Albert S Khouri

Use of Fixed-Dose Combination Drugs for the Treatment of Glaucoma

Glaucoma is a leading cause of irreversible visual loss. This potentially blinding disease is a progressive optic neuropathy associated with elevated intraocular pressure (IOP). Initial therapy for glaucoma typically consists of topical medications or laser treatment to lower IOP. Frequently, more than one medication is required to achieve adequate control of IOP. However, more medications means more bottles and greater complexity for the patient. There are several potential benefits of fixed combination medications compared with using the individual components separately. These include a reduction in the total number of drops and preservative instilled per day, cost savings, improved tolerability and compliance and avoiding the washout effect resulting from rapid-sequence instillation of multiple drops. Attempts to develop effective fixed combinations of glaucoma medications date back several decades. In recent years, fixed combinations of commonly paired drugs have been approved by various regulatory bodies in different countries and have gained wide acceptance. Current commercially available, fixed combination drugs include the topical β-adrenoceptor antagonist timolol 0.5% combined with a prostaglandin, a topical carbonic anhydrase inhibitor or an α-adrenoceptor agonist. Although there is no uniformity among registration trial designs, most published literature compares the efficacy of the fixed combination to the individual components and to concomitant use of both components. Various factors inherent to study design such as medication run-in, washout periods and peak and trough effects have to be taken into consideration when analysing the demonstrated efficacy of fixed combinations. Fixed combination treatments offer effective IOP control while reducing the washout effect and exposure to preservatives. They are also convenient. However, fixed combinations also remove the possibility of titrating the individual components both in terms of concentration and timing of administration. In addition, fixed combinations might not always provide the same efficacy as proper use of the individual components. The clinician must make individualised assessments when weighing the convenience of these medications against their limitations for specific patients.

Ocular telehealth screenings in an urban community.

The current U.S. economic recession has resulted in a loss of income, housing, and healthcare coverage. Our major goal in this socioeconomic setting was to provide ophthalmic remote health screenings for urban soup kitchen and homeless populations in order to identify and refer undetected vision-threatening disease (VTD). We assessed visual acuity, blood pressure, pulse/oxygen saturation, body mass index, and intraocular pressure for 341 participants at soup kitchens as part of the homeless outreach program in Newark, NJ. History of diabetes, hypertension, and smoking, last ocular examination, and ocular history were noted. Imaging was performed with an 8.2 megapixel non-mydriatic retinal camera with high-speed Internet ready for off-site second opinion image evaluation. Positive VTD findings were identified in 105 participants (31%) (mean age, 53.6 years), of whom 78% were African American, 73% males, and 62% smokers. We detected glaucoma in 34 participants (32%), significant cataract in 22 (21%), diabetic retinopathy in 5 (5%), optic atrophy in 1 (1%), age-related macular degeneration in 1 (1%), and other retinal findings in 43 (41%). The incidence of VTDs was higher among this cohort than among study groups in previous screenings (31% vs. 12%). This finding shows an increase in ocular morbidity in a younger, at-risk population with elevated rates of hypertension, diabetes, and smoking. Functional visual impairment was 2.5 times higher than the national average (16% vs. 6.4%). Comprehensive, community-based screenings can provide more sensitive detection of VTDs in high-risk groups with low access to ophthalmic care and can be an integral part of recession solutions for improving healthcare.

Evolving global risk assessment of ocular hypertension to glaucoma.

Purpose of review To discuss current knowledge of global risk assessment in ocular hypertension. Recent findings The ophthalmologist treating patients with ocular hypertension is frequently faced with the clinical dilemma of which patients to treat and how vigorous treatment should be. The goal of risk assessment for glaucoma is to identify patients at greatest risk for symptomatic vision loss. Risk factors can be identified by history such as age, race, and family history or can be clinically observed by examination such as elevated intraocular pressure, optic nerve head appearance, central corneal thickness, and visual field abnormalities. Risk assessment is a well accepted tool in other fields of medicine. Parallels can be drawn between the evolution of risk assessment for coronary artery disease and glaucoma. Validated risk calculators for ocular hypertension are currently available mostly derived from the Ocular Hypertension Treatment Study. Summary The aim of assessing global risk for conversion from ocular hypertension to glaucoma is to identify patients who are most likely to benefit from early treatment. Calculation of risk should be accompanied by thorough analysis of risks, benefits, and alternatives for the individual patient.

Long term efficacy of repeat selective laser trabeculoplasty

Purpose: To evaluate long term intraocular pressure (IOP) control after repeat selective laser trabeculoplasty (SLT). Methods: This single center study retrospectively reviews the electronic medical records of patients with open angle glaucoma undergoing repeat SLT. Eyes with prior argon laser trabeculoplasty, or incisional surgery before or during the study period were excluded. Demographics, laser parameters, number of glaucoma medications and IOP at baseline and after 1, 4, 8, 12, 18 and 24 months were collected. The percentage of subjects with IOP reduction >20% and ≥15% from baseline was determined. Results: A total of 45 eyes of 25 subjects with mean age of 73 ± 9 years undergoing repeat SLT were included. Repeat SLT was performed at a mean interval of 28.3 ± 12.7 months after initial treatment. Mean IOP reductions were statistically significant with repeat SLT as compared to baseline at 1, 4, 8, 12, 18 and 24 months’ follow-up. Change in IOP after first and repeat SLT were comparable at most time points except at 4, 8 and 12 months when initial treatment had yielded significantly greater reductions. At 24 months, 29% and 39% of eyes achieved IOP reduction >20% and ≥15% respectively after repeat SLT as compared to 36% and 54% of eyes following initial treatment (P > 0.05). Conclusion: Repeat SLT is effective in lowering IOP up to 24 months. Long term IOP control was achieved in 29–39% of eyes following repeat treatment in this cohort of patients.

DICOM transmission of simultaneous stereoscopic images of the optic nerve in patients with glaucoma.

We evaluated the Digital Imaging and Communications in Medicine (DICOM) standard for the transmission of stereoscopic images of the optic nerve. Digital optic nerve images were obtained from patients with glaucoma. Fifteen simultaneous stereo images from consecutive patients were analysed independently twice, in random order, by two glaucoma specialists to establish baseline values of vertical and horizontal cup-to-disc (CDV and CDH) ratios and image quality (1 = worst, 5 = best). Images were transmitted to a distant location and returned to the sending site using DICOM standards in both directions. The received images were reassessed again by the two glaucoma specialists. The image file size slightly increased for all received images (mean 2545 kByte) in comparison with the transmitted images (mean 2460 kByte). The mean baseline values for CDV, CDH and quality score were 0.66, 0.59 and 3.9, respectively. The corresponding mean values for the received images were 0.66, 0.62 and 3.73, respectively. The differences between transmitted and received images were not significant. Clinical interpretation of digital stereoscopic images of glaucomatous optic nerves appears to be unaffected by DICOM capture and transmission.

Clinical results with the use of a temporary keratoprosthesis in combined penetrating keratoplasty and vitreoretinal surgery.

Purpose To evaluate surgical outcomes using a temporary intraoperative keratoprosthesis (KP) in patients undergoing combined pars plana vitrectomy (PPV) and penetrating keratoplasty (PKP). Methods From January 2001 to August 2008, medical records of 23 patients undergoing combined KP/PPV/PKP for traumatic and nontraumatic corneal and retinal pathologies were studied. Only patients with ≥6 months follow-up were included. Patient characteristics, diagnoses, visual acuity, intraocular pressure, and status of the retina and cornea at baseline, and postoperatively on day 1, months 1 and 6, and yearly until the last follow-up, were collected. Functional (best-corrected visual acuity: improved, stable, worsened) and anatomic outcomes (clear corneal graft, retinal reattachment) were defined prior to review. Results Twenty-four eyes underwent combined KP/PPV/PKP (mean follow-up 36 months). At final follow-up, best-corrected visual acuity improved in 8 (40%) eyes, remained stable in 8 (40%), and worsened in 4 (20%). Corneal graft was clear in 18(79%) eyes; 5(21%) had graft failure. Retinal reattachment occurred in 22 (92%) eyes; 2 (8%) developed a localized traction retinal detachment not warranting additional surgery. Derangement in intraocular pressure was common (13 [54%] eyes). Three eyes (13%) showed signs of phthisis preoperatively that resolved with reestablishment of normal intraocular pressure postoperatively. Conclusions Temporary KP during PPV/PKP surgery allowed surgical intervention in eyes with complex anterior and posterior segment disease. Corneal graft clarity and successful retinal reattachment was possible in the majority of eyes.

Prevalence and determinants of retinopathy in a cohort of Lebanese type II diabetic patients

OBJECTIVE Our aim was to determine the prevalence and the risk factors for diabetic retinopathy (DR) in a cohort of type II diabetic patients in Lebanon. DESIGN Prospective observational cohort study. PARTICIPANTS Five hundred consecutive patients with type II diabetes mellitus followed at the American University of Beirut Medical Center diabetes clinic were enrolled in the study. METHODS All patients 18 years or older with diabetes mellitus who did not have gestational diabetes and who were able to complete the laboratory data and the retinal examination were invited to participate in the study; they were followed up for a period of 3 years. RESULTS DR was present in 175 patients (35%), 130 (26%), and 45 (9%) having nonproliferative and proliferative DR, respectively. Clinically significant macular edema was present in 42 patients (8%). Microvascular and macrovascular diabetic complications, duration of disease, glycemic control, presence of hypertension (p < 0.003), systolic blood pressure (p = 0.04), and insulin use (p < 0.001) were individually significantly associated with a higher prevalence of DR on bivariate analysis. However, on multivariate regression analysis, only glycosylated hemoglobin >7% (odds ratio [OR] 2.81, 95% CI 1.06-7.43, p = 0.038), duration of diabetes (per 10 years, OR 9.0, 95% CI 4.0-20.0, p < 0.001), macroalbuminuria (OR 2.6, 95% CI 1.14-5.96 p = 0.023), and systolic blood pressure (per 10 mm Hg, OR 1.27, 95% CI 1.0-1.56, p = 0.037) were independent risk factors for DR. CONCLUSIONS The elevated prevalence of DR in type II diabetic patients with high risk profiles calls for early medical intervention and education about DR and its identified controllable risk factors.

Repeat selective laser trabeculoplasty can be effective in eyes with initial modest response.

Purpose: To evaluate the effectiveness of repeat selective laser trabeculoplasty (SLT) in eyes exhibiting only a modest response upon initial treatment. Materials and Methods: Retrospective chart review was conducted of 51 eyes that received initial 360 degree SLT (SLT1) and subsequent SLT (SLT2) from 2003-2011 at a large academic ophthalmology practice. Successful response (S) was a post-treatment 12 month mean IOP reduction ≥20% from baseline, while modest response (M) was <20% reduction over the same time. Chi-squared and log rank analyses were used to determine if success after SLT2 depended on having successful (S1) or modest (M1) response after SLT1. Results: IOP was significantly reduced from baseline in both SLT1 and SLT2. The proportion of eyes with S2 was not significantly different between those with initial M1 or S1 (36.67% vs. 52.38%, respectively; P = 0.26). Log rank analysis revealed no differences between M1 and S1 in determining SLT2 success (P = 0.41). This outcome was similar when the analyses were performed for the right and left eye independently. Conclusion: The proportion of eyes that successfully responded to repeat SLT did not differ based upon whether the response to initial SLT was successful or modest. This raises the possibility that repeat SLT should not be excluded as an option for those eyes that have only a modest initial response.

Technique for intraoperative reuse of Ex-PRESS delivery system.

Purpose:To report a new technique for reloading the Ex-PRESS glaucoma filtration device on the Ex-PRESS delivery system (Alcon Laboratories) for revised placement of an implant. Patient and Methods:The Ex-PRESS is provided on a single-use delivery system. A patient who underwent Ex-PRESS placement was noted intraoperatively to have had an unsatisfactory implant position upon initial insertion. The used inserter metallic rod was manipulated to resume its original shape. The implant was removed and reloaded onto the delivery system, which was then used to place it in the desired position. Results:Intraoperative delivery system reloading is possible and facilitates repositioning of the Ex-PRESS implant. Conclusions:This technique for reloading the Ex-PRESS will allow the surgeon to make adjustments to an unsatisfactorily positioned implant upon initial insertion. This may help optimize implant positioning, minimize insertion malpositioning, and reduce the cost and time of using more than 1 device.

Software-Assisted Optic Nerve Assessment for Glaucoma Tele-Screening

Increased optic nerve head (ONH) cup-to-disc ratio (CDR) may indicate glaucoma but evaluation needs to be performed by a trained examiner. This research assessed new software to calculate CDR from ONH images. Digital stereoscopic ONH images from 28 subjects acquired during screening using a nonmydriatic 45-degree camera with 8.2-Megapixel resolution (Canon, Tokyo, Japan) were analyzed by 3 individuals with different levels of ophthalmic training: glaucoma specialist (GS), an optometrist (OD), and trainees. Images were logged and accessed by raters masked to each others evaluations. Images from two groups were included: normal-appearing ONH (Group 1) and confirmed glaucoma (Group 2). All images were captured in DICOM format. Images were evaluated on a 32-bit, 1,600 x 1,200-pixel resolution monitor. EyeScape software (v. 7.4, Synemed, Inc., Benicia, CA) was used for CDR analysis. Software CDR determination requires an operator to place ONH disc and cup contour lines. Once lines were placed, the software provided CDR calculations (range 0.00-1.00). A total of 84 ONH evaluations were analyzed. Overall CDR mean, standard deviation, standard error of the mean, and mean difference from GS CDR evaluations were determined. Reproducibility was similar for all operators. The trainee had a small, statistically significant greater CDR in group 1 and 2 evaluations. Evaluation of ONH images for CDR can be performed using EyeScape software, by individuals with different levels of ophthalmic training. Accurate determination of CDR is important in tele-screening for vision-threatening diseases, and can aid in identifying subjects with suspicious ONH in need of specialty eye care.