Search

SignificanceThink 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.PurposeThe 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.MethodsExperts 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.ResultsThe 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.ConclusionsThe 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.

Valid and updated clinical indicators can serve as important tools in assessing and improving eyecare delivery. Indicators for diabetic eyecare in Australia were previously developed from guidelines published before 2013 and then used to assess the appropriateness of care delivery through a nationwide patient record card audit (the iCareTrack study). To reflect emerging evidence and contemporary practice, this study aimed to update clinical indicators for optometric care for people with type 2 diabetes in Australia. Forty-five candidate indicators, including existing iCareTrack and new indicators derived from nine high-quality evidence-based guidelines, were generated. A two-round modified Delphi process where expert panel members rated the impact, acceptability, and feasibility of the indicators on a 9-point scale and voted for inclusion or exclusion of the candidate indicators was used. Consensus on inclusion was reached when the median scores for impact, acceptability, and feasibility were ≥7 and >75% of experts voted for inclusion. Thirty-two clinical indicators with high acceptability, impact and feasibility ratings (all median scores: 9) were developed. The final indicators were related to history taking (n = 12), physical examination (n = 8), recall period (n = 5), referral (n = 5), and patient education/communication (n = 2). Most (14 of 15) iCareTrack indicators were retained either in the original format or with modifications. New indicators included documenting the type of diabetes, serum lipid level, pregnancy, systemic medications, nephropathy, Indigenous status, general practitioner details, pupil examination, intraocular pressure, optical coherence tomography, diabetic retinopathy grading, recall period for high-risk diabetic patients without retinopathy, referral of high-risk proliferative retinopathy, communication with the general practitioner, and patient education. A set of 32 updated diabetic eyecare clinical indicators was developed based on contemporary evidence and expert consensus. These updated indicators inform the development of programs to assess and enhance the eyecare delivery for people with diabetes in Australia. [ABSTRACT FROM AUTHOR]

Pain associated with mechanical, chemical, and thermal heat stimulation of the ocular surface is mediated by trigeminal ganglion neurons, while cold thermoreceptors detect wetness and reflexly maintain basal tear production and blinking rate. These neurons project into two regions of the trigeminal brain stem nuclear complex: ViVc, activated by changes in the moisture of the ocular surface and VcC1, mediating sensory-discriminative aspects of ocular pain and reflex blinking. ViVc ocular neurons project to brain regions that control lacrimation and spontaneous blinking and to the sensory thalamus. Secretion of the main lacrimal gland is regulated dominantly by autonomic parasympathetic nerves, reflexly activated by eye surface sensory nerves. These also evoke goblet cell secretion through unidentified efferent fibers. Neural pathways involved in the regulation of meibomian gland secretion or mucin release have not been identified. In dry eye disease, reduced tear secretion leads to inflammation and peripheral nerve damage. Inflammation causes sensitization of polymodal and mechano-nociceptor nerve endings and an abnormal increase in cold thermoreceptor activity, altogether evoking dryness sensations and pain. Long-term inflammation and nerve injury alter gene expression of ion channels and receptors at terminals and cell bodies of trigeminal ganglion and brainstem neurons, changing their excitability, connectivity and impulse firing. Perpetuation of molecular, structural and functional disturbances in ocular sensory pathways ultimately leads to dysestesias and neuropathic pain referred to the eye surface. Pain can be assessed with a variety of questionaires while the status of corneal nerves is evaluated with esthesiometry and with in vivo confocal microscopy.

Realistic benchmarks can serve as comparators for optometrists wishing to engage in clinical practice audits of their glaucoma care. The iCareTrack study established the appropriateness of glaucoma care delivery through clinical record audits of Australian optometry practices. Benchmarks required for monitoring and improving glaucoma care delivery do not exist. This study developed realistic benchmarks for glaucoma care and then benchmarked the performance of practices from the iCareTrack study to establish aspects of care that warrant attention from quality improvement initiatives. Benchmarks were developed from the pre-existing iCareTrack dataset using the Achievable Benchmarks of Care (ABC) method. The iCareTrack study had audited the appropriateness of glaucoma care delivery against 37 clinical indicators for 420 randomly sampled glaucoma patient records from 42 Australian optometry practices. The four-step ABC method calculates benchmarks based on the top 10% of best-performing practices adjusted for low patient encounter numbers. iCareTrack results were compared to the benchmarks to explore the distribution of practices that were at, above or below benchmark. Benchmarks were developed for 34 of 37 iCareTrack indicators. For 26 (of 34) indicators, the benchmarks were at or above 90% appropriateness. The benchmarks for 14 (of 34) iCareTrack indicators were met by more than 80% of eligible practices, indicating excellent performance. Some aspects of glaucoma care such as peripheral anterior angle assessment, applanation tonometry, and visual field assessment appeared to be delivered sub-optimally by optometrists when compared to the benchmarks. This study established benchmarks for glaucoma care delivery in optometry practices that reflect realistic and top achievable performance. The large number of indicators with benchmarks above 90% confirmed that glaucoma care can and should be delivered by optometrists at very high levels of appropriateness. Benchmarking identified pockets of sub-optimal performance that can now be targeted by quality improvement initiatives. [ABSTRACT FROM AUTHOR]

Traditionally, refraction is performed, and spectacles are manufactured in in 0.25D-steps. Trial and spectacle lenses manufactured in smaller increments may allow for a more accurate refraction and prescribed spectacles. To determine whether refraction in 0.05D-steps improves the proportion of eyes achieving achieve duochrome equality, and whether spectacles prescribed in 0.05D-steps offer any vision benefits, compared to 0.25D-steps. Myopic young adults were enrolled into two prospective studies conducted at different sites. Study 1 comprised 66 participants (refracted under cycloplegia) while Study 2 comprised 51 participants (not cyclopleged). A standard refraction was performed in both studies and a trial frame and trial lenses were used to determine the spherical endpoint of duochrome equality (0.25D-steps first then 0.05D-steps). In Study 2, the cylindrical component was refined in 0.05D-steps before the spherical endpoint in 0.05D-steps. Monocular high-contrast-visual-acuity (HCVA) was measured while wearing the final refractions. Participants in Study 2 wore spectacles manufactured in 0.25D and 0.05D-steps for 7 days each in a randomized, double-masked study. Both spectacles appeared identical. Outcome measures assessed on dispensing and after 7 days of wear comprised monocular acuity-based measurements (HCVA, low-contrast-visual-acuity, vanishing-optotype-acuity, contrast-sensitivity) and subjective ratings. The Quality-of-Vision questionnaire and subjective preference were assessed after 7 days. Both studies showed a higher proportion of eyes achieved duochrome equality (P < 0.001) and better average monocular HCVA (P ≤ 0.006) in 0.05D-steps. Study 2 showed 0.05D-step spectacles provided better average results for all monocular acuity-based measurements (P < 0.006) and were preferred by 65% (P = 0.04) of participants after 7 days (P = 0.04). There were no differences between spectacles for any other measures (P > 0.1). Refraction performed, and spectacles manufactured in 0.05D-steps for this study improved average acuity-based outcomes and were preferred by most participants to spectacles in traditional 0.25D-steps. [ABSTRACT FROM AUTHOR]