Dose-Response-Relationship between Number of Laser Burns and IOP Reduction in Cyclophotocoagulation: An Animal Study

Purpose. The relationship between number of laser burns of cyclophotocoagulation (CPC) and intraocular pressure (IOP) reduction is unknown. This animal model was established to reveal a possible dose-response-relationship between the number of applied laser burns and the IOP lowering effect. Methods. 30 chinchilla bastard rabbits were divided into 5 groups and treated with either 1, 5, 10, 20, or 30 CPC burns, respectively. IOP was followed up for 1 week. IOP reduction of a single 30-burn treatment was compared with a fractionated treatment (three sessions; one week in between; 10 burns/session). Results. IOP reduction increases nonlinearly with the number of CPC burns (max. -6.1±1.4 mmHg). Fractionated treatment shows similar IOP reduction with less complications and more constant results compared to single session treatment. Conclusions. The study reveals a complex relationship between IOP reduction and the number of CPC burns. Fractionated CPC gives comparable IOP reduction at a higher degree of safety

Predicting Surgical Success in Patients with Idiopathic Epiretinal Membrane Using the Spectral-Domain Optical Coherence Tomography Segmentation Module for Single Retinal Layer Analysis

<p><i>Introduction:</i> Idiopathic epiretinal membrane (ERM) is a proliferation of cells formed on the internal surface of the retina and may cause a slow decrease in visual acuity (VA). The aim of this study was to evaluate the individual layers of the retina by optical coherence tomography (OCT) before and after vitrectomy with ERM peeling in order to refine surgical decision-making.</p> <p><i>Methods:</i> Forty-seven eyes of 45 patients (aged 55–87 years) with ERM were enrolled retrospectively from a tertiary referral center. OCT examination was performed preoperatively and at a mean of 3.2 months postoperatively in all cases. Nine retinal surfaces were subjected to automated all-layer segmentation using the manufacturer’s software and assessed for their correlation with VA.</p> <p><i>Results:</i> There was a significant correlation between the initial retinal morphology and change in VA postoperatively. Patients who gained at least two lines of VA had a significantly higher total retinal perimacular volume and retinal nerve fiber layer (each <i>p</i> < 0.0001) preoperatively.</p> <p><i>Conclusion:</i> Patients with high preoperative retinal volumes and therefore increased tractive components seemed to benefit more from surgery than those with low tractive components.</p

Effects of glaucoma drugs on ocular hemodynamics in normal tension glaucoma: a randomized trial comparing bimatoprost and latanoprost with dorzolamide [ISRCTN18873428]

Abstract Background Reduced choroidal perfusion is hypothesized to play a role in the pathogenesis of normal tension glaucoma. Thus the impact of antiglaucomatous eye drops on ocular perfusion has been the focus of recent research and the subject of intensive investigations. The present study investigates whether topically applied latanoprost or bimatoprost influence ocular perfusion in patients with normal tension glaucoma and compares these effects with that changes detected after the treatment with dorzolamide. Methods Ocular hemodynamics were assessed by color Doppler imaging (CDI) shortly before and after a one-month treatment with either latanoprost, bimatoprost or dorzolamide. Primary end-points of the study were peak systolic and end-diastolic blood flow velocities in the short posterior ciliary artery (SPCA) under the new therapy. Intraocular pressure (IOP) and additional perfusion parameters in the SPCA and other retrobulbar vessels were tracked as observational parameters. n = 42 patients with normal tension glaucoma were enrolled in the study. Results Systolic and diastolic blood flow velocities in the SPCA showed no significant alteration after the treatment with latanoprost or bimatoprost. Dorzolamide lead to increase of peak systolic velocity. IOP was reduced by all three agents in a range reported in the literature. Conclusion Topically applied latanoprost and bimatoprost act in a hemodynamically neutral manner and have the capability to lower IOP even in patients with normal tension glaucoma and low initial IOP level. Dorzolamide accelerates blood flow in systole. None of the tested compounds has a negative impact on hemodynamics in the short posterior ciliary arteries.</p

Ocular ultrasound as an easy applicable tool for detection of Terson's syndrome after aneurysmal subarachnoid hemorrhage.

Intraocular hemorrhage in patients suffering from aneurysmal subarachnoid hemorrhage is known as Terson's syndrome and is an underestimated but common pathology. We therefore designed a prospective single-blinded study to evaluate the validity of ocular ultrasound compared to the gold standard indirect funduscopy in the diagnosis of Terson's syndrome.Fifty-two patients (104 eyes in total) suffering from aneurysmal subarachnoid hemorrhage were enrolled in this study. Two investigators independently performed a single-blinded ocular ultrasound using a standard intensive care ultrasound system to detect an intraocular hemorrhage. Indirect funduscopy following iatrogenic mydriasis served as the gold standard for confirmation or exclusion of an intraocular hemorrhage. Statistical analyses were performed to evaluate the sensitivity and specificity, positive and negative predictive values of the method as well as the learning curve of ocular ultrasound.Indirect funduscopy detected Terson's syndrome in 11 of 52 (21.2%) respectively in 21 of 104 (20.2%) eyes in patients suffering from subarachnoid hemorrhage. Sensitivity and specificity increased with the number of ocular ultrasound examinations for both investigators, reaching 81.8% and 100% respectively. Positive and negative predictive values were different for both investigators (63.6% vs. 100% positive and 100% vs. 95.7% negative) but were both correlated to the amount of intraocular hemorrhage. A low Glasgow Coma scale (p = 0.015) and high Hunt & Hess grade (p = 0.003) was associated with a higher rate of Terson's syndrome.Ocular ultrasound using standard ultrasound equipment has been confirmed as a reliable, easy-to-handle bedside screening tool for detecting Terson's syndrome. Nevertheless funduscopy remains the gold standard to detect Terson's syndrome

Effects of glaucoma drugs on ocular hemodynamics in normal tension glaucoma: a randomized trial comparing bimatoprost and latanoprost with dorzolamide ISRCTN18873428-0

<p><b>Copyright information:</b></p><p>Taken from "Effects of glaucoma drugs on ocular hemodynamics in normal tension glaucoma: a randomized trial comparing bimatoprost and latanoprost with dorzolamide [ISRCTN18873428]"</p><p>BMC Ophthalmology 2005;5():6-6.</p><p>Published online 5 Apr 2005</p><p>PMCID:PMC1087849.</p><p>Copyright © 2005 Zeitz et al; licensee BioMed Central Ltd.</p

Effects of glaucoma drugs on ocular hemodynamics in normal tension glaucoma: a randomized trial comparing bimatoprost and latanoprost with dorzolamide ISRCTN18873428-2

<p><b>Copyright information:</b></p><p>Taken from "Effects of glaucoma drugs on ocular hemodynamics in normal tension glaucoma: a randomized trial comparing bimatoprost and latanoprost with dorzolamide [ISRCTN18873428]"</p><p>BMC Ophthalmology 2005;5():6-6.</p><p>Published online 5 Apr 2005</p><p>PMCID:PMC1087849.</p><p>Copyright © 2005 Zeitz et al; licensee BioMed Central Ltd.</p

Effects of glaucoma drugs on ocular hemodynamics in normal tension glaucoma: a randomized trial comparing bimatoprost and latanoprost with dorzolamide ISRCTN18873428-1

<p><b>Copyright information:</b></p><p>Taken from "Effects of glaucoma drugs on ocular hemodynamics in normal tension glaucoma: a randomized trial comparing bimatoprost and latanoprost with dorzolamide [ISRCTN18873428]"</p><p>BMC Ophthalmology 2005;5():6-6.</p><p>Published online 5 Apr 2005</p><p>PMCID:PMC1087849.</p><p>Copyright © 2005 Zeitz et al; licensee BioMed Central Ltd.</p>olamide led to a statistical increase of PSV

Ocular Ultrasound of a normal eye.

<p>The ultrasound probe is applied to the closed eye and transmission gel used to avoid any pressure on the eye. The normal eye (here right eye) appears as a round hypoechoic (grey-black) structure, and the cornea (2) is a thin hyperechoic (white) layer next to the eyelid (1). This is adjacent to the anterior chamber (hypoechoic water-filled cavity). Below the chamber, a hyperechoic iris and ciliary bodies (4) follow with the anterior (hyperechogenic) reflection of the lens (3). The lens itself is hypoechogenic with a smaller reflection on the rear side (5). The vitreous body is hypoechogenic due to its water-filled cavity. Retina may not be differentiated from choroidal layers, while the optic nerve appears as a hypoechoic linear structure (7) entering the vitreous chamber (6).</p