Prophylaxis of endophthalmitis with topical povidone-iodine

The authors conducted an open-label nonrandomized parallel trial to examine whether the preoperative application of povidone-iodine to the ocular surface reduces the incidence of endophthalmitis after intraocular surgery. During an 11-month period, topical 5% povidone-iodine was used to prepare the conjunctiva in 1 set of 5 operating rooms, while silver protein solution was used in another set of 5 rooms. In all cases, surgeons continued to use their customary prophylactic antibiotics. A significantly lower incidence of culture-positive endophthalmitis (P less than 0.03) was observed in the operating rooms using povidone-iodine (2 of 3489 or 0.06%) compared with those using silver protein solution (11 of 4594 or 0.24%). Use of topical povidone-iodine in over 3000 cases was not associated with any adverse reactions. In a majority of the observed cases of endophthalmitis, some form of intraoperative communication with the vitreous cavity existed.

Adverse effects of topical antiglaucoma medication. II. The outcome of filtration surgery

OBJECTIVE

To determine the effect of long-term topical antiglaucoma therapy on the results of glaucoma filtration surgery and to relate any differences to the cell population profile of the conjunctiva.

METHODS

Filtration surgery was performed in 124 patients (trabeculectomy in 112 and triple procedures [trabeculectomy, cataract extraction, and intraocular lens implantation] in 12), and the outcome of these procedures was assessed after a minimum follow-up of 6 months. A conjunctival biopsy specimen was obtained at the time of surgery. The patients were divided into four groups according to the type of topical therapy administered. The duration of therapy tended to be greater for the patients treated with a greater number of medication types. The outcome of trabeculectomy was assessed in 106 of the patients.

RESULTS

In comparison with the briefly treated-primary surgery group, the success rate of trabeculectomy (90% [n = 28]) was similar to that in the group treated with beta-blockers (93% [n = 29]). The trabeculectomy success rate for patients treated with beta-blockers and miotics was significantly lower (72%, P < .01 [n = 29]), and that for the group treated with beta-blockers, miotics, and sympathomimetics was even lower (45%, P < .001, [n = 20]).

CONCLUSIONS

Various treatment regimens were associated with differential effects on the success rate of trabeculectomy. Long-term topical combination therapy was identified as a significant risk factor for failure of trabeculectomy. Preoperative conjunctival cell counts from patients whose trabeculectomies were successful were compared with those whose trabeculectomies failed. Failure was associated with significantly more pale cells (P < .01), macrophages (P < .05), and lymphocytes (P < .05) in the epithelium; fibroblasts (P < .05) and macrophages (P < .05) in the superficial substantia propria; and both macrophages and lymphocytes in the deep substantia propria (P < .01). Thus, preoperative subclinical conjunctival inflammation induced by previous topical medication was identified as a risk factor for failure of trabeculectomy.

Plasma delta-9 tetrahydrocannabinol concentrations and clinical effects after oral and intravenous administration and smoking

Delta-9-tetrahydrocannabinol (THC) was given intravenously, by smoking, and by mouth to 11 healthy subjects. Plasma profiles of THC after smoking and intravenous injection were similar whereas plasma levels after oral doses were low and irregular, indicating slow and erratic absorption. Based on AUC0-360 min systemic availability of THC after smoking was estimated to be 18 +/- 6%. Oral THC in a chocolate cookie provided systemic availability of 6 +/- 3%. Of the two major clinical signs of cannabis intoxication, reddened conjunctivae persisted for as long as THC levels were above 5 ng/ml, and tachycardia was a less reliable measurement of prevailing THC levels or "high." The time courses of plasma concentrations and clinical "high" were of the same order for intravenous injection and smoking, with prompt onset and steady decline over a 4-hr period. The appearance of "high" lagged behind the increase in plasma concentrations, suggesting that brain concentrations were increasing as plasma concentrations decreased. After oral THC, the onset of clinical effects was much slower and lasted longer, but effects occurred at much lower plasma concentrations than after the other two methods of administration.

Ocular surface inflammatory changes induced by topical antiglaucoma drugs: human and animal studies

OBJECTIVES

To investigate conjunctival and trabecular specimens from patients with glaucoma according to the duration and number of drugs received before filtration surgery, and to confirm, in a complementary experimental model, the role of preservative by comparing the effects of preserved and nonpreserved timolol.

STUDY DESIGN

Experimental animal and human tissue study.

PARTICIPANTS

Paired specimens of conjunctiva and trabeculum were taken from 61 patients undergoing trabeculectomy. Twenty-six patients were treated with 2 or more drugs for at least 1 year; 30 had received a beta-blocker for more than 1 year and 5 underwent primary surgery. A second study was performed in 25 rats receiving topical solutions in both eyes for 1 month.

INTERVENTION

Immunohistochemistry was performed in all biopsy specimens using 12 different monoclonal antibodies. Ocular structures from rats treated for 1 month with preserved 0.5% timolol, nonpreserved 0.5% timolol, or 0.01% benzalkonium chloride were similarly investigated in an experimental study.

MAIN OUTCOME MEASURES

Inflammatory cell infiltrates and fibroblasts were evaluated in biopsies, as well as in animal specimens, together with histologic changes induced by the drugs applied.

RESULTS

Twenty-four of 26 conjunctivae and 21 of 24 trabecular pieces from multitreated patients were found to be abnormally infiltrated by cells expressing inflammatory or fibroblastic markers or both. Nineteen of 30 conjunctivae and 9 of 22 trabeculums in the monotherapy group and only 1 of 5 specimens from the primary surgery group were abnormal. In rats, preserved timolol and benzalkonium similarly showed infiltrates together with toxic histopathologic changes as compared to the nonpreserved timolol and control groups.

CONCLUSIONS

These two combined studies confirmed histopathologic effects of antiglaucomatous drugs on the conjunctiva and showed similar effects in the trabecular meshwork. The experimental study showed that benzalkonium chloride is at least, to a large part, responsible for these toxic or immunoinflammatory effects or both on the ocular structures.

The Draize eye test

Hundreds of substances are used daily that can damage eyesight. People's eyes are open to accidental or intentional exposure during the production, transportation, use, and disposal of chemical preparations. Ensuring the safety of consumer products was born during the mid twentieth century in the aftermath of chemical warfare research, and was motivated by the hazards of unsafe cosmetics. Justified by an exigency for public protection, the Draize eye test became a governmentally endorsed method to evaluate the safety of materials meant for use in or around the eyes. The test involves a standardized protocol for instilling agents onto the cornea and conjunctiva of laboratory animals. A sum of ordinal-scale items of the outer eye gives an index of ocular morbidity. Advances in ocular toxicology are challenging the validity, precision, relevance, and need of the Draize eye test. Preclinical product-safety tests with rabbits and other mammals also raise ethical concerns of animal wellbeing. Some use the Draize test as a rallying point for how animals are treated in science and industry. A battery of cellular systems and computer models aim to reduce and ultimately to replace whole-animal testing. Molecular measures of ocular toxicity may eventually allow comprehensive screening in humans. The Draize eye test was created and refined for humanitarian reasons and has assuredly prevented harm. Its destiny is to be progressively supplanted as in vitro and clinical alternatives emerge for assessing irritancy of the ocular surface.

Hyperosmolar Saline Is a Proinflammatory Stress on the Mouse Ocular Surface

PURPOSE

To investigate whether hyperosmolar stress stimulates production of inflammatory mediators and activates the mitogen-activated protein kinase (MAPK) signaling pathways, c-jun n-terminal kinases (JNKs), extracellular-regulated kinases (ERKs), and p38 on the mouse ocular surface.

METHODS

129SvEv/CD-1 mixed mice were treated with a balanced salt solution (BSS) (305 mOsM) or a hyperosmotic saline solution (HOSS) (500 mOsM). Untreated age-matched mice were used as controls. The concentrations of interleukin 1beta (IL-1beta) and tumor necrosis factor alpha (TNF-alpha) were measured by enzyme-linked immunosorbent assay. Gelatinase activity was determined by in situ zymography. Corneal and conjunctival epithelia were lysed for Western blot with MAPK antibodies or used for semiquantitative reverse transcription and polymerase chain reaction and gene array.

RESULTS

Compared with age-matched controls and mice treated with BSS, the concentration of IL-1beta in tear fluid washings and the concentrations of IL-1beta and TNF-alpha and gelatinolytic activity in the corneal and conjunctival epithelia were significantly increased in mice treated with HOSS for 2 days. The expressions of IL-1beta, TNF-alpha, and matrix metalloproteinase 9 (MMP-9) messenger RNA by the corneal and conjunctival epithelia were also notably stimulated in mice treated with HOSS. The levels of phosphorylated JNK1/2, ERK1/2, and p38 MAPKs in the corneal and conjunctival epithelia were slightly increased in mice treated with BSS, but markedly increased in mice treated with HOSS.

CONCLUSIONS

These results show that the hyperosmolarity stimulates expression and production of IL-1beta, TNF-alpha, and MMP-9 and activates JNK, ERK, and p38 MAPK signaling pathways on the mouse ocular surface. These findings suggest that hyperosmolar stress, as it may occur in dry eye, promotes ocular surface inflammation.

Long-term morphologic effects of antiglaucoma drugs on the conjunctiva and Tenon's capsule in glaucomatous patients

Conjunctival and Tenon's capsule biopsies from two patient groups were quantitatively analyzed by light microscopy. Group A consisted of 20 patients with a primary glaucoma for whom surgery was a planned primary treatment modality. Group B was comprised of 20 patients with a primary glaucoma who had received at least two types of antiglaucoma topical medication, for a minimum of 1 year (mean, 7.7 years) before surgery. All slides were examined by two masked observers. A significant increase in the number of macrophages, lymphocytes, mast cells, and fibroblasts in the conjunctiva and Tenon's capsule and a significant decrease in the number of epithelial goblet cells were seen in the group that received long-term drop therapy. These results suggest that exhaustive medical therapy, before surgery is offered, increases the number of tissue inflammatory cells. It is possible this may enhance the risk of external bleb scarring and filtration surgery failure.

Corneal and Conjunctival Changes Caused by Commonly Used Glaucoma Medications

PURPOSE

To evaluate the extent of epithelial corneal and conjunctival changes associated with prolonged use of topical glaucoma medications.

METHODS

Thirty eyes of 15 New Zealand white rabbits were randomized to 1 of 6 treatment groups: artificial tears (Refresh Tears, carboxymethyl cellulose 0.5%) BID, brimonidine Purite 0.15% BID, bimatoprost 0.03% QD, dorzolamide 2% BID, timolol maleate 0.5% BID, or latanoprost 0.005% QD for 30 days. Corneal damage was evaluated by scanning electron microscopy and graded on a standard scale by a masked observer. Conjunctival inflammation was evaluated with light microscopy, and inflammatory cells were counted in the epithelium and superficial and deep stroma by a masked observer according to a standard protocol.

RESULTS

In the cornea, artificial tears produced significantly less damage than dorzolamide or latanoprost (P = 0.001), and brimonidine Purite produced significantly less damage than dorzolamide, timolol, or latanoprost (P = 0.001). The mean damage scores with bimatoprost were significantly lower than with dorzolamide, timolol, or latanoprost (P = 0.002). In the conjunctiva, the number of inflammatory cells in the epithelium was significantly lower in eyes treated with artificial tears or brimonidine Purite than in eyes treated with timolol or latanoprost (P = 0.042).

CONCLUSIONS

Although the adverse effects of glaucoma medications on the ocular surface are likely multifactorial, 1-month treatment with glaucoma medications containing higher levels of benzalkonium chloride (BAK) resulted in greater corneal damage and conjunctival cell infiltration than medications preserved with Purite or with lower levels of BAK. Using glaucoma medications with alternative preservatives or low levels of BAK may help preserve ocular health.

Untoward effects associated with practolol administration: oculomucocutaneous syndrome

Keratoconjunctivitis sicca, conjunctival scarring, fibrosis, metaplasia, and shrinkage developed in 27 patients as an adverse reaction to practolol. Rashes, nasal and mucosal ulceration, fibrous or plastic peritonitis, pleurisy, cochlear damage, and secretory otitis media also occurred in some cases. Three patients suffered profound visual loss though most retained good vision. Symptoms and signs improved on withdrawal of the drug, but reduction of tear secretion persisted in most patients.

Conjunctival Proinflammatory and Proapoptotic Effects of Latanoprost and Preserved and Unpreserved Timolol: An Ex Vivo and In Vitro Study

PURPOSE

To compare the toxicity of latanoprost and preserved and unpreserved timolol on conjunctival cells. Expression of inflammatory markers and MUC5AC-related mucin production were evaluated by impression cytology in a case-control ex vivo study. The proapoptotic effect of the same drugs was also evaluated in vitro in a conjunctival cell line and compared with that of benzalkonium chloride (BAC).

METHODS

Impression cytology (IC) specimens were obtained from a series of normal subjects and from patients with glaucoma treated for at least 1 year with latanoprost eye drops or preserved or unpreserved timolol. All groups were comparable in age and duration of treatment. Expression of HLA-DR, intercellular adhesion molecule (ICAM)-1, and mucin was evaluated in a masked manner by flow cytometry. For the in vitro study, a human conjunctiva-derived cell line was treated with 0.02% BAC-containing latanoprost or timolol, unpreserved timolol, or 0.02% BAC alone for 15 minutes, followed or not by 4 or 24 hours of cell recovery in normal medium. Cell viability and chromatin condensation were evaluated using microplate cold light cytofluorometry with the neutral red and the Hoechst 33342 tests, respectively. The Hoechst-neutral red ratio was defined for the apoptosis assay, and cytoskeleton changes were assessed by confocal microscopy.

RESULTS

No difference was found between normal eyes and those receiving unpreserved timolol. Preserved latanoprost and timolol significantly increased the inflammatory marker expression and decreased MUC5AC expression, but to a significantly higher extent in the preserved timolol group compared with latanoprost. In vitro, 0.02% BAC-containing timolol and latanoprost triggered conjunctival cell apoptosis-however, to a significantly lesser extent than did 0.02% BAC alone. Unpreserved timolol did not cause any cell toxicity.

CONCLUSIONS

These ex vivo and in vitro studies demonstrate that BAC-containing latanoprost and timolol exhibit higher proinflammatory and proapoptotic effects on conjunctival cells than does unpreserved timolol. Latanoprost caused less toxicity, however, than preserved timolol, and both drugs were less toxic than BAC alone. These results suggest a potential protective effect of the prostaglandin analogue and to a lesser extent of timolol against the toxicity of BAC in conjunctival cells.

Effects of 5-fluorouracil and mitomycin C on cultured rabbit subconjunctival fibroblasts

The authors investigated effects of two antimetabolites, 5-fluorouracil (5-FU) and mitomycin C (MMC), on proliferation and motility of cultured rabbit subconjunctival fibroblasts. Both drugs caused dose-dependent inhibition of fibroblast proliferation. These effects were reversible at lower doses (0.33 mg/l of 5-FU, 1.0 X 10(-3) mg/l of MMC) and at an early stage of treatment, but became irreversible at higher doses or after longer treatment times. The degree of growth inhibition reached a plateau after 7 days of treatment. Neither drug altered fibroblast migration in the agarose droplet motility assay or on the intra-cytoplasmic actin distribution by epifluorescent-light microscopy. These results indicate that 5-FU and MMC inhibit subconjunctival fibroblast function predominantly by their effect on cell proliferation rather than on cell motility. The clinical implications of these results may possibly support the use of a much lower total dose of subconjunctival antimetabolite than used in the 5-FU clinical trial.

Adverse effects of topical antiglaucoma medication. I. The conjunctival cell profile

OBJECTIVE

To determine the effect of various long-term topical antiglaucoma regimens on the cell population profile of the conjunctiva.

METHODS

Conjunctival biopsy specimens from 124 patients undergoing filtration surgery were assessed quantitatively by light microscopy. Preoperatively, the patients had used a drug for only a brief period (group A; n = 28), a beta-blocker alone (group B; n = 31), a beta-blocker in combination with a miotic (group C; n = 33), or a combination of beta-blocker, miotic, and sympathomimetic (group D; n = 32).

RESULTS

The conjunctiva in groups A and B was similar. Group C conjunctiva differed, but the changes were most marked in biopsy specimens from patients in group D, where there was a significant decrease in goblet cells (P < .05); increase in pale cells, macrophages, and lymphocytes within the epithelium (P < .001); and increase in fibroblasts (P < .001), macrophages (P < .001), mast cells (P < .05), and lymphocytes (P = .01) in the substantia propria. In addition, the effect of duration of therapy was assessed. Administration of topical medication for more than 3 years was found to increase the numbers of pale cells within the epithelium (P < .05); fibroblasts (P < .05), macrophages (P < .001), lymphocytes (P < .01), and mast cells (P = .001) within the superficial substantia propria; and the numbers of fibroblasts (P = .01) and macrophages (P < .05) within the deep substantia propria.

CONCLUSIONS

The compared treatment regimens affected the conjunctiva to different degrees, with multiple-drug topical therapy exerting the greatest effect on the degree of subclinical inflammation within the conjunctiva. The results also indicated that administration of topical medication, irrespective of type, for 3 years or more induced a significant degree of subclinical inflammation.

Prolonged localized tissue effects from 5-minute exposures to fluorouracil and mitomycin C

Rabbits undergoing full-thickness glaucoma filtering surgery were exposed for 5 minutes to one of three intraoperative treatments: (1) distilled water; (2) fluorouracil, 50 mg/mL; or (3) mitomycin C, 0.4 mg/mL. Tissue samples were taken from the subconjunctival and scleral tissues at the treated area and 90 degrees and 180 degrees from the center of the treated area and the adjacent cornea 2 mm from the limbus, 1 hour, 5 days, and 30 days postoperatively. The biopsy specimens were then placed in tissue culture media and the fibroblast outgrowths measured. Five-minute intraoperative treatments with fluorouracil resulted in a reversible delay of fibroblast outgrowths from treated subconjunctival and scleral tissues of just over 1 week in this model, whereas treatment with mitomycin C, 0.4 mg/mL, resulted in prolonged inhibition of at least 30 days. These effects were localized to the area treated. The many clinical implications of these findings are discussed.

Chitosan nanoparticles as a potential drug delivery system for the ocular surface: toxicity, uptake mechanism and in vivo tolerance

PURPOSE

To study the in vitro and in vivo interaction of chitosan nanoparticles (CSNPs), a new particulate drug carrier, with epithelial cells on the ocular surface.

METHODS

CSNPs labeled with fluorescein isothiocyanate-bovine serum albumin were produced by ionotropic gelation. Human conjunctival epithelial cells (IOBA-NHC) were exposed for 15, 30, 60, and 120 minutes to three different CSNP concentrations. Immediately after treatment and after a 24-hour recovery period in culture medium, cell survival, and viability were measured. The association of CSNPs with IOBA-NHC cells was investigated by confocal microscopy. The influence of temperature and the effect of metabolic inhibition were studied by fluorometry. The in vivo uptake and acute tolerance of the ocular surface to CSNPs were evaluated in rabbits.

RESULTS

Cell survival and viability of CSNP-exposed cells were equivalent to that of the control. Uptake of CSNPs was continuous for the 2-hour duration of these experiments and was temperature dependent. Metabolic inhibition by sodium azide had no effect on CSNP uptake. The rabbit ocular surface showed no signs of inflammation or alteration after CSNP exposure compared with the control. Fluorescence microscopy of rabbit eyeball and lid sections confirmed in vivo uptake by conjunctival and corneal epithelia.

CONCLUSIONS

CSNPs were internalized by IOBA-NHC cells by an active transport mechanism that did not compromise cell viability. Moreover, these nanoparticles were well tolerated by the ocular surface tissues. These facts add further support for the potential use of these colloidal systems to delivery drugs to the ocular surface.

Ocular surface alteration after long-term treatment with an antiglaucomatous drug

BACKGROUND

This study was undertaken to see whether long-term locally applied ocular medications produced any alterations in the ocular surface, and, in particular, whether it caused damage to the mucus layer of the tear film.

METHODS

The authors studied the ocular surface of 40 control subjects (group 1), 21 patients (group 2) chronically treated with a commercial preparation of 0.5% timolol maleate, and 20 previously untreated glaucomatous patients (group 3) in need of treatment with the same drug. Parameters studied were Schirmer's test, lacrimal meniscus height, break-up time, fluorescein and rose Bengal stains, conjunctival impression cytology, mucus staining, and the ferning test.

RESULTS

Patients in groups 2 and 3 showed a significant decrease (P less than 0.001) in the number of normal Schirmer's and break-up time tests. All had positive vital stains. Results showed a significant decrease (P less than 0.001) in goblet-cell density, mucus granules, and reticular sheets, and an increase (P less than 0.001) in pathologic crystallization patterns.

CONCLUSION

These results demonstrate that chronic application of a commercial preparation of timolol maleate damaged the ocular surface, especially the mucus layer of the tear film.

Topical omega-3 and omega-6 fatty acids for treatment of dry eye

OBJECTIVE

To study the efficacy of topical application of alpha-linolenic acid (ALA) and linoleic acid (LA) for dry eye treatment.

METHODS

Formulations containing ALA, LA, combined ALA and LA, or vehicle alone, were applied to dry eyes induced in mice. Corneal fluorescein staining and the number and maturation of corneal CD11b(+) cells were determined by a masked observer in the different treatment groups. Real-time polymerase chain reaction was used to quantify expression of inflammatory cytokines in the cornea and conjunctiva.

RESULTS

Dry eye induction significantly increased corneal fluorescein staining; CD11b(+) cell number and major histocompatibility complex Class II expression; corneal IL-1alpha and tumor necrosis factor alpha (TNF-alpha) expression; and conjunctival IL-1alpha, TNF-alpha, interferon gamma, IL-2, IL-6, and IL-10 expression. Treatment with ALA significantly decreased corneal fluorescein staining compared with both vehicle and untreated controls. Additionally, ALA treatment was associated with a significant decrease in CD11b(+) cell number, expression of corneal IL-1alpha and TNF-alpha, and conjunctival TNF-alpha.

CONCLUSIONS

Topical ALA treatment led to a significant decrease in dry eye signs and inflammatory changes at both cellular and molecular levels.

CLINICAL RELEVANCE

Topical application of ALA omega-3 fatty acid may be a novel therapy to treat the clinical signs and inflammatory changes accompanying dry eye syndrome.

Dry Eye Management: Targeting the Ocular Surface Microenvironment

Dry eye can damage the ocular surface and result in mild corneal epithelial defect to blinding corneal pannus formation and squamous metaplasia. Significant progress in the treatment of dry eye has been made in the last two decades; progressing from lubricating and hydrating the ocular surface with artificial tear to stimulating tear secretion; anti-inflammation and immune regulation. With the increase in knowledge regarding the pathophysiology of dry eye, we propose in this review the concept of ocular surface microenvironment. Various components of the microenvironment contribute to the homeostasis of ocular surface. Compromise in one or more components can result in homeostasis disruption of ocular surface leading to dry eye disease. Complete evaluation of the microenvironment component changes in dry eye patients will not only lead to appropriate diagnosis, but also guide in timely and effective clinical management. Successful treatment of dry eye should be aimed to restore the homeostasis of the ocular surface microenvironment.

A phase III study of subconjunctival human anti-transforming growth factor beta(2) monoclonal antibody (CAT-152) to prevent scarring after first-time trabeculectomy

OBJECTIVE

To evaluate CAT-152 (lerdelimumab), a monoclonal antibody to transforming growth factor-beta2 (TGF-beta2), in preventing the progression of fibrosis in patients undergoing first-time trabeculectomy for primary open-angle (POAG) or chronic angle-closure glaucoma (CACG).

DESIGN

Randomized, double-masked, multicenter, placebo-controlled trial.

PARTICIPANTS

Individuals with a diagnosis of POAG, CACG, pseudoexfoliative glaucoma (PEXG), or pigmentary glaucoma (PG), with a recorded intraocular pressure (IOP) of more than 21 mmHg, visual field or optic disc changes characteristic of glaucoma, and taking the maximum tolerated dose of medication.

INTERVENTION

Patients received unilateral trabeculectomy with either 4 subconjunctival injections of CAT-152 (100 microg in 100 microl phosphate buffer) or 4 placebo injections, administered immediately before and on completion of trabeculectomy, and on the first day and at 1 week after surgery. Patients were followed up for 12 months after surgery.

MAIN OUTCOME MEASURES

The primary outcome measure was treatment success in the study eye (unmedicated IOP of 6-16 mmHg inclusive), at the 6- and 12-month follow-up. Secondary outcome measures were the incidence of postoperative intervention with 5-fluorouracil (5-FU); incidence of surgical failure; time to surgical failure; and incidence of vascularity, microcysts, and encapsulation or demarcation of the bleb site.

RESULTS

Of the 388 patients evaluated in the trial, 81% (n = 274) had either POAG or CACG, combined into a single set (POAG/CACG) analyzed by intent-to-treat (ITT) criteria. Separate ITT analyses were carried out for all participants (+PEXG/PG group), with similar results. The treatment success rate was 60% in the CAT-152 group and 68% in the placebo group (P = 0.23). No statistically significant differences emerged in the secondary end points. Patients requiring 5-FU for postsurgical management were more likely to be treatment failures (P = 0.0003). Patients with a primary diagnosis of PG (n = 49) had a higher success rate than those with other diagnoses (P = 0.0077). Administration of CAT-152 was not associated with an increased incidence of adverse events. The immunogenicity of CAT-152 was very low.

CONCLUSIONS

At the dose level and regimen studied, there was no difference between CAT-152 and placebo in preventing the failure of primary trabeculectomy. The safety profile of CAT-152 was similar to that of placebo.

Local anaesthetic activity of beta-caryophyllene

In this work we studied the local anaesthetic activity of beta-caryophyllene, one of the main components of clove oil obtained from the dried flower-buds of Syzygium aromaticum (Myrtaceae family). We compared its activity to a chemically related compound, caryophyllene oxide. Anaesthetic activity was evaluated in vivo in the rabbit conjunctival reflex test and in vitro in a rat phrenic nerve-hemidiaphragm preparation. Beta-caryophyllene (10(-4) - 1 microg/ml), but not caryophyllene oxide, was able to reduce drastically, in a dose-dependent manner, the electrically evoked contractions of the rat phrenic hemidiaphragm. In the rabbit, conjunctival reflex test treatment with a solution of beta-caryophyllene (10-1000 microg/ml) allowed a dose-dependent increase in the number of stimuli necessary to provoke the reflex. As in the in vitro results, caryophyllene oxide was ineffective also in the in vivo test. In conclusion, these data evidence the local anaesthetic activity of beta-caryophyllene, which appears to be strictly dependent on its chemical structure.

Regulation of ocular mucin secretion by P2Y2 nucleotide receptors in rabbit and human conjunctiva

The effects of adenine analogues on secretion of high molecular weight, mucin-like glycoproteins (mucins) by conjunctival goblet cells were investigated using isolated rabbit and human conjunctiva. Mucin secretion was assayed using a quantitative dot-blot assay of Helix pomatia agglutinin-horseradish peroxidase binding to mucins absorbed to nitrocellulose filters. In rabbit conjunctiva, exogenous ATP (10(-7)-10(-3) m) induced a concentration-dependent, four-fold increase in mucin secretion that reached a plateau 15 min after drug addition. The rank order of potency of agonists was UTP>=ATPgammaS>ATP>ITP>ADP>>AMP. Adenosine, alpha,beta-methylene- ATP and beta,gamma-methylene-ATP were ineffective in stimulating mucin release. The response to ATP was unmodified by the putative P2 purinergic antagonists suramin or reactive blue (5x10(-5) m). In human conjunctiva, ATP and UTP were nearly equipotent in stimulating mucin secretion with an EC50 congruent with5x10(-6) m. These findings demonstrate that rabbit and human conjunctival cells contain functional P2Y2 (formerly designated as P2U) nucleotide receptors that govern mucin secretion. These receptors may provide useful pharmacological targets for therapeutic modulation of tear film mucins in dry-eye disorders and/or corneal wound healing.

In vitro study of inflammatory potential and toxicity profile of latanoprost, travoprost, and bimatoprost in conjunctiva-derived epithelial cells

PURPOSE

Conjunctiva-derived epithelial cells were used to investigate, in vitro, the expression of various inflammation-associated markers known to be overexpressed in patients with glaucoma after contact with the three major commercially available eye drops containing prostaglandin analogues. The impact on cellular viability and apoptosis in the same cell line was evaluated, to address the possible proinflammatory and/or toxic origin of the most frequent clinical impairments induced by prostanoids (i.e., conjunctival hyperemia).

METHODS

Conjunctiva-derived cells were treated in vitro with the commercial solutions of latanoprost, travoprost, bimatoprost, prostaglandin (PG)F2alpha, tumor necrosis factor (TNF)-alpha, and different concentrations of benzalkonium chloride (BAC). Expressions of three inflammation- and immune-related markers, intercellular adhesion molecule (ICAM)-1, platelet-endothelial cell adhesion molecule (PECAM)-1 and HLA DR, were evaluated with flow cytometry after 24 to 72 hours of contact at low, subtoxic concentrations. Toxicological tests were also performed with cold-light cytofluorometry, in which cellular viability and apoptosis were evaluated with the neutral red and Hoechst/propidium iodide tests, respectively.

RESULTS

TNFalpha induced or stimulated expression of the three inflammatory markers, whereas the PGF2alpha, latanoprost, travoprost, and bimatoprost solutions did not induce an increase in these markers and even produced a marked reduction of ICAM-1 and PECAM-1 expression in those solutions most concentrated in BAC, thus suggesting a toxic phenomenon in cellular membranes induced by the preservative rather than the medication itself. Cytotoxic assays confirmed this hypothesis and showed significant toxicity with prostaglandin analogues after prolonged contact, proportional to the concentration of BAC in the solution and similar to that of the corresponding concentration of BAC alone, bimatoprost having both the least concentration of BAC and the least cytotoxic in these experimental conditions.

CONCLUSIONS

The comparison of latanoprost, travoprost, and bimatoprost, in their commercial formulations, showed that none of them appeared to induce direct stimulation of the inflammatory pathways involving adhesion molecules or class II antigens, although these markers have been found ex vivo in conjunctival specimens from patients treated with prostaglandins. In fact, their toxicity was mild and seemed to be primarily related to the concentration of BAC, their common preservative, which may be the major factor responsible for long-term ocular surface reactions in patients receiving topical prostaglandins, but most likely is not a factor in early and transient conjunctival hyperemia.

Topical cyclosporine inhibits conjunctival epithelial apoptosis in experimental murine keratoconjunctivitis sicca

PURPOSE

Increased apoptosis in the conjunctival epithelium has been observed in experimental murine keratoconjunctivitis sicca (KCS). Topical cyclosporine (CsA) has been noted to reduce conjunctival epithelial apoptosis in chronic canine and human KCS. The purpose of this study is to determine if topical CsA treatment inhibits conjunctival epithelial apoptosis in a murine model of KCS.

METHODS

Dry eye was induced in 3 groups of C57BL6 mice by subcutaneous injection of scopolamine TID and exposure to an air draft and low-humidity environment for 16 hours per day for 12 days. The dry eye control group received no topical treatment; a second group received 1 microL of 0.05% CsA topically TID (dry eye + CsA); and the third group received 1 microL of the castor oil vehicle of CsA topically TID (dry eye + vehicle). Normal mice were used as untreated controls. After 12 days, the mice were killed, and the right eyes and eyelids were excised, frozen, and cryosectioned. Transmission electron microscopy (TEM) was performed on conjunctival and corneal samples taken from the left eyes. Apoptosis was detected in frozen sections with the ApopTag (ISOL) In Situ Oligo Ligation Kit, which specifically detects DNA fragmentation. Immunohistochemical staining was performed to detect activated caspase-3. Conjunctival goblet cell number was counted in tissue sections stained with period acid Schiff (PAS) reagent. These assays were performed on 2 separate sets of mice.

RESULTS

Compared with untreated controls and dry eye mice receiving CsA, the number of ISOL-positive epithelial cells in the bulbar and tarsal conjunctiva was significantly greater in the dry eye control and dry eye mice + vehicle groups (P < 0.01 for both groups). There was no significant difference in the number of ISOL-positive conjunctival epithelial cells between the dry eye control and dry eye + vehicle mice. There was no significant difference in ISOL-positive cells in the corneal epithelium between the untreated controls and the 3 treatment groups. Dry eye + CsA mice showed less activated caspase-3 staining than the dry eye control and the dry eye + vehicle groups. TEM showed loss of superficial differentiated cells and extensive nuclear fragmentation characteristic of apoptosis in the dry eye control and dry eye + vehicle groups but not in the dry eye + CsA group. There was significant loss of goblet cells in the bulbar and tarsal conjunctivae of the dry eye control and the dry eye + vehicle groups compared with untreated controls and the dry eye + CsA group.

CONCLUSIONS

Topical CsA significantly reduced conjunctival epithelial apoptosis and protected against goblet cell loss in experimental murine KCS. Inhibition of apoptosis appears to be a key mechanism for the therapeutic effect of CsA for KCS.

Cetirizine reduces inflammatory cell recruitment and ICAM-1 (or CD54) expression on conjunctival epithelium in both early- and late-phase reactions after allergen-specific challenge

BACKGROUND

Allergen-specific conjunctival challenge (ASCC) is a safe and reproducible experimental model of allergic conjunctivitis and a useful tool in the evaluation of effectiveness and possible mechanisms of action of drugs commonly used in the treatment of allergic diseases.

OBJECTIVE

The protective effect of cetirizine on inflammatory changes after ASCC was assessed in 12 patients with rhinoconjunctivitis caused by Parietaria judaica in a double-blind study.

METHODS

After a screening ASCC was performed, patients were randomized into two treatment groups; each patient was given cetirizine (oral tablets) 10 mg twice daily, or matching placebo for 3 1/2 days in off-pollen season. Clinical evaluation (itching, hyperemia, lacrimation, and swelling of eyelids) and cytologic assessment (number of inflammatory cells in conjunctival scraping and evaluation of intercellular adhesion molecule-1 (ICAM-1)/CD54 expression on epithelial cells) were performed at baseline, 30 minutes (i.e., early-phase reaction [EPR]), 6 hours, and 24 hours (i.e., late-phase reaction [LPR]) after ASCC, before and after treatment.

RESULTS

The EPR clinical events and the EPR total number of inflammatory cells were significantly reduced by cetirizine compared with placebo. The LPR clinical events and inflammatory cell recruitment were reduced by cetirizine in a similar manner. Both eosinophil and neutrophil numbers were decreased by active drug in EPR and LPR. Furthermore, ICAM-1/CD54 expression was significantly reduced by cetirizine in both the EPR and LPR compared with placebo.

CONCLUSIONS

This study shows that cetirizine has a protective effect on clinical and cellular EPR and LPR events (including ICAM-1/CD54 expression on epithelium) induced by ASCC.

Development, characterization and in vivo evaluation of benzocaine-loaded liposomes

This study reports the development and in vivo evaluation of a liposomal formulation of the local anaesthetic benzocaine. Multi-lamellar (MLV) and small uni-lamellar (SUV) vesicles entrapping benzocaine were prepared using 50:50 w/w phosphatidylcholine-cholesterol as lipophilic phase and 50:50 v/v ethanol-water as hydrophilic phase. Liposome size, Zeta-potential, encapsulation efficiency and skin penetration properties were determined. Drug permeation from liposomal dispersions, as such or formulated in Carbopol gel, was evaluated through artificial lipophilic membranes and excised abdominal rat skin, whereas in vivo anaesthetic effect was tested on rabbits. Interestingly, addition of the drug into the hydrophilic phase, rather than into the lipophilic one, during liposome preparation enabled an improvement of the MLV's entrapment efficiency from 29.7% to 82.3%. On the other hand, sonication conditions to obtain SUV influenced size and polydispersity index of the vesicles and reduced the entrapment efficiency by about 30%. All liposomal-benzocaine formulations showed sustained release properties and a more intense anaesthetic effect than plain drug. Permeation experiments from drug solutions in gel containing the same amount of ethanol as in the liposomal formulations made it possible to exclude a possible enhancer effect of this solvent, at least when not used in liposomal formulations. MLV with the drug added into the hydrophilic phase gave the most effective formulation, showing a permeability coefficient value 2.5 times higher than that of the plain drug and allowing a significant improvement (P<0.01) not only of intensity but also of duration of anaesthetic effect of benzocaine. These results suggest that a suitably developed liposomal formulation of benzocaine can be of actual value for improving its clinical effectiveness in topical anaesthesia.