Elisha Bartov

Modified sutureless sclerotomies in pars plana vitrectomy

PURPOSE To study the effectiveness and safety of a modified sutureless sclerotomy technique in pars plana vitrectomy. METHODS We rotated the scleral tunnels of the original sutureless sclerotomy technique through 90 degrees, thus rendering them parallel to the corneoscleral limbus. This modified technique was applied to 25 consecutive eyes (25 patients) that had pars plana vitrectomy during a 2-month period. RESULTS Twenty (80%) of 25 eyes (25 patients) did not require suturing of the sclerotomy sites associated with pars plana vitrectomy. Eight (11%) of 75 sclerotomy sites required suturing to ensure watertight closure. No clinically significant complications were encountered. CONCLUSION The modified sutureless sclerotomy technique was found to be safe, more convenient, and easier to perform, especially in eyes with small interpalpebral space.

Risk Factors Associated With Late Infection of Filtering Blebs and Endophthalmitis

Late infection of filtering blebs and endophthalmitis are hazardous complications of glaucoma filtering surgery frequently associated with bleb failure and loss of functional vision. To determine possible risk factors for the development of these complications, characteristics of nine eyes of nine patients after filtering surgery in whom late endophthalmitis developed were compared with those in patients who had received a comparable operation at the same time in whom endophthalmitis did not develop. An average of 7.7 +/- 6.2 years (range, 6 months to 18 years) elapsed between the time of the filtering procedure and the initial appearance of endophthalmitis. Factors associated with increased risk were: increased axial length, thin and leaky bleb, conjunctivitis, upper respiratory infection, and the winter season.

High-resolution wide-field imaging of perfused capillaries without the use of contrast agent

Purpose: Assessment of capillary abnormalities facilitates early diagnosis, treatment, and follow-up of common retinal pathologies. Injected contrast agents like fluorescein are widely used to image retinal capillaries, but this highly effective procedure has a few disadvantages, such as untoward side effects, inconvenience of injection, and brevity of the time window for clear visualization. The retinal function imager (RFI) is a tool for monitoring retinal functions, such as blood velocity and oximetry, based on intrinsic signals. Here we describe the clinical use of hemoglobin in red blood cells (RBCs) as an intrinsic motion-contrast agent in the generation of detailed noninvasive capillary-perfusion maps (nCPMs). Patients and methods: Multiple series of nCPM images were acquired from 130 patients with diabetic retinopathy, vein occlusion, central serous retinopathy, age-related macular degeneration, or metabolic syndrome, as well as from 37 healthy subjects. After registration, pixel value distribution parameters were analyzed to locate RBC motion. Results: The RFI yielded nCPMs demonstrating microvascular morphology including capillaries in exquisite detail. Maps from the same subject were highly reproducible in repeated measurements, in as much detail and often better than that revealed by the very best fluorescein angiography. In patients, neovascularization and capillary nonperfusion areas were clearly observed. Foveal avascular zones (FAZ) were sharply delineated and were larger in patients with diabetic retinopathy than in controls (FAZ diameter: 641.5 ± 82.3 versus 463.7 ± 105 μm; P < 0.001). Also visible were abnormal vascular patterns, such as shunts and vascular loops. Conclusion: Optical imaging of retinal capillaries in human patients based on motion contrast is noninvasive, comfortable, safe, and can be repeated as often as required for early diagnosis, treatment guidance, and follow up of retinal disease progression.

Long-term follow up of accidental parafoveal laser burns.

The findings after 12 years of follow-up evaluation of 2 patients who sustained accidental parafoveal and juxtafoveal Nd:YAG laser injuries are reported. In both cases, the fovea was not destroyed by the initial insult and early scar formation. Both cases demonstrated, after more than a decade, minimal visual deficit without significant late complications. In spite of early decrease in visual performance, the long-term prognosis for Q-switched Nd:YAG laser retinal lesions in which the fovea was not directly involved in the injury or its repair mechanisms is relatively benign.

A quantitative in vitro model for silicone oil emulsification. Role of blood constituents.

To understand why some patients seem to be protected from emulsification and others are not, the authors developed an in vitro model for quantitative analysis of silicone oil emulsification. The pro-emulsifying potential of substances and blood components that may have access to the vitreous cavity in a patients eye was analyzed. In this model, red blood cell ghosts had the highest emulsifying effect; plasma and lymphocytes also had a significant emulsifying effect. Phospholipids in membranes and other soluble blood components may play important roles in this process. These results suggest the importance of avoiding and removing hemorrhage and avoiding inflammation when silicone oil is used in vitreoretinal surgery.

Inter-device Variability of the Stratus Optical Coherence Tomography

PURPOSE To assess inter-device measurement variability with the Stratus optical coherence tomography (OCT). DESIGN Evaluation of diagnostic test technology. METHODS Eight eyes of eight healthy subjects were examined with four different Stratus machines in four medical centers during a period of five hours using fast retinal nerve fiber layer (RNFL) and fast macula protocols. Inter-device measurement variability and signal strength was assessed with standard deviation, coefficient of variance, and intraclass correlation coefficient (ICC). Spearman correlation coefficient was calculated between signal strength and thickness measurements. RESULTS Statistically significant differences were not found for all macular parameters and all but one RNFL parameter. Mean signal strengths obtained with the four Stratus machines were significantly different; the newer the machine, the stronger signal strength it produced. Some RNFL parameters were moderately and statistically significantly correlated with signal strength. CONCLUSIONS We did not observe statistically significant differences in any macular and all but one RNFL parameter between the four Stratus OCT machines. Signal strength was significantly different between the machines, and significantly correlated with some RNFL parameters. Inter-machine variability in RNFL measurements may have clinical significance. Signal strength should be included in the assessment of measurements obtained on different machines and in serial examinations with a single Stratus machine during patient follow-up.

Nucleus fragmentation in a scleral pocket for small incision extracapsular cataract extraction

Abstract We present a technique for planned manual extracapsular cataract extraction (ECCE) incorporating a modification of mini‐nuc ECCE in which the scleral tunnel is made wide enough to allow a nucleus of any size to settle in the tunnel. A 5.0 mm, inverted chevron incision is used in which the exposed part of the nucleus lodged in the scleral pocket can be manually picked and fragmented until it is small enough to be removed through the incision. The chevron incision is flexible enough to allow a, medium‐sized nucleus to be extracted without fragmentation and implantation of a rigid 6.0 mm poly(methyl methacrylate) lens. Vector analysis of preoperative and 3 month postoperative keratometric results in 30 patients showed that the surgically induced vector was 0.54 diopter (D) ± 0.58 (SD). Mean reduction in astigmatism was 0.08 ± 0.39 D. The sutureless technique is fast and safe, allows a nucleus of any size to be extracted through a constant size 5.0 mm incision, and results in minimal postoperative astigmatism.

Blood-Flow Velocity in Glaucoma Patients Measured with the Retinal Function Imager

ABSTRACT Purpose: Circulatory abnormalities in the retina, optic nerve and choroid have been detected by various technologies in glaucoma patients. However, there is no clear understanding of the role of blood flow in glaucoma. The purpose of this study was to compare retinal blood-flow velocities using the retinal function imager (RFI) between glaucoma and healthy subjects. Materials and Methods: Fifty-nine eyes of 46 patients with primary open-angle glaucoma (POAG), 51 eyes of 31 healthy individuals and 28 eyes of 23 patients with glaucomatous optic neuropathy (GON) but normal perimetry were recruited for this study. Three eyes of 2 patients in the glaucoma group and 2 eyes of 1 patient in the GON group had normal pressure at the time of diagnosis. Eighty-three percent of the glaucoma patients and 73% of the patients in the GON group were treated with anti-glaucoma medications. All patients were scanned by the RFI. Differences among groups were assessed by mixed linear models. Results: The average venous velocity in the GON group (3.8 mm/s) was significantly faster than in the glaucoma (3.3 mm/s, p = 0.03) and healthy (3.0 mm/s, p = 0.005) groups. The arterial velocity in the GON group was not different from any of the other study groups (4.7 mm/s). The arterial and venous velocity in the POAG eyes was not different than in the healthy eyes (arterial: 4.3 versus 4.2 mm/s, p = 0.7; venous: 3.3 versus 3.0 mm/s, p = 0.3). A subgroup of 13 glaucoma patients who had perimetric glaucoma in 1 eye and normal visual field (VF) in the fellow eye showed a trend of lower velocity in the glaucoma eyes. Conclusions: Changes in retinal blood-flow velocity were detected only in the pre-perimetric state, but not in perimetric glaucoma. These findings might represent early dysregulation in the retinal vasculature.

Minimal astigmatism after sutureless planned extracapsular cataract extraction

Purpose: To evaluate astigmatism after mini‐nuc extracapsular cataract extraction (ECCE) in which a chevron incision is enlarged to 6.0 to 7.0 mm for easier nucleus removal and to compare the results with those using a 5.0 mm incision. Setting: Department of Ophthalmology, The Edith Wolfson Medical Center, Sackler Faculty of Medicine, Tel‐Aviv University, Holon, Israel. Methods: Thirty eyes of 29 patients were enrolled in this study. Keratometry was performed preoperatively and 3 to 9 months postoperatively. The incision length was 6.0 mm in 6 eyes, 6.5 mm in 10 eyes, and 7.0 mm in 14 eyes that had mature cataract. Results: The mean induced astigmatism calculated by simple subtraction was 0.12 diopter (D) ± 0.51 (SD), 0.16 ± 0.98 D, and 0.67 ± 0.91 D for the 6.0 mm, 6.5 mm, and 7.0 mm incision, respectively. By vector analysis, the mean induced astigmatism was 0.60 ± 0.30 D, 0.75 ± 0.67 D, and 1.36 ± 0.77 D, respectively. Results by both methods showed no significant difference between the previously reported 5.0 mm incision and the 6.0 mm and 6.5 mm incisions. The 7.0 mm group had statistically significantly greater induced astigmatism than the 5.0 mm group (P = .01, simple subtraction; P =.002, vector analysis). Conclusions: Enlarging the size of the chevron incision up to 7.0 mm resulted in a small increase in induced astigmatism. The enlarged incision simplified the operative technique.

Reduced retinal blood flow-velocity in severe hyperlipidemia measured by the retinal function imager

Severe hyperlipidemia is associated with rare ocular manifestations, including iris and retinal xanthomas, lipid keratopathy, and lipemia retinalis. The later condition of lipemic discolorization of the retinal vessels and fundus has rarely been described in cases of severe hypertriglyceridemia [1]. We report here a case of a patient with lipemia retinalis where retinal blood flow velocity was measured in the acute phase and after a reduction in triglyceride level was achieved.