Locally administered ocular corticosteroids: benefits and risks

Evaluation of an intravitreal fluocinolone acetonide implant versus standard systemic therapy in noninfectious posterior uveitis

PURPOSE

To evaluate the safety and efficacy of an intravitreal fluocinolone acetonide (FA) implant compared with standard therapy in subjects with noninfectious posterior uveitis (NIPU).

DESIGN

Randomized, controlled, phase 2b/3, open-label, multicenter superiority trial.

PARTICIPANTS

Subjects with unilateral or bilateral NIPU.

METHODS

One hundred forty subjects received either a 0.59-mg FA intravitreal implant (n = 66) or standard of care (SOC; n = 74) with either systemic prednisolone or equivalent corticosteroid as monotherapy (> or =0.2 mg/kg daily) or, if judged necessary by the investigator, combination therapy with an immunosuppressive agent plus a lower dose of prednisolone or equivalent corticosteroid (> or =0.1 mg/kg daily).

MAIN OUTCOME MEASURES

Time to first recurrence of uveitis.

RESULTS

Eyes that received the FA intravitreal implant experienced delayed onset of observed recurrence of uveitis (P<0.01) and a lower rate of recurrence of uveitis (18.2% vs. 63.5%; P< or =0.01) compared with SOC study eyes. Adverse events frequently observed in implanted eyes included elevated intraocular pressure (IOP) requiring IOP-lowering surgery (occurring in 21.2% of implanted eyes) and cataracts requiring extraction (occurring in 87.8% of phakic implanted eyes). No treatment-related nonocular adverse events were observed in the implant group, whereas such events occurred in 25.7% of subjects in the SOC group.

CONCLUSIONS

The FA intravitreal implant provided better control of inflammation in patients with uveitis compared with systemic therapy. Intraocular pressure and lens clarity of implanted eyes need close monitoring in patients receiving the FA intravitreal implant.

Dose-response relationship of inhaled corticosteroids and cataracts: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

The risk of cataracts associated with the long-term use of inhaled corticosteroids (ICS) is poorly recognized, yet may be of major public health importance. The aim of this study was to determine the dose-response relationship of ICS use and risk of cataracts in adults.

METHODS

A systematic review and meta-analysis was performed of case-control studies of cataracts and ICS use, which included at least two doses of ICS and in which the number of cases and controls using each dose of ICS was reported. The primary outcome variable was risk of cataracts.

RESULTS

Four case-control studies were identified, with a total of 46 638 cases and 146 378 controls. There was a significant relationship between the risk of cataracts and ICS dose, with a random effects pooled odds ratio for risk of cataracts per 1000 microg increase in daily beclomethasone dipropionate dose of 1.25 (95% CI: 1.14-1.37).

CONCLUSIONS

The risk of cataracts was increased by approximately 25% for each 1000 microg per day increase in the dose of beclomethasone dipropionate or equivalent. These findings reinforce the importance of prescribing within the therapeutic dose-response range for ICS in asthma and the need to determine the dose-response relationship for the efficacy of ICS in COPD. Screening for the presence of cataracts could usefully be undertaken in older subjects with asthma and COPD, particularly current or ex-smokers.

Efficacy of intravitreal triamcinolone after or concomitant with laser photocoagulation in nonproliferative diabetic retinopathy with macular edema

PURPOSE

To investigate the clinical effects and outcomes of intravitreal injection of 4 mg of triamcinolone acetonide (IVTA) after or concomitant with macular laser photocoagulation (MP) for clinically significant macular edema (CSME).

METHODS

Forty-nine eyes of 49 patients with nonproliferative diabetic retinopathy and CSME were randomized into three groups. The eyes in the laser group (n=17), group 1, were subjected to MP 3 weeks after IVTA; the eyes in the IVTA group (n=13), group 2, were subjected to MP, concomitant with IVTA; the eyes in the control group (n=19), group 3, underwent only IVTA application. Visual acuity (VA), fundus fluorescein angiography, and photography were performed in each group.

RESULTS

In the first group, the mean VA improved from 0.17-/+0.09 at baseline to 0.28-/+0.15 (p=0.114) and in the second group, deteriorated from 0.19-/+0.08 at baseline to 0.14-/+0.08 at the sixth month (p=0.141), respectively. In Group 3, the mean VA improved from 0.16-/+0.08 at baseline to 0.28-/+0.18 (p=0.118) at the end of the follow-up. When VA was compared between the control and study groups, significant difference was detected at the sixth month (p=0.038).

CONCLUSIONS

MP after IVTA improved VA, rather than MP concomitant with IVTA, and only IVTA application for CSME. MP after IVTA may reduce the recurrence of CSME and needs further investigations in a longer period.

Management of ocular inflammation and pain following cataract surgery: focus on bromfenac ophthalmic solution

Recently, several new ophthalmic NSAID products have been introduced for commercial use in the United States. The purpose of this review is to briefly overview the ophthalmic NSAIDs currently in use and to discuss the management of postoperative ocular inflammation and pain following cataract surgery with a particular focus on bromfenac ophthalmic solution 0.09%. Bromfenac ophthalmic solution 0.09% is indicated for the reduction of ocular pain and inflammation following cataract surgery. Studies have shown that bromfenac ophthalmic solution 0.09% has equivalent efficacy to the other topical NSAIDs in reducing postsurgical inflammation and controlling pain. The unique chemical structure of bromfenac makes it both a potent inhibitor of the COX-2 enzyme and a highly lipophilic molecule that rapidly penetrates to produce early and sustained drug levels in all ocular tissues. Clinically, these pharmacokinetic features are manifested in a rapid reduction of postsurgical inflammation and pain with bid dosing. Bromfenac ophthalmic solution 0.09% is a versatile agent and is effective when used as either monotherapy or as an adjunct therapy to steroids.

Iatrogenic Cushing syndrome caused by ocular glucocorticoids in a child

A boy aged 7.6 years presented to our Unit of Paediatric Endocrinology for evaluation of obesity. Progressive weight gain (10 kg) started 6 months earlier after an accidental penetrating orbital injury on the right eye. During this period the child has been treated with oral betamethasone (0.5 mg/day) for 1 month and dexamethasone 2% ocular drops (2 hourly by day) for 6 months. Physical examination showed he was 113.5 cm in height (-1.5 SD), weight 36.0 kg, blood pressure 110/90 mmHg (90th centile), body mass index 28 (+5 SD), truncal obesity, buffalo hump, "moon-face", increased lanugo hair and supraclavicular fullness. Endocrinological work-up revealed undetectable levels of basal adrenocorticotropic hormone (ACTH), basal and ACTH-stimulated cortisol and 24 h urine excretion cortisol, confirming the diagnosis of iatrogenic Cushing syndrome. The abrupt withdrawal of ocular glucocorticoids by the parents evoked two adrenal crises; 4 months later the patient recovered. In conclusion, we would alert doctors that every formulation of glucocorticoids, no ocular drops excluded, can determine severe systemic side effects and iatrogenic Cushing syndrome.

Superiority of tacrolimus 0.1% ointment compared with fluticasone 0.005% in adults with moderate to severe atopic dermatitis of the face: results from a randomized, double-blind trial

BACKGROUND

No specific data are available on tacrolimus ointment as a second-line treatment in adults with facial eczema.

OBJECTIVES

To compare tacrolimus 0.1% and fluticasone 0.005% ointments in adults with moderate to severe atopic dermatitis (AD) of the face in whom conventional treatment was ineffective or poorly tolerated.

METHODS

Patients were randomized to double-blind treatment of facial AD with twice-daily tacrolimus ointment (n = 288) or fluticasone ointment (n = 280) for 3 weeks or until clearance. After day 21, patients could continue without the study treatment, apply the same ointment once daily, or switch to the other medication twice daily, depending on lesion clearance and patient/physician satisfaction. The primary endpoint was the day-21 response [> or = 60% reduction in the modified Local Eczema and Severity Index (mLEASI) score]. Secondary endpoints included facial erythema and pruritus, global clinical response, treatment switching at day 21 and safety. RESULTS Response with tacrolimus ointment (93%) was superior to that with fluticasone (88%; P = 0.026). Improvements in mLEASI components were also greater with tacrolimus ointment. Facial erythema and pruritus improved in both groups. Global clinical response was rated 'marked improvement' or better in 88% and 79% of patients in the tacrolimus ointment and fluticasone groups, respectively. At day 21, 9% of patients switched from fluticasone to tacrolimus ointment, while 4.5% switched from tacrolimus ointment to fluticasone. Adverse events were more frequent with tacrolimus ointment as a result of the higher incidence of application-site skin burning sensation. Safety of both drugs was in line with their respective summary of product characteristics.

CONCLUSIONS

Tacrolimus 0.1% ointment has superior efficacy to fluticasone 0.005% ointment for twice-daily treatment of adults with moderate to severe facial AD in whom conventional therapy was inadequately effective or not tolerated. Tacrolimus 0.1% ointment is a safe and effective second-line treatment for the control of moderate to severe AD of the face.

Therapeutic effect of melatonin in experimental uveitis

Uveitis is a common ophthalmic disorder that can be induced in hamsters by a single intravitreal injection of bacterial lipopolysaccharide (LPS). To examine the therapeutic effects of melatonin on uveitis, a pellet of melatonin was implanted subcutaneously 2 hours before the intravitreal injection of either vehicle or LPS. Both 24 hours and 8 days after the injection, inflammatory responses were evaluated in terms of i) the integrity of the blood-ocular barrier, ii) clinical signs, iii) histopathological studies, and iv) retinal function. Melatonin reduced the leakage of proteins and cells in the anterior segment of LPS-injected eyes, decreased clinical signs such as dilation of the iris and conjunctival vessels, and flare in the anterior chamber, and protected the ultrastructure of the blood-ocular barrier. A remarkable disorganization of rod outer segment membranous disks was observed in animals injected with LPS, whereas no morphological changes in photoreceptor outer segments were observed in animals treated with melatonin. Furthermore, melatonin prevented a decrease in LPS-induced electroretinographic activity. In addition, melatonin significantly abrogated the LPS-induced increase in retinal nitric-oxide synthase activity, tumor necrosis factor-alpha, and nuclear factor kappaB p50 and p65 subunit levels. These results indicate that melatonin prevents the clinical, biochemical, histological, ultrastructural, and functional consequences of experimental uveitis, likely through a nuclear factor kappaB-dependent mechanism, and support the use of melatonin as a new therapeutic strategy for the treatment of uveitis.

Tolerability of loteprednol/tobramycin versus dexamethasone/tobramycin in healthy volunteers: results of a 4-week, randomized, double-masked, parallel-group study

OBJECTIVE

To compare the ocular comfort and tolerability of loteprednol etabonate 0.5%/tobramycin 0.3% (LE/T; Zylet) with dexamethasone 0.1%/tobramycin 0.3% (DM/T; TobraDex) in healthy volunteers.

RESEARCH DESIGN AND METHODS

In this multicenter, randomized, double-masked, parallel-group study, healthy volunteers (n = 306) were randomized to receive LE/T or DM/T four times per day for 28 days. Subjects recorded subjective ratings for seven comfort/tolerability parameters using an electronic patient diary (EPD). The primary endpoint was the difference at week 4 from the ratings of an artificial tear at baseline in comfort/tolerability parameters between treatment groups, using a noninferiority paradigm.

CLINICAL TRIALS REGISTRATION

ClinicalTrials. gov, NCT 00532961.

RESULTS

The 97.5% confidence intervals for the lower bound were within -10 for all of the seven comfort/ tolerability parameters evaluated (pain, stinging/burning, irritation, itchiness, foreign-body sensation, dryness, and light sensitivity). Secondary analysis revealed small but significant within-treatment differences in pain favoring LE/T over tears and in light sensitivity favoring tears over DM/T (p < 0.01). Small between-treatment differences in the changes from baseline tear ratings to individual study visits favored LE/T for pain, stinging/burning, irritation, itchiness, foreign-body sensation, and light sensitivity at visit 4 (p < or = 0.04); for pain, stinging/burning, and foreignbody sensation at visit 5 (p < or = 0.03), and for dryness and light sensitivity at visit 6 (p < or = 0.05).

CONCLUSIONS

LE/T satisfied all conditions of noninferiority to DM/T in comfort and tolerability. Subjects receiving LE/T were more likely to report better ocular comfort/tolerability ratings relative to baseline artificial tears than subjects receiving DM/T.

LIMITATIONS

The study population consisted of healthy volunteers.

Effectiveness of a new tobramycin (0.3%) and dexamethasone (0.05%) formulation in the treatment of experimental Pseudomonas keratitis

OBJECTIVE

To quantitatively determine, in a Pseudomonas keratitis model, the anti-inflammatory and bactericidal properties of a new formulation of tobramycin (0.3%) and dexamethasone (0.05%) that utilizes a xanthan gum vehicle.

RESEARCH METHODS

In a randomized and masked fashion, rabbit corneas (n>/=16 eyes per group) were intrastromally injected with 10(3) colony-forming units (CFU) of P. aeruginosa. Eyes were untreated or were administered a single drop every 15 min between 16 and 17 h postinfection (PI) and then a single drop every 30 min between 17 and 22 h PI, a total of 15 drops of either 0.1% dexamethasone and 0.3% tobramycin (TobraDex; Tdex) or a new formulation 0.3% tobramycin and 0.05% dexamethasone with xanthan gum (TobraDex ST; ST). Slit lamp examination scores (SLE+/-SEM) were derived from grading seven parameters at 22 h PI. Rabbits were sacrificed at 23 h PI and the log CFU+/-SEM per cornea was determined.

RESULTS

Untreated eyes had SLE scores of 11.11+/-0.43 and had log CFU of 7.27+/-0.06. Eyes treated with Tdex, as compared to the untreated eyes, had significantly lower SLE scores (7.39+/-0.21, p<0.0001) and significantly fewer bacteria (6.32+/-0.29 log CFU, p=0.0213). Eyes treated with ST had a SLE score (6.56+/-0.19) that was significantly lower than both the untreated eyes (p<0.0001) and the eyes treated with Tdex (p=0.0124). Furthermore, eyes treated with ST had significantly fewer log CFU (5.78+/-0.30) than untreated eyes (p=0.0001) or eyes treated with Tdex (p=0.0434).

CONCLUSIONS

The ST formulation with xanthan gum demonstrated statistically superior anti-inflammatory and bactericidal properties as compared to Tdex.

LIMITATIONS

Variations in inoculation procedures produced limited eye-to-eye differences in the infection.

Effects of loteprednol/tobramycin versus dexamethasone/tobramycin on intraocular pressure in healthy volunteers

PURPOSE

To compare the steroid-induced intraocular pressure (IOP) and other ocular adverse effects of loteprednol etabonate 0.5% and tobramycin 0.3% ophthalmic suspension with those of dexamethasone 0.1% and tobramycin 0.3% ophthalmic suspension.

METHODS

Three hundred six healthy volunteers received either loteprednol etabonate/tobramycin (n = 156) or dexamethasone/tobramycin (n = 150) at 4-hour intervals 4 times a day in both eyes for 28 days in this randomized, double-masked, multicenter, parallel-group trial. IOP, visual acuity (VA), and ocular health were assessed at all study visits (days 1, 3, 8, 15, 22, and 29), whereas undilated direct ophthalmoscopy was completed at the baseline and final visits. Adverse events (AEs) were assessed at all follow-up visits.

RESULTS

The number of subjects experiencing IOP increases of >or=10 mm Hg from baseline at any study visit for the loteprednol etabonate/tobramycin group (3 subjects, 1.95%) was significantly lower than that for the dexamethasone/tobramycin group (11 subjects, 7.48%; P = 0.0280), as were mean changes from baseline IOP (P < 0.05 at all visits). The lowest VA recorded for any subject at any visit was 20/40 and reductions of >or=2 lines at any visit were observed in 14 (4.55%) eyes for loteprednol etabonate/tobramycin and in 23 (7.82%) eyes for dexamethasone/tobramycin (P = 0.1257). Both treatments were well tolerated.

CONCLUSIONS

Loteprednol/tobramycin was significantly less likely to produce elevations in IOP than was dexamethasone/tobramycin in healthy subjects treated for 28 days. Both loteprednol etabonate/tobramycin and dexamethasone/tobramycin were well tolerated with low risks for systemic AEs and ocular AEs other than elevation in IOP for dexamethasone/tobramycin.

Steroid-induced ptosis: case studies and histopathologic analysis

PURPOSE

The purpose of this study was to review patients who developed ptosis after subtenon's steroid injection and to study the mechanism of steroid-induced ptosis in an animal model.

METHODS

Part 1. Twenty-two patients with uveitis who had received posterior subtenon's triamcinolone acetonide injections were retrospectively reviewed. Demographics, type of uveitis, type and number of surgeries, pre and postoperative marginal reflex distance (MRD1), and clinical outcomes were evaluated. Part 2. Study of rabbit levator muscle and aponeurosis histopathology after subtenon's triamcinolone injection was performed.

RESULTS

Part 1. The average age was 44.6 years (range: 14-85 years) with a mean follow-up of 14 months. The most common causes of uveitis included uveitis after cataract extraction (five), pars planitis (three), multifocal choroiditis (three), and juvenile rheumatoid arthritis (three). The average time to documented onset of ptosis was 13.9 months (range: 0-49 months). In patients who received only one steroid injection, the average time to ptosis recorded was 2.7 months (range: 0-6 months). Seventeen patients underwent ptosis repair. Part 2. No ptosis was noted in the experimental and control groups. Histopathologic analysis of levator tissues revealed no significant difference in atrophy or degree of inflammation between experimental and control groups.

CONCLUSIONS

Ptosis following subtenon's steroid injection ranged from mild to moderate and occurred a few months after steroid injection. Prior studies of muscles and periocular tissues exposed to corticosteroids demonstrated degenerative muscle changes; our studies revealed no histopathologic changes in the levator muscle or aponeurosis.

Pharmacology of ocular allergy

PURPOSE OF REVIEW

To evaluate the pharmacology of current drug development directed towards ocular allergy. Increased worldwide prevalence of ocular allergy has stimulated expansion of management strategies towards physiologic and immunologic drug targets.

RECENT FINDINGS

Present drug targets are located in the conjunctival mucosal surface at the initial site of allergen exposure. Pharmacologic intervention attends to early and late phase reactions. Targets generating a response include mast cells, IgE, released preformed mediator histamine, and newly formed mediators, such as prostaglandins, leukotrienes and cytokines. Methods to simulate allergy and measure efficacy of drugs are the conjunctival allergen challenge and the conjunctival provocation test. Pharmacologic outcome is measured via cytologic biomarkers and clinical signs/symptoms of redness, itching, lid swelling and chemosis. Endpoint instruments such as the Ocular Allergy Index and Eye Allergy Patient Impact Questionnaire have emerged from the field of pharmacoeconomics.

SUMMARY

Important pharmacologic properties of targets have been revealed. First, histamine is more specifically antagonized by second generation antihistamines. Second, newly formed mediators and downstream responders (prostaglandins, leukotrienes, interleukins, intercellular adhesion molecule 1, tumor necrosis factor, vascular cell adhesion molecule, eosinophils and neutrophils) are more selectively antagonized by dual/multiple-action agents.

Biodegradable scleral implants as new triamcinolone acetonide delivery systems

The goal of this study was to develop ocular scleral implants able to release triamcinolone acetonide (TA) overall several months. Scleral discs were manufactured by a compression-molding method using a new synthetic polymer, poly(methylidene malonate) (PMM2.1.2), as matrix. Implants with good mechanical properties adapted for in vivo implantation have been obtained when using high M(w) PMM2.1.2 (100,000 - 150,000 Da) associated with ethoxylated derivatives of stearic acid (Simulsol) or oligomers of methylidene malonate as plasticizer. After implantation in rabbit eyes, scleral implants showed a good ocular biocompatibility. Indeed, the clinical follow-up and ocular inflammation parameters, such as inflammatory cell number and protein content in aqueous humor, demonstrated that implants were well tolerated and did not provoke abnormal inflammation. Implants were able to release significant concentrations of TA in the vitreous and the sclera throughout 5 weeks.

An update on the use of ophthalmic ketorolac tromethamine 0.4%

Ketorolac tromethamine 0.4% ophthalmic solution, a recent reformulation of the original ketorolac tromethamine 0.5% solution, is indicated for the reduction of ocular pain and burning/stinging following cataract and refractive surgery. Studies have demonstrated that ketorolac tromethamine 0.4% has equivalent efficacy to ketorolac tromethamine 0.5% in reducing postsurgical inflammation and controlling pain. Several studies have demonstrated that, as well as reducing pain and ocular inflammation, ketorolac tromethamine 0.4% effectively treats cystoid macular oedema, inhibits miosis and may prevent cystoid macular oedema when used both pre- and postoperatively. Ketorolac tromethamine 0.4% is a versatile agent and is effective when used as either monotherapy or as an adjunct therapy to steroids.

RETINAL TOXICITY OF INTRAVITREAL TRIAMCINOLONE ACETONIDE

PURPOSE

To evaluate the morphologic effects of intravitreal triamcinolone acetonide (TA) on rabbit retina.

METHODS

Intravitreal injections of 0.5 mg, 1 mg, 4 mg, 8 mg, and 20 mg of TA (Kenalog-40; Bristol-Myers Squibb, Princeton, NJ) in 0.1 mL were given to pigmented rabbits. For control, 0.1 mL of TA vehicle and saline were injected. Animals were killed on day 14, and retinas were analyzed by light as well as electron microscopy.

RESULTS

No ophthalmoscopic change was found. Eyes injected with 0.5 mg and 1 mg of TA did not have morphologic abnormality. Eyes injected with 4 mg, 8 mg, and 20 mg showed destruction of photoreceptor outer segments and migration of macrophage-like cells in the subretinal space. Eyes injected with 20 mg showed more extensive damage and increased pigment granules in the retinal pigment epithelium cells with large oil droplets in the cytoplasm. Electron microscopy also showed loss of photoreceptor/retinal pigment epithelium interdigitations. Eyes injected with vehicle or saline did not show morphologic changes.

CONCLUSION

Single intravitreal injection of 0.5 mg or 1 mg of TA did not produce morphologic retinal changes in pigmented rabbits. However, injections of 4 mg, 8 mg, and 20 mg of TA produced outer retina toxic effects. These findings suggest that long-term retinal toxicity studies should be carried out, using single and repeated injections before this therapy becomes more widely used.

Corneal ulceration and perforation with ketorolac tromethamine (Acular) use after PRK

PURPOSE

To report a case of corneal ulceration and perforation after PRK connected with high doses of ketorolac tromethamine (Acula).

METHODS

A 31-year-old man presented 5 days after PRK in the left eye with corneal ulceration and perforation requiring penetrating keratoplasty. The patient admitted to using Acular every hour, ciprofloxocin every hour, and prednisolone acetate 1% QID postoperatively.

RESULTS

Laboratory tests, including corneal cultures, were normal. A diagnosis of corneal ulceration secondary to incorrect use of high-dose ketorolac tromethamine was made.

CONCLUSION

Judicious patient counseling is recommended when using topical NSAIDs in the setting of PRK.

Giant cell arteritis

Giant cell arteritis (GCA) is an immune-mediated vasculitis, affecting medium- to large-sized arteries, in individuals over the age of 50 years. Visual loss is a frequent complication of GCA, and once it occurs it tends to be both permanent and profound. Although major advances have been made in recent years in genetics, molecular biology and the description of the vessel wall morphology, the aetiology and pathogenesis of GCA are still incompletely understood. Over the years there has been much debate over whether polymyalgia rheumatica and GCA are separate or linked entities. Recent investigations support that polymyalgia rheumatica and GCA are two different expressions of the same underlying vasculitic disorder. A single cause or aetiological agent has not as yet been identified. Except for the histopathology of the arterial wall, there are no laboratory findings specific for GCA, and no particular signs or symptoms specific for the diagnosis. GCA typically causes vasculitis of the extracranial branches of the aorta and spares intracranial vessels. Transmural inflammation of the arteries induces luminal occlusion through intimal hyperplasia. Clinical symptoms reflect end-organ ischaemia. Branches of the external and internal carotid arteries are particularly susceptible. Corticosteroids remain the only proven treatment for GCA, the regimen initially involving high doses followed by a slow taper. However, early detection and treatment with high-dose corticosteroids is effective in preventing visual deterioration in most patients.

Ophthalmic drug design based on the metabolic activity of the eye: soft drugs and chemical delivery systems

Despite its apparent easy accessibility, the eye is, in fact, well protected against the absorption of foreign materials, including therapeutic agents, by the eyelids, by the tear-flow, and by the permeability barriers imposed by the cornea on one side and the blood-retinal barrier on the other. Most existing ophthalmic drugs were adapted from other therapeutic applications and were not specifically developed for the treatment of eye diseases; hence, they are not well suited to provide eye-specific effects without causing systemic side effects. A real breakthrough in the area of ophthalmic therapeutics can be achieved only by specifically designing new drugs for ophthalmic applications to incorporate the possibility of eye targeting into their chemical structure. Possibilities provided along these lines by designing chemical delivery systems (CDSs) and soft drugs within the framework of retrometabolic drug design are reviewed here. Both are general concept applicable in almost any therapeutic area. This review will concentrate on beta-adrenergic agonists and anti-inflammatory corticosteroids, where clinical results obtained with new chemical entities, such as betaxoxime, adaprolol, loteprednol etabonate, and etiprednol dicloacetate, exist to support the advantages of such metabolism-focused, ophthalmic-specific drug design approaches.

Glucocorticoid eye drops inhibit growth in the newborn rabbit

AIM

To investigate if postoperative treatment with dexamethasone eye drops has the capacity to affect longitudinal growth in newborn rabbits.

METHODS

Thirty-four male and female rabbits had clear lens extraction performed in one eye at 3 wk of age and were then treated either intensively (group 1) or less intensively (group 2) with de-escalating doses of dexamethasone eye drops for 8 wk (average doses 0.27 and 0.10 mg/kg body weight/day, respectively). The control group (group 3) received vehicle eye drops only. Body weight and crown-rump length were recorded every week. After 8 wk of treatment, all rabbits were killed and the left femur was measured.

RESULTS

Rabbits treated with dexamethasone eye drops gained weight slower (711+/-42 and 989+/-153 g weight increase for groups 1 and 2, respectively) than control animals (group 3; 1224+/-87 g weight increase; p<0.001 vs group 1, p<0.01 vs group 2). Longitudinal growth, determined as increase in crown-rump and femur lengths, was impaired by dexamethasone eye drops in a dose-dependent way. Crown-rump length increased by 8.25+/-0.86, 10.90+/-1.19 and 15.35+/-1.31 cm in groups 1, 2 and 3, respectively (p<0.001 for all comparisons). At endpoint, i.e. after 8 wk of treatment, the average femur length was 6.36+/-0.21, 7.39+/-0.27 and 8.37+/-0.28 cm in groups 1, 2 and 3, respectively (p<0.001 for all comparisons).

CONCLUSION

Dexamethasone, administered topically as eye drops, has systemic effects and impairs longitudinal growth in young rabbits. Therefore, we propose that growth should be closely monitored in all children intensively treated with glucocorticoid eye drops.

Reduced bone mineral density and radial bone growth in young rabbits treated with dexamethasone eye drops

OBJECTIVE

To investigate the effect of dexamethasone eye drops on bone metabolism in newborn rabbits.

METHODS

Thirty-four 3-week-old rabbits had unilateral clear lens extraction and were randomized into three groups. Postoperatively, group 1 received high-dose and group 2 low-dose dexamethasone eye drops (average doses 0.27 and 0.10 mg/kg body weight/day, respectively). These rabbits also received a postoperative subconjunctival injection of betamethasone. Group 3 (control) received vehicle eye drops only. After 8 weeks of treatment, all animals were killed and the left femurs were isolated and subjected to peripheral quantitative computerized tomography (pQCT) and dual X-ray absorptiometry (DXA) analyses.

RESULTS

DXA showed that rabbits treated with either a high or low dose of dexamethasone eye drops had significantly reduced areal bone mineral density (BMD), area and total bone mineral content (BMC) of the femur. Measurements with pQCT demonstrated a dose-dependent reduction in cortical BMC, cortical volumetric BMD and cortical area. These effects were associated with an inhibition of radial femur growth, cortical thickness and periosteal and endosteal circumferences.

CONCLUSION

Dexamethasone eye drops have systemic effects affecting several bone parameters in young rabbits. Any long-term systemic effects of ocular glucocorticoids need to be further studied.

Préparation d’un collyre de ciclosporine à 2 %

PURPOSE

Cyclosporine administration is very effective in the case of immunological diseases of the cornea, conjunctive or uvea. Moreover, it is widely used in the case of high-risk rejection corneal transplantation. We present a preparation of cyclosporine 2% eye drops.

METHODS

Cyclosporine 2% eye drops are prepared following a particular formulation including one part commercially available cyclosporine oral solution (Sandimmun) diluted in four parts of sterile castor oil. Manufacturing procedures maintain the sterile state of the preparation with a laminar airflow hood placed in a particulate controlled room, with pharmacists, technicians and clerical personnel wearing sterile clothes. Physical and chemical monitoring during and after manufacture for each batch guarantees the process and minimizes the risk of batch rejection. Chemical analysis of cyclosporine is conducted using a validated stability-indicating high-performance liquid chromatographic assay (reverse-phase). Blood dosages taken after the first administration at the 24th hour (after administration of the 6th drop) check for systemic integration.

RESULTS

Cyclosporine 2% eye drops are fairly stable: 12 months after manufacturing, concentrations result in levels not statistically different from concentrations measured the day of preparation. After a daily regimen of six drops in the eye, cyclosporine 2% eye drops have a very low systemic bioavailability, because the blood concentrations only reach the detection limit of the fluorescence polarization immunoassay used for cyclosporine drug monitoring. This explains the absence of systemic toxicity.

CONCLUSION

Cyclosporine 2% eye drops can be available in the hospital pharmacy. The eye drops are stable at room temperature and can be delivered up to 12 months after manufacture. No local adverse effects have been noted, probably in relation with the very low concentration of ethanol in the ocular preparation.

Topical corticosteroid therapy for cicatricial conjunctivitis associated with chronic graft-versus-host disease

A retrospective chart review was performed on seven patients treated with topical ocular corticosteroid therapy for progressive cicatricial conjunctivitis associated with chronic graft-versus-host disease (GVHD) following hematopoietic stem cell transplantation. A clinical grading criteria for conjunctival GVHD based on the degree of cicatrization was developed and patients graded prior to therapy. During the treatment course, the dose and frequency of topical corticosteroids and clinical outcomes were recorded. A complete response was defined as a complete resolution of the conjunctival hyperemia with either total resolution of the conjunctival fibrovascularization or presence of inactive conjunctival scarring. Prednisolone acetate 1% eye drops were used in a total of eight courses of therapy in seven patients. A complete response was documented in all seven patients with a total treatment duration of 7 weeks (median, range: 3-16 weeks). Additional studies are required to determine the long-term safety and efficacy of topical corticosteroids for cicatricial conjunctivitis associated with ocular GVHD in the context of a randomized, prospective clinical trial.

Prescribing trends in infectious keratitis: a survey of New Zealand ophthalmologists

PURPOSE

To obtain an overview of the treatment of infectious diseases of the cornea by New Zealand ophthalmologists and to analyse the data in the context of evidence-based treatment recommendations.

METHODS

A questionnaire was sent to all New Zealand ophthalmologists. It comprised 23 multiple-choice questions pertaining to the characteristics of the respondents, the nature of their practice and their prescribing preferences in infectious conjunctivitis and keratitis.

RESULTS

Of the 93 ophthalmologists surveyed, 80.6% returned the questionnaire. Of those in clinical practice, 91.4% regularly treated patients with corneal disease. A subspecialty interest in cornea was stated by 12.5% of these. This paper reports observations for adenoviral conjunctivitis and adenoviral, Herpes simplex, varicella zoster, bacterial, acanthamoebal and fungal keratitis. In some conditions prescribing practice varied dramatically, such as in adenoviral conjunctivitis where 50% of respondents prescribed a corticosteroid and 51.6% an antibiotic, whereas 37.5% prescribed only lubrication or no topical treatment. In other conditions there was a high degree of agreement between ophthalmologists; indeed, all ophthalmologists treated Herpes simplex dendritic keratitis with topical acyclovir. No statistically significant differences in prescribing habits were identified between subspecialist and non-subspecialist groups, although some important clinical differences emerged. There were occasional marked differences in response when the age group of respondents was considered, particularly in relation to the management of adenoviral infections and bacterial keratitis.

CONCLUSIONS

The findings of this survey suggest that the majority of New Zealand ophthalmologists generally follow international guidelines for the management of infectious keratitis. The identified variations in management provide a foundation for informed clinical debate and the development of treatment guidelines, in line with evidence-based recommendations.

Use of immunosuppressive agents in uveitis

PURPOSE OF REVIEW

This review summarizes current patterns in the use of immunosuppressive agents in patients with uveitis.

RECENT FINDINGS

A number of immunosuppressive agents are currently available for the treatment of uveitis. Reports of safety and efficacy, although numerous, have been largely nonrandomized and performed without controls, limiting, to some extent, the strength and generalizability of their conclusions. Nonetheless, the volume of case reports and case series provides compelling evidence that immunosuppressive agents are effective at providing long-term control in patients with moderate to severe chronic or recurrent uveitis. The choice of immunosuppressive agent is complex, and depends on the cause and severity of the patient's underlying inflammation, the presence or absence of associated systemic inflammation, and the patient's prior response to immunosuppressive treatments.

SUMMARY

Although corticosteroids remain the primary initial treatment for patients with uveitis, use of noncorticosteroid immunosuppressive agents in selected patients with uveitis allows for improved control and decreased risk of corticosteroid-induced side effects.

Severe infective keratitis leading to hospital admission in New Zealand

AIM

To identify key risk factors and the management and outcome of severe infective keratitis leading to public hospital admission in New Zealand.

METHODS

Over a 2 year period, all admissions of presumed infective keratitis to Auckland Hospital were identified. The clinical records of all 103 cases were retrospectively reviewed with respect to clinical features, risk factors, management, and outcomes.

RESULTS

The mean time from first symptoms or signs and presentation to hospital was 8.9 (SD 15.5) days. The majority of subjects, 88%, had at least one of the risk factors commonly associated with infective keratitis including previous ocular surgery (30%), contact lens wear (26%), topical corticosteroid use (25%), and ocular trauma (24%). Corneal scraping was performed in 92% and of a total of 105 scrapes, 71% were positive. Bacteria were isolated in all these cases, the majority being Gram positive organisms (72%). The most common isolates identified were coagulase negative Staphylococcus (16%), Propionibacterium acnes (14%), Staphylococcus epidermidis (11%), and Streptococcus pneumoniae (9%). In addition, yeasts were isolated in 5%, fungi in 4%, virus in 2%, and chlamydia in 1%. Importantly, polymicrobial infection accounted for 33% of culture positive cases. Antimicrobial treatment was changed on the basis of culture results in 17 cases (16.5%). Median initial visual and final best corrected visual acuity was 6/36-6/48 (logMAR 0.86) (IQR 0.39-2.00) and 6/12-6/15 (logMAR 0.360) (IQR 0.15-1.70), respectively. Previous ocular surgery and topical corticosteroid use were significantly associated with poorer visual acuity. The mean hospital stay was 5.8 days and the median 4.0 (IQR 2.0-8.0) days. Longer duration of stay was associated with the presence of hypopyon, larger ulcers, previous ocular surgery, and poor visual acuity.

CONCLUSIONS

Infectious keratitis is an important cause of ocular morbidity. A significant proportion of cases have potentially modifiable risk factors. Previous ocular surgery and topical corticosteroid use, in particular, were associated with poorer visual outcomes. Many cases of severe keratitis might be avoided, or their severity reduced, by appropriate education of patients and ophthalmologists.