Conditioning of hydrogel lenses by a multipurpose solution containing an ocular lubricant.

PURPOSE: The addition of the ocular lubricant hydroxypropyl methylcellulose (HPMC) to a multipurpose contact lens solution conditions the hydrogel lens surface. This investigation reports the clinical benefits to contact lens wearers and the improved physical properties of the solution with HPMC added. METHODS: One-hundred forty-seven subjects wearing a variety of hydrogel lenses used a multipurpose solution with and without addition of HPMC and were assessed for product comfort and preference. In the laboratory, conditioning by HPMC was demonstrated in fluid coating, dynamic contact angle, uptake of fluid on hydrogel lenses, and release of HPMC from lenses after soaking. RESULTS: Lens wearers reported the multipurpose solution with HPMC more comfortable, including measures relating to maintaining lens moisture over time. The multipurpose solution with HPMC produced a thicker and longer-lasting layer of fluid on hydrogel lenses and other plastics than other multipurpose solutions. HPMC was found to adsorb to both group 1 and 4 lens materials and release gradually, with detectable amounts releasing from the lens beyond 12 hours. CONCLUSIONS: The conditioning properties of the multipurpose solution with HPMC produce improved wetting of lenses and enhanced lens wearing comfort. Binding of HPMC to the lens surface and subsequent time-release is the probable mechanism for these benefits.

A comparison of contact lens-related complications in various daily wear modalities.

PURPOSE: To determine the incidence of contact lens-related complications in various daily wear contact lens modalities. METHODS: The charts of 138 daily wear contact lens patients (35 daily disposable, 34 two week replacement, 34 frequent replacement, and 35 conventional daily wear lens users) were reviewed for subjective and objective contact lens problems. We also looked at two subgroups: first time lens wearers and patients with previous lens-related problems. The rate of lens related complications were calculated as events per person per year (E/P/Y) of lens wear for each year and for the total 3-year study. The percentage of patients in each group who experienced any complication was calculated. We also compared the complication rate for the groups in our current study to the rates calculated for disposable extended wear and conventional extended wear patients from our previous study. RESULTS: We found that the E/P/Y were significantly lower for daily disposable lens wearers, but no significant differences were noted for all other lens wear modalities. There was a trend in most groups toward decreased numbers of complications in the second and third years of lens wear. Of the 23 individual signs and symptoms that were analyzed, three occurred most frequently among daily disposable lens wearers, two were most common in the 2-week replacement group, four occurred most often in frequent replacement patients, and eight were most frequent in conventional daily lens wearers. (In three categories, there were two groups with ties for the highest rate of occurrence, and two categories with zero rates for all groups.) Most of the observed differences in complication rates for individual signs and symptoms did not reach the level of statistical significance. CONCLUSIONS: Daily disposable lens wearers had the lowest overall complication rate.

Efficacy and safety of ketorolac tromethamine 0.5% and levocabastine 0.05%: a multicenter comparison in patients with seasonal allergic conjunctivitis.

This multicenter, double-masked, randomized, parallel-group study compared the efficacy and safety of ketorolac tromethamine 0.5% ophthalmic solution with levocabastine 0.05% and ketorolac tromethamine vehicle in patients with seasonal allergic conjunctivitis. One drop of ketorolac, levocabastine, or vehicle was instilled in each eye four times daily for 6 weeks. In the majority of efficacy variables, ketorolac produced the greatest improvements, followed by levocabastine and vehicle. Ketorolac was significantly more effective (P < .05) than vehicle in reducing mean itching scores, palpebral hyperemia, bulbar hyperemia, and edema. Patients treated with ketorolac reported significant improvements (P < .05) in their ability to sleep and to concentrate on work, compared with those who received vehicle. No significant differences were noted among the treatment groups in safety or tolerability. Ketorolac tromethamine 0.5% ophthalmic solution instilled four times daily is effective and safe in reducing the signs and symptoms of seasonal allergic conjunctivitis.

Ligneous conjunctivitis: biochemical evidence for hypofibrinolysis.

Ligneous conjunctivitis (LC) is a rare disease of unknown etiology characterized by the growth of "woody" plaques on ocular and extraocular mucosa. These lesions are comprised of fibrin and both direct and indirect evidence implicates hypofibrinolysis as the primary defect in LC. To further elucidate the pathophysiology of LC we investigated the biochemical aspects of ligneous lesions with respect to the fibrinolytic system. Ligneous lesions were obtained from the right eye of a 15 year-old female patient with longstanding LC since age 2.5 year. Ligneous conjunctivitis in this patient has exhibited a chronic recurrent coarse and has involved multiple muscosal sites. Samples analyzed included an abundant mucoid thread from the conjunctival fornix and the ligneous plaque attached to the inferior tarsus. Samples were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) to characterize protein profiles and by a variety of zymographic methods to visualize fibrinolytic enzymes. We found that mucoid and ligneous samples were distinct entities. Specifically, ligneous samples contained polypeptides with electrophoretic profiles characteristic of intact fibrin, and were replete in fibrin-bound tissue plasminogen activator (t-PA). Despite the presence of ample t-PA, ligneous samples were essentially devoid of fibrinolytic activity. In contrast, neither proteins nor t-PA could be detected in mucoid samples when fractionated by 7.5-15% SDS-PAGE or analyzed by fibrin zymography, respectively. Despite the absence of t-PA, mucoid samples were replete in fibrinolytic activity. This activity was plasminogen independent, heterogenous and inhibited by PMSF. Degradation profiles suggested that this activity represented in part alpha-chymotrypsin, consistent with this patient's treatment regime, as well as plasmin, elastase and an unidentified neutrophil-derived activity. Interestingly, ligneous samples contained both latent and activated forms of matrix metalloproteinase-9 (MMP-9), whereas mucoid samples contained predominantly activated forms of MMP-9. LC is characterized by defective fibrinolysis, despite the presence of ample t-PA and intact fibrin, and by an abundant mucoid thread which binds both endogenous and exogenous enzymes including serine protease(s) and collagenase(s). The implications of these results with respect to a role for exuberant mucus production or abnormal mucins in the development of a relative mucosal-site specific plasmin(ogen) deficiency is discussed.

Giant papillary conjunctivitis in frequent replacement contact lens wearers: a retrospective study.

PURPOSE: We conducted a retrospective study of 47 patients who wore frequent replacement contact lenses on a daily-wear basis to determine the incidence of giant papillary conjunctivitis (GPC) and to assess the potential risk factors that may predispose frequent replacement contact lens wearers to develop GPC. METHODS: We reviewed the records of patients with no prior contact lens experience who were fit with frequent replacement contact lenses from September 1993 to February 1997. RESULTS: Forty-seven of 260 patients met the requirements for inclusion in the study. Ten (21.27%) patients had developed GPC. The incidence varied with the frequency of contact lens replacement. The contact lens replacement schedule ranged from 1 day to 12 weeks. In those patients replacing their contact lenses every 4 weeks or at a longer interval, the incidence of GPC was 36%, while for patients who replaced their lenses more frequently, the incidence was 4.5%. Coated contact lenses were also more common among patients who replaced their lenses at 4 weeks or longer (P = 0.23). A significantly greater number of patients in the GPC group incorporated enzymatic cleaning into their contact lens care system (P = .0004). A history of allergy was more prevalent in patients who developed GPC and was statistically significant (P = .012). There was no significant difference found between the groups for age, gender, average daily wearing time, FDA classification of contact lens material, time in contact lenses from fitting to diagnosis or last follow-up period, or the parameters and fitting characteristics of the contact lenses. CONCLUSION: The frequency at which patients replace their contact lenses appears to be an important variable in developing GPC. Although frequent replacement contact lenses do not eliminate GPC, patients on a 1-day to 3-week replacement cycle had a significantly lower risk of developing GPC than patients who replaced their lenses at longer intervals. Lens coating was present less often on contact lenses replaced daily and up to 3 weeks. For patients who are at high risk for GPC, replacing lenses at intervals ranging of one day to two weeks appears to offer a better strategy for avoiding GPC than incorporating enzymatic cleaning into their lens care system.

Giant papillary conjunctivitis in frequent-replacement contact lens wearers: a retrospective study.

PURPOSE: A retrospective study was done of 47 patients who wore frequent-replacement contact lenses on a daily basis and replaced them every 1 day to 12 weeks. The incidence of giant papillary conjunctivitis (GPC) was determined, and potential risk factors that may predispose frequent-replacement contact lens wearers to develop GPC were assessed. METHODS: The records of patients who were fitted with frequent-replacement contact lenses with no prior contact lens experience (September 1993 to February 1997) were reviewed. RESULTS: Forty-seven of 260 patients met the requirement for inclusion in this study. Ten (21.27%) of the patients developed GPC. The incidence varied according to how often the contact lenses were replaced. Incidence was 36% in patients who replaced their lenses at 4 weeks or longer and 4.5% in patients who replaced their lenses at less than 4 weeks. Lenses were coated more often in patients who replaced their lenses at 4 weeks or longer (pi = .23). A significantly greater number of patients in the GPC group incorporated enzyme into their contact lens care system (pi = .0004). A history of allergy was present, significantly more often in patients who developed GPC (pi = .012). There was no significant difference between the groups for age, sex, average daily wearing time, Food and Drug Administration classification of contact lens material, time in contact lenses from fitting to diagnosis or last follow-up period, or the parameters and fitting characteristics of the contact lenses. CONCLUSION: The frequency of contact lens replacement appears to be an important variable in development of GPC. Although frequent-replacement contact lenses do not eliminate GPC, patients on a 1-day to 3-week replacement cycle had a significantly lower risk of developing GPC than patients who replaced their lenses at longer intervals. Coating was present less often on lenses replaced every 1 day to 3 weeks. In patients who are at high risk for GPC, replacing lenses at intervals of 1 day to 2 weeks appears to offer a better strategy in avoiding GPC than incorporating enzymatic cleaning into their care system.