The CLAO journal : official publication of the Contact Lens Association of Ophthalmologists, Inc最新文献

Purpose: To compare the effects of eyelid scrubbing with an eyelid cleansing solution (ECS) to eyelid scrubbing with ECS and the addition of antibacterial or anti-inflammatory pharmaceuticals on the clinical appearance, microbial status, tissue histology, and the inflammatory cell profile of the normal eyelid margin.

Methods: Eyelid scrubbing was performed twice daily using ECS; ECS with the antibacterial sulfacetamide (ECS+); and ECS with sulfacetamide and prednisolone acetate (ECS++) over a 21 day period on three groups of 16 rabbits with clinically normal eyelids.

Results: Significant hyperemia of the margin occurred in all three groups over the 3 week period; however, the degree of hyperemia was less with ECS+ (P<0.05) and ECS++ (P<0.05). Chemosis, tearing, mucus discharge, and the microbial status were not significantly different than controls. There were no marked histologic differences in the tissues, except for increased red blood cell packing in the small vessels near the lid margins in scrubbed eyelids, consistent with hyperemia. The inflammatory cell profile showed minimal changes that were not statistically significant in any of the three groups, except that >50% of mast cells showed evidence of degranulation.

Conclusions: Use of ECS with an antibiotic, or an antibiotic and steroid solution, resulted in less inflammation than scrubbing with ECS alone.

Purpose: We studied the potential effect of ethyl-6-O-decanoyl-glucoside (EDG) on papillary hypertrophy in contact lens wearers who were recruited on the basis of papillary hypertrophy and a long history of contact lens wear. The contact lens care solutions were 0.00025% chlorhexidine acetate (CHX) with or without 0.005% EDG.

Methods: Nineteen subjects wearing both ionic and non-ionic contact lenses for 6-18 hours used either CHX or CHX+EDG as a cleaning and disinfecting agent. CHX and CHX+EDG was used simultaneously by each subject but in different eyes during two consecutive periods of 8 weeks. Symptoms and signs were recorded at three examinations during the study. The protein content of contact lenses and tryptase activity of tear fluids were measured.

Results: The degree of papillary hypertrophy did not decrease in either the CHX or CHX+EDG groups. Also, there were no differences in protein content of lenses nor tryptase activity of tear fluids in either group. There was a significant correlation between papillary hypertrophy and tryptase activity during the study.

Conclusions: Despite the earlier finding that EDG prevents development of papillary hypertrophy in contact lens wearers, EDG still cannot reverse established signs of papillary hypertrophy.

Purpose: We designed a 3-year, prospective, randomized, masked clinical trial to evaluate the relationship of contact lens oxygen transmissibility and bacterial adherence to exfoliated surface epithelial cells in human overnight and extended lens wearers in a single center; corneal cell desquamation rate, surface epithelial cell size, and tear lactate dehydrogenase (LDH) levels were also determined concurrently.

Methods: One hundred nine human volunteers were successfully fit with test lenses prospectively and completed this study. Seven soft and three rigid gas permeable (RGP) lenses with stratified oxygen transmissibility were evaluated. After one week adaptation to daily wear, patients continually wore test lenses bilaterally for three months on a six nights wear, one night off basis. Before and after 24 hour, 1 month, and three months extended contact lens wear, exfoliated surface epithelial cells were collected using a modified corneal irrigation chamber. Bacterial binding was determined by measuring Pseudomonas aeruginosa (PA) adherence to exfoliated corneal epithelial cells. The number of exfoliated cells with adherent bacteria were counted using fluorescence microscopy. The effects of contact lens wear on the corneal surface were further assessed by alterations in tear LDH, and by surface epithelial cell size and epithelial thickness using in vivo tandem scanning confocal microscopy (TSCM). Baseline values of outcome measures served as controls for individual patients; a concurrent group of controls were also followed to monitor seasonal or possible individual fluctuations.

Results: Quantitative evidence demonstrated that lens physical oxygen transmissibility properties and not lens type significantly correlated inversely with binding of PA to human exfoliated corneal epithelial cells after overnight and extended wear (R=0.258, P=0.0084); there was a significant decrease in surface epithelial cell desquamation and a significant increase in surface cell size following wear for all test lenses (P<0.05). Epithelial thinning was also observed following lens wear (P<0.05).

Conclusions: These results establish for the first time a significant correlation between contact lens-induced increases in epithelial PA binding and lens oxygen transmissibility in humans. New ultra-oxygen permeable test lenses did not appear to increase bacterial binding over individual control levels; all test lenses suppressed surface epithelial cell shedding. Taken together, these findings suggest that a new generation of contact lenses constructed from ultra-transmissible oxygen materials may offer a significant potential advance in safety for extended wear.

Purpose: To compare the incidence of corneal decompensation after Molteno shunt to trabeculectomy.

Methods: We conducted a retrospective analysis of the corneal status of 55 patients with primary open angle glaucoma. We compared 24 eyes of 24 patients who underwent Molteno tube shunt placement (Group 1) to fifteen eyes of 14 patients with multiple surgical procedures, including a trabeculectomy (Group 2). We also compared Group 1 to 28 eyes of 17 patients who underwent only one trabeculectomy (Group 3).

Results: The three groups were similar with respect to age, sex, and intraocular pressure (IOP). The average follow-up time from the last surgery in Group 1 was 17.9 months (1-90 months), 22.4 months (2-63 months) in Group 2, and 19.6 months (1-37 months) in Group 3. The average number of surgeries was 3.0 (1-4) in Group 1 and 2.53 (1-4) in Group 2. The surgeries included trabeculectomy, cataract extraction, combined procedures, penetrating keratoplasty, pars plana vitrectomy, and scleral buckle. The incidence of corneal edema was 50% (12/24)in Group 1, 6.7% (1/15) in Group 2, and 0% in Group 3 (0/28). The average time to corneal decompensation was 21 months in Group 1 (1-120 months) and 15 months in Group 2.

Conclusion: Patients undergoing Molteno shunt placement have a higher rate of corneal decompensation compared to patients undergoing trabeculectomy.

Purpose: To compare the visual performance of soft contact lenses and spectacles.

Methods: Twenty eyes of ten patients were examined. Each patient was fit with Acuvue, Cibasoft, and Biomedics contact lenses in random order. LogMar visual acuity and contrast sensitivity using the VectorVision CSV-1000 were measured.

Results: There was no significant difference in visual acuity between any contact lenses (P=.15). Contrast sensitivity at 12 cycles/degree was significantly lower for the Cibasoft lens compared to spectacles (P=.04). There was no significant difference between spectacles and contact lenses for remaining spatial frequencies (P=.07-.35).

Conclusions: Visual acuity appears to be an insensitive method for evaluating soft contact lenses. The lathe-cut manufacturing process may be responsible for reduced visual function compared to cast-molded lenses. Further study in this area is needed.

Purpose: We evaluated six single-bottle, multi-purpose lens care solutions and a two component lens care system for disinfection efficacy according to the stand-alone primary criteria within the recently published U.S. Food and Drug Administration (FDA) Guidelines.

Methods: One-tenth mL of 1 x 10(8) colony forming units (CFU)/mL of bacterial and fungal challenge organisms was added to each test solution. Following a specified period (e.g., each manufacturer's labeled minimum disinfection time), aliquots of inoculated test solution were neutralized and plated on validated recovery media. After incubation the number of viable microorganisms were enumerated and mean log reductions determined.

Results: ReNu and ReNu MultiPlus met the FDA's acceptance criteria for stand-alone disinfectants against all challenge organisms: Staphylococcus aureus, Serratia marcescens, Pseudomonas aeruginosa, Candida albicans, and Fusarium solani. Opti-Free Express failed to meet the FDA's stand-alone disinfectant acceptance criteria for S. aureus, S. marcescens and C. albicans and Opti-Free Express with Opti-Free Supraclens failed to meet the acceptance criteria for either S. aureus and C. albicans. Opti-One failed to meet the FDA's stand-alone disinfectant acceptance criteria for C. albicans and F. solani. Both Complete and Solo-Care failed to meet the FDA's acceptance criteria for C. albicans.

Conclusions: This evaluation provides a direct comparison of antimicrobial activity (based on stand-alone criteria) for commercially available multi-purpose lens care solutions at their labeled minimum disinfection times. The results of this study should be considered when selecting appropriate lens care systems for patients.

Purpose: We performed a qualitative and quantitative assessment of contact lens performance at 1 and 6 months among 24 patients enrolled in the Piggyback Bifocal Contact Lens Study.

Methods: We fit 24 presbyopic patients with the Piggyback Bifocal Contact Lens System (i.e., a plano soft lens with a 9.4 mm cutout portion on which a bifocal RGP lens rides or "piggybacks"). Patients were evaluated prior to inclusion in the study and then at one month and six months after obtaining their lenses. Evaluations included slit lamp examination, evaluation of visual acuity at near and distance, and subjective rating of the patients' comfort.

Results: At one month, 61% of patients had Snellen acuities of 20/30 or better, 79% had near acuities of J2 or better, and 60% rated their comfort as good or very good. At six months, 100% of patients had Snellen acuities of 20/30 or better, 90% had near acuities of J2 or better, and 86% of patients rated their comfort as good or better. Twelve patients did not complete the study due to their decision to drop the study.

Conclusions: The Piggyback Bifocal Contact Lens System is a well-tolerated, satisfactory means of optical correction for the motivated presbyope.

Purpose: We conducted a 3-month, randomized, comparative cross-over study to evaluate the clinical performance of lenses manufactured from omafilcon A on subjects with signs and symptoms of dry eye. The subjects' own daily wear soft lenses were used as controls.

Methods: Seventy-six subjects with objective evidence of dry eye, as defined in the NEI/Industry Workshop Report 1995, were fit with either the omafilcon A lenses (Proclear) or new control lenses. Subjects wore the lenses for 6 weeks and then crossed over to bilateral wear of the other lenses for an additional 6 weeks. During each part of the study, we examined subjects at 1 week, 1 month, and 6 weeks. Signs and symptoms of dry eye were evaluated, and on-eye dehydration of the lens was assessed.

Results: When the subjects were wearing the omafilcon A lenses, there was a statistically significant improvement in a number of subjective parameters including comfort, dryness, frequency of eye irritation, and frequency of burning. We found significantly less on-eye dehydration of the lens and fluorescein corneal staining with the omafilcon A lenses.

Conclusions: This study indicated that the daily wear of omafilcon A lenses provided better comfort, fewer symptoms, less on-eye dehydration, and less fluorescein corneal staining than other soft daily wear contact lenses in subjects with mild to moderate dry eye.