Mark D. Bona

10-Year Framingham risk in patients with retinal vein occlusion: a systematic review and meta-analysis

OBJECTIVE Cardiovascular risk factors predispose individuals to retinal vein occlusions (RVOs). Yet, the future risk for development of cardiovascular disease in persons with RVOs is uncertain. We performed a literature review and meta-analysis of studies to determine the 10-year Framingham risk for individuals with RVO. METHODS A literature search was performed in MEDLINE and EMBASE. Studies were eligible if they included subjects with RVO and presented data on age, sex, smoking status, systolic blood pressure, total cholesterol, and high-density lipoprotein. The 10-year Framingham risk was calculated. Sensitivity analysis was performed and hypothesis testing was carried out using the upper tail z test with α = 0.05 to compare the estimated Framingham risk in RVO patients with the risk in the general Canadian population. Subgroup meta-analysis was carried out by Cochrane Collaboration Review Manager 4.5 software (Cochrane IMS, Copenhagen, Denmark). RESULTS A final list of 6 articles was included. The estimated 10-year Framingham risk score in subjects with RVO was 10.1% (95% CI 9.9-10.2). Sensitivity analysis found Framingham risk score to be greatest in male smokers. The Framingham risk in subjects with RVO was significantly greater than the general Canadian population. In a subgroup analysis, the 10-year risk was significantly greater in subjects with RVO compared with control subjects. CONCLUSIONS Patients with RVO have an increased 10-year risk for cardiovascular disease. This risk is greatest for male smokers (high risk). These patients may benefit from therapy aimed at controlling their risk factors. All individuals with an increased Framingham risk should be warned about vision loss as a potential complication of systemic atherosclerotic disease.

Predicting retinal tears in posterior vitreous detachment

OBJECTIVE The purpose of this study is to determine whether patients with acute posterior vitreous detachment (PVD) who develop delayed retinal tears within the first 6 weeks after initial presentation have predictive characteristics. DESIGN Prospective cohort study. PARTICIPANTS All patients presenting to the Hotel Dieu Hospital Emergency Eye Clinic between September 2008 and July 2009 diagnosed with acute PVD were offered enrollment. METHODS At the initial visit, patients were given the previously validated Queens University Posterior Vitreous Detachment Patient Diary to record their daily symptoms for 6 weeks. Two or 6 weeks later, patients were reexamined in detail, and their diaries were collected and analyzed. Exact logistic regression was used to establish characteristics predictive of delayed retinal tears. RESULTS In our study population of 99 patients, 2 developed delayed retinal tears. One had retinal hemorrhages and the other had a cloud-like floater at initial presentation. Vitreal or retinal hemorrhage, large number of floaters at initial presentation, and high floater frequency at initial presentation indicated a high risk of delayed retinal tear formation, yielding a median unbiased estimated odds ratio of 36.18 with p value 0.009. No other presenting risk factors or symptomatology followed daily over the first 6 weeks after acute PVD were predictive of delayed retinal tear formation. CONCLUSIONS PVD patients with retinal or vitreal hemorrhage, a significant number of floaters or a cloud like appearance to the floaters, or high floater frequency are at higher risk of developing delayed retinal tears.

Punctal Plug Retention Rates for the Treatment of Moderate to Severe Dry Eye: A Randomized, Double-Masked, Controlled Clinical Trial

PURPOSE To compare retention rates of Super Flex (Eagle Vision, Memphis, Tennessee, USA; Softplug-Oasis Medical Inc, Glendora, California, USA) vs Parasol (Odyssey Medical, Memphis, Tennessee, USA; Beaver Visitec International, Waltham, Massachusetts, USA) punctal plugs. DESIGN Randomized, double-masked, interventional controlled clinical trial. METHODS Institutional study at Hotel Dieu Hospital (Queens University) of 50 eyes, from patients with moderate to severe dry eye. Each eye from eligible patients was separately randomized to receive Super Flex or Parasol punctal plugs. The main outcome measure was plug retention at 6 months. Secondary outcome measures included objective tests of Schirmer I (mm), tear meniscus height (mm), tear break-up time (s), inferior fluorescein corneal staining (National Eye Institute [NEI] scale), and average lissamine green conjunctival staining (NEI scale). RESULTS Punctal plug retention was significantly different at 6 months (P = .011). Sixty-eight percent of Parasol plugs were retained compared to 32% of Super Flex plugs. Parasol plugs required less frequent artificial tear use at 6 months (P = .024). There was a statistically significant improvement in all secondary outcome measures (Schirmer, tear meniscus height, tear break-up time, fluorescein corneal staining) at 6 months within plug groups except conjunctival staining. There were no additional significant differences between groups and no plug complications reported. CONCLUSIONS Punctal plugs improve symptoms of moderate to severe dry eye; however, retention rates differ significantly. These data will allow us to guide patient decision making for the safe and effective treatment of punctal plugs for moderate to severe dry eye.

Visual function analysis in acute posterior vitreous detachment

OBJECTIVE To determine whether the visual function of patients with posterior vitreous detachment (PVD)changes between the initial visit and a 6-week follow-up visit, and to compare their visual function with that of patients with macular degeneration, cataract, glaucoma, low vision, cytomegalovirus (CMV) retinitis, or diabetic retinopathy and a reference population. DESIGN Prospective cohort study. PARTICIPANTS All patients presenting to the Hotel Dieu Hospital Emergency Eye Clinic between September 2008 and June 2009 who were diagnosed with acute PVD were offered enrollment in the study. METHODS Patients were administered the National Eye Institute Visual Function Questionnaire NEI VFQ-25 at two points in time. The composite scores from the initial and the 6-week visits were compared. The scores were also compared with established normative data and 6 ophthalmologic diagnoses. RESULTS The NEI VFQ-25 composite score for patients with acute PVD (n = 84) at baseline was 93.26 ± 5.59 (mean ± SD). After 6 weeks and a second ocular examination, there was no statistical difference in the composite score of 93.47 ± 6.20 (mean ± SD). (1-sided paired t-test, t = 0.57; P = 0.28). CONCLUSIONS The visual function of patients with acute PVD remains stable over the first 6 weeks after diagnosis. It is significantly higher than that of patients with 6 other ophthalmologic conditions but comparable to that of a normal population.

Assessing the iPad as a tool for low-vision rehabilitation

OBJECTIVE It has been demonstrated consistently that patients with poor vision have a reduced quality of life and functional status and higher rates of psychologic distress. This study aims to assess whether the iPad has potential as a visual aid in patients with low vision. DESIGN Qualitative study with key-informant interviews. PARTICIPANTS Patients who identified as having impaired vision were recruited from a low vision ophthalmology clinic. METHODS Patients participated in a 4-session iPad training course. The goal of the course was to teach patients with low vision how to operate an iPad, with a particular emphasis on how to optimize iPad settings and accessibility features in response to some of the challenges faced by patients with low vision. Three interviews were conducted with each participant: before the course, immediately after the course, and 3 months after the course. The purpose of the interviews was to gain an understanding of their experience with low vision and to assess if and how the iPad had influenced this experience. A grounded theory qualitative approach was used for analysis. RESULTS Six patients took part in the study and were divided into 2 separate courses to minimize course size. Participants had favorable views regarding the course. Five of the 6 participants were using the iPad on a daily basis 3 months after the course. Thematic analysis revealed that use of the iPad led to both a heightened sense of independence and improved social connectivity. It is theorized that use of the iPad as a low-vision aid may enhance a patients sense of self-worth. CONCLUSIONS With proper training, the iPad has the potential to be a valuable tool for low-vision patients. Its features help patients to gain independence and to stay connected within their social circles. Further research with a larger patient population and quantifiable endpoints should focus on these themes.

Cyanoacrylate tissue adhesive on a polyglactin scaffold in strabismus surgery: a laboratory study.

BACKGROUND The use of cyanoacrylate tissue adhesives in strabismus surgery has been variously successful, depending primarily on achieving adequate bond strength and minimizing extraocular muscle slippage. We investigate a novel approach to this problem, involving cyanoacrylate tissue adhesive on a polyglactin 910 scaffold as a means to secure extraocular muscle to the sclera for strabismus surgery. METHODS In this experimental laboratory study, butyl-cyanoacrylate was used to fix a polyglactin 910 scaffold to the sclera of cadaver eyes. After allowing for polymerization, a force was applied to the mesh until the polyglactin-sclera bond failed. The maximum load (g) required for bond failure was recorded. The effects of surface area of the polyglactin 910 mesh as well as time required for cyanoacrylate tissue adhesive polymerization on bond strength were investigated. RESULTS All combination of variables tested, except for experiments involving polyglactin 910 mesh that is 30 mm(2) with a polymerization time of 15 seconds or 30 seconds and polyglactin 910 mesh that is 40 mm(2) with a polymerization time of 15 seconds, achieved a bond strength that was significantly greater than those forces seen in a physiologic setting (P > 0.05). Increasing area or time resulted in increasing bond strength. Area and time were found to be independent variables. CONCLUSIONS The cyanoacrylate tissue adhesive-derived polyglactin-sclera bond achieved a maximum load greater than those seen in a physiologic setting. Our novel approach demonstrates a clinically feasible alternative to traditional means for bonding muscle to sclera in strabismus surgery.