Shannon E McCabe

Bio: Shannon E McCabe is an academic researcher from Charles Stark Draper Laboratory. The author has contributed to research in topics: LASIK & Medicine. The author has an hindex of 2, co-authored 16 publications receiving 34 citations.

Comparative efficacy of bepotastine besilate 1.5% ophthalmic solution versus olopatadine hydrochloride 0.2% ophthalmic solution evaluated by patient preference.

Abstract: Background: The aim of this study was to compare patient-perceived relief of ocular itch, nasal symptoms, and eye drop comfort when allergic conjunctivitis was treated with bepotastine besilate 1.5% versus olopatadine hydrochloride 0.2%. Methods: This randomized, observer-masked, single-center, crossover study included 30 patients with ocular itching associated with allergic conjunctivitis accompanied by nasal symptoms. Patients were treated with bepotastine besilate 1.5% twice daily (7 am and 4 pm) or olopatadine hydrochloride 0.2% once daily (7 am) for 14 days. Following a 7-day washout period during which only preservative-free artificial tears were used twice daily, patients were crossed over to the alternative treatment for 14 days. Parameters evaluated by twice-daily patient diaries included each treatment’s ability to relieve ocular itch, ability to relieve itchy/runny nose, ability to relieve ocular allergy symptoms, and eye drop comfort. At the conclusion of the study, patients were also asked to identify which agent provided better all-day relief of ocular itching, better all-day relief of itchy/runny nose, superior comfort, and for which treatment they would prefer a prescription. Results: According to the mean daily diary responses, bepotastine besilate 1.5% provided significantly better relief of evening ocular itch, relief of morning and evening itchy/runny nose, and relief of morning and evening ocular allergy symptoms. At study end, 63.3% and 66.7% of patients preferred bepotastine besilate 1.5% for all-day relief of ocular itching and all-day relief of itchy/runny nose, respectively. At study end, there was no significant difference in the number of patients preferring one treatment over the other for comfort. Overall, 66.7% of patients stated that they would prefer to treat their allergic conjunctivitis with bepotastine besilate 1.5% over olopatadine hydrochloride 0.2%. Conclusion: Based on their evaluation of therapeutic performance, patients preferred bepotastine besilate 1.5% over olopatadine hydrochloride 0.2% by two-to-one for the treatment of

Ectasia After Corneal Refractive Surgery: A Systematic Review

Abstract: The incidence of ectasia following refractive surgery is unclear. This review sought to determine the worldwide rates of ectasia after photorefractive keratectomy (PRK), laser-assisted in situ keratomileusis (LASIK), and small incision lenticule extraction (SMILE) based on reports in the literature. A systematic review was conducted according to modified Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Publications were identified by a search of eight electronic databases for relevant terms between 1984 and 2021. Patient characteristics and preoperative values including manifest refractive spherical refractive equivalent (MRSE), central corneal thickness (CCT), anterior keratometry, postoperative residual stromal bed (RSB), and percent tissue altered (PTA) were summarized. In addition, annual rates of each refractive surgery were determined, and incidence of post-refractive ectasia for each type was calculated using the number of ectatic eyes identified in the literature. In total, 57 eyes (70 eyes including those with preoperative risk factors for ectasia) were identified to have post-PRK ectasia, while 1453 eyes (1681 eyes including risk factors) had post-LASIK ectasia, and 11 eyes (19 eyes including risk factors) had post-SMILE ectasia. Cases of refractive surgery performed annually were estimated as 283,920 for PRK, 1,608,880 for LASIK, and 96,750 for SMILE. Reported post-refractive ectasia in eyes without preoperative identifiable risk factors occurred with the following incidences: 20 per 100,000 eyes in PRK, 90 per 100,000 eyes in LASIK, and 11 per 100,000 eyes in SMILE. The rate of ectasia in LASIK was found to be 4.5 times higher than that of PRK. Post-refractive ectasia occurs at lower rates in eyes undergoing PRK than LASIK. Although SMILE appears to have the lowest rate of ectasia, the number of cases already reported since its recent approval suggests that post-SMILE ectasia may become a concern. Considering that keratoconus is a spectrum of disease, pre-existing keratoconus may play a larger role in postoperative ectasia than previously accounted for in the literature.

Corneal Refractive Surgery in Patients with a History of Herpes Simplex Keratitis: A Narrative Review.

Abstract: The incidence of herpes simplex keratitis (HSK) in patients following corneal refractive surgery is higher than in the general population, and several case reports of ocular morbidity in HSK infection following corneal refractive surgery have been published. HSK is listed by the American Academy of Ophthalmology as a relative contraindication to corneal refractive surgery, although specifics have not been further elucidated. This review summarizes the current literature regarding reactivation of HSK following corneal refractive surgery and provides a guideline for considering corneal refractive surgery in a patient with a previous history of HSK. Based on the current literature, we recommend that corneal refractive surgery is appropriate for patients with a history of HSK without multiple recurrences who have had no evidence of disease for at least one year. In addition to a thorough history and physical examination, we also recommend these patients begin 400 mg twice daily of oral acyclovir or valacyclovir 500 mg once daily for two weeks prior to surgery and continue this regimen for at least two weeks postoperatively or while on topical steroids.

Corneal Donation: Current Guidelines and Future Direction

Abstract: Purpose: This review aims to outline current practices and guidelines of corneal donation and eye banking, describes the implications of COVID-19 and emerging diseases on the corneal donor pool, and discusses future trends to improve and increase the efficiency of the processes involved in corneal donation and eye banking. Summary: Corneal screening, preservation, corneal storage, and prevention of systemic disease transmission from donor to recipient have been crucial in shaping the policies of the FDA and eye banks across the world. Eye banks globally have developed varying guidelines and criteria for evaluating the viability of donor corneas. Variables such as the age of the donor, medical history, and potential disease transmission are important screening parameters. While known infectious diseases may be transmissible through the cornea, emerging infectious diseases that are not well studied may be more transmissible than other infections. In particular, coronavirus has impacted corneal transplantation as SARS-CoV-2 expression has been detected in corneal tissue and conjunctiva. In recent years, partial-thickness corneal transplantations have been introduced. Lamellar grafts and other corneal layers are now utilized for transplantation of the specific areas that are damaged.

Toric Implantable Collamer Lens for the Treatment of Myopic Astigmatism.

Abstract: Purpose To report visual outcomes following surgical correction of myopic astigmatism with Visian Toric implantable collamer lens (ICL) (STAAR Surgical, Monrovia, CA, USA) at a single tertiary refractive center in the United States. Patients and methods Toric ICL was implanted in 96 eyes (55 patients) with mean preoperative sphere of -8.98 ± 3.04 diopters (D) and cylinder of -2.67 ± 1.02 D from December 2018 to February 2021. Primary visual outcomes of efficacy, safety, stability, predictability of refractive correction, and astigmatic analysis were reported at three and twelve months postoperatively. Secondary subjective outcomes included patient-reported dry eye symptoms and glare/halos at postoperative visits. Other secondary outcomes were biometric data and postoperative vault over time. Results At three and twelve months, 75 and 46 eyes were evaluated, respectively. At twelve months, the mean manifest refraction spherical equivalent (MRSE) was -0.23 ± 0.47 D with 93% achieving within ±1.00 D of target refraction. The manifest refractive cylinder (MRC) at twelve months was -0.73 ± 0.51 D, with 86% within ±1.00 D of target. Uncorrected distance visual acuity (UDVA) was 20/20 or better in 74% of eyes at twelve months. No patients lost ≥2 lines of corrected distance visual acuity (CDVA) at twelve months. The mean angle of error was -0.9 ± 10.2° at three months and -1.6 ± 12.8° at twelve months. One patient required bilateral lens rotation, four patients underwent secondary enhancement with LASIK/PRK, and seven patients underwent postoperative limbal relaxing incisions. Conclusion This initial single-site experience finds Toric ICL implantation for myopic astigmatism to be safe and effective. Patients can achieve markedly improved UDVA in a single surgery with stable vision over time and minimal adverse subjective symptoms.

Topical antihistamines and mast cell stabilisers for treating seasonal and perennial allergic conjunctivitis

Abstract: Background Seasonal/perennial allergic conjunctivitis is the most common allergic conjunctivitis, usually with acute manifestations when a person is exposed to allergens and with typical signs and symptoms including itching, redness, and tearing. The clinical signs and symptoms of allergic conjunctivitis are mediated by the release of histamine by mast cells. Histamine antagonists (also called antihistamines) inhibit the action of histamine by blocking histamine H1 receptors, antagonising the vasoconstrictor, and to a lesser extent, the vasodilator effects of histamine. Mast cell stabilisers inhibit degranulation and consequently the release of histamine by interrupting the normal chain of intracellular signals. Topical treatments include eye drops with antihistamines, mast cell stabilisers, non-steroidal anti-inflammatory drugs, combinations of the previous treatments, and corticosteroids. Standard treatment is based on topical antihistamines alone or topical mast cell stabilisers alone or a combination of treatments. There is clinical uncertainty about the relative efficacy and safety of topical treatment. Objectives The objective of this review was to assess the effects of topical antihistamines and mast cell stabilisers, alone or in combination, for use in treating seasonal and perennial allergic conjunctivitis. Search methods We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2014, Issue 7), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to July 2014), EMBASE (January 1980 to July 2014), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 17 July 2014. We also searched the reference lists of review articles and relevant trial reports for details of further relevant publications. Selection criteria We included randomised controlled trials (RCTs) comparing topical antihistamine and mast cell stabilisers, alone or in combination, with placebo, no treatment or to any other antihistamine or mast cell stabiliser, or both, that examined people with seasonal or perennial allergic conjunctivitis, or both. The primary outcome was any participant-reported evaluation (by questionnaire) of severity of four main ocular symptoms: itching, irritation, watering eye (tearing), and photophobia (dislike of light), both separately and, if possible, by an overall symptom score. We considered any follow-up time between one week and one year. Data collection and analysis Two review authors independently extracted data and assessed risk of bias. Disagreements were resolved by discussion among review authors and the involvement of a third review author. We followed standard methodological approaches used by Cochrane. Main results We identified 30 trials with a total of 4344 participants randomised, with 17 different drugs or treatment comparisons. The following antihistamines and mast cell stabilisers were evaluated in at least one RCT: nedocromil sodium or sodium cromoglycate, olopatadine, ketotifen, azelastine, emedastine, levocabastine (or levocabastine), mequitazine, bepotastine besilate, combination of antazoline and tetryzoline, combination of levocabastine and pemirolast potassium. The most common comparison was azelastine versus placebo (nine studies). We observed a large variability in reporting outcomes. The quality of the studies and reporting was variable, but overall the risk of bias was low. Trials evaluated only short-term effects, with a range of treatment of one to eight weeks. Meta-analysis was only possible in one comparison (olopatadine versus ketotifen). There was some evidence to support that topical antihistamines and mast cell stabilisers reduce symptoms and signs of seasonal allergic conjunctivitis when compared with placebo. There were no reported serious adverse events related to the use of topical antihistamine and mast cell stabilisers treatment. Authors' conclusions It seems that all reported topical antihistamines and mast cell stabilisers reduce symptoms and signs of seasonal allergic conjunctivitis when compared with placebo in the short term. However, there is no long-term data on their efficacy. Direct comparisons of different antihistamines and mast cell stabilisers need to be interpreted with caution. Overall, topical antihistamines and mast cell stabilisers appear to be safe and well tolerated. We observed a large variability in outcomes reported. Poor quality of reporting challenged the synthesis of evidence.

A contemporary look at allergic conjunctivitis

Abstract: Allergic eye disease is common, yet often overlooked in North America. In the U.S., up to 40% of the population is deemed to be affected and this number is growing. Symptoms and signs of ocular allergy can lead to decreased productivity and negatively impact quality of life (QoL). Various treatment options exist to achieve symptom control. For allergic conjunctivitis, ophthalmic agents include antihistamines, mast cell stabilizers, dual-activity agents, nonsteroidal anti-inflammatory drugs (NSAIDs), steroids and some off-label treatments. Immunotherapy is recommended as a therapeutic option. This review provides a summary of the forms of ocular allergies, with a focus on symptoms and signs, impact on QoL, physical examination, diagnosis and therapeutic options of allergic conjunctivitis. Through multidisciplinary collaborations, a simplified algorithm for the treatment of allergic conjunctivitis is proposed for Canadian clinical practice.

Allergic conjunctivitis: an update on diagnosis and management.

Abstract: Purpose of reviewThe focus of this review is to provide a logical paradigm for the diagnosis and treatment of ocular allergies, with a focus on seasonal allergic conjunctivitis (SAC) and perennial allergic conjunctivitis (PAC)Recent findingsSeveral classes of topical medications are currently avail

Comparison of Oral Antiviral Therapy With Valacyclovir or Acyclovir After Penetrating Keratoplasty for Herpetic Keratitis

Abstract: Aims: To compare the outcome of prophylactic oral valacyclovir (VAL) or oral acyclovir treatment (ACV) in patients having undergone penetrating keratoplasty for herpetic keratitis (HK). Methods: All patients having received a penetrating keratoplasty for HK and being treated postoperatively with either oral VAL or oral ACV (inclusion period from 12/97 to 3/06 and 5/92 to 9/96, respectively) were retrospectively evaluated. Records were analysed for postoperative reactivation of recurrent HK, graft rejection, endothelial cell loss, central corneal thickness and visual acuity after a follow-up of up to 5 years. Results: Twenty patients received VAL and were compared with 19 patients being treated with ACV. Two patients developed clinical signs of recurrent herpetic disease in the VAL group compared with three patients in the ACV group. Two patients from both groups each developed an irreversible graft failure. Best corrected visual acuity improved in both treatment groups from baseline (logMAR) −1.97 (VAL), −1.47 (ACV) to −0.85, −0.72, respectively, at the 1-year follow-up and slightly deteriorated after 5 years in the ACV group (−0.71 VAL vs −1.14 ACV). Conclusion: Prophylactic oral VAL treatment is at least as effective as ACV in preventing recurrence in patients who underwent corneal transplantation for HK. The tolerability of the two drugs is similar, but the dosing for VAL might be more comfortable for patients.