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ABSTRACT: PURPOSE:: Ocular hypertension is a potentially serious complication after penetrating keratoplasty (PKP). Our objective is to determine the risk factors, incidence, patient characteristics, response to pressure-lowering medical therapy, and graft outcome associated with elevation of intraocular pressure after PKP. METHODS:: One hundred forty-six consecutive eyes that had PKP between June 2001 and June 2003 were operated and managed at Hadassah-Hebrew University Medical Center. Chart review was performed seeking preoperative and postoperative data on risk factors for ocular hypertension after PKP. Univariate and logistic regression analysis were performed to identify significant risk factors. RESULTS:: After surgery, 70 eyes (47.9%) had at least 1 period of ocular hypertension, with a mean intraocular pressure (IOP) of 27.15±5.66 mm Hg. Ocular hypertension appeared after a mean postoperative period of 70.3±15.8 days, and continued for an average period of 15.6±2.0 days. In 35 eyes (23.9%), a second episode of IOP elevation was noted 212.2±46.8 days after the surgery. Logistic regression analysis revealed that preexisting glaucoma (P=0.009) and an additional surgical procedure combined with PKP (P=0.007) were the main factors predicting ocular hypertension after PKP. In 11 eyes (7.53%) the topical pressure-lowering therapy failed, and they required glaucoma filtering surgery. CONCLUSIONS:: The incidence of ocular hypertension after PKP is high, and at least 1 episode of high IOP was noted in almost half of our patients. A history of preexisting glaucoma and an additional surgical procedure combined with PKP were found to be significant factors predicting the occurrence of ocular hypertension.
Journal of glaucoma 02/2013; · 1.74 Impact Factor
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ABSTRACT: The peripapillary retinal nerve fiber layer (RNFL) thickness pattern in the normal human eye has been well characterized using data obtained with scanning laser polarimetry and optical coherence tomography. The authors sought to characterize the normative peripapillary RNFL thickness and pattern using histologic sections obtained from healthy postmortem human eyes.
Seventeen unpaired normal postmortem eyes were recruited into this study. Each eye was sectioned using the "umbrella technique" to obtain four concentric peripapillary rings, each centered on the optic disc, with diameters of 3.0, 3.5, 4.0, and 4.5 mm. RNFL thickness data along each ring section was measured at 100 equidistant locations. Thickness data, for each ring diameter, across all eyes were averaged to arrive at normative thickness values for the peripapillary RNFL thickness in eyes processed using this technique.
Average RNFL thicknesses (+/-SD) for the 3.5-mm diameter ring were as follows: overall, 60.3 +/- 19.5 microm; superior, 75.3 +/- 26.5 mum; inferior, 69.4 +/- 22.4 microm; nasal, 48.1 +/- 15 microm; temporal, 49.2 +/- 26.4 microm. Qualitatively, the RNFL thickness showed a double-hump pattern with relatively similar superior and inferior peaks and with temporal and nasal troughs. Progressively larger peripapillary rings showed progressively thinner RNFL thickness at all quadrants. In contrast, the relative thickness percentage for each quadrant remained unchanged among the four different diameter rings.
Histologic data from a group of healthy postmortem eyes demonstrate the pattern of RNFL thickness in normal eyes. These data corroborate imaging findings of peripapillary RNFL thickness patterns obtained using commercially available RNFL imaging devices.
Investigative Ophthalmology & Visual Science 04/2008; 49(3):941-4. · 3.60 Impact Factor
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ABSTRACT: The presence of retinal nerve fiber layer (RNFL) split bundles recently was described in normal eyes scanned using scanning laser polarimetry. In this study, the authors set out to ascertain whether RNFL split bundles can be found in histologic sections of normal human eyes.
Histologic study of postmortem human eyes.
Fourteen normal postmortem eyes obtained from 13 individuals.
Peripapillary RNFL thickness measurements were plotted, for each eye, from ring sections of 3.0, 3.5, 4.0, and 4.5 mm in diameter. The presence of superior or inferior split RNFL patterns, or both, was sought.
The presence of superior or inferior split bundles or both in the histologic data.
Five of 14 eyes demonstrated a distinct histologic pattern of RNFL split bundles, of which 3 were found superiorly and 2 inferiorly. None of these 14 eyes demonstrated both a definite superior and a definite inferior split.
This study provides histologic evidence demonstrating that RNFL split bundles are likely a true anatomic finding, rather than an imaging artifact, and that their presence seems to be relatively common in normal eyes. The presence of a split bundle, being a normal variant, should be distinguished from RNFL loss.
Ophthalmology 01/2008; 114(12):2259-64. · 5.45 Impact Factor
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Ophthalmology 07/2007; 114(6):1236-7. · 5.45 Impact Factor
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ABSTRACT: To obtain iris biopsy samples of sufficient quality and quantity for histopathological analysis using a novel punch biopsy technique.
Two patients underwent iris tumour biopsy at an ocular oncology service. A trabeculectomy punch (Kelly Descemet's membrane punch) with a 1.0 mm diameter head and a 0.75 mm deep bite was inserted through a clear cornea perforated by a SatinSlit 3.2 mm angled slit knife into a viscoelastic-filled anterior chamber. The Kelly punch was placed over the lesion and pressed down before the punch was made. After obtaining the sample, the Kelly punch was removed from the eye and then opened over a dry cellulose sponge. Tissue samples were placed in 4% formalin and processed routinely for standard staining with H&E, periodic acid Schiff and immunostains.
In both patients, by using the punch biopsy technique with the Kelly punch, we were able to obtain a 0.8 x 0.6 mm piece of tissue, large enough for any histological analysis. H&E staining showed spindle cell melanoma. Tissue sections, stained positive with MART-1 (melanoma antigen recognised by T cells) and negative with cytokeratin, established the diagnosis of melanoma of the iris in each of these patients.
Iris biopsy with the punch technique yields a tissue biopsy specimen, as opposed to cytology samples obtained by fine needle aspiration biopsy. This technique is quick, simple to perform and requires non-expensive and easily available equipment. The tissue obtained is of sufficient quality and quantity to enable routine and special stainings.
British Journal of Ophthalmology 05/2007; 91(5):660-2. · 2.90 Impact Factor
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ABSTRACT: To report the clinical course of early transient reduction of uncorrected visual acuity (UCVA) after LASIK surgery resulting from steroid-induced elevation of intraocular pressure (IOP).
Twenty-nine eyes of 15 patients who received topical corticosteroids after uneventful myopic LASIK surgery and had a decrease in UCVA within the first 3 weeks were evaluated retrospectively.
Intraocular pressure increased by 4 to 30 mmHg from preoperative to postoperative days 4 to 20. Twenty-seven of 29 eyes had a decrease in UCVA and/or best spectacle-corrected visual acuity (BSCVA). All eyes, except one, had edema without evidence of inflammation in the interface or the remainder of the cornea. Discontinuation of topical corticosteroids and application of anti-glaucoma medications resulted in a decrease of IOP to normal levels, reduction or disappearance of the edema, and recovery of BSCVA.
Early onset steroid-induced elevation of IOP after LASIK may cause corneal edema and a sudden decrease in UCVA. Rapid diagnosis and treatment can control IOP and recover the visual loss.
Journal of refractive surgery (Thorofare, N.J.: 1995) 04/2007; 23(3):244-51. · 2.54 Impact Factor
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ABSTRACT: To compare the measurement of the basal diameter of choroidal melanoma, an important parameter for planning treatment and as a prognostic factor, by standardized ophthalmic ultrasound versus that obtained using a wide-angle fundus camera.
The longest and shortest basal diameters of 104 consecutive choroidal melanomas of patients seen at the ocular oncology service of the Hadassah University Hospital were measured by B-scan ultrasound and compared with those measured by a wide-angle fundus camera (Panoret-1000). Each diameter was measured thrice by two ophthalmic photographers, and intra-observer and interobserver reproducibility were calculated as well.
The measurements of both the long and short diameters of the choroidal melanomas were significantly larger when measured by Panoret-1000 as compared with the B-scan ultrasound. There was no significant difference among the three measurements of each of the photographers. The interobserver reproducibility between the two photographers was high.
Our findings can be attributed to the larger extent of the pigmentation of the melanoma compared to its recognized elevation. Since pigmentation of choroidal melanoma is easier to recognize than its elevation, we assume that measurement by a wide-angle fundus camera is more accurate in pigmented tumors, and should be adopted for measuring the basal diameter of choroidal melanomas in planning treatment and follow-up.
Ophthalmologica 02/2006; 220(3):194-7. · 1.42 Impact Factor
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ABSTRACT: Four masked examiners studied the usefulness of the glass-rod for estimating intraocular pressure (IOP) in a living, anesthetized rabbit eye manometrically set to 135 different random values. With training, the average error in IOP estimation improved from 7.42 +/- 5.56 mmHg to 5.13 +/- 4.48 mmHg. Gentle palpation of the corneal apex with a glass-rod provides tactile and visual clues that may assist in estimating the IOP.
Annals of Ophthalmology 02/2006; 38(3):195-9. · 0.16 Impact Factor
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ABSTRACT: Purpose: To demonstrate that slow-growing intracranial suprasellar mass lesions can be associated with optic disc cupping, clinically indistinguish-able from glaucomatous optic neuropathy. Cases: At a neuro-ophthalmology tertiary clinic, a retrospective chart review identified four patients of presumed normal tension glaucoma and supra-sellar tumors. In all four patients with normal intraocular pressure, the appearance of the optic disc resembled typical glaucomatous optic nerve damage with disc cupping and parapapillary atrophy. Conclusion: In few patients, typical glaucomatous abnormalities of the optic nerve head may occur in association with slow-growing suprasellar tumors.
Neuro-Ophthalmology. 01/2006; 30:111-115.
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ABSTRACT: To ascertain operator learning effect, and to quantify the interoperator reproducibility, using the newly introduced GDx VCC (variable corneal compensator) scanning laser polarimeter.
Prospective instrument validation study.
Three operators with no prior experience in operating the GDx VCC examined one randomly chosen eye of each of 30 randomly ordered subjects (15 glaucoma patients and 15 normal subjects).
Each study eye was scanned by the 3 operators in a random sequence during a single session. Five GDx parameters were analyzed: TSNIT (temporal, superior, nasal, inferior, temporal) Average, TSNIT Standard Deviation (SD), Superior Average, Inferior Average, and Nerve Fiber Indicator (NFI).
Retinal nerve fiber layer (RNFL) thickness GDx parameters across operators.
A learning effect was not found for any of the operators for any of the 5 GDx parameters studied. Reproducibility for each GDx parameter was measured as the mean SD value of the measurements taken by the 3 operators. Interoperator reproducibilities for normal and glaucomatous eyes, respectively, were 0.8 and 1.6 microm (TSNIT Average), 1.7 and 2.2 microm (Superior Average), 1.6 and 2.7 microm (Inferior Average), 1.3 and 1.7 microm (TSNIT SD), and 1.4 and 4.6 microm (NFI). The data obtained by each operator were highly correlated with those of the other 2 operators.
With the commercially available GDx VCC, a learning effect was not found for 3 novice operators. In addition, RNFL measurements seem highly reproducible across operators.
Ophthalmology 03/2005; 112(2):257-61. · 5.45 Impact Factor
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ABSTRACT: To determine typical patterns of repeatable glaucomatous visual field progression.
Retrospective analysis of data obtained from two prospective studies.
Included were 72 eyes of 72 patients tested up to six times over 2 years, and 40 eyes of 40 patients followed annually for up to 12 years. Each patient had two abnormal baseline visual fields, abnormal optic nerves, and serial fields. Progression was identified using three methods: by glaucoma change probability using total deviation (GCP-TD) and pattern deviation (GCP-PD) plots and by a clinical criteria. Progression was categorized as deepening or expansion of an existing scotoma, or a new scotoma.
The percentage of eyes repeatably progressed ranged from 17% to 27%. The most common pattern of progression was a deepening of an existing scotoma in the annual group, followed by expansion. With two follow-ups required, percentages for deepening only were 20% (clinical classifier). A combination of expansion and deepening was most common for the GCP criteria: 15% (GCP-TD classifier), and 10% (GCP-PD classifier) for the annual group. For the semiannual group, deepening was most common with the clinical criteria (11% of eyes), and deepening with expansion was most common by GCP criteria (14%, GCP-TD and GCP-PD). No eyes showed repeatable new scotomas.
Glaucomatous visual fields progress in the area of the visual field where baseline testing showed an existing scotoma. Follow-up testing might be improved by concentrating on already defective locations and using sparser test patterns or screening algorithms in normal areas of the visual field.
American Journal of Ophthalmology 01/2005; 138(6):1029-36. · 4.22 Impact Factor
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Pamela A Sample,
Kwokleung Chan,
Catherine Boden,
Te-Won Lee, Eytan Z Blumenthal,
Robert N Weinreb,
Antje Bernd,
John Pascual,
Jiucang Hao,
Terrence Sejnowski,
Michael H Goldbaum
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ABSTRACT: To determine whether an unsupervised machine learning classifier can identify patterns of visual field loss in standard visual fields consistent with typical patterns learned by decades of human experience.
Standard perimetry thresholds for 52 locations plus age from one eye of each of 156 patients with glaucomatous optic neuropathy (GON) and 189 eyes of healthy subjects were clustered with an unsupervised machine classifier, variational Bayesian mixture of factor analysis (vbMFA).
The vbMFA formed five distinct clusters. Cluster 5 held 186 of 189 fields from normal eyes plus 46 from eyes with GON. These fields were then judged within normal limits by several traditional methods. Each of the other four clusters could be described by the pattern of loss found within it. Cluster 1 (71 GON + 3 normal optic discs) included early, localized defects. A purely diffuse component was rare. Cluster 2 (26 GON) exhibited primarily deep superior hemifield defects, and cluster 3 (10 GON) held deep inferior hemifield defects only or in combination with lesser superior field defects. Cluster 4 (6 GON) showed deep defects in both hemifields. In other words, visual fields within a given cluster had similar patterns of loss that differed from the predominant pattern found in other clusters. The classifier separated the data based solely on the patterns of loss within the fields, without being guided by the diagnosis, placing 98.4% of the healthy eyes within the same cluster and spreading 70.5% of the eyes with GON across the other four clusters, in good agreement with a glaucoma expert and pattern standard deviation.
Without training-based diagnosis (unsupervised learning), the vbMFA identified four important patterns of field loss in eyes with GON in a manner consistent with years of clinical experience.
Investigative Ophthalmology & Visual Science 09/2004; 45(8):2596-605. · 3.60 Impact Factor
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ABSTRACT: Choroidal detachment is a known complication of topical hypotensive agents when used to treat eyes sensitized by prior surgery. We document the abrupt development of an extensive choroidal detachment after initiation of dorzolamide therapy in a surgically untreated eye with primary open-angle glaucoma.
Observational case report.
A 76-year-old woman with primary open-angle glaucoma and no history of ocular surgery developed a choroidal detachment 12 hours after initiation of therapy with dorzolamide eye drops. Choroidal detachment was diagnosed clinically and confirmed by echography.
Withdrawal of the drug and initiation of corticosteroid drops resulted in prompt resolution of the choroidal detachment.
Choroidal detachment can occur in surgically untreated eyes after use of a topical carbonic anhydrase inhibitor.
American Journal of Ophthalmology 09/2004; 138(2):285-6. · 4.22 Impact Factor
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American family physician 08/2004; 70(1):155-6. · 1.70 Impact Factor
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Eytan Z Blumenthal
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ABSTRACT: To present a technique of ocular sectioning that enables continuous histologic measurements of peripapillary retinal nerve fiber layer (RNFL) thickness in a concentric ring around the optic disc, corresponding to similar regions measured by in vivo imaging techniques.
Two pig eyes and two normal human eyes were processed using the "umbrella" technique, in which peripapillary concentric ring sections were obtained, at increasing diameters, all centered on the optic disc. Each histologic ring section contains a continuous circumferential 360 degrees retinal slice, oriented approximately perpendicular to the retinal surface. Every histologic slice contains each axon of the retina, sectioned perpendicular to each axon's long axis and at an equal set distance from the disc margin.
Ring sections from pig and human eyes are presented and correlated to known RNFL anatomy. For the two human eyes, peripapillary RNFL thickness was quantified and plotted, resulting in the expected double-hump pattern.
The umbrella technique provides, on a single histologic section, all necessary information for quantifying the entire RNFL layer of that eye, in a standardized fashion. This technique can simplify the process of analyzing the RNFL thickness histologically, assist in obtaining a normative database of RNFL thickness in humans, and be implemented as a histologic end point in animal studies evaluating new treatment modalities for glaucoma.
Investigative Ophthalmology & Visual Science 06/2004; 45(5):1404-9. · 3.60 Impact Factor
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ABSTRACT: To evaluate whether healthy young children are able to perform automated static perimetry reliably using the frequency-doubling technology (FDT) perimeter.
Prospective, observational case series.
Forty healthy children aged 4 to 14 years.
Subjects underwent, in 1 randomly chosen eye, 2 consecutive visual field (VF) tests using the C-20 full-threshold program of the commercially available FDT.
Global measures included mean deviation (MD), pattern standard deviation (PSD), test duration and reliability indices, including fixation losses and false-positive and false-negative errors. Fixation losses are checked 6 times throughout the examination, rather than being continuously monitored. Two scoring systems, based on the total deviation probability plot, classified each VF as normal or abnormal.
All subjects completed the VF test. The better of 2 examinations (as determined by the MD score) was used for analysis. The average test duration was 4.9+/-0.7 minutes for the entire group. The mean MD and PSD were -0.78+/-4.9 and 6.7+/-6.2, respectively. A clear correlation to age was found for MD, PSD, abnormality of the VF, and test duration (all P<0.05). Of all VFs, 32.5% were unreliable, such that at younger than 8 years of age, 42.9% of the VFs were unreliable, compared with 23.1% for those older than 8 years. Younger than 8 years of age, 78.6% of VFs were abnormal, whereas for ages 8 years and older, 26.9% of VFs were abnormal.
Frequency-doubling technology seems to be a clinically feasible VF method for evaluating young children older than approximately 8 years of age. The reliability indices, MD, test duration, and the reproducibility of the VF test were found to be highly correlated with age, in such a way that these parameters all improved with increasing age.
Ophthalmology 03/2004; 111(3):435-9. · 5.45 Impact Factor
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ABSTRACT: Editing surgical videos requires a basic understanding of key technical issues, especially when transforming from analog to digital media. These issues include an understanding of compression-decompression (eg, MPEGs), generation quality loss, video formats, and compression ratios. We introduce basic terminology and concepts related to analog and digital video, emphasizing the process of converting analog video to digital files. The choice of hardware, software, and formats is discussed, including advantages and drawbacks. Last, we provide an inexpensive hardware-software solution.
Journal of Cataract [?] Refractive Surgery 11/2003; 29(10):1874-7. · 2.26 Impact Factor
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Archives of Ophthalmology 11/2003; 121(10):1502-3. · 3.71 Impact Factor
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ABSTRACT: To quantify factors affecting test-retest variability of threshold measurements over a series of 3 serial visual fields (VF).
Prospective comparative observational study.
Forty-one normals, 10 suspects and 35 stable glaucoma patients.
All subjects performed 3 standard and 3 short-wavelength automated perimetry (SWAP) VFs. At each VF location, severity (defined as age-corrected total deviation) and test-retest variability (TRV), defined as the standard deviation of 3 serial threshold values, were calculated. A multiple regression model (constructed separately for standard VF and SWAP) incorporated 13 factors: severity, location, eccentricity, study group, diagnosis, superior versus inferior hemifield, nasal versus temporal hemifield, one-versus-two thresholds, age, mean pupil size, pupil size variability, between-subject variation, and residual variation.
Variability in threshold sensitivity VF values.
Mean TRV (+/- standard deviation) for normal, suspect and glaucoma eyes, respectively, was: 1.28 +/- 0.87, 1.53 +/- 1.04 and 2.20 +/- 1.79 dB for standard VF, and 1.87 +/- 1.35, 1.86 +/- 1.24 and 2.68 +/- 1.85 dB for SWAP. The contribution of each factor to the model for standard VF and SWAP (SWAP in parentheses) were: severity 15.5% (6.9%); location 2.7% (4.1%); eccentricity 1.1% (0.64%); diagnosis 2.9% (5.9%); "superior versus inferior" hemifield 0.17% (1.7%); "nasal versus temporal" hemifield 0.06% (0.02%); one-versus-two thresholds 0.04% (0.16%); age 0.1% (0.06%); mean pupil size 0.59% (0.1%); pupil size variability 3.2% (2.8%); between-subject 8.0% (13.5%) and residual variation 61.0% (66.6%). Excluding between-subject and residual variation, the 11-factor model was able to account for less than one third of the variability seen in both standard VF and SWAP.
Severity of defect and between subject variation exerted the largest effect on TRV. However, even if all 11 factors could be adjusted for, it would reduce the magnitude of TRV by only 30%. More work is needed to reduce the remaining variability inherent in psychophysical testing and to better understand the intrinsic physiological variability present both in healthy and diseased eyes. It is possible that a larger number of VFs used for the calculation of TRV might further reduce the magnitude of the remaining variability found in this study.
Ophthalmology 11/2003; 110(10):1895-902. · 5.45 Impact Factor
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American family physician 10/2003; 68(5):933-4. · 1.70 Impact Factor
