Cold-stored mulberry leaves affect antioxidant system and silk proteins of silkworm (Bombyx mori) larva.

BACKGROUND: Cold storage has been widely used to maintain the quality of vegetables, but whether eating cold-stored vegetables affects health remains unknown. RESULTS: This study used silkworms as an animal model to evaluate the effects of nutrient changes in cold-stored mulberry leaves (CSML) on health. Compared with fresh mulberry leaves (FML), CSML contained lower vitamin C, soluble sugars and proteins, and higher H2 O2 , suggesting decreased antioxidant ability and nutrition. The CSML did not obviously affect larval survival rate, body weight or dry matter rate, cocoon shape, weight and size, or final rates of cluster and cocooning relative to the FML, suggesting CSML did not alter overall growth and development. However, the CSML increased the initial rates of cluster and cocooning and upregulated BmRpd3, suggesting CSML shortened larval lifespan and enhanced senescence. CSML upregulated BmNOX4, downregulated BmCAT, BmSOD and BmGSH-Px and increased H2 O2 in silkworms, suggesting CSML caused oxidative stress. CSML upregulated ecdysone biosynthesis and inactivation genes and elevated ecdysone concentration in silkworms, suggesting that CSML affected hormone homeostasis. CSML upregulated apoptosis-related genes, downregulated sericin and silk fibroin genes and decreased sericin content rate in silkworms, suggesting oxidative stress and protein deficiency. CONCLUSION: Cold storage reduced nutrition and antioxidant capability of mulberry leaves. CSML did not influence growth and development of silkworm larva, but affected health by causing oxidative stress and reducing protein synthesis. The findings show that the ingredient changes in CSML had negative effects on health of silkworms. © 2023 Society of Chemical Industry.

Comparison of the Effects of 0.1% Fluorometholone and 1% Prednisolone on Intraocular Pressure and Schirmer Tear Test in Equine Eye.

This research was performed to compare the effects of prednisolone and fluorometholone on intraocular pressure (IOP) and Schirmer tear test (STT) in the normal equine eye. Sixteen normal mares aged between 6 and 10 years were used for this study. Horses were randomly assigned to two groups. Eight horses in the first group received 0.2 mL of topical 1% prednisolone in one eye and the contralateral eye was used as control (0.2 mL of saline was instilled). The second group received 0.2 mL of 0.1% fluorometholone in a randomly selected eye and the contralateral eye served as control and received 0.2 mL of saline. STT values and IOP were determined using STT strips and rebound, respectively, at the baseline, and 30-, 60-, 90-, and 180-minutes post eyedrop instillation. Mean (SD) IOPs at the baseline in the treated eyes of the first and second groups were 28.5 (5.4) and 27.5 (4.9) mm Hg, respectively. STT values at the baseline in the treated eyes of the first and second groups were 26.0 (1.8) mm/min and 24.0 (4.0) mm/min, respectively. Neither prednisolone nor fluorometholone caused significant changes in the IOP during 3 hours of monitoring (P > .05). There were no significant differences in the mean levels of STT in the control and treatment eyes, either between groups or within each group (P > .05). In conclusion, one dose (0.2 mL) of 1% prednisolone or 0.1% fluorometholone after 3 hours did not alter the IOP and STT in healthy horses. Further research for a longer period on normal horses and horses with uveitis is warranted.

Protective Effect of Flavonoids from Mulberry Leaf on AAPH-Induced Oxidative Damage in Sheep Erythrocytes.

To evaluate the antioxidant activity of flavonoids extracted from Chinese herb mulberry leaves (ML), flavonoids from mulberry leaves (FML) were extracted and purified by using ultrasonic-assisted enzymatic extraction and D101 macroporous resin. Using LC-MS/MS-Liquid Chromatography with tandem mass spectrometry analysis, hesperidin, rutoside, hyperoside, cyanidin-3-o-glucoside, myricitrin, cyanidin, and quercetin were identified, and NMR and UV were consistent with the verification of IR flavonoid characteristics. The antioxidant activity of FML has also been evaluated as well as the protective effect on 2,2 0-azobis (2-amidinopropane) dihydrochloride (AAPH)-induced oxidative stress. The results showed that FML exhibited powerful antioxidant activity. Moreover, FML showed dose-dependent protection against AAPH-induced sheep erythrocytes' oxidative hemolysis. In the enzymatic antioxidant system, pretreatment with high FML maintained the balance of SOD, CAT, and GSH-Px; in the non-enzymatic antioxidant system, the content of MDA can be effectively reduced after FML treatment. This study provides a research basis for the development of natural products from mulberry leaves.

Fluorometholone inhibits high glucose-induced cellular senescence in human retinal endothelial cells.

Diabetic retinopathy (DR) is a common diabetic complication that severely impacts the life quality of diabetic patients. Recently, cellular senescence in human retinal endothelial cells (HRECs) induced by high glucose has been linked to the pathogenesis of DR. Fluorometholone (FML) is a glucocorticoid drug applied in the treatment of inflammatory and allergic disorders of the eye. The objective of the present study is to investigate the protective function of FML on high glucose-induced cellular senescence in HRECs. The in vitro injury model was established by stimulating HRECs with 30 mm glucose. After evaluating the cytotoxicity of FML in HRECs, 0.05% and 0.1% FML were used as the optimal concentration in the entire experiment. It was found that the excessive released inflammatory factors including tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-8 (IL-8) in HRECs induced by high glucose were significantly suppressed by FML, accompanied by the inhibitory effects on the expression levels of vascular endothelial growth factor (VEGF) and tissue factor (TF). Declined telomerase activity and enhanced senescence-associated ß-galactosidase (SA-ß-gal) activity were found in high glucose-challenged HRECs, which were dramatically alleviated by FML, accompanied by the inactivation of the p53/p21 and retinoblastoma (Rb) signaling. Interestingly, FML ameliorated high glucose-induced dephosphorylation of Akt. Lastly, the protective effects of FML against high glucose-induced cellular senescence in HRECs were abolished by the co-treatment of the PI3K/Akt signaling inhibitor LY294002, suggesting the involvement of this pathway. Taken together, these data revealed that FML-inhibited high glucose-induced cellular senescence mediated by Akt in HERCs, suggesting a novel molecular mechanism of FML.

Fluorometholone modulates gene expression of ocular surface mucins.

PURPOSE: Mucins are vital to keep the ocular surface hydrated. Genes encoding for mucins contain a glucocorticoid response element. The purpose of this study was to evaluate the effect of fluorometholone, a glucocorticoid receptor agonist used in the management of dry eye, on the gene expression of conjunctival and corneal epithelial cell mucins. METHODS: Stratified cultures of human conjunctival and corneal epithelial cells were exposed to 25, 50 and 100 nM of fluorometholone alone or in presence of mifepristone, a glucocorticoid receptor antagonist. The mRNA was isolated from the cells and reverse transcribed to cDNA. The cDNA was used for quantification of gene expression of mucin (MUC) 1, 4, 16 and 19 using real-time PCR. RESULTS: Fluorometholone caused a dose- and time-dependent increase in the gene expression of MUC1, MUC4, MUC16 and MUC19 in the conjunctival as well as corneal epithelial cells. Mifepristone, a glucocorticoid receptor antagonist, inhibited fluorometholone-mediated increase in the gene expression of conjunctival and corneal mucins. At the tested concentration, neither fluorometholone nor mifepristone caused any notable changes in the cellular phenotype or viability of conjunctival and corneal epithelial cells. CONCLUSION: Fluorometholone increases the gene expression of MUC1, MUC4, MUC16 and MUC19 in the conjunctival and corneal epithelial cells through activation of glucocorticoid receptors. The increased expression of mucins can be an additional possible mechanism contributing to the beneficial effects of fluorometholone in dry eye in addition to its well-known anti-inflammatory effects.

Efficacy and Safety of Loteprednol 0.5% and Fluorometholone 0.1% After Strabismus Surgery in Children.

PURPOSE: To compare the effects of topical loteprednol and fluorometholone in children who underwent strabismus surgery. METHODS: This is a retrospective observational case series. A total of 60 Korean children who underwent strabismus surgery between January 2016 and September 2016 were included. Patients were prescribed topical loteprednol etabonate 0.5% or fluorometholone 0.1% until 3 weeks after surgery. Four parameters (intraocular pressure [IOP], conjunctival injection, conjunctival inflammation, and patient discomfort) were assessed every week for up to 4 weeks after surgery. Main outcome measures were comparison of parameters between the 2 groups at each following week after surgery. In addition, factors associated with clinically meaningful IOP elevation were evaluated. RESULTS: IOP was significantly elevated at the second and third postoperative week compared with baseline (P = 0.028 and 0.001) in the loteprednol group but not significantly in the fluorometholone group. The mean IOP of the loteprednol group at 1 and 3 weeks after surgery were significantly higher than that of the fluorometholone group (P = 0.032 and 0.017, respectively). Multivariate analysis revealed that age ≤8 years (odds ratio 14.52, 95% confidence interval 1.16-139.05) was associated with IOP >21 mmHg. There was no significant difference between the 2 groups in patient discomfort, conjunctival inflammation, and conjunctival injection. CONCLUSIONS: Loteprednol and fluorometholone showed similar anti-inflammatory effect after strabismus surgery in children. Loteprednol appeared to have more effect on IOP elevation than fluorometholone, especially in children ≤8 years of age. When treating young patients with loteprednol, clinicians should be aware of IOP elevation.

Development of fluorometholone-loaded PLGA nanoparticles for treatment of inflammatory disorders of anterior and posterior segments of the eye.

The main objective of this study was the development and optimization of fluorometholone-loaded PLGA nanoparticles for the treatment of inflammatory conditions of the eye. Design of experiments was used to obtain nanoparticles with the best physicochemical characteristics. The optimized nanoparticles containing 1.5 mg·mL-1 of fluorometholone showed a negative surface charge (-30 mV) and an average size below 200 nm being suitable for ocular administration. Drug-polymer interaction studies confirmed no new bonds were formed during the synthesis. Nanoparticles performance was assessed with biopharmaceutical behavior studies, ocular tolerance, anti-inflammatory efficacy and bioavailability. The biopharmaceutical behavior of the drug from nanoparticles was adjusted to hyperbola order showing a significantly greater permeation in the cornea than in the sclera. The optimized formulation had significantly greater anti-inflammatory effects than the commercial formulation. In addition, nanoparticles increased drug penetration toward the vitreous. Polymeric nanoparticles of fluorometholone could provide a suitable alternative for the treatment of inflammatory disorders of the anterior and posterior segments of the eye against of conventional topical formulations.

A Randomized Clinical Trial of Topical Diclofenac, Fluorometholone, and Dexamethasone for Control of Inflammation After Strabismus Surgery.

PURPOSE: To evaluate the comparative effects and safety of topical diclofenac sodium, fluorometholone, and dexamethasone for controlling inflammation after routine strabismus surgery. METHODS: This was a randomized clinical trial. Ninety-nine patients admitted for surgery to treat intermittent exotropia were randomly assigned to receive 1 of 3 postoperative eye drops between January 2015 and February 2016. The primary efficacy outcomes were pain and conjunctival injection. Pain score from 0 to 10 was evaluated in each patient at postoperative days 1, 2, 3, and 5, in addition to weeks 1, 2, and 4. Conjunctival injection was graded from 1 to 4 at postoperative weeks 1, 2, and 4. We also evaluated intraocular pressure (IOP), discomfort attributed to the drops, and development of any other side effects. RESULTS: Conjunctival injection grade was the lowest in the diclofenac sodium group at postoperative weeks 1 and 2 (P < 0.001 and P = 0.03). There was no significant difference in pain score among the 3 groups. Mean IOP was the highest in the dexamethasone group at postoperative weeks 1, 2, and 4 (P < 0.001, P < 0.001, and P = 0.02). Significant IOP elevation (≥10 mmHg relative to preoperative IOP) was observed in 6 patients in the dexamethasone group. There was no difference in discomfort upon administration of the drops among the 3 groups, and no other adverse events developed. CONCLUSION: Diclofenac sodium was more effective against conjunctival injection than the 2 topical corticosteroids tested, but had a similar effect on postoperative pain as them. IOP elevation developed only in the dexamethasone group.

Corticosteroids effects on LPS-induced rat inflammatory keratocyte cell model.

PURPOSE: Corticosteroids are efficient anti-inflammation treatments. However, there are still arguments on whether it should be used in keratitis. This study was to observe the effect of corticosteroids on keratocytes both in normal condition and inflammation status in vitro. METHODS: Rat keratocytes were cultured and used for examination. 10 µg/ml lipopolysaccharide (LPS) was used to establish the inflammatory keratocyte cell model, and prednisolone acetate (PA), dexamethasone (Dex) and fluorometholone (Flu) were used as corticosteroids treatments. 5 d-growth curve and cell viabilities were assayed by CCK8, and cell morphologies and migration rate were studied. TNF-α, IL-6 and IL-1ß levels were examined by ELISA. Western blotting was used to quantified type VI collagen (Col VI) and matrix metalloproteinase 9 (MMP9) expressions, and immunofluorescence staining assays of Col I and Col VI were carried out. RESULTS: In normal condition, proliferation and migration of keratocytes were slightly influenced in PA, Dex and Flu groups. The secretion of Col I and Col VI was suppressed and MMP9 expression increased in corticosteroids groups. But no significant difference was seen in TNF-α, IL-6 and IL-1ß expression levels. In inflammatory status, TNF-α, IL-6 and MMP9 levels increased in LPS group, while they significantly decreased in corticosteroids groups. Although keratocytes viabilities and migration were slightly affected in 24 h, no significant differences were seen between LPS group and corticosteroids groups in 5-d proliferation. Col I and Col VI secretion in LPS-keratocytes was maintained with corticosteroids treatments. CONCLUSIONS: Corticosteroids showed lightly effects on keratocytes proliferation and migration, but it successfully decreased TNF-α, IL-6 level and maintained the secretion of and Col I and Col VI, while suppressed the expression of MMP9 in LPS-induced keratocytes. PA was suggested to use in early stage of keratitis clinical treatment.

Glucocorticoids suppress renal cell carcinoma progression by enhancing Na,K-ATPase beta-1 subunit expression.

Glucocorticoids are commonly used as palliative or chemotherapeutic clinical agents for treatment of a variety of cancers. Although steroid treatment is beneficial, the mechanisms by which steroids improve outcome in cancer patients are not well understood. Na,K-ATPase beta-subunit isoform 1 (NaK-ß1) is a cell-cell adhesion molecule, and its expression is down-regulated in cancer cells undergoing epithelial-to mesenchymal-transition (EMT), a key event associated with cancer progression to metastatic disease. In this study, we performed high-throughput screening to identify small molecules that could up-regulate NaK-ß1 expression in cancer cells. Compounds related to the glucocorticoids were identified as drug candidates enhancing NaK-ß1 expression. Of these compounds, triamcinolone, dexamethasone, and fluorometholone were validated to increase NaK-ß1 expression at the cell surface, enhance cell-cell adhesion, attenuate motility and invasiveness and induce mesenchymal to epithelial like transition of renal cell carcinoma (RCC) cells in vitro. Treatment of NaK-ß1 knockdown cells with these drug candidates confirmed that these compounds mediate their effects through up-regulating NaK-ß1. Furthermore, we demonstrated that these compounds attenuate tumor growth in subcutaneous RCC xenografts and reduce local invasiveness in orthotopically-implanted tumors. Our results strongly indicate that the addition of glucocorticoids in the treatment of RCC may improve outcome for RCC patients by augmenting NaK-ß1 cell-cell adhesion function.

Some Anti-Inflammatory Agents Inhibit Esterase Activities of Human Carbonic Anhydrase Isoforms I and II: An In Vitro Study.

Carbonic anhydrases (CAs) are known as a drug-target enzymes. The inhibitors of the enzyme are important compounds for discovering new therapeutic agents and understanding in detail protein-drug interactions at the molecular level. For this purpose, the in vitro effects of some anti-inflammatory agents such as tenoxicam, fluorometholone acetate, and dexamethasone were investigated on esterase activity of human erythrocyte CA-I and CA-II in this study. hCA-I and hCA-II were purified by affinity chromatography with a yield of 47.25% and 87%, and a specific activity of 642.8 EU/mg proteins and 5576.9 EU/mg proteins, respectively. SDS-PAGE was performed to determine the purity of the enzymes. Inhibitory effects of the drugs on hCA-I and hCA-II were determined by spectrophotometric method. IC50 values for hCA-I and hCA-II were 0.198, 2.18, 11.7, 0.11, 17.5 and 14 µm using tenoxicam, fluorometholone acetate, and dexamethasone, respectively. For fluorometholone acetate and dexamethasone, Ki values from Lineweaver-Burk plots were obtained as 1.044 and 21.2 µm (noncompetitive) for hCA-I and 9.98 and 8.66 µm (non-competitive) for hCA-II. In conclusion, tenoxicam, fluorometholone acetate, and dexamethasone showed potent inhibitory effects on esterase activity of hCA-I and hCA-II isozymes under in vitro conditions.

Influence of glucocorticosteroids on the biomechanical properties of in-vivo rabbit cornea.

Understanding corneal biomechanical responses during long-term glucocorticosteroids administration is important in clinical practice. The purpose of this study is to investigate the biomechanical influence of fluorometholone 0.1% eye drops on rabbit cornea. Thirty-eight Japanese white rabbits were randomly divided into three groups; a fluorometholone group, a supernatant group and a blank control group. For each rabbit in fluorometholone group, one cornea was treated with fluorometholone 0.1% eye drops four times a day for 8 weeks, while corneas of rabbits in supernatant group were treated in the same frequency with supernatant fraction centrifuged from fluorometholone 0.1% eye drops. The rabbits in the blank control group were not given any treatment. At the end of the 8 week observation period, the rabbits were euthanized and the eyes immediately enucleated and prepared for inflation testing. The experimental pressure-deformation data was used to derive the stress-strain behavior of each eye using an inverse modeling procedure. Comparisons of mechanical stiffness of corneas were conducted among the three groups to determine the influence of fluorometholone. The results showed that corneal stiffness decreased as the fluorometholone administration time prolonged. Comparisons of tangent modulus indicated average stiffness reductions of 34.2% and 33.5% in the fluorometholone group compared to the supernatant and control groups, respectively, at the end of the observation period. The stiffness-reduction effect of fluorometholone on the cornea should be considered in clinical management, especially when administrating it to biomechanically weakened corneas, such as after refractive surgeries and in cases of keratoconus.

Effect of fluorometholone/tetrahydrozoline fixed combination on conjunctival autograft morphology after primary pterygium excision.

PURPOSE: To evaluate the effect of a fluorometholone/tetrahydrozoline fixed combination on conjunctival graft morphology after primary pterygium excision. METHODS: The patients who underwent pterygium excision with conjunctival autograft transplantation were randomized into three groups based on postoperative medications as the fluorometholone/tetrahydrozoline group, fluorometholone group, and dexamethasone group. Conjunctival graft thickness was measured with anterior segment optical coherence tomography. The conjunctival graft hyperemia was evaluated using a high definition external camera. RESULTS: The mean graft thickness was significantly lower in the fluorometholone/tetrahydrozoline group compared with fluorometholone and dexamethasone groups at 2 weeks (P = 0.002 and P = 0.012, resp.) and at 1 month after surgery (P = 0.003 and P = 0.013, resp.). The conjunctival hyperemia score was significantly lower in the fluorometholone/tetrahydrozoline group compared with fluorometholone and dexamethasone groups at 2 weeks (P = 0.000 and P = 0.000, resp.) and at 1 month (P = 0.039 and P = 0.040, resp.). The graft thickness and conjunctival hyperemia score were similar among the groups at 1 week and 3 months (P > 0.05). CONCLUSION: The findings of the present study revealed that treatment with the fluorometholone/tetrahydrozoline fixed combination may be helpful to decrease graft edema and to achieve better cosmetic appearance at 2 weeks and 1 month after pterygium excision.

Effect of chitosan-N-acetylcysteine conjugate in a mouse model of botulinum toxin B-induced dry eye.

OBJECTIVE: To evaluate the effect of a thiolated polymer lubricant, chitosan-N-acetylcysteine conjugate (C-NAC), in a mouse model of dry eye. METHODS: Eye drops containing 0.5% C-NAC, 0.3% C-NAC, a vehicle (control group), artificial tears, or fluorometholone were applied in a masked fashion in a mouse model of induced dry eye from 3 days to 4 weeks after botulinum toxin B injection. Corneal fluorescein staining was periodically recorded. Real-time reverse transcriptase-polymerase chain reaction and immunofluorescence staining were performed at the end of the study to evaluate inflammatory cytokine expressions. RESULTS: Mice treated with C-NAC, 0.5%, and fluorometholone showed a downward trend that was not statistically significant in corneal staining compared with the other groups. Chitosan-NAC formulations, fluorometholone, and artificial tears significantly decreased IL-1beta (interleukin 1beta), IL-10, IL-12alpha, and tumor necrosis factor alpha expression in ocular surface tissues. CONCLUSIONS: The botulinum toxin B-induced dry eye mouse model is potentially useful in evaluating new dry eye treatment. Evaluation of important molecular biomarkers suggests that C-NAC may impart some protective ocular surface properties. However, clinical data did not indicate statistically significant improvement of tear production and corneal staining in any of the groups tested. CLINICAL RELEVANCE: Topically applied C-NAC might protect the ocular surface in dry eye syndrome, as evidenced by decreased inflammatory cytokine expression.

[Characteristics of pharmacodynamics of drugs after excimer laser surgery (an experimental study)]. / Osobennosti farmakodinamiki lekarstvennykh sredstv posle éksimerlazernykh operatsii (éksperimental'noe issledovanie).

Pharmacodynamics of dexamethasone, fluoromethanol, sodium diclofenak, and tobramicin after photorefraction keratectomy (PRK) and intrastromal laser keratectomy (ILK) was studied in rabbits. Eximer laser operations modulated the barrier functions of the cornea. The highest concentrations of drugs in anterior chamber humor during the first 20 min after instillations was observed after ILK in comparison with the control (intact cornea). The highest coefficient of effective drug diffusion through the cornea was observed after PRK in comparison with ILK. The drug efficiency was higher after ILK than after PRK, which is seen from the maximum concentrations of drugs entering the cornea immediately after instillation and prolongation of the drug effect due to its decelerated diffusion through the cornea.

Relationship between the concentration of copper and iron in the aqueous humour and intraocular pressure in rabbits treated with topical steroids.

PURPOSE: To evaluate the concentration of copper and iron in the aqueous humour of steroid-treated eyes, particularly to study the concentration of these metals in relation to steroid-induced increases in intraocular pressure (IOP). METHODS: Adult rabbits of both sexes were selected in order to study the effect of steroids on the concentrations of copper and iron in the aqueous humour and on IOP. The rabbits were acclimatised for 2 weeks prior to the instillation of various drugs into the eyes. Then a steroid (dexamethasone, betamethasone or fluoromethalone) was instilled in both eyes of the rabbits, for about 1 month. Intraocular pressure was measured twice a week. When IOP was significantly increased, the animals were killed. The aqueous humour was collected and analysed for copper and iron using atomic absorption spectrophotometry coupled with graphite fumace. RESULTS: After about 30 days of steroid treatment the mean (+/- SD) IOP in dexamethasone, betamethasone and fluoromethalone treated groups was 17.5 (+/- 4.81) mmHg, 18.48 (+/- 4.5) mmHg and 21.8 (+/- 5.7) mmHg, respectively. These values were significantly higher compared to the control group where the mean IOP was 11.6 (+/- 2.2) mmHg. The concentration of copper in the aqueous humour of steroid-treated rabbits was significantly lower (P < 0.001) compared to the control group. However, the concentration of iron was not significantly different between the control and steroid treated rabbits. CONCLUSION: A greater increase in IOP was observed in the fluoromethalone-treated group compared to the dexamethasone and betamethasone-treated groups, but the difference was not significant. The lower concentrations of copper in aqueous humour in steroid-treated eyes may play an important role in the maintenance of IOP. The concentration of iron was not significantly different compared to the control group. These results may help to explain the role of these metals in the pathogenesis of open angle glaucoma.

Effects of lodoxamide, disodium cromoglycate and fluorometholone on tear leukotriene levels in vernal keratoconjunctivitis.

PURPOSE: We compared tear leukotriene B4 (LTB4) and leukotriene C4 (LTC4) levels of vernal keratoconjunctivitis (VKC) patients with those of age-matched controls and evaluated the effects of disodium cromoglycate (DCG) 2%, lodoxamide 0.1% and fluorometholone 0.1% on the tear LTB4 and LTC4 levels of the VKC patients. METHODS: Thirty VKC patients were divided into three groups and their tear LTB4 and LTC4 levels measured with an enzyme-linked immunoassay technique before and after treatment with either lodoxamide 0.1%, DCG 2% or fluorometholone 0.1%. The results were compared with the tear LTB4 and LTC4 levels of 10 healthy control subjects. During this trial period, clinical scores for signs and symptoms of VKC were also evaluated. RESULTS: In the VKC patients median tear LTB4 and LTC4 levels were 349.0 pg/ml (range 213.3-707.7 pg/ml) and 225.2 pg/ml (range 196.1-241.1 pg/ml) respectively--significantly higher than the control group (p = 0.0065 for LTB4 and p = 0.0003 for LTC4). After treatment, LTB4 levels decreased significantly in all treatment groups when compared with baseline (for the lodoxamide group, p = 0.01; for the DCG group, p = 0.008; for the fluorometholone group, p = 0.045). LTC4 levels were also significantly reduced after treatment in all three treatment groups (for the lodoxamide group, p = 0.0209; for the DCG group, p = 0.0284; for the fluorometholone group, p = 0.0109). CONCLUSIONS: Tear LTB4 and LTC4 levels are significantly higher in VKC patients than controls, which points to a possible role of lipoxygenase pathway products in the pathophysiology of ocular allergic disorders. Lodoxamide 0.1%, DCG 2% and fluorometholone 0.1% were all effective in reducing LTB4 and LTC4 levels in VKC.

Effect of diclofenac, ketorolac, and fluorometholone on arachidonic acid metabolites following excimer laser corneal surgery.

OBJECTIVE: To compare the ability of several topical anti-inflammatory agents to modulate the production of prostaglandin E2 after excimer laser ablation in rabbit cornea. METHODS: Adult New Zealand white rabbits were subjected to phototherapeutic keratectomy with a commercially available excimer laser. Prostaglandin E2 and leukotriene B4 were detected by enzyme-linked immunoassay, and leukocyte infiltration was determined histologically. RESULTS: Prostaglandin E2 and leukocyte infiltration increased in the cornea after excimer ablation. Treatment with topical fluorometholone and diclofenac sodium significantly reduced prostaglandin E2 levels. Corneas treated with diclofenac had significantly higher levels of leukocyte infiltration than those treated with ketorolac tromethamine. No changes in leukotriene B4 levels were detected in this model. CONCLUSIONS: As a group, topical anti-inflammatory medications tend to lower prostaglandin E2 levels in rabbit corneas subjected to excimer ablation, but differ in their ability to reduce polymorphonuclear leukocyte infiltration. Further work is needed in this model to understand how these drugs alter leukocyte infiltration of the remaining stromal bed.

Effect of corticosteroids on rabbits corneal keratocytes after photorefractive keratectomy.

BACKGROUND: To determine the corticosteroid effect on the activity and repopulation of keratocytes after photorefractive keratectomy (PRK). METHODS: A 193-nm excimer laser (VISX Twenty/Twenty) created a central ablation depth of 22 microns (diameter:5 nm) on 22 corneas of 16 albino rabbits. Two ablated eyes were examined 6 hours following PRK. Twelve eyes received no postoperative corticosteroids and eight were treated with topical fluoromethalone for 3 months. Corneas were examined 1, 3, 6, and 12 months after PRK by immunofluorescence and transmission electron microscopy. RESULTS: Corticosteroids reduced haze (p=0.02), but all corneas (treated or untreated) cleared 6 months after PRK. Keratocytes were absent from the anterior 100 microns of the stroma 6 hours after PRK. However, the number and activity of keratocytes were significantly greater in this area in untreated corneas at 1 month and then gradually decreased. By 6 and 12 months, the number of keratocytes approached controls. Treated corneas had fewer keratocytes than either controls or untreated eyes (p<0.01) and by 3 months, a subepithelial acellular zone of 30 to 50 microns thickness appeared and persisted until at last 12 months after PRK. CONCLUSIONS: Corticosteroids have a transient effect in reducing haze and seem to inhibit keratocyte movement, leading to an acellular subepithelial region beneath the ablated area.