Assessment of a Novel Lens Surface Treatment for Scleral Lens Wearers With Dry Eye

Biomedical applications of functional hydrogels: Innovative developments, relevant clinical trials and advanced products

Functional hydrogels are used for numerous biomedical applications such as tissue engineering, wound dressings, lubricants, contact lenses and advanced drug delivery systems. Most of them are based on synthetic or natural polymers forming a three-dimensional network that contains aqueous media. Among synthetic polymers, poly(meth)acrylates, polyethyleneglycols, poly(vinylalcohols), poly(vinylpyrrolidones), PLGA and poly(urethanes) are of high relevance, whereas natural polymers are mainly polysaccharides such as hyaluronic acid, alginate or chitosan and proteins such as albumin, collagen or elastin. In contrast to most synthetic polymers, natural polymers are biodegradable. Both synthetic and natural polymers are often chemically modified in order to improve or induce favorable properties and functions like high mechanical strength, stiffness, elasticity, high porosity, adhesive properties, in situ gelling properties, high water binding capacity or drug release controlling properties. Within this review we provide an overview about the broad spectrum of biomedical applications of functional hydrogels, summarize innovative approaches, discuss the concept of relevant functional hydrogels that are in clinical trials and highlight advanced products as examples for successful developments.

Utilizing PROSE as a Drug Delivery Device for Preservative-Free Cyclosporine 0.05% for the Treatment of Dry Eye Disease: A Pilot Study

Purpose

To evaluate the tolerability of utilizing Prosthetic Replacement of the Ocular Surface Ecosystem (PROSE) as a drug delivery device for preservative-free cyclosporine 0.05% for the treatment of dry eye disease.

Patients and Methods

Fourteen current daily PROSE wearers were enrolled, with four screen failures and one subject that did not complete the study protocol due to burning and stinging. Nine subjects, 18 eyes completed the study protocol. All participants were instructed to instill one drop of preservative-free cyclosporine 0.05% in the PROSE reservoir and then fill the rest of the reservoir with preservative-free normal saline. After applying the PROSE and wearing for 6 hours, the PROSE was removed, and the protocol was repeated for at least another 4 additional hours of wear. Baseline, 1 week and 1 month symptom and sign data were collected.

Results

At one month, OSDI improved by an average of 3.83 ± 6.87 from baseline (p = 0.07) and there was no statistically significant change in best corrected visual acuity. Without comparing with placebo, there was statistically significant (p < 0.05) improvement in mean per subject and mean per eye corneal fluorescein staining, conjunctival lissamine staining, and conjunctival hyperemia by slit lamp examination at one-month follow-up.

Conclusion

Utilizing PROSE as a drug delivery system for non-preserved cyclosporine 0.05% was well tolerated in regard to both ocular symptoms and ocular surface signs. Results from this pilot study are suggestive of efficacy. The results of this study support progressing this protocol to a larger scale randomized controlled double blinded prospective clinical trial.

BCLA CLEAR Presbyopia: Management with contact lenses and spectacles

This paper seeks to outline the history, market situation, clinical management and product performance related to the correction of presbyopia with both contact lenses and spectacles. The history of the development of various optical forms of presbyopic correction are reviewed, and an overview is presented of the current market status of contact lenses and spectacles. Clinical considerations in the fitting and aftercare of presbyopic contact lens and spectacle lens wearers are presented, with general recommendations for best practice. Current options for contact lens correction of presbyopia include soft simultaneous, rigid translating and rigid simultaneous designs, in addition to monovision. Spectacle options include single vision lenses, bifocal lenses and a range of progressive addition lenses. The comparative performance of both contact lens and spectacle lens options is presented. With a significant proportion of the global population now being presbyopic, this overview is particularly timely and is designed to act as a guide for researchers, industry and eyecare practitioners alike.

Scleral Lenses for Managing Dry Eye Disease in the Absence of Corneal Irregularities: What Is the Current Evidence?

Scleral lenses (SLs) are large-diameter rigid contact lenses that are a mainstay treatment for eyes with corneal irregularities. In recent years, there has been increased interest in the role of managing dry eye disease (DED) with SLs, as many patients with DED have reported symptomatic relief with SL wear. The role of SLs for DED management when there are associated corneal irregularities is supported by individual case reports and studies. This has prompted practitioners to begin advocating using SLs in DED cases, even in the absence of associated corneal irregularities and other ocular surface diseases (OSDs). There have also been discussions on potentially placing SLs earlier in the treatment hierarchy of DED, where it currently sits at a more advanced level of intervention (Step 3) in the TFOS DEWS II Report. This review will present the currently available, albeit sparse, evidence that supports and suggests this practice, as well as ancillary evidence supporting the purported benefits of SL wear in DED. The advantages of SL wear, such as corneal healing, absence of tear evaporation and contact lens dehydration, and improved visual acuity with associated increased wear comfort, and how this will benefit DED patients will be explored. Conversely, the challenges associated with fitting SLs in DED patients, including increased midday fogging, poor wettability, and subjective patient satisfaction, will also be presented, as well as a discussion on the key considerations for SL fitting in this population. Overall, while more research is needed to support the use of SLs in DED patients without associated corneal irregularities and other forms of OSD, the use of these lenses may prove to have a potentially wider role given their reported ancillary benefits in these populations.

Lens and solution properties in patients with and without midday fogging

INTRODUCTION

Midday fogging is a complication of scleral lens (SL) wear that interrupts clear vision during the course of wear. SLs can be made with a variety of gas permeable materials, sizes and surface treatments, and various solutions are available for storing the lenses and for filling them before application on the eye. Many of these factors have been implicated as possible contributors to midday fogging. This study explored the lens and solution properties in habitual SL wearers with and without midday fogging.

METHODS

In this prospective study, 48 habitual SL wearers were evaluated and asked to report whether they experienced midday fogging and if they removed their lenses during the day. They completed the Ocular Surface Disease Index (OSDI), which is a validated tool for dry eye assessment. Lens parameters (material, coatings and diameter) and lens storage and filling solutions were documented. Backward elimination of regression terms evaluated the lens and solution properties in those with and without fogging. OSDI scores were compared using the Mann-Whitney analysis.

RESULTS

Collectively, the lens properties and solutions accounted for 27.7% of the variance related to midday fogging. None of the factors alone had a significant impact upon midday fogging. The median (interquartile range) OSDI score for those with fogging [37 (35)] was significantly different from those without fogging [10 (15)], with the scores corresponding to severe dry eye and normal eyes, respectively.

CONCLUSION

SL wearers with midday fogging exhibited similar symptoms to patients with severe dry eye. Lens and solution characteristics may play a small role in patients with midday fogging, although changing just a single factor is not likely to impact its presence.

Average Scleral Lens Replacement Period at a Tertiary Care Hospital

OBJECTIVE

To evaluate the average scleral lens replacement period at a tertiary care hospital.

METHODS

Patients were identified retrospectively through electronic medical records. Inclusion criteria included scleral lens patients treated at the USC Department of Ophthalmology who had reordered a scleral lens at least once in one eye. Lens order histories were evaluated, and statistical analysis included a multivariable, mixed-methods, linear, regression model.

RESULTS

Two hundred fifty-one patients (120 men and 131 women; average age 57.1±17.4 years, range 9-93 years) and a total of 445 eyes (227 OD, 218 OS; 199 irregular corneas, 246 ocular surface disease) were included. The average replacement period for a scleral lens was 23.9±14.3 months (range 5-2,617 days). Patients with greater scleral lens experience had a statistically significant increase in their average scleral lens replacement period; for every one year of additional experience wearing scleral lenses, average replacement period increased by 30.7 days ( P =0.001). There was no statistically significant correlation between average scleral lens replacement period and sex, diagnosis, prior outside scleral lens treatment, lens brand, or lens diameter.

CONCLUSION

The average scleral lens replacement period in this patient cohort at a tertiary care hospital was 23.9±14.3 months (1.99±1.19 years). Further studies are needed to better understand the impact of scleral lens age on ocular health and vision. Certainly, proper scleral lens training and education are essential to ensure optimal lens condition and treatment outcomes.

Current Trends in Scleral Lens Prescription, Management, and Evaluation

OBJECTIVES

To report current trends in scleral contact lens prescription and management, including lens designs prescribed, care products recommended, and procedures performed during routine scleral lens (SL) evaluation.

METHODS

An online survey was designed by the Scleral Lenses in Current Ophthalmic Practice Evaluation study team and administered to eye care practitioners attending a specialty contact lens meeting. The survey was available from November 8, 2019, through March 31, 2020. Participants' demographic data were collected, along with information on lens diameters, landing zone (LZ) designs, recommended care products, and components of routine SL evaluation.

RESULTS

In total, 715 participants responded to at least one of the survey items of interest. Most lenses prescribed (63%) were 16 mm or more in diameter. Lenses with toric LZs were the most frequently prescribed (48%), followed by spherical (40%), quadrant-specific (8%), and impression-based or image-based designs (3%). Most participants (61%) recommended hydrogen peroxide products for lens care. Nonpreserved saline in a single-use vial was most frequently recommended to fill the bowl of the lens before application. Intraocular pressure was measured during SL evaluation by 45% of participants; 38% of participants routinely measured corneal thickness.

CONCLUSIONS

Practitioners increasingly are prescribing SLs with advanced LZ designs. Most practitioners recommend hydrogen peroxide-based disinfection systems and single-use vials of nonpreserved saline for lens care and application. Because differences in components of routine SL evaluations were reported, clinicians may benefit from reaching a consensus on essential components of SL evaluation.

How Can We Best Measure the Performance of Scleral Lenses? Current Insights

Scleral lenses (SLs) present several unique advantageous characteristics for patients. As these lenses are mainly fitted in severely diseased eyes, a thorough evaluation of the ocular surface before and after SL fitting and the on-eye SL fitting evaluation are essential and help minimize potential physiological complications. This review will explore the current and emerging techniques and instrumentation to best measure SL performance ensuring optimal lens fitting, visual quality, comfort and physiological responses, highlighting some potential complications and follow-up recommendations. A single physician could perform the great majority of evaluations. Still, the authors consider that the assessment of SL fitting should be a collaborative and multidisciplinary job, involving contact lens practitioners, ophthalmologists and the industry. This publication has reviewed the most up-to-date work and listed the most used techniques; however, the authors encourage the development of more evidence-based recommendations for SL clinical practice.

Subjective Responses to Various Filling Solutions in the Posterior Fluid Reservoir of Miniscleral Lenses at Application

PURPOSE

To compare the effect of the use of different lubrication eye drops and nonpreserved saline for the application of miniscleral contact lenses (CLs) on subjective experience during 6 hr of lens wear.

METHODS

Experienced soft CL wearers aged 18 to 45 years (inclusive) were enrolled in this prospective, randomized, double-masked, three arm comparison cross-over study. Subjects were custom fitted with KATT 16.5 mm diameter miniscleral lenses, ordered to their prescription. Subjects attended visits on three separate days and were randomized to receive instillation of an HP-guar/nanoemulsion drop or an HP-guar/sodium hyaluronate (HA) eye drop into the miniscleral lens before filling with saline or filling with saline alone (control). Subjective responses were collected up to 6 hr postapplication. Generalized linear mixed models with multinomial distribution and cumulative logit link were used to compare the rate at which responses improved post-CL application for the different treatments.

RESULTS

Twenty-four participants completed the study. Dryness symptoms were more likely to improve at a slower rate postlens application with saline alone compared with the addition of HP-guar/nanoemulsion (P=0.005) or HP-guar/HA (P=0.049) before lens application. Furthermore, the addition of HP-guar/nanoemulsion was more effective than saline alone in improving symptoms of fluctuating vision (P=0.011), grittiness/burning/stinging (P=0.001), and foreign body sensation (P=0.006) more quickly.

CONCLUSIONS

The use of postlens lubrication may be useful in enhancing adaptation to miniscleral lenses.