Drug-induced corneal deposits: an up-to-date review.

This review assesses different clinical aspects of the various known drug-induced corneal deposits, based on the corneal layer involved (epithelium, stroma and/or endothelium), and based on the drug class. The most well-known condition caused by drug deposits is vortex keratopathy, or corneal verticillata, which is a whorl-like opacity in the corneal epithelium. Vortex keratopathy is commonly caused by certain cationic amphiphilic drugs such as amiodarone, antimalarials, suramin, tamoxifen, chlorpromazine and non-steroidal anti-inflammatory drugs. These deposits usually occur once a certain dose of the drug is reached. Most cases present with mild to moderate symptoms with minimal visual impairment. Most of these deposits resolve automatically, after months to years of drug cessation. Notably, other drug classes can cause deposits in all three layers of the cornea. Chlorpromazine, gold, rifabutin, indomethacin and tyrosine kinase inhibitors can cause stromal deposits, with reduced visual acuity when the anterior stroma is involved. Chlorpromazine and rifabutin can also cause deposits in the endothelial layer of the cornea. Regardless of the type of corneal deposit, local therapies such as topical lubricants or corticosteroids may help improve symptoms. Drug cessation or modification can also be helpful but should be weighed against the systemic risks of the underlying disease.

Frozen versus fresh corneal graft carriers in Boston keratoprosthesis surgery: 10-year outcomes.

OBJECTIVE: To compare 10-year clinical outcomes of frozen versus fresh corneal graft carriers for the Boston Keratoprosthesis type 1 (KPro). DESIGN: Prospective, non-masked randomized controlled trial. PARTICIPANTS: Nineteen eyes of 19 patients having undergone Boston KPro type 1 implantation using a fresh or frozen graft carrier. METHODS: All patients that underwent Boston KPro type 1 implantation by a single experienced surgeon using an allograft carrier between October 2008 and March 2010 at the Centre Hospitalier de l'Université de Montréal were considered. Patients were excluded if they had a history of prior KPro implantation in the same eye. A subset of the patient cohort enrolled in the initial study protocol of 24 months continued follow-up to 120 months. Participants were randomized to receive either a fresh or frozen corneal graft carrier depending on tissue availability from the eye bank on the day of KPro implantation. RESULTS: Nineteen eyes of 19 patients were included, with 11 in the fresh group and 8 in the frozen group. At 10 years, in the fresh and frozen groups respectively, device retention was 91% and 75%; mean best corrected visual acuity increased from counting fingers preoperatively to 20/300 and 20/125; and incidence of complications per patient was 2.36 and 2.37. There were no statistically significant differences between groups for any of these outcome measures (p > 0.05 for all analyses). CONCLUSIONS: Fresh and frozen corneal graft carriers offer similar clinical outcomes for KPro implantation in terms of device retention, change in visual acuity, and rate of complications at 10 years.

Management of corneal melt in patients with Boston Keratoprosthesis Type 1: Repair versus repeat.

PURPOSE: To evaluate outcomes of Boston keratoprosthesis (KPro) repair versus repeat KPro as treatment for corneal melt in KPro patients. METHODS: Retrospective study of adult KPro patients with melt managed by KPro repair or repeat KPro by one surgeon (MH-D). Incidence of sight- or globe-threatening complications, risk of recurrence of melt and change in BCVA before and 3 months after the procedure were compared between both treatment groups. Change from pre-melt BCVA to final BCVA was compared between primary versus secondary repeat KPro after repair attempt. RESULTS: This study included 19 eyes of 19 patients with melt and mean follow-up of 8.7 years. Primary repeat KPro was performed in 6 eyes (32%) and KPro repair in 13 eyes (68%). There were no significant differences in gender, age, or incidence of complications after KPro repair versus after repeat KPro (92% and 83% complication rate respectively, p > 0.05). The odds ratio for melt recurrence after KPro repair versus repeat KPro was 24 (95% CI 1.68-340). Change in BCVA was not significantly different in KPro repair versus repeat KPro nor in primary versus secondary repeat KPro (p > 0.05). CONCLUSIONS: Repeat KPro offers a lower risk of recurrence of melt compared to KPro repair. However, repair may be considered when timely access to a new KPro and corneal graft is not possible. Delaying repeat KPro does not significantly affect final BCVA. Finally, repeat KPro is the only effective treatment when melt has led to extrusion or uncontrollable infection.

Management of meibomian gland dysfunction: a review.

Meibomian gland dysfunction is the leading cause of evaporative dry eye disease and is one of the most common conditions encountered by eye care providers. The disorder is characterized by obstruction of the meibomian gland terminal ducts and/or changes in their glandular secretion, resulting in changes in tear film stability, inflammation, and symptoms of irritation. There is no gold standard treatment for meibomian gland dysfunction, but rather a diversity of options. Conservative measures include warm compresses and lid hygiene, but there is growing interest and need for medical treatments and procedures. Potential medical treatments include antibiotics, nonsteroidal and steroidal anti-inflammatory agents, essential fatty acid supplementation, hormone therapy, and control of Demodex infestation. Procedures include intraductal meibomian gland probing, the use of electronic heating devices, intense pulsed light therapy, and intranasal neurostimulation. We provide an update on meibomian gland dysfunction treatments based on recent studies.

Safety of Propofol versus Nonpropofol-Based Sedation in Children Undergoing Gastrointestinal Endoscopy: A Systematic Review and Meta-Analysis.

BACKGROUND: The majority of children who undergo gastrointestinal (GI) endoscopy require anesthesia or procedural sedation for comfort, cooperation, and procedure efficiency. The safety profile of propofol is not well established in children but has been studied in the literature. OBJECTIVE: The aim of this study is to evaluate and compare the safety of propofol-only sedation for GI endoscopy procedures to other anesthetic regimes in the pediatric population. METHODS: A search was conducted in the MEDLINE, Embase, and Cochrane Library databases. Randomized clinical trials and prospective cohorts were included in the study. RESULTS: No significant difference was noted in total complications between the two cohorts with a pooled OR of 1.31 (95% CI: 0.57-3.04, chi2 = 0.053, I2 = 54.31%). The pooled rate of complications in the studies was 23.4% for those receiving propofol only and 18.2% for those receiving other anesthetic regimens. Sensitivity analysis was performed removing a study with a very different control comparison compared to the rest of the studies included. Once excluded, there was minimal heterogeneity in the remaining studies and a significant difference in overall complications was detected, with more complications seen in the propofol-only group compared to the other anesthetic groups (OR 1.87, 95% CI 1.09-3.20). CONCLUSION: Significantly higher incidence of cardiorespiratory complications was noted in the propofol-only versus other anesthetic regimens in pediatric patients undergoing GI endoscopy in this meta-analysis. However, the overall quality of the evidence is very low. HOW TO APPLY THIS KNOWLEDGE FOR ROUTINE CLINICAL PRACTICE: Clinicians providing sedation to a pediatric population for GI endoscopy should consider there may be increased risks when using a propofol-only regimen, but further study is needed.

Prevalence and determinants of visual impairment in Canada: cross-sectional data from the Canadian Longitudinal Study on Aging.

OBJECTIVE: To determine the prevalence and determinants of visual impairment in Canada. DESIGN: Cross-sectional population-based study. PARTICIPANTS: 30,097 people in the Comprehensive Cohort of the Canadian Longitudinal Study on Aging METHODS: Inclusion criteria included being between the ages of 45 and 85 years old, community-dwelling, and living near one of the 11 data collection sites across 7 Canadian provinces. People were excluded if they were in an institution, living on a First Nations reserve, were a full-time member of the Canadian Armed Forces, did not speak French or English, or had cognitive impairment. Visual acuity was measured using the Early Treatment Diabetic Retinopathy Study (ETDRS) chart while participants wore their usual prescription for distance, if any. Visual impairment was defined as presenting binocular acuity worse than 20/40. RESULTS: Of Canadian adults, 5.7% (95% CI 5.4-6.0) had visual impairment. A wide variation in the provincial prevalence of visual impairment was observed ranging from a low of 2.4% (95% CI 2.0-3.0) in Manitoba to a high of 10.9% (95% CI 9.6-12.2) in Newfoundland and Labrador. Factors associated with a higher odds of visual impairment included older age (odds ratio [OR] = 1.07, 95% CI 1.06-1.08), lower income (OR = 2.07 for those earning less than $20 000 per year, 95% CI 1.65-2.59), current smoking (OR = 1.52, 95% CI 1.25-1.85), type 2 diabetes (OR = 1.20, 95% CI 1.03-1.41), and memory problems (OR = 1.44, 95% CI 1.04-2.01). CONCLUSIONS: Refractive error was the leading cause of visual impairment. Older age, lower income, province, smoking, diabetes, and memory problems were associated with visual impairment.

Eye care utilization and its determinants in Canada.

OBJECTIVE: To provide the frequency and potential determinants of eye care utilization over the last 12 months among Canadians between the ages of 45 and 85 years old. DESIGN: Cross-sectional population-based study. PARTICIPANTS: 30,097 people in the Comprehensive Cohort of the Canadian Longitudinal Study on Aging. METHODS: Inclusion criteria included being between the ages of 45 and 85 years old, community-dwelling and living near one of the 11 data collection sites across 7 Canadian provinces. Eye care utilization was defined as the self-report of a visit to an optometrist or ophthalmologist in the past 12 months. RESULTS: In the last year, 57% of 28 728 adults visited an eye care provider although there was heterogeneity between provinces. The highest eye care utilization was found in Ontario at 62%, whereas the lowest was in Newfoundland and Labrador at 50%. Of concern, 25.3% of people with diabetes above the age of 60 years had not seen an eye care provider in the last year. Our novel finding was that current smokers were less likely to use eye care compared to never smokers (odds ratio [OR] = 0.76, 95% confidence interval [CI] 0.67-0.87). Confirming previous research, men compared to women (OR = 0.67, 95% CI 0.62-0.71), people with less than a bachelor's degree compared to more than a bachelor's degree (OR = 0.87, 95% CI 0.79-0.95), and people making less income (linear trend p < 0.05) were less likely to use eye care. CONCLUSIONS: Disparities exist in eye care utilization in Canada. Efforts should be made to reduce these disparities to reduce avoidable vision loss.

Fungal Infections in Boston Keratoprosthesis Patients: Lessons Learned and Novel Developments on the Horizon.

The Boston Keratoprosthesis (B-KPro) is a widely accepted modality of corneal restoration in eyes where traditional penetrating keratoplasty has little chance of success. It is the most commonly used keratoprosthesis worldwide. While the introduction of broad-spectrum antibiotic prophylaxis has virtually eliminated cases of bacterial endophthalmitis, fungal colonization and infections are a growing concern. This review of the literature summarizes risk factors for fungal infections in KPro eyes, rates of fungal infection and colonization, clinical presentation, causative organisms, management, and outcomes. We also focus on current recommendations for antifungal prophylaxis, and highlight the role of translational research at the Massachusetts Eye and Ear Infirmary (MEEI, Boston, USA) with its aim of developing novel strategies for reducing rates of fungal infections in KPro patients.