Chlamydial conjunctivitis in contact lens wearers: successful treatment with single dose azithromycin.

PURPOSE: To reveal clinical presentations of chlamydial conjunctivitis in contact lens wearers as well as to evaluate the clinical and microbiological efficacy of oral azithromycin in the treatment of this condition. METHODS: Twenty contact lens users with chlamydial conjunctivitis were included in this retrospective study. Chlamydial infection was diagnosed by isolation of Chlamydia trachomatis in cell culture of conjunctival scrapings. All patients were treated with a single 1 g oral dose of azithromycin. Follow-up clinical and microbiological examinations were performed 1 month after treatment. RESULTS: All patients suffered from some ocular symptoms such as itching, burning, tearing, and nonspecific irritation, but none had apparent conjunctival injection or any conjunctival discharge. The majority (90%) had bilateral complaints. Mild follicular reaction, limited to the lateral part of lower fornices, was present in 17 patients; the remaining patients had normal biomicroscopical findings. Four weeks following the single azithromycin dose, C. trachomatiswas eradicated in all patients and 17 (85%) were free of symptoms. CONCLUSION: Chlamydial infection should be considered more frequently in differential diagnosis of symptomatic contact lens wearers. Azithromycin is the most promising agent for the treatment of chlamydial conjunctivitis due to its excellent bacteriological efficacy and very convenient single dose administration.     

Side effects in the treatment of herpetic keratitis

Various side effects due to antiherpetic drugs observed in the last ten years in our department were studied. A total of 132 patients were treated with 5-iodo-2'-deoxyuridine (IDU), 69 with trifluorothymidine (F3T), 58 with acyclovir (ACV) and 33 with adenine arabinoside (ara-A). Patch tests were routinely done when patients exhibited contact dermatitis. Of the patients treated with IDU, 3 (2.3%) showed contact dermatitis, 2 (1.5%) follicular conjunctivitis and 1 (0.8%) punctate keratopathy. Of the patients treated with F3T, 7 (10.1%) exhibited contact dermatitis and 1 (1.4%) follicular conjunctivitis. In the group treated with ACV, 2 (3.4%) patients showed punctate keratopathy. The patients who received ara-A did not show any side effects. We found that F3T caused contact dermatitis more frequently in Japanese people than Europeans. These side effects were resolved by switching to another anti-herpetic drug without the occurrence of cross-allergy. Therefore, switching to another drug is strongly recommended when patients exhibit side effects in the treatment of herpetic keratitis. Other complications were allergy to atropine and to drug preservative.     

Tolerance to different kinds of contact lenses in young atopic and non-atopic wearers.

PURPOSE: To study tolerance to three types of soft and onetype of rigid gas permeable (RGP) contact lens in young atopic and non-atopic subjects starting to wear contact lenses. METHODS: A prospective study was conducted in 73 young subjects (mean age: 18.7 years, range: 11-37 years). Each subject was allotted at random to one of four groups. Each group of subjects used a different type of contact lens for a year. Tolerance was determined by means of self-assessment by the subjects, ophthalmologic methods, and cytology. The study was conducted on a blind basis. The investigators assessing tolerance did not know what kind of lens a patient had been wearing. RESULTS: Fifty-six percent of subjects who had used soft contact lenses, but only 14% of RGP lens users described their lenses as very comfortable to wear. Sixty-three percent of non-atopic subjects but only 47% of atopic subjects described their lenses as very comfortable to wear. No differences were found between the three types of soft contact lens. Four cases of giant papillary conjunctivitis (GPC) and two cases of macropapillary reaction were recorded. No connections with atopy, type of lens, or lens care solution were found. CONCLUSIONS: Higher percentages of users of soft contact lenses than users of RGP contact lenses described their lenses as very comfortable to wear. Wearing of all types of lenses was associated with follicular or papillary reactions in some subjects. Young people can wear contact lenses safely only if monitoring takes place at least twice a year.     

Grading static versus dynamic images of contact lens complications

Background: This study was conducted to investigate grading performance when estimating the severity of static versus dynamic images of contact lens‐related ocular pathology. Methods: Thirty‐eight subjects used the Efron Grading Scales for Contact Lens Complications to grade the severity of ocular pathological changes depicted in static and dynamic (movie clip) computer‐displayed images of each of the following contact lens complications: bulbar conjunctival redness, limbal redness, papillary conjunctivitis, corneal staining, corneal infiltrates and meibomian gland dysfunction. The viewing of static and dynamic images was separated by seven weeks. Results: Grades assigned to dynamic images were 0.6 and 0.7 grading scale units higher than those assigned to static images for limbal redness and papillary conjunctivitis, respectively (p < 0.0001 for both). No difference was observed for the other four complications. There was an apparent trend for grading variability to be reduced (that is, observers grading in closer agreement) when grading dynamic versus static images. Conclusions: Absolute grades based on an assessment of signs of pathology represented in static images may, in some instances, underestimate the true severity of the condition.     

Comparison of the performance of 6- or 30-night extended wear schedules with silicone hydrogel lenses over 3 years.

AIM: To compare the clinical performance of silicone hydrogel lenses worn for 6- or 30-nights, with monthly replacement, for 3 years. METHODS: In this 3-year prospective clinical trial, 161 subjects were enrolled and 154 commenced extended wear. Clinical performance was assessed by comparing discontinuations and lens surface characteristics (front surface deposits, lens wettability, number of mucin balls), lens fitting performance (primary gaze movement, lens tightness), and physiologic parameters (limbal and bulbar redness, corneal and conjunctival staining, microcysts) and subjective parameters (ratings of comfort and vision) between groups. RESULTS: Eighty-eight subjects remained in the study after 36 months. There were no differences in the probability of subjects surviving in either group, and the major cause of lens-related discontinuation in both groups was contact lens-induced papillary conjunctivitis. There were no clinically important differences in performance between wear schedules. CONCLUSION: The long-term clinical performance of silicone hydrogels worn for 6- or 30-nights continuously was similar. Clinical markers of hypoxia were low in both groups, and the 6-night wear schedule was not superior to the 30-night wear schedule with regard to preventing lens spoilage, improving corneal physiology, or subjective symptoms of comfort and vision.     

Disposable 1-day Acuvue contact lenses for the delivery of lomefloxacin to rabbits' eyes.

PURPOSE: To investigate the ability of a disposable soft contact lens (1-Day Acuvue) to deliver lomefloxacin, a fluoroquinolones antibiotic, into the cornea and aqueous humor of rabbits. METHODS: Experiments were conducted on adult albino rabbits. 1-Day Acuvue lenses were immersed for 1 hour in commercially-available lomefloxacin eye solution and then placed on the cornea. After 0.5, 2, 4,6, and 8 hours, the animals were killed and the lenses were removed and placed into a 20 mL saline bath. Corneal tissue and aqueous humor samples were also obtained at these times. The release of lomefloxacin from the lenses was calculated by measuring the amount of drug remaining in the lenses after removal from the rabbit eyes. The concentration of lomefloxacin in the cornea and anterior chamber following the wearing of lomefloxacin-loaded lenses was compared with the concentrations following frequent-drop therapy (one drop of lomefloxacin hourly for 8 hours). RESULTS: In vivo, lomefloxacin was released from 1-Day Acuvue lenses gradually over 8 hours. The cornea and aqueous humor levels in the eyes following the wear of lomefloxacin-loaded lenses were significantly higher than those achieved by frequent-drop therapy. The drug levels in the cornea and aqueous humor generally remained above the 90% minimal inhibitory concentration for 8 hours in the 1-Day Acuvue lens group. CONCLUSIONS: 1-Day Acuvue contact lenses soaked in 0.3% lomefloxacin can release sufficient amounts of lomefloxacin and in this study produced higher levels in both the cornea and aqueous humor than that achieved by frequent-drop therapy for up to 8 hours. We conclude that 1-Day Acuvue contact lens can be used as a drug delivery system for lomefloxacin.     

The ocular response to extended wear of a high Dk silicone hydrogel contact lens

Purpose: A four‐month extended wear clinical trial was conducted to compare die ocular effects of a high Dk Balafilcon A silicone hydrogel lens and a low Dk HEMA 38.6 per cent H²O soft lens. Method: Twenty‐four subjects who were adapted to daily wear of soft lenses wore a high Dk lens in one eye and a low Dk HEMA lens in the other eye for four months on an extended wear basis after one week of daily wear. Thirteen progress evaluations were conducted using standard clinical procedures. Results: Eighteen subjects (75 per cent) completed the study. The high Dk lens induced significantly less bulbar and limbal injection and corneal vascularisation dian the low Dk HEMA lens (p < 0.05). Epithelial microcysts were observed only in the eyes wearing the low Dk lens. A significant increase in myopia was found in die eyes wearing die low Dk HEMA lens (mean = 0.50 D, p < 0.01) compared to die insignificant myopic increase of 0.06 D in the eyes wearing the high Dk lens. Three subjects developed small infiltrates in the high Dk lens wearing eyes and significantly more post‐lens debris was observed under the high Dk lens. Six subjects developed papillary conjunctivitis in die eye wearing silicone hydrogel lenses but only two of those were discontinued from the study. Conclusion: No hypoxia‐related effects were observed with extended wear of the high Dk Balafilcon A silicone hydrogel lens.     

Prostaglandin F2 alpha-1-isopropylester lowers intraocular pressure without decreasing aqueous humor flow

Using fluorophotometry, we performed a randomized, dose-response study of the effects of a prostaglandin derivative on aqueous humor flow. Prostaglandin F2 alpha 1-isopropylester, 0.224 micrograms, 0.448 micrograms, and 1.120 micrograms, in saline with polysorbate 80 was instilled into one eye of 20 subjects in three separate dose studies. Polysorbate 80 in saline was instilled in the fellow eye as a control. The drug had no measurable effect on aqueous humor flow or corneal endothelial permeability. Intraocular pressure measured eight hours after administration of the highest dose, 1.120 micrograms, was 20% lower in the treated eye as compared to the fellow eye (P less than .001).     

Absorption of topical disodium cromoglycate and its preservatives by soft contact lenses

Disodium cromoglycate (2%) (DSCG) was administered four times daily for one month to 10 patients using extended wear contact lenses. The same regimen was also followed for five days by 25 patients using daily wear soft contact lenses. The contact lenses and their soaking solutions were collected at the end of the wearing period and analyzed for DSCG, benzalkonium chloride (BAK), 2-phenylethanol, and EDTA. The lens soaking solutions and eluates prepared from the lenses were tested. In the extended wear group, small amounts of DSCG were detected in both the eluates and the soaking solutions. In the daily wear group DSCG was detected in small amounts in the soaking solutions but not in the eluates. BAK, EDTA, and 2-phenylethanol were not detected in any of the eluates or soaking solutions. During the study, no side effects of DSCG were observed in any of the patients. In animal experiments, radioactive DSCG was applied once to a series of rabbit eyes. Four hours after administration of the labelled DSCG, the animals' tears, cornea, and aqueous humor were examined for DSCG. Of the instilled dose, approximately 0.2% was found in the cornea, and less than 0.04% was found in the aqueous humor. We conclude that commercial DSCG applied topically to contact lenses does not result in the accumulation of either the drug or its preservatives in lenses and that DSCG can be safely applied directly onto a worn contact lens.     

The influence of lens conditioning on signs and symptoms with new hydrogel contact lenses

Background: Daily disposable contact lenses are considered to be the pinnacle of safe contact lens wear, yet it has been suggested that it takes some period of wear for the lens surface to reach optimal compatibility with the ocular surface. This study assesses the influence of brief treatment with a conditioning drop on the ocular response to new contact lenses over a single day of wear. Methods: The study was a single‐masked, paired (contralateral) comparison of the signs and symptoms with wear of new Acuvue 2 contact lenses pretreated with a conditioning agent containing carboxymethylcellulose (carmellose, CMC) against new lenses inserted directly from the blister pack. Sixty‐one subjects participated in the study, of whom 59 were considered eligible for data analysis. Subjects were also divided into symptomatic and asymptomatic lens wearers based on their overall comfort level in lens wear. Symptoms and signs were recorded at lens delivery and following eight hours of wear. Results: A set of slitlamp signs, comprising corneal staining (p < 0.05), limbal redness (p < 0.05), bulbar conjunctival hyperaemia (p < 0.05), bulbar conjunctival staining (p < 0.01) and palpebral conjunctival redness (p < 0.05) showed small but statistically significant (p < 0.05) end‐ofday mean values in favour of the lens that was conditioned with the rewetting agent. These data were supported by the proportion of subjects showing lower gradings with conditioned lenses versus unconditioned lenses, as follows: corneal staining (35 per cent versus 12 per cent, p <0.05), limbal redness (43 per cent versus 22 per cent, p < 0.05), bulbar conjunctival hyperaemia (50 per cent versus 15 per cent, p < 0.05), bulbar conjunctival staining (46 per cent versus 30 per cent, p < 0.1) and palpebral conjunctival hyperaemia (28 per cent versus 17 per cent, NS). For those subjects reporting symptoms with lens wear (n = 12), there was a statistically significant (p < 0.05) preference in terms of comfort as a result of preconditioning. Conclusions: The results of the investigation suggest that use of a conditioning agent can provide a more physiologically suitable environment for a new lens, thereby reducing the clinical signs associated with lens discomfort. The protocol used here, which is based on a statistical paradigm using standard pictorial grading scales, allows high sensitivity in detecting small changes in ocular parameters.     

An experimental study of gentamycin delivery into cornea and aqueous humor from the collagen corneal shield]

Collagen corneal shields immersed in 13.33 mg/ml gentamycin solution for 5 minutes were placed in rabbit eyes and the gentamycin concentrations in the cornea and aqueous humor were determined with radioimmunoassay. The results were compared with those achieved by soft contact lens, subconjunctival injection, and frequent instillations. It was found that (1) 1 and 3 hours after application, the collagen corneal shield produced significantly higher concentration of gentamycin in the aqueous than did the other methods, and in the cornea than did the contact lens or instillations; and (2) 6 hours after application, the antibiotic level in the cornea dropped lower than that by subconjunctival injection, but still 15-30 times higher than the bactericidal concentration.     

Neutrophil chemotactic factors in the tears of giant papillary conjunctivitis patients.

This study was designed to determine the presence of neutrophil chemotactic factors in the tears of patients with giant papillary conjunctivitis (BPC) secondary to contact lenses. Chemotactic activity was measured using modified Boyden chambers and the chemoattractant formylmethionyl-leucyl-phenylalanine (f-MLP) for 100 percent response. Elevated levels of chemotactic activity were found in the tears of symptomatic patients (80.8 +/- 6.4, % f-MLP) compared with control tears of asymptomatic contact lens wearers (15.7 +/- 3.3%) and non-contact lens wearers (5.6 +/- 1.2%). Using radioimmunoassay, C5a (serum-derived chemoattractant), leukotriene-B4, and interleukin-1 (immune cell-derived chemoattractants) were not detected in the tears of symptomatic patients. The authors determined whether injured conjunctival cells participate in this process by releasing neutrophil chemotactic factors. Isolated rabbit bulbar conjunctiva incubated with culture medium for 4 and 6 hr released high levels of neutrophil chemotactic factors. The release of these factors from injured conjunctiva support the premise that physical trauma of conjunctival cells induced by contact lenses may be an important component of the pathophysiology of giant papillary conjunctivitis.     

Immunosuppressive effect of cholera toxin B on allergic conjunctivitis model in the guinea Pig

Purpose: To investigate the immunosuppressive effects of mucosal immune therapy in experimental allergic conjunctivitis.Method: We used 11 white Hartrey guinea pigs divided into two groups. Six animals (treated group) received pretreatment with topical instillation of cholera toxin B (4 &mgr;g/30 ml) and ovalbumin (10 &mgr;g/30 ml). The other group of 5 animals served as control. All the animals received intra-abdominal injection of ovalbumin (100 g/mL) and aluminum hydroxide (5 mg/mL) repeated twice 2 weeks apart. Allergic conjunctivitis was induced by topical instillation of ovalbumin solution (5 mg/mL) 1 week after the above procedure. Result: Both groups developed palpebral and bulbar edema with hyperemia 30 minutes after instillation. The allergic reaction was significantly less in score in the treated than in the control group (Mann-Whitney U-test: P <.01). The clinical findings subsided after 6 hours. The treated group showed less eosinophilic infiltration in the conjunctiva and the limbus, particularly in the conjunctival epithelium, than in the control group at 6 and 24 hours.Conclusion: Pretreatment with topical cholera toxin B and antigen suppresses clinical and histological findings in experimentally induced allergic conjunctivitis.     

Use of collagen corneal shields versus soft contact lenses to enhance penetration of topical tobramycin

We compared the corneal penetration in rabbits of topical tobramycin in the presence of collagen corneal shields and bandage soft contact lenses. A collagen corneal shield was placed on six albino rabbit eyes, while therapeutic soft contact lenses (61.4% poly-2-hydroxyethyl-methacrylate/38.6% water) were placed on six eyes. Four control eyes received no shield or contact lens. Topical tobramycin was applied to all 16 eyes every five minutes for six doses. Samples of aqueous humor were removed at 15 and 60 minutes following the last dose. Collagen corneal shields allowed a significant (P less than .05) increase in tobramycin penetration into the anterior chamber at 60 minutes compared with hydrophilic soft contact lenses or controls.     

Immunosuppressive effect of cholera toxin B on allergic conjunctivitis model in the guinea pig]

PURPOSE: To investigate the immunosuppressive effects of mucosal immune therapy in experimental allergic conjunctivitis. METHOD: We used 11 white Hartrey guinea pigs divided into two groups. Six animals (treated group) received pretreatment with topical instillation of cholera toxin B (4 micrograms/30 ml) and ovalbumin (10 micrograms/30 ml). The other group of 5 animals served as control. All the animals received intraabdominal injection of ovalbumin (100 g/ml) and aluminium hydroxide (5 mg/ml) repeated twice 2 weeks apart. Allergic conjunctivitis was induced by topical instillation of ovalbumin solution (5 mg/ml) one week after the above procedure. RESULT: Both groups developed palpebral and bulbar edema with hyperemia 30 minutes after instillation. The allergic reaction was significantly less in score in the treated than in control group (Mann Whitney U-test: p < 0.01). The clinical findings subsiced after 6 hours. The treated group showed less eosinophilic infiltration in the conjunctiva and the limbus, particularly in the conjunctival and the limbus, particularly in the conjunctival epithelium, than in control group at 6 and 24 hours. CONCLUSION: Pretreatment with topical cholera toxin B and antigen suppresses clinical and histological findings in experimentally induced allergic conjunctivitis.     

Evaluation of topical cromolyn sodium in the treatment of vernal keratoconjunctivitis

A randomized, double-masked, placebo-controlled multicenter study was conducted for 6 weeks in 12 centers to evaluate the efficacy and safety of cromolyn sodium 4% ophthalmic solution (Opticrom) for the treatment of active bilateral vernal conjunctivitis. Objective clinical signs were graded weekly by an ophthalmologist while patients kept a daily record of the severity of their symptoms. Sixty-five patients completed the study; 35 received cromolyn sodium and 30 were treated with a matching placebo (the drug vehicle). Statistically significant differences in favor of cromolyn sodium treatment were found for conjunctival injection, limbal injection, limbal edema, tearing, and symptoms summary score. There were few side effects (usually mild stinging and burning which did not require drug stoppage). Only one patient required drug discontinuation for possible drug- or vehicle-related side effects. Cromolyn sodium was found to be significantly more effective than placebo in treating the signs and symptoms of vernal keratoconjunctivitis (VKC). When results were stratified in terms of the atopic status of the patient, it was clear that the allergic patients responded better to cromolyn sodium than did those in whom allergic (IgE-mediated) factors appeared unimportant in the disease process.     

Diffusion of pefloxacin in the aqueous humor and crystalline lens after repeated oral administration in man

The intraocular penetration of pefloxacin was evaluated in 38 patients undergoing extracapsular cataract extraction. Patients were treated for three days with 400 mg of pefloxacin every twelve hours (the first dose being 800 mg). The mean maximum concentration of pefloxacin reached six hours after the last dose in the aqueous humor was 7.69 +/- 3.50 mg/l and reached twelve hours after the last dose in the lens was 4.59 +/- 3.15 micrograms/g. Antibiotic levels were measured by high performance liquid chromatography. Several doses until plasma steady state were effective in obtaining a higher level than a single dose of 400 mg. The ratio between aqueous humor and serum concentrations ranged between 0.50 and 0.89 (mean 68%). These concentrations in aqueous humor were higher than the MIC90 of pefloxacin for most bacterial pathogens involved in endophthalmitis 24 hours after the last dose.     

Effects of drug vehicles on ocular uptake of tetracycline.

Varying concentrations of tetracycline hydrochloride were topically applied to the rabbit eye in several ophthalmic vehicles. The antibiotic levels in the corneal epithelium, aqueous humor, and lens were markedly elevated by increasing the drug concentration and the drug contact time with the eye. The ocular levels of tetracycline were increased by the vehicle in this ascending order: isotonic saline, 1.4% polyvinyl alcohol, 1% alpha-methylcellulose, and a 6:4 mixture of white petrolatum-mineral oil ointment. Tetracycline hydrochloride as a 2.0% suspension in ointment produced anterior chamber and corneal concentrations for several hours in the range of bacteriostasis for many gram-negative bacteria that occasionally invade the eye.     

Giant Papillary Conjunctivitis A Mechanical Aetiology

Recent reports in the literature have described cases of giant papillary conjunctivitis occurring In contact lens wearers. An immunologic basis has been proposed for the syndrome. This paper seeks to present another form of giant papillary conjunctivitis occurring in certain aphakic patients. In these cases the cause seems to be purely mechanical and it Is suggested that mechanical factors should be borne in mind when investigating giant papillary conjunctivitis in contact lens wearers. The ten aphakic cases referred to in this paper had all the routine cataract extractions using continuous 10–0 nylon suturing. Trouble occurred when the end of the nylon suture protruded vertically through the conjunctival epithelium and was accompanied by irritation, excessive mucus production, and slight congestion around the protruding suture end. The most outstanding feature, however, was the subtarsal appearance where giant papillae were seen in the area irritated by the suture end. On removal of the offending suture comfort was immediately restored, mucus hypersecretion disappeared in a day or two and the papillae themselves had largely disappeared within a month. In this paper the known causes, clinical appearances and differentiation between follicular and papillary hypertrophy are discussed.     

Immunosuppressive effect of cholera toxin B on allergic conjunctivitis model in guinea pig

PURPOSE: To investigate the new method of immunotherapy using cholera toxin B (CTB) in experimental allergic conjunctivitis. METHODS: We used 21 white Hartley guinea pigs. The animals were sensitized by intraperitoneal injection of ovalbumin (100 microg/mL) and albumin hydroxide (5 mg/mL) repeated after an interval of 2 weeks. One week after the second injection, conjunctivitis was induced by topical instillation of ovalbumin (5 mg/mL). The animals were divided into two groups, CTB group and control group. The CTB group underwent pretreatment of topical instillation of CTB (4 microg/30 mL) and ovalbumin (10 microg/30 mL), three times a day for 3 days, 1 week before the intraperitoneal injection. The control group did not undergo the pretreatment. Clinical examination was performed at 0.5, 6, and 24 hours after the development of conjunctivitis. Histological examination was performed at 6 and 24 hours. RESULTS: Both groups developed palpebral and bulbar edema with hyperemia 30 minutes after instillation of ovalbumin. The allergic reaction score was significantly less in the CTB group than in the control group (Mann-Whitney U-test: P <.01). The clinical reactions subsided after 6 hours. The CTB group showed less eosinophilic infiltration in the conjunctiva and the limbus, particularly in the conjunctival epithelium, than the control group at 6 and 24 hours. CONCLUSION: Pretreatment with topical CTB and antigen suppresses clinical and histological findings in experimentally induced allergic conjunctivitis.