To investigate sensitive outcome measures based exclusively on abnormal points in microperimetry testing of eyes with intermediate age-related macular degeneration (iAMD). 25 eyes of 25 subjects with ...iAMD had undergone 2 successive tests of mesopic microperimetry with the Macular Integrity Assessment Microperimeter (MAIA), using a custom grid of 33 points spanning the central 14 degrees of the macula. Each point was defined as abnormal if its threshold sensitivity was lower than 1.65 standard deviations (SD) (5%) or 2 SD (2.5%) than the expected threshold in healthy eyes according to the MAIA internal database. Among the 25 eyes there were 11.8 ± 9 and 8.4 ± 8.2 abnormal points at < 5% and < 2.5%, with mean deviation of thresholds from normal - 4.9 ± 1.2 dB and - 5.8 ± 1.5 dB, respectively. These deviations were greater, and their SD smaller, compared with the complete microperimetry grid, - 2.3 ± 2.0 dB. The 95% limits of agreement for average threshold between the 2 successive tests were smaller when only abnormal points were included. Analyzing only abnormal grid points yields an outcome parameter with a greater deviation from normal, a more homogenous dataset, and better test-retest variability, compared with analysis of all grid points. This parameter may thus be more sensitive to change, while moderately limiting the number of potential recruits. The proposed outcome measures should be further investigated as potential endpoints in clinical trials in iAMD.
To compare parameters of biomechanical response of the human cornea measured as corneal hysteresis (CH) and corneal resistance factor (CRF) in patients with diabetes mellitus and healthy control ...subjects.
Department of Ophthalmology, Assaf Harofeh Medical Center, Zerifin, Israel.
In the right eye of each participant, the CH, CRF, Goldmann-correlated intraocular pressure (IOPg), and corneal-compensated intraocular pressure (IOPcc) were measured with the Ocular Response Analyzer. Central corneal thickness (CCT) was measured by ultrasonic pachymetry and intraocular pressure by Goldmann applanation tonometry (IOP GAT). Findings were compared between the 2 groups (control and diabetic).
Forty diabetic patients (17 women, 23 men) and 40 healthy subjects (19 women, 21 men) were prospectively recruited. The mean CH was 9.3 mm Hg +/- 1.4 (SD) and 10.7 +/- 1.6 mm Hg and the mean CRF was 9.6 +/- 1.6 mm Hg and 10.9 +/- 1.7 mm Hg in the control group and diabetic group, respectively (both P < .0001). Diabetic corneas were significantly thicker (P = .019); the mean CCT was 530.3 +/- 35.9 microm in the control group and 548.7 +/- 33.0 microm in the diabetic group. The CH and CRF remained significantly different in multivariate analysis that included CCT. There was no statistically significant difference between the 2 groups in IOPcc, IOPg, or IOP GAT measurements.
Diabetes mellitus affected biomechanical parameters of the human corneas, including increased CH, CRF, and CCT. Whether this observation has implications in the clinical management and understanding of corneal ectasia and glaucoma requires further study.
To assess variations in the biomechanical properties and central corneal thickness (CCT) throughout the female menstrual cycle.
Department of Ophthalmology, Assaf Harofeh Medical Center, Zerifin ...Israel.
Case series.
Young healthy women were prospectively recruited. Every participant was assessed at the beginning of the menstrual cycle, at ovulation, and at the end of the cycle. At every time point, corneal hysteresis (CH) and the corneal resistance factor (CRF) were measured with the Ocular Response Analyzer and the CCT was measured with an ultrasonic pachymeter.
Twenty-two eyes of 22 women (mean age 19.5 years ± 1.5 SD) were included. The CH was statistically significantly decreased at ovulation (10.1 mm Hg) compared with the beginning (11.1 mm Hg, P<.001) and the end (11.4 mm Hg, P<.001) of the cycle. The CRF was also significantly decreased at ovulation (9.8 mm Hg) compared with the beginning (10.6 mm Hg, P<.001) and the end (10.5 mm Hg, P<.001) of the cycle. The central cornea was thinnest at the beginning (535 μm) and statistically significantly thicker at ovulation (542 μm, P<.001) and at the end of the menstrual cycle (543 μm, P<.001).
The CCT and biomechanical parameters significantly varied during the menstrual cycle. The CH and CRF were temporarily decreased at ovulation. The cornea was thinnest at the beginning and thicker at ovulation and at the end of the cycle. Such corneal changes may be important to consider during screening of candidates for laser refractive surgery.
Glaucoma is a leading cause of global blindness, especially preventable blindness. The increased prevalence of glaucoma has led to a growing demand for newer, safer, more rapid, and simpler ...treatments for the reduction of intraocular pressure (IOP). In this study, we evaluated the safety and feasibility of performing filtration glaucoma surgery with an Ab-Interno Er:YAG laser in rabbits.
Nine New Zealand White rabbits age 16 weeks were studied. After subconjunctival injection of mitomycin C (MMC), a novel Ab-Interno Er:YAG laser probe was inserted into the anterior chamber (AC) through a clear corneal 1 mm paracentesis and directed at the trabecular meshwork adjacent to the MMC injection area. A pulsed laser beam was applied to create a patent sclerostomy connecting the AC to the subconjuctival space, resulting in a filtering bleb. The laser system used was the Er:YAG laser system - LAS25-FCU, (Pantec Biosolutions AG, Liechtenstein). Parameters used: Wave lengh: 2940 nm, Pulse length: 100-400 μsec,frequency: 250 Hz. Average laser power in accordance to the fiber tip diameter: 0.85 W(range 0.8-0.92 W). Complete ocular exams, including IOP measurements, were performed on 1, 7, 14, and 23 days postoperatively. Three rabbits were sacrificed on days 1, 14, and 23, and histological examinations were performed on all nine eyes.
All procedures resulted in a functional medium-large superior bleb without significant complications. The bleb was sustained in all rabbits by day 14 and in one of the three rabbits that reached the last follow-up at 23 days. No cases of postoperative hypotony were observed. There was a transient significant reduction in mean IOP on postoperative days 5 and 7 (P = 0.028). Histopathological analysis revealed a patent full-thickness scleral tunnel with only a minor degree of surrounding coagulation necrosis.
The Ab-Interno laser sclerostomy procedure is potentially safe and effective based on initial experience in an in-vivo rabbit animal model.
Anterior segment imaging allows for an objective method of visualizing the anterior segment angle. Two of the most commonly used devices for anterior segment imaging include the anterior segment ...optical coherence tomography (AS-OCT) and the ultrasound biomicroscopy (UBM). AS-OCT technology has several types, including time-domain, swept-source, and spectral-domain-based configurations. We performed a literature search on PubMed for articles containing the text "anterior segment OCT," "ultrasound biomicroscopy," and "anterior segment imaging" since 2004, with some pertinent references before 2004 included for completeness. This review compares the advantages and disadvantages of AS-OCT and UBM, and summarizes the most recent literature regarding the importance of these devices in glaucoma diagnosis and management. These devices not only aid in visualization of the angle, but also have important postsurgical applications in bleb and tube imaging.
Ocular anterior segment changes in pregnancy Goldich, Yakov; Cooper, Michael; Barkana, Yaniv ...
Journal of cataract and refractive surgery,
11/2014, Volume:
40, Issue:
11
Journal Article
Peer reviewed
To evaluate the changes occurring in the cornea, anterior segment anatomy, and intraocular pressure (IOP) in pregnant women.
Department of Ophthalmology, Assaf Harofeh Medical Center, Zerifin, ...Israel.
Prospective single-center comparative study.
The Ocular Response Analyzer dynamic bidirectional applanation device and the Pentacam HR Scheimpflug imaging system were used to obtain data on the anterior eye segments of healthy pregnant and nonpregnant women.
Sixty pregnant and 60 nonpregnant women were enrolled. The Goldmann-correlated IOP and corneal-compensated IOP were significantly lower in the pregnant group (mean 10.96 mm Hg versus 12.97 mm Hg, P<.001; and 10.97 mm Hg versus 13.16 mm Hg, P<.001, respectively). The corneal front steep keratometry value was statistically significantly higher in the pregnant group (44.81 diopters D versus 44.1 D, P=.039). No significant difference was found in corneal hysteresis, the corneal resistance factor, corneal posterior curvature, central corneal thickness and volume, anterior chamber depth and volume, or iridocorneal angle.
Pregnancy was associated with greater corneal curvature and lower IOP. Further studies should be performed to learn whether these alterations result from changes in corneal biomechanical properties during pregnancy.
No author has a financial or proprietary interest in any material or method mentioned.
Decreased blood flow to the optic nerve (ON) and neuroinflammation are suggested to play an important role in the pathophysiology of glaucoma. This study investigated the potential neuroprotective ...effect of azithromycin, an anti-inflammatory macrolide, and sildenafil, a selective phosphodiesterase-5 inhibitor, on retinal ganglion cell survival in a glaucoma model, which was induced by microbead injection into the right anterior chamber of 50 wild-type (WT) and 30 transgenic toll-like receptor 4 knockout (TLR4KO) mice. Treatment groups included intraperitoneal azithromycin 0.1 mL (1 mg/0.1 mL), intravitreal sildenafil 3 µL, or intraperitoneal sildenafil 0.1 mL (0.24 μg/3 µL). Left eyes served as controls. Microbead injection increased intraocular pressure (IOP), which peaked on day 7 in all groups and on day 14 in azithromycin-treated mice. Furthermore, the retinas and ON of microbead-injected eyes showed a trend of increased expression of inflammatory- and apoptosis-related genes, mainly in WT and to a lesser extent in TLR4KO mice. Azithromycin reduced the BAX/BCL2 ratio, TGFβ, and TNFα levels in the ON and CD45 expression in WT retina. Sildenafil activated TNFα-mediated pathways. Both azithromycin and sildenafil exerted a neuroprotective effect in WT and TLR4KO mice with microbead-induced glaucoma, albeit via different pathways, without affecting IOP. The relatively low apoptotic effect observed in microbead-injected TLR4KO mice suggests a role of inflammation in glaucomatous damage.
Purpose To compare measurements of anterior chamber depth (ACD) and corneal curvature obtained with the Pentacam to other commonly used devices. Design Prospective, nonrandomized clinical trial. ...Methods Measurements of ACD and keratometry were prospectively obtained in 22 eyes of 11 subjects with the Pentacam compared with measurements of the ultrasound (US) A-scan and IOLMaster (ACD), and with those of automated keratometry (AK) and IOLMaster (keratometry) at the Assaf Harofeh Medical Center. Results The mean interdevice differences in keratometry for Pentacam vs AK, Pentacam vs IOLMaster, and AK vs IOLMaster were −0.046 diopters, −0.471 diopters, and −0.424 diopters, respectively. Measurements of keratometry by the IOLMaster differed statistically significantly from those of Pentacam ( P < .01) and AK ( P < .01). For measurement of keratometry, 95% limits of agreement were −1.321 to 1.229 diopters for the Pentacam and AK, −1.478 to 0.536 diopters for the Pentacam and IOLMaster, and −1.026 to 0.178 diopters for the AK and IOLMaster. The mean interdevice differences in ACD for the Pentacam vs US, Pentacam vs IOLMaster, and US vs IOLMaster were 0.103, 0.099, and −0.004 mm, respectively. Measurements of ACD by the Pentacam differed statistically significantly from those of US ( P < .05) and IOLMaster ( P < .01). For measurement of ACD, 95% limits of agreement were −0.197 to 0.404 mm for the Pentacam and US, −0.169 to 0.367 mm for the Pentacam and IOLMaster, and −0.332 to 0.324 mm for the US and IOLMaster. Conclusions For some clinical applications, measurements of ACD and corneal curvature with the tested machines may differ greatly and therefore may not be interchangeable.
Purpose: To characterize ocular surface temperature (OST) in healthy eyes and its association with systemic risk factors of cardiovascular and ischemic heart disease. Methods: This prospective ...cross-sectional study included consenting subjects who were examined at the Institute for Medical Screening in Sheba Medical Center. A Therm-App™ thermal imaging camera (Opgal LTD, Israel) was used for OST acquisition, and the mean OST of the medial canthal, lateral canthal, and central cornea regions were measured. Room and body temperatures were also recorded. Past medical and ocular history as well as data from various clinical examinations performed at the same visit were obtained. Results: Thermographic images were obtained from 186 subjects, 150 of which were included in the final analysis. OST was significantly higher in the medial canthal, central cornea, and lateral canthal regions in people with a history of ischemic heart disease (p = 0.02, p = 0.02, and p = 0.03, respectively). There were no significant OST differences (ANOVA test) associated with the presence of hypertension, diabetes mellitus, or active smoking status. Conclusions: OST correlated positively with the presence of ischemic heart disease. This correlation, its pathophysiological base, and its clinical application warrants further investigation.
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