Sector pupillary dilation: an alternative technique

Sector pupillary dilation is a method for controlled delivery of topical ophthalmic adrenergic agonists to stimulate the dilator muscle focally in patients predisposed to pharmacologically induced acute angle-closure glaucoma. Sector pupillary dilation can be achieved by applying a sterile cotton-tipped applicator moistened with 2.5% phenylephrine ophthalmic solution at the 6:00 o'clock limbus. A pilot study (N = 2) was conducted of one blue-eyed subject (M, age 38 years) and one brown-eyed subject (F, age 36 years) using drug contact times of 5 to 30 s in 5-s intervals. The horizontal and vertical pupil diameters were measured using photographs taken every 10 min for 1 h and every 20 min for the second hour. Sector pupil dilation developed with all application times. For the blue-eyed subject maximum sector dilation (delta = V-H = 1.5 mm) occurred with a 20-s contact time and peaked after 40 min. For the brown-eyed subject, the sector dilation effect was less marked and did not demonstrate a clear-cut peak time.     

应用不同浓度的克拉霉素眼用凝胶治疗兔金黄色葡萄球菌性角膜溃疡

目的：通过观察对金黄色葡萄球菌性角膜溃疡的疗效，筛选克拉霉素眼用凝胶的合适浓度。方法：角膜实质层接种法建立40只家兔右眼金黄色葡萄球菌性角膜溃疡模型。将模型随机分成5组，每组8只兔（8只眼），各组分别给予空白基质、0．1％克拉霉素眼用凝胶、0．25％克拉霉素眼用凝胶、左氧氟沙星凝胶、0．25％克拉霉素眼用凝胶联合重组牛碱性成纤维细胞生长因子（Recombinantbovinebasicfibroblastgrowthfactor，Rb—bFGF），每天4次，每次2滴，分别在第1、3、5、7、10、14天观察角膜病变情况及溃疡面积大小。结果：在相同的给药方法下，0．1％克拉霉素眼用凝胶、0．25％克拉霉素眼用凝胶、左氧氟沙星凝胶、0．25％克拉霉素眼用凝胶联合Rb—bFGF均能使金黄色葡萄球菌性角膜溃疡面积缩小、角膜病变好转，与空白基质组相比有统计学差异（P〈0．05）；0．25％克拉霉素眼用凝胶组疗效明显优于0．1％克拉霉素眼用凝胶组（P〈0．05）。结论：制备的0．25％克拉霉素眼用凝胶对金黄色葡萄球菌性角膜溃疡疗效肯定，可以进一步开发应用于临床。     

Short-term effect of latanoprost on ocular circulation in ocular hypertension

PURPOSE: To determine the short-term effects of latanoprost on retrobulbar circulation in ocular hypertension. METHODS: Forty-six eyes of 23 consecutive bilateral ocular hypertensive patients with an intraocular pressure (IOP) of greater than 22 mmHg were evaluated in a prospective controlled study. All subjects received a single drop of latanoprost 0.005% in one eye and placebo in the fellow control eye. Systemic circulatory parameters, intraocular pressure, blood flow velocities, and resistance indices of the ophthalmic, short posterior ciliary and central retinal arteries were measured using colour Doppler imaging at baseline and 2 h and 8 h after dosing. RESULTS: Latanoprost lowered IOP significantly after 2 h and 8 h (P < 0.01). The mean IOP reduction was 6.7 mmHg 8 h after dosing. At baseline, there were no statistically significant differences in any retrobulbar vessels of eyes that received a single drop of latanoprost when compared with the eyes that received placebo (P > 0.05). Comparisons with baseline and latanoprost conditions revealed that latanoprost did not alter the blood flow velocities and resistance indices in the ophthalmic (P > 0.05), posterior ciliary (P > 0.05) and central retinal (P > 0.05) arteries 2 h and 8 h after dosing. The systolic and diastolic blood pressures (p = 0.74, p = 0.29, respectively) and pulse rate (p = 0.68) remained unchanged over the 8-h period. CONCLUSIONS: This study found that a single drop of latanoprost significantly reduces intraocular pressure 8 h after dosing. However, it does not have any short-term effects on the retrobulbar haemodynamics in ocular hypertensive eyes.     

Effectiveness and tolerance of piroxicam 0.5% and diclofenac sodium 0.1% in controlling inflammation after cataract surgery

PURPOSE: To compare the efficacy and tolerance of piroxicam 0.5% ophthalmic solution and diclofenac sodium 0.1% ophthalmic solution in controlling inflammation after phacoemulsification and intraocular lens (IOL) implantation. SETTING: Ophthalmological Department, San Donà di Piave Hospital, Venice, Italy. MATERIALS AND METHODS: Forty consecutive patients--18 men and 22 women--between 55 and 85 years of age (mean age, 75.1 +/- 7.12 years) who were scheduled for cataract extraction with phacoemulsification and IOL implantation were randomized to receive 0.5% piroxicam ophthalmic solution (piroxicam group, 20 patients) or 0.1% diclofenac sodium ophthalmic solution (diclofenac group, 20 patients) for 1 month postoperatively. Best-corrected visual acuity (BCVA) and intraocular pressure (IOP) measurements and slit-lamp biomicroscopy for the evaluation of corneal edema, Descemet membrane folds, Tyndall, and cells in the anterior chamber were carried out in all patients 1 day, 4 days, and 1 month postoperatively. Subjective symptoms after the nonsteroidal anti-inflammatory drug (NSAID) ophthalmic solution instillation were assessed using a questionnaire. RESULTS: There were no significant differences between the two groups in postoperative IOP, BCVA, anterior chamber flare and cell levels, corneal edema, or Descemet membrane folds. Ocular discomfort, evaluated as burning or stinging sensation after NSAID ophthalmic solution instillation, was significantly more frequent and intense in the diclofenac-treated eyes. Two eyes in the diclofenac group had a mild transient punctate keratitis. CONCLUSIONS: These results suggest that piroxicam is as effective as diclofenac sodium in preventing inflammation after cataract surgery with IOL implantation, and its better tolerance and safety can provide higher patient compliance.     

Ocular gelfoam disc-applicator for pupillary dilation in humans.

This study investigates a gelfoam disc device as an alternative topical ophthalmic drug delivery system for pupillary dilation in humans. Gelfoam (Pharmacia & Upjohn) discs were impregnated with 0.60 mg of tropicamide racemate and 1.7 mg of 1-phenylephrine hydrochloride by an ethanol solvent evaporation method. Twenty randomly selected human subjects received baseline examinations, including blood pressure, pulse rate and biomicroscopy of the ocular surface. One impregnated gelfoam disc was placed in the inferior fornix of a randomly selected eye. Simultaneously, the fellow eye was treated with two topically administered drops, one from a phenylephrine hydrochloride 2.5% solution and one from a tropicamide 1% solution. A single, masked observer measured the pupillary diameter in both eyes at various time intervals under constant ambient conditions. Administration of the topical drops was repeated in the fellow eye. At maximum pupillary dilation, the disc was removed, and a post-dilation biomicroscopic exam was performed. Blood pressure and pulse rate were rechecked. The gelfoam-treated eyes' median change in dilation diameter was approximately 25% greater (a two-fold increase in pupillary area) (p< 0.001) at 15.2 min (median time to maximum dilation) than the topically treated fellow eyes. The median change in systolic blood pressure (+1.0 mmHg) and diastolic blood pressure (-1.0 mmHg) was not statistically significant (p>0.1). The average pulse rate was decreased 7 beats per minute (p=0.004). A gelfoam disc may serve as an ophthalmic drug delivery system for pupillary dilation or as a model for other multiple-dose topical drugs.     

Effect of topical timolol maleate on the ophthalmic artery blood pressure

The effects of topical timolol maleate 0.5% on the ophthalmic artery diastolic (OABPd), systolic (OABPs) and mean blood pressure (OABPm) were investigated in 19 healthy subjects using compression ophthalmodynamometry. In a randomized, double-blind study, one eye of each subject received one drop of timolol maleate 0.5% and the fellow eye received a drop of placebo. Measurements of OABPd and OABPs were performed just prior to instillation of the drops, and then 2 hr later. OABPm was calculated as OABPm = OABPd + 1/3 (OABPs - OABPd). No significant changes in OABPd, OABPs or OABPm were observed following the drops in the timolol-treated eyes or in the placebo-treated eyes. A significant difference (P = 0.0198) was found, however, when the changes in OABPm occurring in the timolol-treated eyes were compared with the changes occurring in the placebo-treated eyes, suggesting that the drug may have an effect upon ophthalmic artery pressure and retinal artery pressure that is expressed differently in each eye.     

Importance of the noncorneal absorption route in topical ophthalmic drug delivery

Transcorneal permeation has traditionally been the mechanism by which topically applied ophthalmic drugs are believed to gain access to the internal ocular structures. Relatively little attention has been given to alternate routes by which drugs may enter the eye. A system has been developed which allowed the investigation in vivo of the contribution of noncorneal absorption to intraocular drug levels after topical dosing. Using timolol and inulin as probe drugs, it was shown that the noncorneal absorption route may contribute significantly to drug penetration into intraocular tissues. Furthermore, results demonstrated that drugs absorbed by the noncorneal route appeared to enter certain intraocular tissues by a mechanism which bypasses the anterior chamber. These studies suggested that intraocular penetration via noncorneal routes involves penetration of drug across the conjunctiva/sclera. Neither reentry from the general circulation after drug absorption into the blood or drug delivery by the local vasculature accounted for the observed results. In terms of topical ophthalmic drug delivery, the noncorneal absorption route may be important for drugs that are poorly absorbed across the cornea due to their physical-chemical properties. We have demonstrated this using inulin as a model for a poorly absorbed, high molecular weight substance.     

Effect of gatifloxacin ophthalmic solution 0.3% on human corneal endothelial cell density and aqueous humor gatifloxacin concentration

PURPOSE: To evaluate the effect of gatifloxacin ophthalmic solution 0.3% (Zymar, Allergan, Inc., Irvine, CA, USA) on corneal endothelial cell density and morphology and to measure gatifloxacin penetration into aqueous humor. METHODS: This was a single-center, open-label clinical study. Ten patients undergoing standard cataract surgery and 20 nonsurgical subjects instilled gatifloxacin 0.3% four times per day for 2 days, then every 10 min for 1 hr on the third day (the surgery day for the cataract patients). Corneal endothelial cells were counted using noncontact specular microscopy. Anterior chamber fluid was withdrawn from the surgical patients, and the gatifloxacin concentration was quantified by high-pressure liquid chromatography. RESULTS: Baseline endothelial cell counts (mean +/- SD) were 2400 +/- 442 in the surgical group and 2520 +/- 212 in the nonsurgical group. The mean differences from baseline 1 hr after the last dose of gatifloxacin 0.3% were -51 +/- 213 (p = 0.23) in the surgical group and -7 +/- 150 (p = 0.42) in the nonsurgical group. In the nonsurgical group, the mean difference from baseline 3 weeks after the last dose was 18 +/- 147 (p = 0.71). The mean concentration (+/- SD) of gatifloxacin in aqueous humor was 1.26 +/- 0.55 microg/ml. CONCLUSIONS: A preoperative, prophylactic course of gatifloxacin 0.3% ophthalmic solution did not significantly affect endothelial cell density or morphology, while meaningful drug concentration was achieved in the aqueous humor.     

Sector pupil dilation with phenylephrine and tropicamide

A comparison of sector pupil dilation produced with 2.5% phenylephrine and 1.0% tropicamide was carried out on nine subjects. We found that 2.5% phenylephrine produced a significant increase in the vertical as compared to the horizontal diameter at 10, 20, 30, 40, and 50 min after instillation of the drug with the maximum vertical diameter occurring at 40 min. The pupil diameter in the vertical and horizontal meridians before drug instillation was 3.7 mm +/- 0.2 (mean +/- SE) whereas at 40 min the vertical and horizontal diameters were 6.7 mm +/- 0.4 and 5.2 mm +/- 0.3, respectively. Instillation of 1% tropicamide produced equal dilation of the vertical and horizontal diameters, which was maximum at 40 min. Before drug instillation, the pupils were 3.7 mm +/- 0.2 (mean +/- SE) in both the horizontal and vertical meridians. At 50 min the pupil diameter was 7.0 mm +/- 0.2 in both meridians in the eye that received tropicamide.     

In vitro behavior of ophthalmic viscosurgical devices during phacoemulsification

PURPOSE: To evaluate the behavior and aspiration of several ophthalmic viscosurgical devices (OVDs) during phacoemulsification. SETTING: Department of Ophthalmology, Tokyo Dental College Suidobashi Hospital, Tokyo, Japan. METHODS: Cohesive OVDs (sodium hyaluronate 1.0% [Healon and Provisc]), dispersive OVDs (sodium hyaluronate 3.0%-chondroitin sulfate 4.0% [Viscoat]), and new-generation OVDs such as viscoadaptive (sodium hyaluronate 2.3% [Healon5]) and viscodispersive (hyaluronic acid 1.65%-chondroitin sulfate 4.0% [DisCoVisc]) OVDs, were stained with fluorescein sodium. The movement of the OVDs during simulated cataract surgery was recorded in porcine eyes under an operating microscope and with a side-view video camera. The initial and complete aspiration times of each OVD during phacoemulsification using 20 and 40 mL/min flow rates and sleeves and the removal times using the irrigation and aspiration (I/A) tip at the end of surgery were evaluated from the recorded videos. RESULTS: The complete aspiration time of the cohesive OVDs was less than 3 seconds but up to 20 seconds with a low flow rate of 20 mL/min with a smaller sleeve. Other OVDs remained in the anterior chamber during phacoemulsification with both flow rates. The removal time for cohesive OVDs was less than 4 seconds and for new-generation OVDs, 10 to 15 seconds. The dispersive OVD required a significantly (P<.05) longer removal time than other OVDs. CONCLUSIONS: Cohesive OVDs are removed easily during phacoemulsification; however, the aspiration rate can be affected by fluidics. New-generation OVDs, such as Healon5 and DisCoVisc, remained in the anterior chamber during phacoemulsification and were removed easily by I/A at the end of surgery. The behavior of these OVDs is preferable during phacoemulsification.     

Safety and efficacy comparison of emedastine 0.05% ophthalmic solution compared to levocabastine 0.05% ophthalmic suspension in pediatric subjects with allergic conjunctivitis. Emadine Study Group

PURPOSE: To determine the efficacy and tolerance of emedastine 0.05% ophthalmic solution compared to levocabastine 0.05% ophthalmic suspension in pediatric subjects. METHODS AND MATERIALS: In a randomized, double-masked, parallel controlled study, emedastine 0.05% ophthalmic solution BID was compared to levocabastine 0.05% ophthalmic suspension BID, for control of the signs and symptoms of allergic conjunctivitis in pediatric subjects ages 3-16. Subjects who met all inclusion and exclusion criteria received masked study medication with instructions to instill drops twice daily, in the morning and evening. A diary was completed by the parents four times daily for the first two and last two weeks of the study. Treatment lasted 42 days. Drug efficacy was assessed at the initial administration in the office at Day 0 and after 3, 7, 14, 30 and 42 days. RESULTS: Overall results showed both drugs have an effect and that emedastine was significantly superior (p < 0.05) to levocabastine for the relief of chemosis on Days 14, 30 and 42; of itching on follow-up Days 30 and 42 (p < 0.05); of redness on Days 30 and 42; for eyelid swelling on Days 14 and 30; and for physician's impression score on Days 7, 14, 30 and 42. CONCLUSION: These results confirm previous preclinical and clinical data on the potent and long acting efficacy of this promising new ophthalmic anti-allergic drug, emedastine in pediatric subjects.     

Ophthalmic drug delivery through contact lenses

PURPOSE: Currently available ophthalmic drug delivery systems are inefficient and may lead to side effects. To increase efficiency and reduce side effects, the authors propose disposable particle-laden soft contact lenses for ophthalmic drug delivery. METHODS: The essential idea is to encapsulate the ophthalmic drug formulations in nanoparticles and to disperse these drug-laden particles in the lens material, such as poly-2-hydroxyethyl methacrylate (p-HEMA) hydrogels. The drug-laden p-HEMA hydrogels were synthesized by free radical solution polymerization of the monomers in presence of nanoparticles. The particle-laden hydrogels were characterized by light-transmission and electron microscopy studies. Release profiles of lidocaine, a model hydrophobic drug, were measured by UV-Vis spectrophotometry. RESULTS: Microemulsions of hexadecane in water stabilized with a silica shell around the particles produced transparent hydrogels. Contact lenses made with particle-laden hydrogels released therapeutic levels of drug for a few days. CONCLUSIONS: Particle-laden hydrogels are promising candidates for ophthalmic drug delivery. They are transparent and can release drugs for extended periods. The drug delivery rates can be controlled by varying the loading of nanoparticles in the gel.     

非球面AcrySof ReSTOR +3D人工晶状体的临床应用观察

目的:与非球面AcrySof ReSTOR +4D人工晶状体比较,初步观察植入ReSTOR +3D和ReSTOR +4D人工晶状体眼的视功能,以评价非球面AcrySof ReSTOR +3D人工晶状体植入术后的效果。方法:全组36例40眼老年性白内障患者行白内障超声乳化吸除联合人工晶状体植入术,术后3mo检查患者的裸眼远、中(60cm)、近视力(40cm),最佳矫正远视力和中、近视力,对比敏感度,进行生活问卷。结果:两组术后的远视力,近视力均无统计学差异(P>0.05),植入非球面AcrySof ReSTOR +3D人工晶状体组平均中距离视力比植入非球面AcrySof ReSTOR +4D人工晶状体组有显著提高(P<0.01)。结论:非球面AcrySof ReSTOR +3D人工晶状体在远、中、近距离均能提供良好的视力,尤其是中距离视力比+4D有了显著改善,有极高的患者满意度和脱镜率。     

Safety and tolerability of olopatadine 0.2% in children and adolescents.

OBJECTIVE: The aim of this study was to evaluate the safety of olopatadine hydrochloride ophthalmic solution 0.2% in children and adolescents 3-17 years of age. METHODS: In this 6-week, randomized, double-masked safety evaluation, eligible subjects with asymptomatic eyes underwent in-office visits at weeks 1, 3, and 6 and were contacted by telephone at weeks 2, 4, and 5. Qualified subjects were assigned randomly in a 2:1 ratio of olopatadine 0.2% to vehicle (identical formation without the active ingredient) for dosing on a once-daily schedule. Safety parameters assessed included adverse events, visual acuity, ocular signs (slit-lamp assessments), dilated fundus examinations, intraocular pressure (IOP), pulse, and blood pressure. RESULTS AND DISCUSSION: An evaluation of 126 subjects (age range, 3-17) revealed no clinically relevant treatment-related changes in visual acuity, IOP, slit-lamp assessments, fundus examinations, or cardiovascular parameters. All adverse events reported were mild or moderate. CONCLUSIONS: Olopatadine 0.2% administered once-daily for 6 weeks is safe and well tolerated in children and adolescent patients.     

Application of lipid microsphere drug delivery system to steroidal ophthalmic preparation

The applicability of a lipid microsphere drug delivery system to ophthalmic preparations was examined using a lipid microsphere containing hydrocortisone 17-butyrate 21-propionate (HBP). 3H-labelled HBP ophthalmic suspension and 3H-labelled HBP lipid microsphere were applied to rabbit eyes, and the eyes were enucleated after 1 and 3 hours to determine 3H-labelled HBP levels in the ocular tissues. The lipid microsphere proved to deliver the drug to the anterior ocular tissues more significantly than the ophthalmic suspension. It is suggested that the lipid microsphere ophthalmic preparation of various lipophilic drugs including steroids may be useful as one of the drug delivery systems for ophthalmic therapy.     

A comparison of the efficacy and duration of action of topically applied proxymetacaine using a novel ophthalmic delivery system versus eye drops in healthy young volunteers.

A novel ophthalmic drug delivery system (NODS) has been developed to give precise and controlled delivery of a drug to the eye. The drug is incorporated into a polyvinyl alcohol flag attached to a carrier. When applied to the eye the flag detaches and gradually dissolves, releasing the drug. We investigated corneal anaesthesia produced by different concentrations of proxymetacaine NODS, and conventional eye drops. Subjects consisted of 28 normal males (mean age 25.3 (SD 3.9) years). Corneal touch sensitivity was measured with a biomicroscope mounted Cochet-Bonnet aesthesiometer. Each subject attended for two visits separated by 7 days. On each visit each eye randomly received one of four proxymetacaine preparations: 44 micrograms, 74 micrograms, 124 micrograms NODS, or 35 microliters of 0.5% proxymetacaine drops (175 micrograms). Corneal touch sensitivity was measured before, and at 1, 2, 5, 10, 15, 20, 30, 45, and 60 minutes following instillation. Complete anesthesia was achieved in the majority of subjects within 1 minute of instillation. The lowest NODS dose (44 micrograms) produced longer lasting anaesthesia than the 35 microliters drop (175 micrograms) (p < 0.05). Higher NODS doses produced a correspondingly greater increase in the duration of anaesthesia. The greater bioavailability achieved by this vehicle allows much lower drug concentrations to be used, reducing the likelihood of systemic adverse reactions.     

Systemic drug profiles in adult optometric outpatients

Systemic drug profiles of adult patients seen in an optometric outpatient setting were determined. The sample consisted of 502 subjects, of whom 214 were taking known medication, 267 were not taking drugs, and 21 subjects were taking unidentified medication. The most frequently used drugs and drug groups were identified and compared to a 1986 national survey that ranked the most frequently prescribed systemic medications. Drug distribution by age, sex, and race of the 22 most frequently prescribed drugs was determined. Implications for the ophthalmic practitioner are discussed.     

Topical lipoic acid choline ester eye drop for improvement of near visual acuity in subjects with presbyopia: a safety and preliminary efficacy trial

ObjectivesThis study evaluated the safety of topical lipoic acid choline ester (UNR844, 1.5%) ophthalmic solution and its efficacy in improving distance-corrected near visual acuity (DCNVA) in subjects with presbyopia.Subjects and methodsThis was a prospective, randomized, double-masked, and multicentre clinical trial. Subjects with a diagnosis of presbyopia (n = 75) were randomized 2:1 to UNR844 or placebo. On days 1–7, all subjects were dosed unilaterally (twice a day, b.i.d.) in their non-dominant eye to ensure safety and tolerability prior to days 8–91 when dosing was changed to bilateral (b.i.d.). Clinical assessments, including DCNVA and adverse events (AEs), were recorded at each study visit. Patients who completed the study were recruited into a non-interventional follow-up study that monitored them until 7 months after their final UNR844 exposure. The primary endpoints were safety and the mean change in DCNVA from baseline in the study eye.ResultsUNR844 administration (n = 50) produced no safety concerns and was well-tolerated, with no clinically-relevant changes in best-corrected distance visual acuity, pupil size, intraocular pressure, or discontinuations due to adverse events. DCNVA improved in the study eye in the UNR844 group compared to placebo during the 91 days of treatment [UNR844 vs. placebo, mean change in LogMAR (SD); −0.159 (0.120) vs. −0.079 (0.116)]. Bilateral DCNVA improved, with 53.1% UNR844 vs. 21.7% placebo subjects gaining ≥10 letters. Improvements in DCNVA were sustained at 5 and 7 months after UNR844 dosing ceased.ConclusionsThese results support further development of UNR844 ophthalmic solution for the treatment of presbyopia.Subject terms: Outcomes research, Prognosis     

Lidocaine hydrochloride gel for ocular anesthesia: results of a prospective, randomized study

BACKGROUND AND OBJECTIVE: This study evaluates the effectiveness of Akten (Akorn, Inc., Buffalo Grove, IL), a novel ophthalmic gel anesthetic agent for complete ocular anesthesia. PATIENTS AND METHODS: This study was conducted as a prospective, randomized, double-blinded, multicenter Phase III clinical trial to evaluate Akten gel. The study had four cohorts of subjects who received sham gel, Akten 1.5%, Akten 2.5%, and Akten 3.5%, respectively. Subjects were assessed for achievement of anesthesia at defined time intervals and questioned for "pain" or "no pain" following pinching of the conjunctiva with 0.3-mm forceps at predetermined intervals. RESULTS: A total of 209 subjects were entered into the study. The percentages of patients achieving the primary endpoint (ie, anesthesia within 5 minutes) were as follows: 22% for sham, 88% for Akten 1.5%, 89% for Akten 2.5%, and 92% for Akten 3.5%, respectively. Safety measures including corneal staining, conjunctival hyperemia, and eye pain with administra-tion were low and comparable in all cohorts. CONCLUSION: Akten gel appears to be an effective and safe ocular anesthetic. All doses were well tolerated and no dose-related corneal toxicity was observed.     

Comparison of the topical ocular antiallergic efficacy of emedastine 0.05% ophthalmic solution to ketorolac 0.5% ophthalmic solution in a clinical model of allergic conjunctivitis.

PURPOSE: To compare the clinical efficacy of emedastine ophthalmic solution to that of ketorolac ophthalmic solution using a conjunctival allergen challenge model. METHODS: The conjunctival allergen challenge model was used in this randomized, double-masked, single center, crossover study. The titer of allergen that elicited a positive allergic reaction was selected. After at least 14 days, 36 subjects were randomized into two groups of 18 to receive either emedastine in one eye and placebo in the contralateral eye, or ketorolac in one eye and placebo in the contralateral eye. Ten minutes after drug instillation, subjects were challenged with antigen. At 3, 10 and 20 minutes following challenge subjects graded ocular itching and were assessed for hyperemia in conjunctival, ciliary, and episcleral vessel beds. Approximately 14 days later, subjects received the alternate treatment in one eye and placebo in the contralateral eye. They were again challenged with allergen and their responses were rated in the same manner. Ocular discomfort was assessed by the subjects after administration of each study drug. RESULTS: Emedastine significantly (p < 0.05) inhibited ocular itching and redness in vascular beds following topical ocular administration. In contrast, ketorolac failed to significantly inhibit ocular itching or redness in this study. Patient assessment of comfort indicated emedastine was significantly (p < 0.05) more comfortable than ketorolac upon topical ocular administration. CONCLUSION: Emedastine is superior to ketorolac in controlling itching and redness, the cardinal symptom and sign of allergic conjunctivitis.