Ocular complications associated with the use of cosmetic contact lenses from unlicensed vendors.

PURPOSE: To call attention to the unauthorized sale of cosmetic contact lenses, resulting in ocular complications. DESIGN Observational case report. METHODS: Retrospective, observational, clinical practice setting. RESULTS: Six patients (five female and one male) were seen urgently for acute eye pain and redness after wearing cosmetic plano contact lenses. None of the patients had previously worn a contact lens or spectacle correction. None of the lenses were dispensed by eye care professionals. One patient developed pseudomonal keratitis, ultimately requiring penetrating keratoplasty for visual rehabilitation. CONCLUSIONS: Colored contact lenses are being dispensed without a prescription or fitting from unlicensed vendors, such as cosmetics, convenience, and accessory stores. Lenses are sold individually and without care instructions. Consequently, uninformed lens wearers are experiencing acute, vision-threatening infections and inflammation.

Corneal topography and contact lenses.

Regardless of whether CVK is used qualitatively for RGP lens design selection or quantitatively in RGP parameter selection, it has a significant role in contact lens practice. Further advancements and testing on CVK-based RGP fitting modules and fluorescein simulations will make CVK an invaluable tool for the RGP lens fitter. Soft lens applications of CVK data are already being tested [42,43]. This technology will become the standard of care for all contact lens patients and will most likely replace the keratometer.

Contact lens fitting following corneal graft surgery.

Contact lens fitting may be required following keratoplasty for either optical or therapeutic reasons. Optical indications for contact lens fitting include the correction of irregular astigmatism, high regular astigmatism, anisometropia and secondary aniseikonia, as well as simple ametropia, where the patient desires to wear contact lenses in preference to spectacles. Therapeutic lenses are not routinely fitted following keratoplasty, although this management is advised in certain cases, such as when there are protruding sutures or epithelial healing is impaired. Designing a contact lens for a patient who has undergone keratoplasty will require the practitioner to carefully assess all the relevant features of the corneal graft. In this regard, there are many factors that need to be considered including the diameter of the graft zone, the topographical relationship between the host cornea and donor cornea, the corneal (graft) toricity and the location of the graft. Special designs, such as reverse geometry lenses, or more complex contact lens modalities, such as piggyback contact lens systems, may be required to achieve success in fitting.

Corneal thickness results in the Menicon Z 30-day continuous wear and ACUVUE 7-day extended-wear contact lens clinical trial.

PURPOSE: This study was conducted to measure the corneal thickness changes associated with wearing 30-day tisilfocon A (Dk = 163) and 6-day etafilcon A (Dk = 28) contact lenses. The probable cause of the outcomes is discussed. METHODS: Thirty subjects were fitted with Menicon Z rigid gas-permeable (RGP) contact lenses and a control group (n = 30) was fitted with ACUVUE hydrogel lenses, at two study sites. After a 2-week period of daily wear, subjects began prolonged wear. Measurements were performed at the dispensing visit, and then at the 2-week daily wear, the 1-week, 6-month, and 12-month extended- and continuous-wear visits. RESULTS: Repeated measures analysis of covariance was performed on mean corneal thickness. There was a significant increase in corneal thickness in the hydrogel lens extended-wear group compared to the RGP group (P = 0.03). The mean corneal thickness in the ACUVUE group was 2.58% higher at the 2-week daily wear visit, 2.38% higher at the 1-week extended-wear visit, 2.96% higher at the 6-month, and 2.97% higher at the 1-year visit compared to the RGP continuous-wear patients. DISCUSSION: Patients wearing high-Dk RGP contact lenses for continuous wear may have thinner corneas (within the normal thickness range) probably because of minimal hypoxia-induced corneal stromal swelling; RGP-induced reversible corneal epithelial compression; deceased epithelial sloughing; or long-term contact lens-induced keratocyte apoptosis. Patients wearing hydrogel contact lenses for extended wear may have thicker corneas because of hypoxia-induced corneal stromal swelling. Additional evidence of corneal hypoxic stress is seen in the higher prevalence of striae and epithelial microcysts in the hydrogel group and greater variability of corneal thickness measurements in the soft contact lens group in our results.

Corneal endothelial morphology results in the Menicon Z 30-day continuous-wear contact lens clinical trial.

PURPOSE: This evaluation was conducted as part of a protocol entitled Evaluation of the Menicon Z Rigid Gas Permeable Contact Lens for up to 30 Days Extended Wear. The purpose of the protocol was to compare corneal endothelial morphology changes after wearing rigid gas-permeable (RGP) Menicon Z contact lenses, continuously for up to 30 days, with ACUVUE (Johnson & Johnson Vision Care) hydrogel contact lenses, worn for up to 6 nights of extended wear. METHODS: Sixty patients, who were adapted to RGP daily wear and soft contact lens daily wear, were recruited at two study sites. The thirty subjects who wore RGP daily wear lenses were fitted with the Menicon Z (tisilfocon A, oxygen permeablility [Dk] = 163) RGP contact lens comprised the test group. The control group subjects (n = 30 former users of daily wear soft contact lenses) were fitted with ACUVUE (etafilcon A, Dk = 28) hydrogel contact lenses. After a 2-week adaptation period of daily wear, subjects began extended wear. Endothelial imaging was performed at the two study sites in this multicenter study (University Hospitals of Cleveland/Case Western Reserve University Department of Ophthalmology [CWRU] and The Ohio State University [OSU]). The hydrogel lens group was instructed to wear their lenses for 7 days and 6 nights before discarding the lenses and to sleep with no lenses on the seventh night. The RGP group was permitted to wear the lenses for up to 30 days and 29 consecutive nights before removing the lenses for cleaning and overnight soaking. RESULTS: CWRU had 24 patients (12 soft contact lens and 12 rigid contact lens) and OSU had 21 patients (12 soft contact lens and 9 rigid contact lens) who completed the study and were included in the analyses. Patients who were withdrawn from the study at CWRU included one RGP patient dropped out because of pregnancy; one RGP patient developed vascularized limbal keratitis and discomfort; one could not be fitted with a bitoric RGP; two soft lens patients moved from the area, and one dropped out because of dry eyes. At OSU, four patients dropped out due to discomfort (two in each lens type);one moved from the study area; one decided not to participate soon after the consent visit; one had worries of reduced vision at 6 months; one subject's attitude changed prior to the 6 month visit; and one subject was withdrawn for reasons of poor study schedule compliance. CONCLUSION: The Menicon Z lens wearers in this study did not show significant endothelial cell morphology changes after 1 year of nearly continuous contact lens wear. This finding is particularly important considering the RGP wearers in this study were older by a average of 10 years (mean age approximately 40) and had worn their contact lenses an average of almost 10 years longer than the soft contact lens wearers.

Quantitative descriptors of corneal topography that influence soft toric contact lens fitting.

PURPOSE: Empirical soft toric contact lens fitting based on manifest refraction and keratometry often presents unanticipated fitting and power errors upon initial lens dispensing. However, corneal topography may provide features that influence soft toric lens performance, flexure, and back vertex power in situ, which may assist in improved fitting guidelines. In this study, quantitative topographic descriptors were generated and analyzed as potential variables in predicting soft toric fitting success. METHODS: One hundred five eyes of 54 patients were empirically fit with back surface toric, prism ballasted, soft contact lenses after videokeratography was performed with the EyeSys 2000 (v. 4.0) or Humphrey Atlas (v. A6) instrument. Custom software was written to generate 54 separate quantitative descriptors of shape and astigmatism from the raw data files. A logistic regression was used to determine which variables significantly contributed to a successful or failed fit. RESULTS: Two types of empirical fitting failures were identified: loose fit (n = 15) and power errors (n = 17). The following variables were associated with a fitting failure: flat simulated keratometry (SimKf2b) within the central 3 mm zone, steep simulated keratometry (SimKs2b) within the central 3 mm zone, a difference between central and peripheral flat meridian axis (DIFFAXIS), and a difference between central and peripheral astigmatism (DIFFASTIG). For fitting failures caused by power errors, a larger steep SimKs2b (p< 0.01) and smaller DIFFAXIS (p< 0.05) were associated with a failed fit. For failures caused by physical fit of a selected base curve, a smaller DIFFAXIS (p< 0.05), larger steep SimKs2b (p< 0.05), and larger DIFFASTIG (p< 0.01) were associated with a failed fit. CONCLUSIONS: Novel quantitative descriptors of corneal shape and toricity derived from topography are associated with empirical soft toric contact lens fitting failures. Future algorithms or recommendations for improved soft toric lens selection may be derived from such indices to develop a predictive model for successful soft toric lens fitting using corneal topography data.