Optometric Physician

Vol. 21, #16   •   Monday, April 19, 2021


Off the Cuff: Acanthamoeba Keratitis: Why So Little Progress?

Contact lenses remain a safe and effective form of refractive correction. Yet, despite years of innovation in materials science, increased use of frequent replacement lenses, and greater public and professional awareness of hygiene and proper lens care, infection rates have not changed in decades. Among the notable exceptions is an increase in contact lens-related Acanthamoeba infections.

What makes this especially concerning is Acanthamoeba infections’ especially ugly clinical triad. Acanthamoeba keratitis is often hard to diagnose. It can be difficult to treat effectively especially if treatment is delayed. Among corneal infections, AK can be especially devastating.

Considering the difficulty of managing Acanthamoeba keratitis, prevention becomes much more important. However, the FDA has remained silent for nearly three years on new disinfection standards for Acanthamoeba, now long overdue. However, I do have some good news from an old friend.

I first met Lynn Winterton when he led R&D at CIBA Vision before moving to Alcon after the Novartis acquisition. Lynn, who is among the most innovative people I know, recently shared data on an advanced lens care product he developed at his company, Better Vision Solutions Group.

With a longstanding interest in contact lens complications and specifically in contact lens-related microbial keratitis, I was blown away by the product’s rapid effectiveness against ISO standard bacteria. However, what was really impressive was the data on acanthamoeba cysts—a 4.5 log reduction against Acanthamoeba castellani cysts.

As I understand it, the product is not currently in production, but it’s being evaluated by several contact lens manufacturers. Especially with Acanthamoeba, which has been linked to lens care product issues, a next-generation product can have tremendous impact. I am looking forward to seeing Lynn’s brainchild become available.


Arthur B. Epstein, OD, FAAO
Chief Medical Editor

Want to share your perspective?
Write to Dr. Epstein at artepstein@optometricphysician.com. The views expressed in this editorial are solely those of the author and do not necessarily represent the opinions of Jobson Medical Information LLC (JMI), or any other entities or individuals.



Visual and Ocular Conditions Among a Homeless Adult Population of Boston

The eye care needs of the homeless population in the United States are not well-known. This study elucidated some of those needs for homeless programs and eye care practitioners. The purpose of this study was to assess the extent of visual and ocular conditions, the frequency of eyeglass orders and receipt of eyeglasses, and the frequency of ophthalmology referrals and receipt of ophthalmological care in an adult homeless population in Boston. A cross-sectional retrospective chart review was conducted for patients of the Boston Health Care for the Homeless Program's Pine Street Inn eye clinic from September 26, 2016, to December 31, 2017. Data on socio demographics, medical history, comprehensive eye examination findings, glasses orders and receipt, and ophthalmology referrals and receipt of care were collected and analyzed.

A total of 424 patients were included in the study. The mean age of the study population was 52.7 (interquartile range, 46 to 60), and the majority were male (74%). The most common systemic conditions were hypertension (40.6%) and diabetes (23.8%). The most common refractive error was presbyopia (67.7%), followed by astigmatism (38.9%), hyperopia (34.0%) and myopia (30.7%). The most common ocular conditions were dry eye (28.6%), visually or clinically significant cataract (20%), and glaucoma/glaucoma suspicion (13.9%). Refractive correction was indicated for 356 patients (84%), but 82 (29%) didn’t receive ordered eyeglasses. Ophthalmology referrals were placed for 61 patients (14.4%), yet only 20 (32.8%) of those referrals were completed.

A significant need for refractive correction and a large gap for ophthalmological care were found among the study population. Researchers wrote that healthcare for homeless programs and eye care practitioners should be aware of the visual and ocular needs of this patient population so as to better meet their needs.

SOURCE: Russo D, Bass O. Visual and ocular conditions among a homeless adult population of Boston. Optom Vis Sci. 2021; Apr 1;98(4):362-6.




Central-to-peripheral Corneal Edema During Wear of Embedded-component Contact Lenses

With active investigation underway for embedded-circuit contact lenses, safe oxygen supply of these novel lenses remains a question. Central-to-peripheral corneal edema for healthy eyes during wear of soft contact (SCL) and scleral lenses (SL) with embedding components was assessed. Various 2-dimensional (2D) designs of SL and SCL with embedded components were constructed on Comsol Multiphysics 5.5. Local corneal swelling associated with the designed lenses was determined by a recently developed 2D metabolic-swelling model. Settled central post-lens tear film thicknesses (PoLTFs) were set at 400 μm and 3 μm for SL and SCL designs, respectively. Each lens design had an axisymmetric central and an axisymmetric peripheral embedment. Oxygen permeability (Dk) of the lens, and the embedments ranged from 0 to 200 Barrer. Dimensions and location of the embedments were varied to assess optimal design configurations to minimize central-to-peripheral corneal edema.

By adjusting oxygen Dk of the central embedment, the peripheral embedment, or the lens matrix polymer, corneal swelling was reduced by up to 2.5 %, 1.5 %, or 1.4 % of the baseline corneal thickness, respectively, while keeping all other parameters constant. A decrease in PoLTF thickness from 400 μm to 3 μm decreased corneal edema by up to 1.8 % of the baseline corneal thickness. Shifting the peripheral embedment farther out towards the periphery and towards the anterior lens surface reduced peak edema by up to 1.3 % and 0.6 % of the baseline corneal thickness, respectively.

To minimize central-to-peripheral corneal edema, investigators wrote that embedments should be placed anteriorly and far into the periphery to allow maximal limbal metabolic support and oxygen transport in the polar direction (i.e., the θ-direction in spherical coordinates). They added that high-oxygen transmissibility for all components and thinner PoLTF thickness are recommended to minimize corneal edema. Furthermore, they added, depending on design specifications, less than 1% swelling over the entire cornea is achievable even with oxygen-impermeable embedments.

SOURCE: Kim YH, Lin MC, Radke CJ. Central-to-peripheral corneal edema during wear of embedded-component contact lenses. Cont Lens Anterior Eye. 2021; Apr 9. [Epub ahead of print].



Polluted Air Exposure Compromises Corneal Immunity and Exacerbates Inflammation in Acute Herpes Simplex Keratitis

Air pollution is a serious environmental issue worldwide in developing countries' megacities, affecting the population's health, including the ocular surface, by predisposing or exacerbating other ocular diseases. Herpes simplex keratitis (HSK) is caused by the herpes simplex virus type 1 (HSV-1). The primary or recurring infection in the ocular site causes progressive corneal scarring that may result in visual impairment. The present study was designed to study the immunopathological changes of acute HSK under urban polluted air, using the acute HSK model combined with an experimental urban polluted air exposure from Buenos Aires City. Researchers evaluated the corneal clinical outcomes, viral DNA and pro-inflammatory cytokines by RT-PCR and ELISA assays, respectively. Then, they determined the innate and adaptive immune responses in both cornea and local lymph nodes after HSV-1 corneal by immunofluorescence staining and flow cytometry.

The results showed that mice exposed to polluted air develop a severe form of HSK with increased corneal opacity, neovascularization, HSV-1 DNA and production of TNF-α, IL-1β, IFN-γ, and CCL2. A high number of corneal resident immune cells, including activated dendritic cells, was observed in mice exposed to polluted air; with a further significant influx of bone marrow-derived cells including GR1+ cells (neutrophils and inflammatory monocytes), CD11c+ cells (dendritic cells) and CD3+ (T cells) during acute corneal HSK. Moreover, mice exposed to polluted air showed a predominant Th1 type T cell response over Tregs in local lymph nodes during acute HSK with decreased corneal Tregs.

These findings provide strong evidence that urban polluted air might trigger a local imbalance of innate and adaptive immune responses that exacerbate HSK severity. Taking this study into account, urban air pollution should be considered a key factor in developing ocular inflammatory diseases.

SOURCE: Sendra VG, Tau J, Zapata G, et al. Polluted air exposure compromises corneal immunity and exacerbates inflammation in acute herpes simplex keratitis. Front Immunol 2021; Feb 25;12:618597.





Industry News

AAOF Announces Recipients of the J&J Vision Award of Excellence in Contact Lens Patient Care Grants

The American Academy of Optometry Foundation announced the recipients of the 2021 Johnson & Johnson Vision Award of Excellence in Contact Lens Patient Care Grant. The award recognizes outstanding fourth-year student clinicians who have demonstrated skillful knowledge of the contact lens field. Each winner will receive a $500 educational award and a personalized plaque. View the receipients.




B+L Announces Positive Topline Results From Phase III NOV03 Trial

Bausch + Lomb announced statistically significant topline data from the first Phase III trial (GOBI trial) evaluating the investigational drug NOV03 (perfluorohexyloctane) as a first-in-class eye drop with a novel mechanism of action to treat the signs and symptoms of dry eye disease associated with meibomian gland dysfunction. The GOBI trial met both of its co-primary endpoints. Read more.



ForeseeHome AMD Home Monitoring Study Confirms Earlier Results

A retrospective study funded by Notal Vision on the use of its ForeseeHome AMD monitoring program found results that were similar to those from the 2014 randomized, controlled AREDS2-HOME study, the company says. Notal says the use of ForeseeHome helped detect wet AMD earlier and with better visual acuity, “a factor previously shown to improve long-term visual outcomes of anti-VEGF treatment.” Read more.

Allergan Launches New Consumer Ad Campaign for Restasis

Allergan is launching a direct-to-consumer (DTC) broadcast TV advertising campaign for Restasis (cyclosporine ophthalmic emulsion) 0.05. The tone of the new 60-second spot is one of empowerment, and features a woman tearing up a floor, fixing a car, curating designs and baking sourdough bread. View the new campaign: Chronic Dry Eye Syndrome Treatment | Restasis®

IDOC Launches HR Management Service

IDOC announced the addition of IDOC HR Now, an HR management service powered by ThinkHR, to its list of member benefits. The service offers unlimited, on-demand access to legal forms, standardized templates and HR experts qualified to address topics that include FMLA, COVID-19, investigations, wages, workers comp, employee handbook, and legal and state-specific compliance requirements. More than 150 IDOC members have adopted the new IDOC HR Now service since its introduction on April 5. Learn more.







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