BCLA CLEAR Presbyopia: Definitions.

Presbyopia is often the first sign of ageing experienced by humans. Standardising terminology and adopting it across the BCLA CLEAR Presbyopia reports, improves consistency in the communication of the evidence-based understanding of this universal physiological process. Presbyopia can be functionally and psychologically debilitating, especially for those with poor access to eyecare. Presbyopia was defined as occurring when the physiologically normal age-related reduction in the eye's focusing range reaches a point that, when optimally corrected for far vision, the clarity of vision at near is insufficient to satisfy an individual's requirements. Accommodation is the change in optical power of the eye due to a change in crystalline lens shape and position, whereas pseudo-accommodation is the attainment of functional near vision in an emmetropic or far-corrected eye without changing the refractive power of the eye. Other definitions specific to vision and lenses for presbyopia were also defined. It is recommended that these definitions be consistently adopted in order to standardise future research, clinical evaluations and education.

CLEAR - Contact lens technologies of the future.

Contact lenses in the future will likely have functions other than correction of refractive error. Lenses designed to control the development of myopia are already commercially available. Contact lenses as drug delivery devices and powered through advancements in nanotechnology will open up further opportunities for unique uses of contact lenses. This review examines the use, or potential use, of contact lenses aside from their role to correct refractive error. Contact lenses can be used to detect systemic and ocular surface diseases, treat and manage various ocular conditions and as devices that can correct presbyopia, control the development of myopia or be used for augmented vision. There is also discussion of new developments in contact lens packaging and storage cases. The use of contact lenses as devices to detect systemic disease has mostly focussed on detecting changes to glucose levels in tears for monitoring diabetic control. Glucose can be detected using changes in colour, fluorescence or generation of electric signals by embedded sensors such as boronic acid, concanavalin A or glucose oxidase. Contact lenses that have gained regulatory approval can measure changes in intraocular pressure to monitor glaucoma by measuring small changes in corneal shape. Challenges include integrating sensors into contact lenses and detecting the signals generated. Various techniques are used to optimise uptake and release of the drugs to the ocular surface to treat diseases such as dry eye, glaucoma, infection and allergy. Contact lenses that either mechanically or electronically change their shape are being investigated for the management of presbyopia. Contact lenses that slow the development of myopia are based upon incorporating concentric rings of plus power, peripheral optical zone(s) with add power or non-monotonic variations in power. Various forms of these lenses have shown a reduction in myopia in clinical trials and are available in various markets.

American Academy of Optometry Microbial Keratitis Think Tank.

SIGNIFICANCE: Think Tank 2019 affirmed that the rate of infection associated with contact lenses has not changed in several decades. Also, there is a trend toward more serious infections associated with Acanthamoeba and fungi. The growing use of contact lenses in children demands our attention with surveillance and case-control studies. PURPOSE: The American Academy of Optometry (AAO) gathered researchers and key opinion leaders from around the world to discuss contact lens-associated microbial keratitis at the 2019 AAO Annual Meeting. METHODS: Experts presented within four sessions. Session 1 covered the epidemiology of microbial keratitis, pathogenesis of Pseudomonas aeruginosa, and the role of lens care systems and storage cases in corneal disease. Session 2 covered nonbacterial forms of keratitis in contact lens wearers. Session 3 covered future needs, challenges, and research questions in relation to microbial keratitis in youth and myopia control, microbiome, antimicrobial surfaces, and genetic susceptibility. Session 4 covered compliance and communication imperatives. RESULTS: The absolute rate of microbial keratitis has remained very consistent for three decades despite new technologies, and extended wear significantly increases the risk. Improved oxygen delivery afforded by silicone hydrogel lenses has not impacted the rates, and although the introduction of daily disposable lenses has minimized the risk of severe disease, there is no consistent evidence that they have altered the overall rate of microbial keratitis. Overnight orthokeratology lenses may increase the risk of microbial keratitis, especially secondary to Acanthamoeba, in children. Compliance remains a concern and a significant risk factor for disease. New insights into host microbiome and genetic susceptibility may uncover new theories. More studies such as case-control designs suited for rare diseases and registries are needed. CONCLUSIONS: The first annual AAO Think Tank acknowledged that the risk of microbial keratitis has not decreased over decades, despite innovation. Important questions and research directions remain.

UV-B exposure to the eye depending on solar altitude.

PURPOSE: To assess the validity of the solar ultraviolet index (UVI) as a determiner of eye risk under different conditions of facial profiles and orientation, and reflected light. METHODS: Ocular UV radiation (UVR) exposure was measured as a function of the time of the day (solar altitude) using a two-dummy-type mannequin dosimetry system with embedded UVR (260-310 nm) sensors, in September and November in Kanazawa, Japan, on a motorized sun-tracking mount with one dummy face directed toward the sun and the other away from the sun. RESULTS: A bimodal distribution of UV-B exposure was found in September for the face directed toward the sun, which differed dramatically from the pattern of ambient UVR exposure and measurements taken on the top of the head and those for the eye taken later in the year. Although the overall level was lower, a higher solar altitude is associated with higher UVR exposure in the condition facing away from the sun. CONCLUSIONS: The UVI is based on ambient solar radiation on an unobstructed horizontal plane similar to our measures taken on the top of the head, which differed so much from our measures of ocular exposure that UVI as a determiner of eye risk is deemed invalid. The use of the UVI as an indicator for the need for eye protection can be seriously misleading. Doctors should caution patients with regard to this problem, and eye protection may be warranted throughout the year.

The effects of 2 week senofilcon-A silicone hydrogel contact lens daily wear on tear functions and ocular surface health status.

PURPOSE: To prospectively investigate the effects of 2 week senofilcon A contact lens (CL) daily wear on the functional visual acuity (VA), ocular surface and tear film. METHODS: Seventeen right eyes of 17 senofilcon A CL wearers without any ocular or systemic diseases were examined before and 2 weeks after lens wear. Visual acuity measurements, tear evaporation rate, ELISA for tear cytokines, strip meniscometry, tear lipid layer interferometry, tear film break-up time (BUT), in vivo confocal microscopy, corneal sensitivity, ocular surface vital staining, Schirmer I test and brush cytology for MUC5AC mRNA expression were performed before and after CL wear. RESULTS: The best corrected Landolt VA, functional VA parameters, the mean lipid layer interferometry grades, tear evaporation rates, Schirmer test values, vital staining scores and in vivo confocal microscopy parameters did not show any significant differences after 2 weeks of CL wear. The tear film BUT showed a significant decrease together with a significant down regulation of MUC5 AC mRNA expression after CL wear. A statistically significant elevation in the mean tear interleukin (IL)-6 concentration was also observed after 2 weeks of CL wear. CONCLUSIONS: Two week senofilcon A daily CL wear seems to be associated with tear instability, a decrease in MUC5AC expression, and elevation of IL-6 in tears without significant alterations in epithelial damage scores or in the morphology or density of in vivo keratoconjunctival cells and nerves. Alterations associated with long term wear and patients with dry eye disease need to be studied in future trials.

Corneal topography and soft contact lens fit.

PURPOSE: To determine which ocular topography variables affect soft contact lens fit. METHODS: Fifty subjects each wore three pairs of soft lenses in random succession (Vistakon Acuvue 2, Vistakon Acuvue Advance, Ciba Vision Night & Day), and various aspects of lens fit were evaluated. The steeper base curves of each type were worn in one eye and the flatter base curves in the other eye. Corneal topography data were collected using a Medmont E300 corneal topographer (Camberwell, Australia). Corneal curvature, shape factor (SF), and corneal height were measured over a 10 mm chord and also over the maximum measurable diameter. These were measured in the horizontal, vertical, steepest, and flattest meridians. RESULTS: With each lens type, the steeper base curve provided the best fit on the greatest proportion of eyes and the significant differences in various aspects of fit were noted between base curves. For each lens type, there was no significant difference in mean K-reading between those eyes best fit with the steeper base curve and those eyes best fit with the flatter base curve. Two of the lenses showed a positive correlation between centration and horizontal corneal height (maximum), whereas one lens showed a negative correlation between centration and horizontal SF (SF = e). Several lenses showed a positive correlation between post-blink movement and horizontal or vertical corneal SF. CONCLUSIONS: The measurement of corneal topography using current Placido disc instrumentation allows a better prediction of soft lens fit than by keratometry, but it is not reliable enough to enable accurate selection of the best fitting base curve. Some correlations are evident between corneal measurements; however, trial fitting remains the method of choice for selection of soft lens base curve.

Passive cigarette smoke exposure and soft contact lens wear.

PURPOSE: To prospectively investigate the effects of passive cigarette smoke exposure on the ocular surface and tear film in soft contact lens (SCL) wearers. METHODS: Twelve right eyes of 12 SCL wearers without any ocular or systemic diseases and 10 right eyes of 10 subjects who never wore CLs were examined before and 2 h after 5 min of passive cigarette smoke exposure in a controlled smoke chamber. Tear evaporation rate measurement, tear film break-up time (TBUT) examination, ocular surface fluorescein, rose bengal stainings, and Schirmer I test were performed at each visit. RESULTS: The mean tear evaporation rates, TBUTs, and vital staining scores were significantly worse in CL wearers compared with healthy control subjects. TBUTs showed significant worsening after passive smoke exposure in both groups. The mean tear evaporation rate and vital staining scores showed a significant increase with brief passive smoke exposure in subjects not wearing CLs but not in CL wearers. CONCLUSION: Even brief passive exposure to cigarette smoke is associated with adverse effects on the ocular surface as evidenced by an increase in tear instability and damage to the ocular surface epithelia in SCL wearers and non-CL wearers.

The role of oxidative stress and inflammation in conjunctivochalasis.

Purpose. To investigate the status of oxidative stress and histopathologic alterations in patients with conjunctivochalasis and compare the findings with those in healthy control subjects. Methods. Eleven patients (n = 20 eyes) with Yokoi grade 3 conjunctivochalasis and 11 health control subjects (n = 22 eyes) were prospectively recruited. ELISA for tear hexanoyl-lysine (HEL) and inflammatory cytokines, tear film break-up time tests, Schirmer test measurements, and fluorescein and rose bengal vital staining were performed. Conjunctival specimens obtained during surgery for conjunctivochalasis and cataract underwent immunohistochemical staining for HEL+8-OHdG, MMP-3, and MMP-9, and positively stained cells were counted. Transmission electron microscopy was also performed, with staining for elastic fibers in the conjunctival stroma. Results. The mean tear stability and vital staining scores were significantly worse in the conjunctivochalasis patients than in the control subjects. The tear HEL and tear cytokine levels showed significantly higher values in eyes with conjunctivochalasis. IL-1beta and IL-6 levels showed a significant correlation with corneal epithelial damage. IL-1beta and TNFalpha showed a significant correlation with 8-OHdG-stained cell counts. Specimens from patients with conjunctivochalasis revealed a significantly higher number of cells positively stained for HEL, 8-OHdG, MMP-3, and MMP-9 than did specimens from age- and sex-matched control subjects. Transmission electron microscopy showed decreased intercellular cohesiveness, with the conjunctival stroma showing an accumulation of elastic fibers. Conclusions. Lipid and DNA oxidative stress were present in the conjunctiva. Increased tear inflammation seemed to coexist with loss of conjunctival epithelial cohesiveness and increased collagenolytic activity, which may explain the conjunctival laxity observed in patients with conjunctivochalasis.

The impact of silicone hydrogel materials on overnight corneal swelling.

PURPOSE: To identify the corneal swelling response associated with silicone hydrogel contact lens wear. METHODS: Twenty-five subjects were recruited to participate in this single-center, controlled, single-masked, clinical trial. The corneal swelling response was evaluated by central corneal pachymetry after overnight wear of balafilcon A, etafilcon A, lotrafilcon A, senofilcon A, and no lens wear. More specifically, after 8 hours of closed-eye wear of each material, corneal thickness was measured immediately on eye opening, in addition to the first 4 hours of open-eye wear. Paired t tests were used to compare the swelling response from each condition to that associated with senofilcon A, and given the numerous statistical comparisons, a P value of

Short-term physiologic response in neophyte subjects fitted with hydrogel and silicone hydrogel contact lenses.

PURPOSE: To investigate the short-term physiologic response to three soft lens materials with different oxygen permeability characteristics. METHODS: Forty-three neophytes were randomly prescribed Acuvue 2, Acuvue Advance (Johnson & Johnson Vision Care), or Focus Night & Day (CIBA Vision) for 4 weeks on a daily-wear basis. A further 19 subjects did not wear lenses (control). Experimental and control subjects were examined 2 and 4 weeks after dispensing. Ocular physiologic response was measured with a slitlamp biomicroscope in a strictly masked fashion. RESULTS: Limbal redness increased in the Acuvue 2 group compared with the other two groups. Conjunctival redness increased more in the Acuvue 2 group than in the Acuvue Advance group. More conjunctival staining was seen with the Acuvue Advance and Focus Night & Day groups compared with the Acuvue 2 group. Increased scores for papillary conjunctivitis were seen in the Focus Night & Day group compared with the Acuvue Advance group. CONCLUSIONS: The reduced level of limbal redness seen with the Acuvue Advance and Focus Night & Day groups suggests that these lenses provide more oxygen to the ocular surface than the Acuvue 2 lens to a degree that can be observed clinically. The conjunctival staining response was similar for the Acuvue Advance and Focus Night & Day groups. The results for the Acuvue Advance and Focus Night & Day groups for papillary conjunctivitis may reflect differences in their material and surface properties.

An evaluation of 1-day disposable contact lens wear in a population of allergy sufferers.

PURPOSE: This was a multi-site, 128-subject, bilateral crossover study to evaluate subjective comfort and slit-lamp findings with 1-day disposable contact lenses in a population of allergy sufferers during periods when allergen levels were elevated. METHODS: The study involved 1-month of single-use daily wear with a 1-day disposable test lens (1. DAY ACUVUE Brand Contact Lenses, Johnson & Johnson Vision Care) and 1-month of daily wear with subjects' habitual lenses replaced to their usual replacement schedule. Pollen and mould counts were obtained for each site 1 week prior to the study and twice weekly throughout the study period. Subjective comfort and slit-lamp findings were recorded at baseline and after 1-month's wear of each modality. RESULTS: Sixty-seven percent of subjects agreed that the 1-day disposable lenses provided improved comfort when compared to the lenses they wore prior to the study, compared with 18% agreeing that the new pair of habitual lenses provided improved comfort. The 1-day disposable lenses showed greater improvement in slit-lamp findings from baseline than new habitual lenses. CONCLUSION: The use of 1-day disposable lenses is an effective strategy for managing allergy-suffering contact lens wearers.

Influence of replacement schedule and care regimen on patient comfort and satisfaction with daily wear frequent-replacement contact lenses.

PURPOSE: This study examines what effects replacement schedule and care regimen have on overall patient satisfaction with daily wear frequent-replacement contact lenses. METHODS: Over 3000 patients were recruited from 313 ophthalmologic practices in France to participate in a 1-month prospective observational clinical study. Subjects included 2108 experienced and 957 novice users of the predominantly prescribed soft contact lenses and care systems in France. All subjects were required to use ACUVUE 2 (Vistakon, Jacksonville, FL) brand contact lenses, replaced once every 2 weeks, and using COMPLETE brand multipurpose solution (Allergan, Irvine, CA) during the study. Practitioners assessed lens fit, and refractive and ocular physiological status. Subjects were surveyed about various subjective attributes at the baseline examination and at the end of the study. RESULTS: Patient satisfaction with the test lenses and care system was found to be excellent for the majority of patients, as evidenced by high subjective satisfaction ratings and the desire of approximately 9 of 10 subjects to continue using the test products after completing the study. Significant improvements were noted with the test lenses and solution compared to previous lenses and solutions for overall satisfaction and comfort variables. CONCLUSIONS: Replacing lenses once every 2 weeks combined with a multipurpose care system incorporating ingredients designed for lens conditioning contributed to significant improvements in lens wearing comfort. Thus, lens replacement frequency and lens-and-solution compatibility should be considered in addition to lens material and design when prescribing contact lenses for new or existing wearers.