Jennie Diec

Contact lens case contamination during daily wear of silicone hydrogels.

Purpose. Contamination of contact lens cases has been associated with the production of adverse responses in the eye during contact lens wear. This study aimed to evaluate the contamination rate and types of microbes contaminating cases during use of contact lens disinfecting solutions and silicone hydrogel lenses. Methods. Two hundred thirty-two participants were allocated to one or more groups. The participants wore one or more of three silicone hydrogel lenses and used one or more of four contact lens disinfecting solutions. Cases were collected after use for 1 month and sent for routine microbial testing. The rate of contamination of cases and the types of microbes contaminating cases were evaluated. Results. Between 76 and 92% of all cases were contaminated. Use of different contact lenses did not affect contamination rate or the types of microbes isolated from cases. Use of AQuify (PHMB as disinfectant) was associated with the highest contamination rate (92%; p = 0.015) of cases for any microbe. Level and type of contamination with use of ClearCare (H2O2) was similar to use of PHMB (polyhexamethylene biguanide)- or Polyquat/Aldox-containing solutions. There was no difference in contamination rate of cases by fungi or Gram-positive bacteria, but for Gram-negative bacteria, use of Opti-Free Express (Polyquat and Aldox as disinfectants) resulted in a lower contamination rate (7% vs. 29 to 45%; p < 0.001). The average number of microbes contaminating a case was significantly less for Opti-Free Express (223 ± 1357 cfu/case) compared with Opti-Free RepleniSH (Polyquat and Aldox as disinfectants; 63,244 ± 140,630 cfu/case; p < 0.001), driven mostly by differences in numbers of Gram-negative bacteria, particularly contamination by Delftia acidovorans in cases exposed to Opti-Free RepleniSH. Conclusions. Different disinfecting solutions used during storage in cases result in different levels of contamination and contamination by different types of microbes. These differences are not simply because of the types of disinfectants used, suggesting that other excipients in, or formulation of, the solution affect contact lens storage case contamination.

Contact lens deposits, adverse responses, and clinical ocular surface parameters.

Purpose. To correlate clinical responses during contact lens wear with the amount of protein or cholesterol extracted from lenses after wear. Methods. Clinical parameters, including adverse response rates and corneal staining, and symptomatology rating during lens wear were collected from a series of clinical tests comprising four different silicone hydrogel lenses with four different multipurpose solutions. To test for correlates, the amount of total protein or cholesterol extracted from lenses after daily wear were compared statistically to clinical parameters. Results. The amount of protein (p = 0.008) or cholesterol (p = 0.01) extracted from lenses was higher for those subjects who showed solution-induced corneal staining. Amount of protein extracted was correlated (p < 0.01) with conjunctival staining (R = −0.23), lens front surface wetting (r = 0.14), and lens fit tightness (R = −0.20). These clinical parameters accounted for 48% of lens protein deposition. The amount of cholesterol extracted from lenses was much more weakly associated with clinical variables. Amount of protein or cholesterol extracted from lenses was not associated with the production of any corneal infiltrative or mechanical adverse event during wear and was only very weakly correlated with insertion comfort of lenses. Conclusions. These results suggest that there may be no physiologically relevant consequence of cholesterol depositing on silicone hydrogel lenses. The amount of protein that deposits onto silicone hydrogel lenses during wear may have more affect on lens performance on-eye. However, the correlations were generally small and may still not indicate any causative relevant physiological response. Further work is required to determine whether there is any direct causative effect to support these correlative findings.

Comparison of ocular comfort, vision, and SICS during silicone hydrogel contact lens daily wear.

Objectives: The aim of this study was to investigate the relationship between solution-induced corneal staining (SICS) and silicone hydrogel contact lens comfort and vision. Methods: A retrospective analysis of a series of open-label studies were conducted with 24 groups of approximately 40 participants, each wearing 1 of 6 silicone hydrogel contact lenses with 1 of 4 lens care products bilaterally for 3 months of daily wear. The presence of SICS and subjective ocular ratings were collected at 2 weeks and at 1 and 3 months. Results: A total of 1,051 participants were enrolled. The participants with SICS rated significantly less favorably than did the participants without SICS for comfort during the day (7.9±1.7 vs. 8.5±1.4, P=0.03), comfort at the end of the day (6.6±2.1 vs. 7.4±1.9, P=0.03), overall dryness (7.4±1.9 vs. 8.0±1.7, P=0.04), dryness at the end of the day (6.7±2.2 vs. 7.5±2.1, P=0.01), feelings of burning and stinging (8.5±2.0 vs. 8.9±1.8, P=0.02), and overall vision (8.2±1.6 vs. 8.7±1.3, P<0.001). Conclusions: The participants with SICS had lower subjective comfort and vision compared with those who did not experience SICS.

Effect of lens care systems on the clinical performance of a contact lens.

Purpose To evaluate subjective responses, rates of solution-induced corneal staining (SICS), and corneal infiltrative events (CIEs) associated with a silicone hydrogel when worn under a daily disposable (DD) or daily wear (DW) modality. Methods Data were obtained from seven prospective clinical trials, involving 283 subjects wearing Senofilcon A contact lenses (Johnson and Johnson Vision Care, Jacksonville, FL). Four groups wore the contact lens on a DW basis using multipurpose solutions (DW-MPS, n = 160), two groups using hydrogen peroxide (DW-H2O2, n = 83), and one group as a DD (n = 40). Participants were followed for 3 months using the same protocol. Subjective ratings were compared between DD and DW groups using a linear mixed model. Rates of SICS and CIE were calculated as the percent frequency of first events within the 3-month study. Association of SICS and CIE with subjective responses was analyzed using a linear mixed model. Results End-of-day comfort and dryness ratings were significantly better for DD (8.5 ± 1.7 and 8.6 ± 1.7, respectively) compared with DW-H2O2 (7.7 ± 1.8, p = 0.01; 7.6 ± 1.9, p = 0.006, respectively) and DW-MPS (7.7 ± 1.7, p = 0.004; 7.6 ± 2.0, p = 0.003, respectively). Compared with DD, a higher incidence of CIE and SICS was found for DW-MPS (0.0 vs. 3.9%, p = 0.021; 0.9 vs. 8.6%, p = 0.002, respectively). Comfort at insertion and end of day and end-of-day dryness scores were significantly lower for participants who experienced SICS (8.2 ± 1.6, 7.0 ± 1.9, and 7.0 ± 2.2) than those who did not (8.8 ± 1.2, p = 0.004; 7.9 ± 1.7, p = 0.002; and 7.9 ± 1.8, p = 0.003, respectively). Comfort at insertion scores were significantly lower for participants who experienced CIEs than those who did not (8.2 ± 1.5 vs. 8.8 ± 1.4, p = 0.032). Conclusions Senofilcon A clinical response is modulated by the lens care products. All lens care products tested reduced subjective responses relative to DD modality, whereas MPS increased the incidence of CIEs and SICS. Senofilcon A performs best when used on a DD basis.

Combined effect of comfort and adverse events on contact lens performance.

Purpose. To report the performance of various contact lenses and lens care solution combinations based on the combined response of subjective comfort and adverse events (AEs). Methods. A retrospective analysis of 28 lens/solution combinations each tested on approximately 40 participants who wore their assigned combination on a daily wear basis and were followed for a 3-month period, with visits at baseline, 2 weeks, and 1 and 3 months. Lenses included frequent replacement and daily disposables. Solutions included hydrogen peroxide and multipurpose types. Subjective comfort (scale of 1 to 10) and AEs were collected and reported as a group mean and percentage, respectively. The data were converted into a ratio between 0 and 1 to represent the relative performance within the combination series, with a higher ratio indicating better performance in both AE rates and comfort. Results. The overall AE rate was 3.6 events per 100 participant-months (95% confidence interval [95% CI], 2.7 to 4.7%). The rate was found to be lower in daily disposables compared with that in daily wear lenses (3.1 vs. 10.9%, p < 0.001). The overall comfort on insertion rating was 8.3 (95% CI, 8.1 to 8.4), and comfort at end of day was 7.2 (95% CI, 7.0 to 7.4). Based on the 28 lens/solution combinations, there was no significant correlation between overall AE rates and comfort on insertion or at end of day (Pearson correlation, −0.34, p = 0.08; and Pearson correlation, −0.23, p = 0.25, respectively). Less than 18% of the combinations tested combined good comfort with low AE rates. Conclusions. Both subjective comfort responses and AE rates varied according to the combination of lens type and care system in use. The combinations with the best comfort ratings did not necessarily have a favorable AE rate. Practitioners can maximize behavior with respect to both these factors by choosing an appropriate care system for the lenses they prescribe.

The clinical performance of lenses disposed of daily can vary considerably.

Objectives: To evaluate clinical performance of three lens types disposed of on a daily disposable (DD) basis. Method: A total of 120 participants were randomized into one of three lens types (etafilcon A, narafilcon A, and senofilcon A), all worn bilaterally on a DD regime. Participants were observed at baseline, 2-week, and 1- and 3-month visits where ocular physiology and lens performance variables were collected on a 0 to 4 grading scale in 0.1 increments. Subjective comfort and vision ratings were collected on a 1 to 100 rating scale and in the form of symptom severity. Results: Forty participants wore each lens type with no differences in age or gender between groups (P>0.05). Etafilcon A exhibited more limbal redness compared with either of the other lens types (P<0.01). More superior corneal staining was noted with narafilcon A lenses compared with senofilcon A (P<0.01), and more superior conjunctival indentation was noted for narafilcon A compared with etafilcon A (P=0.001). No differences were found between lenses in the 1 to 100 rating scale (P>0.05). Narafilcon A showed more moderate to severe dryness symptoms and symptoms of blurred vision at lens wearing visits (P<0.05). One bilateral contact lens papillary conjunctivitis, one unilateral superior epithelial arcuate lesion, and one infiltrative keratitis were associated with narafilcon A only. Of the seven discontinuations, six were from the narafilcon A group. Conclusion: Different contact lens materials and designs, worn on the same DD modality, elicit different ocular and patient responses. Narafilcon A did not perform clinically as well as etafilcon A and senofilcon A worn on a DD modality.

Effect of phospholipid deposits on adhesion of bacteria to contact lenses

Purpose. Protein and lipid deposits on contact lenses may contribute to clinical complications. This study examined the effect of phospholipids on the adhesion of bacteria to contact lenses. Methods. Worn balafilcon A (n = 11) and senofilcon A (n = 11) were collected after daily wear and phospholipids were extracted in chloroform:methanol. The amount of phospholipid was measured by electrospray ionization mass spectrometry. Unworn lenses soaked in phospholipids were exposed to Pseudomonas aeruginosa and Staphylococcus aureus. After 18 h incubation, the numbers of P. aeruginosa or S. aureus that adhered to the lenses were measured. Phospholipid was tested for possible effects on bacterial growth. Results. A broad range of sphingomyelins (SM) and phosphatidylcholines (PC) were detected from both types of worn lenses. SM (16:0) (m/z 703) and PC (34:2) (m/z 758) were the major phospholipids detected in the lens extracts. Phospholipids did not alter the adhesion of any strain of P. aeruginosa or S. aureus (p > 0.05). Phospholipids (0.1 mg/mL) showed no effect on the growth of P. aeruginosa 6294 or S. aureus 031. Conclusions. Phospholipids adsorb/absorb to contact lenses during wear, however, the major types of phospholipids adsorbed to lenses do not alter bacterial adhesion or growth.

Prompt diagnosis and treatment of microbial keratitis in a daily wear lens.

Purpose. Microbial keratitis (MK) is a serious sight-threatening complication occurring with and without contact lens wear. The task of diagnosing MK is difficult because each presentation of the disease is different and can be mistaken for noninfectious ulcers such as contact lens peripheral ulcer (CLPU). The purpose of this article is to present a case report of MK initially diagnosed as a CLPU. Case Report. We report the incidence of a 21-year-old female presenting with signs and symptoms in her left eye, which initially suggested a CLPU. At the 24-h follow-up, contrary to expected indications of healing, her condition had deteriorated. The diagnosis was reevaluated as an MK. Ciloxan was prescribed under care of an ophthalmologist. Despite initial misdiagnosis, due to aggressive topical treatment and the peripheral location of the lesion, <1 line of vision was lost. Discussion. Defined signs and symptoms criteria have been established for the differential diagnoses of MK and CLPU. However, there is often an overlap in the signs and symptoms that can complicate the diagnosis. A critical sign, however, is progress immediately after lens wear is discontinued. Prophylaxis and rapid appropriate treatment and follow-up are vitally important if there is any doubt and to ensure correct diagnosis and resolution. Conclusion. Any diagnosis of CLPU must be monitored carefully to ensure it is not MK. Prompt diagnosis and treatment of MK are essential for a good visual outcome.

Extended depth of focus contact lenses vs. two commercial multifocals: Part 2. Visual performance after 1 week of lens wear

Purpose To compare the visual performance of prototype contact lenses designed via deliberate manipulation of higher-order spherical aberrations to extend-depth-of-focus with two commercial multifocals, after 1 week of lens wear. Methods In a prospective, participant-masked, cross-over, randomized, 1-week dispensing clinical-trial, 43 presbyopes [age: 42–63 years] each wore AIROPTIX Aqua multifocal (AOMF), ACUVUE OASYS for presbyopia (AOP) and extended-depth-of-focus prototypes (EDOF) appropriate to their add requirements. Measurements comprised high-contrast-visual-acuity (HCVA) at 6 m, 70 cm, 50 cm and 40 cm; low-contrast-visual-acuity (LCVA) and contrast-sensitivity (CS) at 6 m and stereopsis at 40 cm. A self-administered questionnaire on a numeric-rating-scale (1–10) assessed subjective visual performance comprising clarity-of-vision and lack-of-ghosting at various distances during day/night-viewing conditions and overall-vision-satisfaction. Results EDOF was significantly better than AOMF and AOP for HCVA averaged across distances (p ≤ 0.038); significantly worse than AOMF for LCVA (p = 0.021) and significantly worse than AOMF for CS in medium and high add-groups (p = 0.006). None of these differences were clinically significant (≤2 letters). EDOF was significantly better than AOMF and AOP for mean stereoacuity (36 and 13 seconds-of-arc, respectively: p ≤ 0.05). For clarity-of-vision, EDOF was significantly better than AOP at all distances and AOMF at intermediate and near (p ≤ 0.028). For lack-of-ghosting averaged across distances, EDOF was significantly better than AOP (p < 0.001) but not AOMF (p = 0.186). EDOF was significantly better than AOMF and AOP for overall-vision-satisfaction (p ≤ 0.024). Conclusions EDOF provides better intermediate and near vision performance than either AOMF or AOP with no difference for distance vision after 1 week of lens wear.

Predicting Short-term Performance of Multifocal Contact Lenses

Objective: To investigate if initial multifocal contact lens (MFCL) performance predicts short-term dispensing performance. Methods: A retrospective analysis of 55 participants (Px) in a masked, crossover, clinical trial, using ACUVUE OASYS for Presbyopia and AIR OPTIX AQUA Multifocal. Subjective questionnaires were administered at the following instances: initial fitting, two take home questionnaires (THQ) completed between days 2 and 4 and at assessment, ≥5 days after fitting. Questionnaires included vision clarity and lack of ghosting at distance, intermediate and near at day/night time points rated on a 1 to 10 (1-step, 10 most favorable) rating scale. Vision stability, vision while driving, overall vision satisfaction, willingness to purchase and comfort, as well as acuity-based measures were also collected. Results: There were no statistical differences in comfort and vision at all distances, in vision stability or driving at either time points between THQ and assessment (P>0.05). However, there was a statistical decline in subjective overall vision satisfaction and comfort between fitting and assessment visits (P<0.001). Willingness to purchase remained the same at fitting and assessment in 68% of Px, whereas only 4% of Px converted to a positive willingness to purchase at assessment. The majority of acuity-based measures remained constant between fitting and assessment visits. Conclusion: Initial performance at fitting was not able to predict short-term performance of MFCL. Subjective measures peaked at fitting and declined thereafter whereas acuity-based measures remained constant. Utility of subjective rating tools may aid practitioners to gauge success of MFCL.