Moshe Lusky

Reproducibility of optic nerve head topography measurements in eyes with undilated pupils.

A confocal scanning diode laser ophthalmoscope (Retina Tomograph, Heidelberg Engineering, GmbH, Heidelberg, F.R.G.) was used to examine the optic nerve head in both normal healthy (n = 10) and glaucomatous (n = 10) eyes. An image series was obtained from 32 transverse optical sections taken at consecutive height planes (50-80 mum each) over a 1.5-2.5-mm scan depth. Each image was then analyzed to create a topographic map containing 256 +/- 256 pixels (65,536 pixels) with afield of view of 10+/-. Images were obtained through undilated pupils. Reproducibility was 30.1 +/- 7.0 and 31.8 +/- 10.6 mum in normal and glaucomatous eyes, respectively. The instrument provides highly reproducible topographic data of the optic nerve head in patients with undilated pupils.

Fibrin Glue as a Suture Substitute: Histological Evaluation of Trabeculectomy in Rabbit Eyes

Purpose: To describe the outcome of the use of fibrin adhesive (Quixil) in penetrating trabeculectomy in a rabbit model. Methods: Fibrin adhesive was used experimentally to attach the conjunctiva and the scleral flap in two groups of 17 New Zealand albino adult rabbits (34 eyes). In the first experiment (20 eyes), the fibrin adhesive was used to reattach the tissue after conjunctival peritomy and scleral flap only in 14 eyes (experiment I). In 6 eyes (controls), the conjunctiva was attached with nylon sutures. In the second experiment (14 eyes), the fibrin adhesive was used after conjunctival peritomy, scleral flap, and penetrating trabeculectomy in 8 eyes (experiment II). In a control group of 6 eyes, nylon sutures were used to attach the scleral flap and the conjunctiva after penetrating trabeculectomy. Biomicroscopy and histopathological examinations were performed on postoperative days 1, 3, 7, 14, 21, and 30. Intraocular pressure was measured before and after surgery in the second experiment. Main outcome measures are histological presence of adhesive in the tissue, degree of capillary congestion, inflammatory reaction, collagen density [scar formation] and clinical (IOP measurements before and after surgery, conjunctival chemosis, anterior chamber reaction, presence of filtering bleb and wound leakage). Results: In experiments I and II, the adhesive was well identified histologically in the tissue as an amorphic eosinophilic substance for up to day 3 and nearly disappeared by day 7. An acute inflammatory reaction was noted for up to 14 days, which converted to chronic inflammation with collagen deposits and scar formation by day 30. Similar inflammatory reaction was observed in the control group. The adhesive had no adverse effects on ocular tissue compared with sutures. One eye in experiment II demonstrated wound dehiscence. Intraocular pressure dropped from 17.35 mmHg preoperatively to 8.28 mmHg on postoperative day 1 in experiment II, and from 17.2 mmHg to 11.5 mmHg in the controls. No significant change in intraocular pressure was noted in experiment I. Conclusions: The fibrin adhesive had no adverse effects on ocular tissue compared with sutures. It might serve as an effective substitute for conjunctival and scleral wound closure in trabeculectomy surgery.

Cyclocryotherapy versus transscleral diode laser cyclophotocoagulation for uncontrolled intraocular pressure.

BACKGROUND AND OBJECTIVE To compare the use of cyclocryotherapy and diode laser cyclophotocoagulation for the treatment of uncontrolled intraocular pressure. PATIENTS AND METHODS Seventy consecutive patients (70 eyes) treated for high, unresponsive intraocular pressure during a 4-year period with cyclocryotherapy (n = 38) or diode laser cyclophotocoagulation (n = 32) with a follow-up period of at least 3 months (mean follow-up = 15.7 months) were compared for intraocular pressure, visual acuity, and complication rate. RESULTS Mean intraocular pressure was reduced from 40.9 +/- 11.9 to 20.5 +/- 10.3 mm Hg in the cyclocryotherapy group, and from 35.9 +/- 9.3 to 21.3 +/- 10.7 mm Hg in the cyclophotocoagulation group. Intraocular pressure was controlled in 60.5% and 62.5% of eyes, respectively. Deterioration in visual acuity occurred in 31.5% of the cyclocryotherapy group and 37.5% of the cyclophotocoagulation group. Severe visual loss to no light perception was noted in 6 eyes and 2 eyes, respectively, and phthisis bulbi in 2 eyes in the cyclocryotherapy group (5.2%) and 1 eye in the cyclophotocoagulation group (3.1%). CONCLUSIONS Cyclocryotherapy and diode laser cyclophotocoagulation are equally effective in decreasing intraocular pressure in patients with persistent uncontrolled glaucoma, with a lower rate of complications associated with diode laser cyclophotocoagulation.

Mitomycin C and 5-fluorouracil antimetabolite therapy for pediatric glaucoma filtration surgery

PURPOSE To evaluate the efficacy and safety of augmented trabeculectomy with 5-fluorouracil (5-FU) and mitomycin C (MMC) compared to 5-FU only for the treatment of pediatric glaucoma. PATIENTS AND METHODS In a prospective randomized clinical trial, 8 children (12 eyes) with pediatric glaucoma, either congenital or secondary to: lens aspiration, Sturge-Weber syndrome, or steroids underwent augmented trabeculectomy. Six patients (8 eyes) underwent augmented trabeculectomy with 5-FU plus MMC and 2 patients (4 eyes) underwent augmented trabeculectomy with 5-FU only. MAIN OUTCOME MEASURES Between-group comparison of postoperative parameters: change in intraocular pressure (IOP), dependence on antiglaucoma medication, number of 5-FU injections, cup-disc ratio, corneal diameter, drug-induced complications. RESULTS In the 5-FU/MMC group, 7/8 eyes showed good control of postoperative IOP (9-16 mm Hg), which was independent of antiglaucoma therapy; only 2 injections of 5-FU were needed. By contrast, in the 5-FU group, no control of the postoperative IOP (21-23 mm Hg) was achieved in 4/4 eyes, and these patients remained dependent on antiglaucoma medication; up to 6 injections of 5-FU were used. There was no deterioration in the cup-disc ratio or the corneal diameter in either group. Results were maintained on follow-up (23-27 months). No significant drug-induced complications were noted. CONCLUSION Augmented trabeculectomy with adjunctive 5-FU/MMC may be an option for the control of pediatric glaucoma in patients with a poor surgical prognosis.

A Comparative Study of Two Dose Regimens of Latanoprost in Patients with Elevated Intraocular Pressure

OBJECTIVE The purpose of the study was to determine whether latanoprost (13,14-dihydro-17-phenyl-18,19,20-trinor PGF2a-isopropyl ester), a new prostaglandin analogue that has been found effective in reducing intraocular pressure (IOP) in humans, is equally effective at lower concentrations than those currently employed. DESIGN AND PARTICIPANTS Fifty patients with glaucoma or ocular hypertension were treated in a randomized, crossover, double-masked fashion with 1 drop of latanoprost (50 microg/ml once daily and 15 microg/ml twice daily) in the affected eye(s) for 3 weeks on each concentration. Tonometry was obtained at 8:00, 13:00, and 17:00 hours at baseline (untreated) and after 3 weeks on each concentration. Placebo (a buffer solution of latanoprost eye drop) was administered for complete masking of the study. RESULTS Mean baseline (untreated) diurnal IOP for the entire sample was 24.7 mmHg. Intraocular pressure was reduced by 6.1 mmHg with latanoprost 15 microg/ml twice daily, and by 7.5 mmHg with 50 microg/ml once daily. Results with both regimens were significant (P < 0.001 each, Students t-test). However, the 50 microg/ml dose was significantly more effective than the 15 microg/ml dose, with a difference of 1.4 mmHg (P < 0.001, ANOVA). Both dose regimens were well tolerated, with little, predominantly mild, ocular discomfort. The higher dose did not cause more hyperemia at 3 weeks than the lower one, i.e., the lower dose yielded a slightly higher score (1.8 mm) on the visual analogue scale (P < 0.29, ANOVA). CONCLUSIONS Latanoprost administered at a concentration of 50 microg/ml once daily effectively reduces IOP in patients with elevated IOP. Administration of a lower concentration (15 microg/ml) twice daily is less effective, but still significant.

Reproducibility of quantitative anterior chamber angle measurements with scheimpflug video imaging.

A Scheimpflug video camera with digital image analysis was used to assess iridocorneal angles in 11 eyes with nonoccludable open angles and nine eyes with occludable narrow angles. Normal eyes had a mean angle width of 28.2 +/- 2.5 degrees and eyes with occludable narrow angles had a mean angle width of 17.5 +/- 3.2 degrees . Interobserver variability was 1.98 degrees and 1.94 degrees in open and narrow angles, respectively. Intraobserver variability was 1.81 degrees . This technique provides a method for longitudinal observation and quantitative assessment of the iridocorneal angle.

Changes in anterior segment parameters after insertion of Ex-PRESS miniature glaucoma implant.

Purpose:The aim of this study was to evaluate the effect of Ex-PRESS Miniature Glaucoma Implant surgery on corneal curvature and anterior segment parameters obtained with the Pentacam rotating Scheimpflug camera (Oculus Inc.). Patients/Methods:In this prospective study, a total of 19 eyes of 19 consecutive patients (11 men, 8 women) were evaluated preoperatively, on the first postoperative day, and at 1 week, 1 month, and 3 months postoperatively with the Pentacam. We compared measurements of anterior and posterior corneal curvature, anterior and posterior corneal astigmatism, anterior chamber depth (ACD), anterior chamber volume (ACV), and anterior chamber angle before and after surgery. All study eyes were pseudophakic. Results:Intraocular pressure decreased significantly from 31.9±10.1 mmHg preoperatively to 6.1±5.7 mmHg on the first postoperative day (P<0.0001) and 15.7±3.6 mmHg at 3 months after surgery (P=0.0011). On the first postoperative day, the anterior corneal astigmatism increased from 2.6±3.3 to 4.7±3.1 D (P=0.19), the posterior corneal astigmatism increased from 0.4±0.2 to 0.9±0.5 D (P=0.008), the ACD decreased from 4.3±0.7 to 3.5±1 mm (P=0.015), and the ACV decreased from 193±35 to 160±49 mm3 (P=0.006). All of these changes in anterior segment parameters were not statistically significant at 3 months after surgery. Conclusions:Ex-PRESS Miniature Glaucoma Implant surgery significantly decreased intraocular pressure and had a transient effect on anterior segment parameters. Corneal curvatures, ACD, ACV, and anterior chamber angle were not affected at 3 months of follow-up.

Digital versus film stereo-photography for assessment of the optic nerve head in glaucoma and glaucoma suspect patients.

Purpose:One of the leading methods for optic nerve head assessment in glaucoma remains stereoscopic photography. This study compared conventional film and digital stereoscopy in the quantitative and qualitative assessment of the optic nerve head in glaucoma and glaucoma suspect patients. Methods:Fifty patients with glaucoma or suspected glaucoma underwent stereoscopic photography of the optic nerve head with a 35-mm color slide film and a digital camera. Photographs/images were presented in random order to 3 glaucoma specialists for independent analysis using a standardized assessment form. Findings for the following parameters were compared among assessors and between techniques: cup/disc (C/D) ratio, state of the optic rim, presence of peripapillary atrophy and appearance of the retinal nerve fiber layer, blood vessels, and lamina cribrosa. The film-based and image-based diagnoses (glaucoma yes/no) were compared as well. Results:Despite high level of agreement across graders using the same method for the horizontal and vertical C/D ratio, (intraclass correlations 0.80 to 0.83), the agreement across graders was much lower for the other parameters using the same method. Similarly the agreement between the findings of the same grader using either method was high for horizontal and vertical C/D ratio, but low for the other parameters. The latter differences were reflected in the disagreement regarding the final diagnosis: The diagnoses differed by technique for each grader in 18% to 46% of eyes, resulting in 38.5% of eyes diagnosed with glaucoma by film photography that “lost” their diagnosis on the digital images, whereas 18.7% of eyes diagnosed as nonglaucomatous by film photography were considered to have glaucoma on the digital images. Conclusions:Although there is consistency between 35-mm film stereoscopy and digital stereoscopy in determining the cup/disc (C/D) ratio, in all other parameters large differences exist, leading to differences in diagnosis. Differences in capturing images between digital and film photography may lead to loss of information and misdiagnosis. Further studies are needed to determine the reliability of the new digital techniques.

Competitive quenching: a possible novel approach in protecting RPE cells from damage during PDT.

Purpose: The purpose of this study is to demonstrate feasibility of using our novel concept, termed competitive quenching, for protecting the choroidal extravascular compartment and retinal pigment epithelium (RPE) from verteporfin (VP)-induced phototoxicity using hypericin. Furthermore, we aim to achieve partitioning of the quencher, hypericin, in the extravascular space and VP within the microvascular compartment of the chorio-retinal complex in vivo. Methods: We protect RPE cells from damage inflicted by photoactivated VP by introducing hypericin into these cells prior to photosensitization to quench the photosensitizing activity of VP. Cell protection levels were measured by MTT and Hemacolor viability assays. Wavelength range used for VP photoexcitation (700 ± 40 nm) excludes the absorption range of hypericin, preventing the latter from photoactivation. Pharmacokinetic conditions, in which hypericin spreads throughout the choroidal and retinal extravascular space while VP is confined to the vasculature, are delineated using double-fluorescence imaging. Results: Cell viability increased 3- to 5-fold when 10–20 μ M hypericin were present in RPE cells during photosensitization with 0.1–0.5 μM VP. VP fluorescence intensity was unchanged by the presence of hypericin in the cells. Hypericin administered intravenously to rats was confined to the choroidal vasculature after 15 min to 2 hr. Subsequently, hypericin partitioned to the choroidal and retinal extravascular space. VP administered at this time was confined to the microvasculature. Conclusions: RPE and choroid may potentially be protected by compartmentalizing hypericin to the extravascular compartment while VP administered shortly before photosensitization is confined to the microvasculature. Adverse photodynamic therapy (PDT) damage to choroidal tissues adjacent to neovasculature targeted for photoablation have the potential of being prevented by competitive quenching with hypericin.

Ultrasonographic findings of the optic disc in congenital glaucoma.

A 2-month-old female infant with intractable congenital glaucoma and diffuse corneal opacification underwent trabeculectomy with 5-fluorouracil (5-FU) injection in both eyes followed by penetrating keratoplasty (PKP) combined with partial cyclocryotherapy in the right eye. The latter procedure was undertaken despite the B-scan ultrasonographic finding of extensive optic disc cupping in order to provide the infant with some degree of improved visual function. The anatomic and functional results are discussed.