ABSTRACT
<p><b>BACKGROUND</b>There are ON- and OFF-pathways in the normal vertebrate retina. Short- and long-flash electroretinogram (ERG) are suitable methods to observe the function of ON- and OFF-pathways in vivo, respectively. It is clear that high intraocular pressure (IOP) might cause dysfunction of cone-dominated photopic negative response (PhNR) in monkeys with high IOP in ON-pathway. However, whether cone-dominated OFF-responses are also affected is less known. The aim of this study was to observe photopic OFF-responses of ERG in monkeys with high IOP.</p><p><b>METHODS</b>Nine monkeys were involved in the experiment from January 2006 to December 2016. High IOP was induced in the right eye by laser coagulation of the mid-trabecular meshwork in five monkeys. Six years after the laser coagulation, both short- and long-flash of the photopic ERG were recorded. Stimulus light was red flashes superimposed on a blue background. Four normal monkeys were examined under the same ERG protocols as controls. Paired t- test was used to compare the difference of each ERG parameter between the lasered eye and the fellow eye. Analysis of variance (ANOVA) with Tukey adjustment was adopted to calculate the differences among the lasered eye, the fellow eye, and the eyes of normal monkeys.</p><p><b>RESULTS</b>The mean amplitude of a-wave (11.73 ± 2.05) and PhNR (8.67 ± 2.44) in lasered eyes was significantly lower than that of a-wave (21.47 ± 3.15) and PhNR (22.05 ± 3.42) in fellow eyes (P = 0.03 and P = 0.01, respectively) in response to short flash. The mean amplitude of d-wave (1.60 ± 0.59) and i-wave (3.13 ± 0.64) was significantly reduced in the lasered eyes than that of d-wave (4.01 ± 0.56) and i-wave (8.79 ± 1.75) in the fellow eyes (P = 0.02 and P = 0.02, respectively) in response to long flash.</p><p><b>CONCLUSIONS</b>Reduced OFF-responses are recorded in monkeys with high IOP when dysfunction of photoreceptor is involved. The reduced OFF-responses to long-flash stimulus show evidence of anomalous retinal circuitry in glaucomatous retinopathy.</p>
ABSTRACT
<p><b>BACKGROUND</b>Optical coherence tomography (OCT) angiography is a novel technique by which we can detect the local perfusion of fundus directly. The aim of this study was to evaluate the reproducibility of optic disc and macular flow perfusion parameters in rhesus monkeys using OCT angiography.</p><p><b>METHODS</b>Eighteen healthy monkeys (18 eyes) were subjected to optic disc and macula flow index measurements via a high-speed and high-resolution spectral-domain OCT XR Avanti with a split-spectrum amplitude de-correlation angiography algorithm. Right eye was imaged 3 times during the first examination and once during each of the two following examinations. The intra-visit and inter-visit intraclass correlation coefficients (ICCs) were both determined.</p><p><b>RESULTS</b>The average flow indices of the four optic disc area layers were 0.171 ± 0.009 (optic nerve head), 0.015 ± 0.004 (vitreous), 0.052 ± 0.009 (radial peripapillary capillary), and 0.167 ± 0.011 (choroid). Average flow indices of the four macula area layers were 0.044 ± 0.011 (superficial retina), 0.036 ± 0.011 (deep retina), 0.016 ± 0.009 (outer retina), and 0.155 ± 0.013 (choroid). Intra-visit (ICC value: 0.821-0.954) and inter-visit (ICC value: 0.844-0.899) repeatability were both high.</p><p><b>CONCLUSIONS</b>The study is about the reproducibility of optic disc and macular perfusion parameters as measured by OCT angiography in healthy rhesus monkeys. Flow index measurement reproducibility is high for both the optic disc and macula of normal monkey eyes. OCT angiography might be a useful technique to assess changes when examining monkeys with experimental ocular diseases.</p>
Subject(s)
Animals , Male , Angiography , Macaca mulatta , Macula Lutea , Diagnostic Imaging , Optic Disk , Diagnostic Imaging , Reproducibility of Results , Tomography, Optical Coherence , MethodsABSTRACT
<p><b>BACKGROUND</b>No population-based assessment of the prevalence and incidence of pediatric glaucoma in China are available. Here we describe the spectrum of hospitalized pediatric glaucoma patients in Beijing Tongren Hospital in China.</p><p><b>METHODS</b>We reviewed the charts of pediatric patients, from birth to 18 years old, with a discharge diagnosis of glaucoma in Beijing Tongren Hospital, from 2002 to 2008. All children were admitted for anti-glaucoma surgery, treating the sequelae of the glaucoma, or managing postoperative complications. We evaluated the demographic characteristics and the proportion of different glaucoma subtypes.</p><p><b>RESULTS</b>Pediatric patients (n = 1452) accounted for 12.91% of the total glaucoma in-patients from 2002 to 2008, and at last data of pediatric glaucoma were presented for 1055 children who came from 28 provinces, municipalities and autonomous regions in China. Boys were more common in all subtypes and at all ages, with a total ratio of boys to girls of 2.32:1. Congenital glaucoma was the most common subtype, accounting for 46.07% in all patients and accounting for 69.95% in children under 3 years of age. The median presenting age of congenital glaucoma patients was 2 years. Patients with traumatic glaucoma were the second most common group (n = 128, 12.13%), and presented at older age (the median presenting age was 11 years). The majority of traumatic glaucoma occurred in children between 10 and 15 years of age (n = 72, 56.25%). Aphakic glaucoma was the third most common (9.19%) subtype.</p><p><b>CONCLUSIONS</b>Congenital glaucoma is the most prevalent glaucoma subtype in hospitalized pediatric patients in Beijing Tongren Hospital. The prevention and treatment of traumatic glaucoma can reduce the incidence of visual damage in developing countries. Close follow-up for glaucoma is important after pediatric cataract surgery.</p>