Jacobs DS, Carrasquillo KG, Cottrell PD, Fernández-Velázquez FJ, Gil-Cazorla R, Jalbert I, Pucker AD, Riccobono K, Robertson DM, Szczotka-Flynn L, Speedwell L, Stapleton F.
CLEAR - Medical use of contact lenses. Cont Lens Anterior Eye 2021;44(2):289-329.
AbstractThe medical use of contact lenses is a solution for many complex ocular conditions, including high refractive error, irregular astigmatism, primary and secondary corneal ectasia, disfiguring disease, and ocular surface disease. The development of highly oxygen permeable soft and rigid materials has extended the suitability of contact lenses for such applications. There is consistent evidence that bandage soft contact lenses, particularly silicone hydrogel lenses, improve epithelial healing and reduce pain in persistent epithelial defects, after trauma or surgery, and in corneal dystrophies. Drug delivery applications of contact lens hold promise for improving topical therapy. Modern scleral lens practice has achieved great success for both visual rehabilitation and therapeutic applications, including those requiring retention of a tear reservoir or protection from an adverse environment. This report offers a practical and relevant summary of the current evidence for the medical use of contact lenses for all eye care professionals including optometrists, ophthalmologists, opticians, and orthoptists. Topics covered include indications for use in both acute and chronic conditions, lens selection, patient selection, wear and care regimens, and recommended aftercare schedules. Prevention, presentation, and management of complications of medical use are reviewed.
Jones L, Hui A, Phan C-M, Read ML, Azar D, Buch J, Ciolino JB, Naroo SA, Pall B, Romond K, Sankaridurg P, Schnider CM, Terry L, Willcox M.
CLEAR - Contact lens technologies of the future. Cont Lens Anterior Eye 2021;44(2):398-430.
AbstractContact 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.
Joseph S, Varadaraj V, Dave SR, Lage E, Lim D, Aziz K, Dudgeon S, Ravilla TD, Friedman DS.
Investigation of the accuracy of a low-cost, portable, autorefractor to provide well-tolerated eyeglass prescriptions: a randomized crossover trial. Ophthalmology 2021;
AbstractPURPOSE: To compare patient preferences for eye glasses prescribed using a low-cost portable wavefront autorefractor versus standard subjective refraction. DESIGN: Randomized, cross-over clinical trial PARTICIPANTS: Patients aged 18-40 years presenting with refractive errors to a tertiary eye hospital in Southern India. METHODS: Participants underwent subjective refraction (SR) followed by autorefraction (AR) using the monocular version of the QuickSee device. An independent optician, masked to the refraction approach, prepared eyeglasses based on each refraction approach. Participants (masked-to-refraction source) were randomly assigned to use either SR- or AR-based eyeglasses first, followed by the other pair, for a week each. At the end of each week, participants had vision checked and were interviewed about their experience with the eyeglasses. MAIN OUTCOME MEASURES: Proportion of patients preferring eyeglasses prescribed using AR and SR RESULTS: The 400 participants enrolled between March 26, 2018 and August 02, 2019, had mean (SD) age of 28.4 (6.6) years and 68.8% were women. There was strong correlation between spherical equivalents using SR and AR (r=0.97, p<0.001) with a mean difference of -0.07 diopters (95% limits of agreement: -0.68 to 0.83). Of the 301 (75.2%) patients who completed both follow-up visits, 50.5% (n=152) and 49.5% (n=149) preferred glasses prescribed using SR and AR, respectively (95% CI: 45.7% - 56.3%; p=0.86). There were no differences in demographic or vision characteristics between participants with different preferences (p>0.05 for all). CONCLUSIONS: We observed strong agreement between the prescriptions from SR and QR, and eyeglasses prescribed using SR and AR were equally preferred by patients. Wider use of prescribing based on AR alone in resource-limited settings is supported by these findings.
Jumelle C, Gholizadeh S, Annabi N, Dana R.
Advances and limitations of drug delivery systems formulated as eye drops. J Control Release 2020;321:1-22.
AbstractTopical instillation of eye drops remains the most common and easiest route of ocular drug administration, representing the treatment of choice for many ocular diseases. Nevertheless, low ocular bioavailability of topically applied drug molecules can considerably limit their efficacy. Over the last several decades, numerous drug delivery systems (DDS) have been developed in order to improve drug bioavailability on the ocular surfaces. This review systematically covers the most recent advances of DDS applicable by topical instillation, that have shown better performance in in vivo models compared to standard eye drop formulations. These delivery systems are based on in situ forming gels, nanoparticles and combinations of both. Most of the DDS have been developed using natural or synthetic polymers. Polymers offer many advantageous properties for designing advanced DDS including biocompatibility, gelation properties and/or mucoadhesiveness. However, despite the high number of studies published over the last decade, there are several limitations for clinical translation of DDS. This review article focuses on the recent advances for the development of ocular drug delivery systems. In addtion, the potential challenges for commercialization of new DDS are presented.
