David T. Wong

Risk Factors for Acute Endophthalmitis after Cataract Surgery: A Population-based Study

OBJECTIVE To identify risk factors for suspected acute endophthalmitis after cataract surgery. DESIGN Population-based retrospective cohort. PARTICIPANTS Administrative data from more than 440,000 consecutive cataract surgeries in Ontario, Canada, from April 1, 2002, to March 31, 2006. METHODS Consecutive physician billing claims for cataract surgery and specific intraoperative and postoperative procedures related to complications of cataract surgery were identified. Acute endophthalmitis was defined using surrogate markers for intraocular infection, including vitrectomy, vitreous injection, or aspiration procedures not in combination with air/fluid exchange or dislocated lens extraction, performed 1 to 14 days after cataract surgery. Anterior vitrectomy performed on the day of surgery was used as a surrogate marker for capsular rupture. MAIN OUTCOME MEASURES Overall rates of endophthalmitis were calculated and grouped by patient demographics, surgical facility, season, year, and association with capsular rupture. RESULTS There were 617 suspected acute endophthalmitis cases of 442,177 cataract surgeries over the 4 years. The overall unadjusted and adjusted rates of suspected acute endophthalmitis were both 1.4 per 1000 cataract surgeries. Men had higher rates than women (1.70 vs. 1.19/1000 surgeries, P<0.0001) with an adjusted odds ratio of 1.40 (95% confidence interval, 1.19-1.64).The oldest age group (>or= 85 years) had the highest rate (2.18/1000), and the youngest group (20-64) had the second highest rate (1.76/1000). The endophthalmitis rates for these age groups were significantly different from those aged 65 to 84 years. The endophthalmitis rate was approximately 10-fold higher in those with capsular rupture compared with those without (13.11 vs. 1.34/1000, P<0.0001), with an adjusted odds ratio of 9.56 (95% confidence interval, 6.43-14.2). CONCLUSIONS The overall rates of suspected acute endophthalmitis are low but significantly higher in certain patient groups. Our population-based analysis can be used as a benchmark for quality-improvement initiatives and can assist clinicians in educating their patients regarding the risks associated with cataract surgery. Future work is required to address the higher rate of endophthalmitis in men, those with capsular rupture, and the oldest patients undergoing cataract surgery.

Subconjunctival Lidocaine before Laser Treatment : A Randomized Trial

PURPOSE The aim of the study was to determine whether subconjunctival anesthesia is effective at reducing pain associated with laser retinopexy. DESIGN This was a single-center, prospective, patient-masked, randomized, controlled trial. PARTICIPANTS In the primary study group, 65 patients were recruited. Thirty-two patients (32 eyes) received anesthetic injection, and 33 patients (33 eyes) received the sham injection. The crossover study group consisted of 28 patients (56 eyes). METHODS Between February 2008 and April 2008, all patients who were consecutively booked to undergo panretinal photocoagulation (PRP) or peripheral laser retinopexy (PLR) were invited to participate in the study. Patients were randomized to receive subconjunctival lidocaine injection or a sham injection before their intended laser retinal treatment. These patients were defined as our primary study group. Patients who required a second laser treatment received the opposite injection in a masked fashion before laser retinal treatment. These patients were defined as our crossover group. Patients in both the primary study group and the crossover group were masked to the treatment given. After the laser treatment, patients completed a pain questionnaire. MAIN OUTCOME MEASURES The primary outcome was incidence of pain. The secondary outcome was severity of pain. RESULTS Primary study group: In the anesthetic treatment group, 19 patients (59%) experienced pain compared with 32 patients (97%) in the sham treatment group (P<0.001). Among the patients who did experience pain, the average pain score was 3.6 in the anesthetic treatment group and 4.1 in the sham treatment group (P=0.55). Crossover study group: In the anesthetic treatment group, 12 patients (43%) experienced pain compared with 28 patients (100%) in the sham treatment group (P<0.001). In patients who did experience pain, the average pain score was 3.3 in the anesthetic treatment group and 4.6 in the sham treatment group. Twenty patients (71%) preferred anesthetic to sham treatments, 1 patient (4%) preferred sham over anesthetic, and 7 patients (25%) thought both laser treatments were the same. CONCLUSIONS Subconjunctival 2% lidocaine significantly reduces the incidence of pain in patients who receive PRP or PLR.

Association of Stop-bang Questionnaire as a Screening Tool for Sleep Apnea and Postoperative Complications: A Systematic Review and Bayesian Meta-analysis of Prospective and Retrospective Cohort Studies

BACKGROUND: The risk of postoperative complications increases with undiagnosed obstructive sleep apnea (OSA). The high-risk OSA (HR-OSA) patients can be easily identified using the STOP-Bang screening tool. The aim of this systematic review and meta-analysis is to determine the association of postoperative complications in patients screened as HR-OSA versus low-risk OSA (LR-OSA). METHODS: The following data bases were searched from January 1, 2008, to October 31, 2016, to identify the eligible articles: Cochrane Central Register of Controlled Trials, MEDLINE, PubMed, Cochrane Databases of Systematic Reviews, Medline-in-Process & other nonindexed citations, Google Scholar, Embase, Web of Sciences and Scopus. The search included studies with adult surgical patients screened for OSA with STOP-Bang questionnaire that reported at least 1 cardiopulmonary or any other complication requiring intensive care unit admission as diagnosis of outcome. We used a Bayesian random-effects analysis to evaluate the existing evidence of STOP-Bang in relation to OSA and to assess the association of postoperative complications with the identified HR-OSA patients by study design and methodologies. RESULTS: This systematic review and meta-analysis was conducted using 10 cohort studies: 23,609 patients (HR-OSA, 7877; LR-OSA, 15,732). The pooled odds of perioperative complications were higher in the HR-OSA versus LR-OSA patients (odds ratio 3.93, 95% credible interval, 1.85–7.77, P= .003; 6.86% vs 4.62%). The length of hospital stay was longer in HR-OSA by 2 days when compared with LR-OSA (5.0 ± 4.2 vs 3.4 ± 2.8 days; mean difference 2.01; 95% credible interval, 0.77–3.24; P= .005). Meta-regression to adjust for baseline confounding factors and subgroup analysis did not materially change the results. CONCLUSIONS: This systematic review and meta-analysis suggests that HR-OSA is related with higher risk of postoperative adverse events and longer length of hospital stay when compared with LR-OSA patients. Our findings support the implementation of the STOP-Bang screening tool for perioperative risk stratification.

Colletotrichum truncatum species complex: Treatment considerations and review of the literature for an unusual pathogen causing fungal keratitis and endophthalmitis

We present a case of Colletotrichum truncatum species complex fungal keratitis and endophthalmitis in an 87-year-old immunocompetent male in whom oral triazole antifungals were contraindicated. The patient had recently returned from 4 months in Jamaica with a one month history of progressively increasing pain and inflammation in his left eye. Corneal samples grew a filamentous fungus and internal transcribed spacer sequencing polymerase chain reaction confirmed the presence of C. truncatum species complex. Samples showed no microbial growth.

Obesity hypoventilation syndrome, sleep apnea, overlap syndrome: perioperative management to prevent complications.

Purpose of review The prevalence of sleep disordered breathing (SDB) is increasing proportional to the prevalence of obesity. Although anesthesiologists are familiar with obstructive sleep apnea (OSA) – the most common SDB, anesthesiologists may not be aware of other SDB such as obesity hypoventilation syndrome (OHS) and overlap syndrome (combination of OSA and chronic obstructive pulmonary disease). The present review provides an update of information regarding the perioperative management of OHS and overlap syndrome. Recent findings OHS and overlap syndrome are associated with significant comorbid conditions and more perioperative morbidity than OSA alone. Similar to OSA, most of the OHS patients are undiagnosed. An increase in serum bicarbonate level is a surrogate marker of hypercapnia. Because 90% of OHS patients have OSA, preoperative screening for OSA combined with estimation of serum bicarbonate level may detect the majority of the patients with OHS. In patients with OSA, OHS, and overlap syndrome, improvement in the perioperative outcome has been shown by initiating positive airway pressure therapy. Summary Identification and preoperative optimization of these high-risk patients are most important. A protocol-based risk mitigation is necessary for improving the intraoperative and postoperative outcome of these patients. As a perioperative physician, anesthesiologists have a key role in the management of patients with SDB.

Obstructive sleep apnea as a risk factor associated with difficult airway management - A narrative review

STUDY OBJECTIVE The association between obstructive sleep apnea (OSA) and difficult airway had been studied in various clinical trials but the relationship between the two conditions has not been clearly established. The objective of this narrative review is to determine if OSA is a risk factor associated with difficult airway. DESIGN The OVID Medline in process, Medline (vis Pub Med), EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Web of Science and SCOPUS were searched up to April 2016 using specific keywords. Inclusion criteria were: [1] airway management in patients with a diagnosis of OSA, [2] comparison of airway management between OSA and non-OSA patients, [3] publications or abstracts in the English language. The incidence of difficult airway between OSA and non-OSA patients was compared using Chi-square analysis or Fishers exact test. MAIN RESULTS Ten studies were included in the final review. Overall, the incidence of difficult tracheal intubation was higher in OSA patients versus non-OSA patients [56/386 (14.5%) vs. 69/897 (7.7%); P=0.0002]. OSA patients also have a higher incidence of difficult mask ventilation [115/4626 (2.5%) vs. 471/64,684 (0.7%); P<0.0001]. Compared to non-OSA patients, OSA was not associated with difficulty in the use of a supraglottic airway (SGA) device [10/663 (1.5%) vs. 162/15,171 (1.1%); P=0.38]. No studies compared difficult surgical airway in OSA and non-OSA patients. CONCLUSIONS OSA was found to be a risk factor associated with difficult tracheal intubation and difficult mask ventilation. There was no association between OSA and difficult SGA use.

Adenovirus-related epidemic keratoconjunctivitis outbreak at a hospital-affiliated ophthalmology clinic

HighlightsWe investigated an outbreak of keratoconjunctivitis caused by adenovirus.Contamination of multidose eye‐drop vials contributed to adenovirus transmission.Single‐dose eye‐drop vials may reduce the risk of keratoconjunctivitis outbreaks. &NA; Adenovirus‐associated epidemic keratoconjunctivitis (A‐EKC) is a cause of large and prolonged outbreaks in ophthalmology clinics and can result in substantial morbidity. A‐EKC outbreaks are often the result of contaminated ophthalmologic equipment, surfaces, or hands. Contaminated multidose eye drops are also a likely culprit, but few prior studies provide clear epidemiologic evidence that adenovirus transmission resulted from contamination of eye drops. We describe an A‐EKC outbreak at a large, hospital‐affiliated eye clinic that affected 44 patients. The unique epidemiology of the outbreak provides strong evidence that contaminated multidose dilating eye drops resulted in adenovirus transmission. Removal of multidose eye medication from the clinic, combined with case finding, enhanced infection control and enhanced environmental cleaning, led to rapid control of the outbreak.

Choroidal melanoma and rhegmatogenous retinal detachment.

A 74-year-old woman was referred to the Ocular Oncology Service with retinal detachment in association with a choroidal melanoma in her left eye. Six months earlier she had noted photopsia in that eye, followed by progressive deterioration of vision. She reported that the vision in her left eye had been blurry for a long time and the cause was unclear. She had controlled hypertension. Ocular examination showed a visual acuity of 20/50 with +0.25 in the right eye and counting fingers with +0.25 in the left. The intraocular pressure, as measured by applanation tonometry, was 18 mm Hg bilaterally. There was a relative afferent pupillary defect in the left eye. Funduscopy of the left eye with the pupil dilated revealed a pigmented mass at the posterior pole measuring 10.5 mm by 6.5 mm in basal diameters. Lipofuscin pigment was visible on the surface of the lesion. An infe-

Association between diabetic eye disease and other complications of diabetes: implications for care. A systematic review

The aim of this systematic review was to examine the associations between diabetic retinopathy (DR) and the common micro‐ and macrovascular complications of diabetes mellitus, and how these could potentially affect clinical practice. A structured search of the PubMed database identified studies of patients with diabetes that assessed the presence or development of DR in conjunction with other vascular complications of diabetes. From 70 included studies, we found that DR is consistently associated with other complications of diabetes, with the severity of DR linked to a higher risk of the presence of, or of developing, other micro‐ and macrovascular complications. In particular, DR increases the likelihood of having or developing nephropathy and is also a strong predictor of stroke and cardiovascular disease, and progression of DR significantly increases this risk. Proliferative DR is a strong risk factor for peripheral arterial disease, which carries a risk of lower extremity ulceration and amputation. Additionally, our findings suggest that a patient with DR has an overall worse prognosis than a patient without DR. In conclusion, this analysis highlights the need for a coordinated and collaborative approach to patient management. Given the widespread use of DR screening programmes that can be performed outside of an ophthalmology office, and the overall cost‐effectiveness of DR screening, the presence and severity of DR can be a means of identifying patients at increased risk for micro‐ and macrovascular complications, enabling earlier detection, referral and intervention with the aim of reducing morbidity and mortality among patients with diabetes. Healthcare professionals involved in the management of diabetes should encourage regular DR screening.

Surgical management of submacular hemorrhage: experience at an academic Canadian centre

OBJECTIVE To report the anatomical and visual outcomes of patients with thick submacular hemorrhage (SMH) treated with pars plana vitrectomy (PPV), subretinal tissue plasminogen activator (t-PA), and pneumatic displacement. DESIGN Single-centre, retrospective case series. PARTICIPANTS A total of 99 eyes of 99 consecutive patients with thick SMH secondary to any underlying etiology treated with PPV with subretinal t-PA and pneumatic displacement by 6 vitreoretinal surgeons at St. Michaels Hospital, Toronto, between July 2004 and August 2016. METHODS All medical records and colour fundus photographs were reviewed for data collection. Blood displacement was evaluated at follow-up visits and classified as complete, partial, or none. Main outcome measures included blood displacement at final follow-up, postoperative Snellen best-corrected visual acuities (BCVA), and complication and recurrence rates. RESULTS Patients had a mean age of 77.7 ± 12.3 years and were followed up for an average of 18.4 ± 22.3 months. Wet age-related macular degeneration was the most common etiology associated with thick SMH (80.8%). Complete blood displacement was observed by final follow-up in 85.9% of the cases, partial displacement in 12.1%, and none in 2.0%. Mean logMAR BCVA improved from 2.03 ± 0.81 (Snellen 20/2143) at baseline to 1.80 ± 1.00 (Snellen 20/1262; p = 0.009) at final follow-up, and baseline BCVA was a significant predictor of final BCVA (p < 0.001). Early postoperative complications included vitreous hemorrhage in 13 eyes and rhegmatogenous retinal detachment in 8. Recurrent SMH was observed in 12 cases. CONCLUSIONS Vitrectomy with subretinal t-PA and pneumatic displacement seems to be an effective treatment for SMH in terms of blood displacement and visual outcomes.