Corneal Cross-linking for the treatment of keratoconus: preliminary results

OBJETIVO: Apresentar os resultados visuais e ceratométricos, seis meses após tratamento foto-terapêutico com luz ultravioleta (UV) e vitamina B2 (Ultra B2), em pacientes com ceratocone progressivo. MÉTODOS: Vinte e cinco olhos de 20 pacientes (15 homens e 5 mulheres) com ceratocone progressivo, determinado pelo aumento de curvatura em exames seriados de topografia corneal, nos últimos seis meses foram avaliados. Acuidade visual não corrigida (UVA), acuidade visual melhor corrigida com óculos (BSCVA), equivalente esférico (SEQ), cilindro refrativo manifesto e a curvatura máxima (max K) pré e pós-operatórios (1, 3 e 6 meses) foram determinadas. Todos os pacientes foram submetidos ao tratamento Ultra B2 usando riboflavina (vitamina B2) e a luz ultravioleta (UV, 370 nm). O epitélio corneal foi removido após assepsia, colocação de blefarostato e anestesia tópica com proparacaína, por meio de solução de álcool hidratado (20 por cento) utilizada por 30 segundos. A córnea foi saturada com vitamina B2 por 15 minutos; em seguida, foi irradiada por luz UV por 30 minutos. Ao final do procedimento, foi colocada lente de contato terapêutica (LCT), mantida até a epitelização total. RESULTADOS: Houve melhora na UVA após o primeiro mês (de 0,15 ± 0,15 para 0,23 ± 0,20), com contínua mudança no terceiro e sexto mês pós-operatório, atingindo a diferença estatisticamente significante nesse período (p=0,025 e p=0,037 respectivamente). BSCVA melhorou de 0,41 ± 0,27 para 0,49 ± 0,29 no sexto mês, sem atingir a diferença estatisticamente significante. A progressão do ceratocone após o procedimento não foi notada em nenhum paciente, em comparação com o avanço topográfico nos 6 meses precedentes. Após 6 meses do procedimento, max K diminuiu em mais que 2,00 D (de 53,02 ± 8,42 para 50,88 ± 6,05 D), SEQ em menos que 1 D (de -3,27 ± 4,08 para -2,68 ± 3,02 D) e o cilindro refrativo em menos que 0,5 D (de -2,29 ± 1,77 para -1,86 ± 0,92), sem atingir diferença estatisticamente...

PURPOSE: To present early visual and keratometric results for corneal cross-linking with riboflavin and UV irradiation in patients with progressive keratoconus. METHODS: Twenty-five eyes of twenty patients (15 males and 5 females) with a progressive keratoconus in the previous 6 months were followed. Unaided visual acuity (UVA), best spectacle corrected visual acuity (BSCVA), spherical equivalent (SEQ), manifest cylinder, and maximal corneal curvature (max K) values were followed at 1, 3 and 6 months. All patients were submitted to corneal cross-linking using riboflavin (vitamin B2) as the photosensitizer and ultraviolet light (UV, wavelength 370 nm). Epithelium was removed with 20 percent alcohol, cornea was soaked with vitamin B2 for 15 min, and then irradiated with UV light for 30 min, after which a bandage contact lens (BCL) was placed. RESULTS: UVA increased after one month (from 0.15 ± 0.15 to 0.23 ± 0.20), and went on increasing at 3 and 6 months, reaching statistical significance (p=0.025 e p=0.037, respectively). BSCVA increased from 0.41 ± 0.27 to 0.49 ± 0.29 at month six, without reaching statistical significance at any time point. Progression of keratoconus stopped in all patients, in contrast with progression in all of them in the six-month period prior to the surgery. Max K decreased by more than 2 D (from 53.02 ± 8.42 to 50.88 ± 6.05 D), SEQ less that 1 D (from -3.27 ± 4.08 to -2.68 ± 3.02 D), while refractive cylinder decreased less than 0.5 D (from -2.29 ± 1.77 to -1.86 ± 0.92 D), without reaching a statistically significant difference. None of the eyes lost any line of BSCVA, 12 maintained the preoperative BSCVA, 7 gained one line, 5 gained two lines, and 1 patient gained three lines of BSCVA. CONCLUSIONS: Corneal cross-linking with riboflavin and UV light seems to be a safe (no loss of BSCVA) and effective (anatomical and optical properties maintained) procedure, which has shown to stop the progression of the keratoconus...

Topical interleukin-1 receptor antagonist inhibits inflammatory cell infiltration into the cornea.

Interleukin (IL)-1alpha and beta are important modulators of many functions of corneal epithelial and stromal cells that occur following injury to the cornea, including the influx of bone marrow-derived inflammatory cells into the stroma attracted by chemokines released from the stroma and epithelium. In this study, we examined the effect of topical soluble IL-1 receptor antagonist on bone marrow-derived cell influx following corneal epithelial scrape injury in a mouse model. C57BL/6 mice underwent corneal epithelial scrape followed by application of IL-1 receptor antagonist (Amgen, Thousand Oaks, CA) at a concentration of 20 mg/ml or vehicle for 24 h prior to immunocytochemical detection of marker CD11b-positive cells into the stroma. In two experiments, topical IL-1 receptor antagonist had a marked effect in blocking cell influx. For example, in experiment 1, topical IL-1 receptor antagonist markedly reduced detectible CD11b-positive cells into the corneal stroma at 24h after epithelial injury compared with the vehicle control (3.5+/-0.5 (standard error of the mean) cells/400x field and 13.9+/-1.2 cells/400x field, respectively, p<0.01). A second experiment with a different observer performing cell counting had the same result. Thus, the data demonstrate conclusively that topical IL-1 receptor antagonist markedly down-regulates CD-11b-positive monocytic cell appearance in the corneal stroma. Topical IL-1 receptor antagonist could be an effective adjuvant for clinical treatment of corneal conditions in which unwanted inflammation has a role in the pathophysiology of the disorder.

Corneal endothelial safety of intracameral preservative-free 1% xylocaine.

PURPOSE: To evaluate the effect of intracameral preservative-free 1% xylocaine on the corneal endothelium as an adjuvant to topical anaesthesia during phacoemulsification and Acrysof foldable IOL implantation. MATERIAL & METHODS: This is a prospective, controlled, randomised, double-masked study. 106 patients with soft to moderately dense (Grade 1-3) senile cataract and corneal endothelial cell density of >1500/mm2 were randomised to the xylocaine group (n=53) and control group(n=53). Central endothelial specular microscopy and ultrasound corneal pachymetry were performed preoperatively. On the first postoperative day the eyes were evaluated for corneal oedema and Descemet's folds. Ultrasound corneal pachymetry was performed at 1, 3 and 12 months. Specular microscopy was performed at 3 and 12 months. Cell loss was expressed as a percentage of preoperative cell density. Six patients could not complete one year follow-up. Chi-square and paired t test (2 tail) statistical tests were applied for analysis. RESULTS: Four (7.54%) patients in the xylocaine group and 5 (9.43%) in the control group had a few Descemet's folds associated with mild central stromal oedema. Corneal thickness increased from 549.3micro +/- 37.2micro to 555.5micro +/- 36.5micro in the xylocaine group and from 553.1micro +/- 36.2micro to 559.3micro +/- 40.5micro in the control group at the one-month postoperative visit. Thickness returned to the preoperative level in xylocaine group 549.6micro +/- 34.5micro and control group 554.7micro +/- 41.1micro at three months. (P=0.484) The percentage of cell loss was 4.47 +/- 2.53% in the xylocaine group and 4.49 +/- 3.09% in the control group at one year. (P=0.97) CONCLUSION: Intracameral preservative-free 1% xylocaine does not appear to affect corneal endothelium adversely during phacoemulsification.

In vivo antiviral efficacy of a dipeptide acyclovir prodrug, val-val-acyclovir, against HSV-1 epithelial and stromal keratitis in the rabbit eye model.

PURPOSE: A dipeptide prodrug of the antiviral nucleoside acyclovir (ACV), val-val-ACV (VVACV), was evaluated in vivo as a potential drug candidate for improving antiviral efficacy against herpetic epithelial and stromal keratitis. METHODS: The effect of 1% VVACV on epithelial keratitis induced by inoculation of HSV-1 strain McKrae (25 microL of 10(5) plaque-forming units [PFU]) in the scarified rabbit cornea and stromal keratitis induced by intrastromal injection of HSV-1 strain RE (10 microL of 10(5) PFU) was compared with that of 1% trifluorothymidine (TFT) and balanced salt solution as the vehicle control. Both eyes of 10 rabbits were used in each treatment group. Lesions were evaluated by slit lamp examinations over a 2-week period after infection. Aqueous humor samples and corneas were analyzed for drug concentrations at the end of each experiment. Cytotoxicity of VVACV in comparison with val-acyclovir (VACV), ACV, and TFT was evaluated in cellular proliferation assays. RESULTS: The dipeptide prodrug VVACV demonstrated excellent activity against HSV-1 in the rabbit epithelial and stromal keratitis models: 1% VVACV was as effective as 1% TFT. The prodrug was also less cytotoxic than TFT, which is the only effective drug currently licensed and routinely used for topical treatment of ocular herpes infections in the United States. CONCLUSIONS: The less cytotoxic and highly water-soluble prodrug VVACV, which showed excellent in vivo activity against HSV-1 in rabbit epithelial and stromal keratitis, is a promising drug candidate for treatment of ocular HSV infections.