Jose Manuel García-Campos

Effect of WEB 2086-BS, an antagonist of platelet-activating factor receptors, on retinal vascularity in diabetic rats

Specific antagonists of platelet-activating factor (PAF) receptors inhibit platelet aggregation and thromboxane synthesis. These two processes have been implicated in the course of diabetic retinopathy. We assessed the effect of a specific PAF receptor antagonist, WEB 2086-BS (3-(4-(2-chlorophenyl)-9-methyl-6H-thieno(3,2-f) (1,2,4 triazolo-(4,3-a(1,4)-diazepine-2-yl)-1-(4-morpholinyl)-1-propanone) on retinal vascularity in a model of experimental streptozocin-induced diabetes in rats. Rats were divided into five experimental groups (10 animals/group): group I, non-diabetic group II, untreated diabetic group III, diabetic given 1 mg/kg per day of WEB 2086-BS (p.o.) group IV, diabetic given 5 mg/kg per day (p.o.) and group V, diabetic given 10 mg/kg per day (p.o.). After 3-month treatment, platelet aggregometry, platelet synthesis of thromboxane B2, aortic production of 6-keto-prostaglandin F1alpha, platelet and vascular lipid peroxidation, and percentage of the retinal area occupied by horseradish peroxidase-labeled vessels were measured. Untreated diabetic rats showed an increase in platelet reactivity, reduced 6-keto-prostaglandin F1alpha production, increased thromboxane B2 and lipid peroxides, and a decrease in the percentage of retinal area occupied by horseradish peroxidase-labeled vessels. WEB 2086-BS produced a decrease in platelet aggregation induced by collagen in whole blood, in thromboxane B2 synthesis and lipid peroxide production, and an increase in the percentage of retinal area occupied by horseradish peroxidase-labeled vessels (13.9+/-1.1% in group II and 9.9+/-0.8% in group V). There was a statistically significant linear correlation (Y= -0.72 + 137X, r2 = 0.7247, P < 0.0007) between thromboxane B2 values and the percentages of retinal area occupied by horseradish peroxidase-labeled vessels in the groups of animals treated with WEB 2086-BS.

Impression cytology of the conjunctival epithelium after antiglaucomatous treatment with latanoprost.

Purpose To study nongoblet and goblet epithelial conjunctival cells after several treatment periods with latanoprost, a prostaglandin analogue. Methods Twelve patients (20 eyes) were studied before the onset of treatment and after 1, 3, and 6 months of latanoprost use. Impression cytology was carried out to analyze cellular density and morphologic parameters such as minimum and maximum diameter and area. Results Nongoblet epithelium cell density did not change over the treatment period. The density of goblet cells increased after 1 month of use, but returned to initial cell density after longer treatment periods. Nongoblet epithelial cells underwent a significant reduction in size after 1, 3, and 6 months of treatment. In addition, the minimum/maximum diameter ratio suggested that after 1 month there were some changes in shape (a slight elongation) when compared to cells of untreated patients. Nevertheless, after longer treatment periods, the cells regained their original shape. No changes in size were observed in goblet cells, except for a slight decrease in maximum diameter after 6 months of treatment, which suggests that the cells became more rounded. Conclusions The density of nongoblet epithelial cells does not change after different treatment periods with latanoprost. However, their size decreases and after short treatment periods their shape also undergoes changes. The density of goblet cells increases after 1 month of treatment, but decreases again after longer periods. Their size does not undergo any modification, although there is a variation in shape after 6 months of treatment.

Study of the effects of ocular hypotensive drugs on number of neurons in the retinal ganglion layer in a rat experimental glaucoma

Purpose We investigated the effects of antiglaucomatous drugs on neurons in the retinal ganglion layer (RGL) in an experimental model of elevated intraocular pressure (IOP). Methods Three episcleral veins of rats with normal IOP were cauterized. Three months later, we examined the effects on the number of neurons in the RGL as well as in rats submitted to treatment with timolol, latanoprost, or brimonidine. The IOP was measured using a calibrated Tono-Pen XL tonometer before and immediately after cauterization and every 2 weeks for the following 3 months as well as immediately before perfusion. Results The IOP was 14.85±0.65 mmHg in the control group, whereas it was 1.25-fold higher (33.5±1.06 mmHg) in the experimental group. After treatment, the IOP returned to baseline levels. The mean number of neurons per mm2 in the RGL was 33% lower in the experimental group (283±10 cells/mm2) compared with the control group (423±11 cells/mm2). In the groups treated with timolol, latanoprost, or brimonidine, the neuronal loss was less (331±10, 360±15, and 333±3 cells/mm2, respectively), although values did not return to baseline levels. Conclusions This experimental model provokes an immediate, constant, and prolonged increase in IOP and the application of hypotensive agents affords a certain degree of protection to neurons in the RGL.

Experimental model of ocular hypertension in the rat: study of the optic nerve capillaries and action of hypotensive drugs.

PURPOSE To investigate quantitatively the effect of elevated intraocular pressure (IOP) on the microvasculature of the optic nerve with and without topical treatment with two hypotensive drugs, timolol and latanoprost. METHODS Three groups of rats underwent cauterization of three episcleral veins to produce elevated IOP in the right eye. Two of these groups were treated with timolol or latanoprost for 3 months. Eyeballs were incubated with anti-GLUT-1 polyclonal antibody. GLUT-1-positive capillaries of the optic nerve head (ONH) and optic nerve exit (ON) were examined and analyzed for their number per square millimeter, volume fraction, length per unit volume, surface area per unit volume, and mean diameter. RESULTS An increase in IOP resulted in a significant decrease in microvessel density in the laminar region (LR) and postlaminar region (PR) and ON compared with the control group. The other parameters fell significantly in all regions of the optic nerve. Topical treatment with timolol or latanoprost did not modify the density of the capillaries, although the other parameters increased significantly compared with the untreated experimental group. Additionally, the mean diameter of the capillaries in the LR and the PR recovered after treatment. CONCLUSIONS The results indicate that the capillaries of the LR and the PR of the ONH are the most susceptible to IOP elevation. The authors suggest that timolol and latanoprost have a certain vascular action by increasing the available blood volume, surface area per unit volume, length per unit volume, and diameter of the capillaries of the ONH in these two regions.

The Effect of Peripapillary Detachment on Retinal Nerve Fiber Layer Measurement by Spectral Domain Optical Coherence Tomography in High Myopia

Purpose: The aim of this study was to investigate the repercussions of peripapillary detachment on retinal nerve fiber layer (RNFL) measurements in patients with highly myopic eyes. Methods: A total of 244 highly myopic eyes underwent a complete ophthalmologic examination that included optical coherence tomography (OCT) to analyze the peripapillary retina and RNFL thickness. Based on the OCT findings, patients were grouped as follows: group A: eyes with a peripapillary intrachoroidal cavitation (PIC); group B: eyes with a peripapillary neurosensory retinal detachment (PNRD), and group C: eyes without a peripapillary detachment. Results: The OCT scans identified a peripapillary detachment in 42 eyes (17.21%). Out of these 42 eyes, 22 showed PIC (52.38%; group A) and 20 had a PNRD (47.62%; group B). The average overall RNFL thickness in groups A, B and C was 74.11 ± 10.88, 88.26 ± 25.72 and 72.75 ± 16.24 μm, respectively (ANOVA test, p = 0.00). Conclusion: Eyes with a PNRD had a significantly greater average RFNL thickness than those without peripapillary detachment in pathologic myopia due to a misidentification of the outer profile of the RFNL. This fact makes the interpretation of RNFL thickness in highly myopic eyes more challenging.

Analysis of peripapillary choroidal thickness in non-arteritic anterior ischaemic optic neuropathy

Purpose To analyse peripapillary choroidal thickness (PCT) in non-arteritic ischaemic optic neuropathy (NAION). Methods 28 patients diagnosed with NAION (37 affected and 19 unaffected eyes) and 38 disease-free control individuals (38 eyes) were analysed using enhanced-depth imaging of spectral-domain optical coherence tomography. A vertical and a horizontal raster scan centred on the optic nerve were obtained per eye. PCT was measured at the superior, inferior, nasal and temporal quadrants from the posterior edge of the retinal pigment epithelium to the choroid–sclera junction at 500 μm intervals up to 2000 μm away from the optic nerve. Statistical analysis was used to compare average PCT and to correlate PCT with other ocular and systemic parameters. Results Mean PCT in NAION eyes and control group was 148.18±42.68 μm and 182.90±59.81 μm, respectively (p=0.005). Except for inferior PCT (p=0.158), superior, nasal and temporal PCT were significantly thinner in the NAION eyes than in the control group (p=0.006, 0.002 and 0.046). Thinner PCT, adjusted for refractive error, was associated with the diagnosis of NAION (p=0.048). Similarly, unaffected contralateral eyes showed a significant thinner PCT compared with the control group (p=0.024). Diagnosis of NAION was negatively associated with PCT in NAION eyes (p=0.008; OR 0.98; 95% CI 0.97 to 0.99) and in their contralateral unaffected eyes (p=0.043; OR 0.98; 95% CI 0.97 to 0.99). Conclusions Eyes affected by NAION and contralateral unaffected eyes showed significantly thinner PCT compared with disease-free control eyes after adjusting for refractive error.

Molluscum contagiosum in a patient with no risk factors.

PURPOSE To report a case of molluscum contagiosum in a patient with no risk factors. METHODS A 38-year-old patient with a tumor located in the lower eyelid that appeared 5 months previously was seen in the authors hospital. The lesion had grown slowly and appeared as a crateriform mass with elevated edges. It was surgically excised and the histopathology study confirmed the diagnosis of molluscum contagiosum. Risk factors were absent. RESULTS The histopathologic study confirms the presence of eosinophilic inclusion bodies in the keratinocytes cytoplasm. CONCLUSIONS External evaluation of the lower lid lesion did not show the morphologic configuration of a molluscum contagiosum. A virus can be suspected if attention is paid to the margin of the eyelid and the patients age.

Two- and three-dimensional topographic analysis of pathologically myopic eyes with dome-shaped macula and inferior staphyloma by spectral domain optical coherence tomography

PurposeTo investigate the posterior anatomical structure of pathologically myopic eyes with dome-shaped macula and inferior staphyloma using spectral domain optical coherence tomography (SD-OCT).MethodsOur database of 260 pathologically myopic eyes was analyzed retrospectively to identify patients with dome-shaped macula and inferior staphyloma. All patients underwent vertical and horizontal SD-OCT scans across the central fovea, with three-dimensional macular map reconstruction. Best-corrected visual acuity, axial length, and choroidal thickness measurements were recorded. The macular bulge height was also analyzed in eyes with dome-shaped macula. In the three-dimensional images, the symmetry and orientation of the main plane of the inward incurvation of the macula were examined.ResultsTwenty-eight (10.7%) of the 260 pathologically myopic eyes had dome-shaped macula of one of three different types: a round radially symmetrical dome (eight eyes, 28.5%), a horizontal axially symmetrical oval-shaped dome (15 eyes, 53.5%), or a vertical axially symmetrical oval-shaped dome (five eyes, 17.8%). The macular bulge height was significantly greater in horizontal oval-shaped dome eyes (p = 0.01, for each comparison). Inferior posterior staphylomas were observed in ten (3.8%) of the 260 pathologically myopic eyes with asymmetrical macular bends.ConclusionsVertical and horizontal OCT sectional scanning in combination with three-dimensional macular map reconstruction provides important information for understanding the posterior anatomical structure of dome-shaped macula and inferior staphyloma in pathologically myopic eyes.

Análisis del grosor macular y de capa de fibras nerviosas en pacientes con esclerosis múltiple en relación con su nivel de gravedad y antecedentes previos de neuritis óptica

INTRODUCTION Quantitative assessment of macular and nerve fibre layer thickness in multiple sclerosis patients with regard to expanded disability status scale (EDSS) and presence or absence of previous optic neuritis episodes. METHODS We recruited 62 patients with multiple sclerosis (53 relapsing-remitting and 9 secondary progressive) and 12 disease-free controls. All patients underwent an ophthalmological examination, including quantitative analysis of the nerve fibre layer and macular thickness using optical coherence tomography. Patients were classified according to EDSS as A (lower than 1.5), B (between 1.5 and 3.5), and C (above 3.5). RESULTS Mean nerve fibre layer thickness in control, A, B, and C groups was 103.35±12.62, 99.04±14.35, 93.59±15.41, and 87.36±18.75μm respectively, with statistically significant differences (P<.05). In patients with no history of optic neuritis, history of episodes in the last 3 to 6 months, or history longer than 6 months, mean nerve fibre layer thickness was 99.25±13.71, 93.92±13.30 and 80.07±15.91μm respectively; differences were significant (P<.05). Mean macular thickness in control, A, B, and C groups was 220.01±12.07, 217.78±20.02, 217.68±20.77, and 219.04±24.26μm respectively. Differences were not statistically significant. CONCLUSIONS The mean retinal nerve fibre layer thickness in multiple sclerosis patients is related to the EDSS level. Patients with previous optic neuritis episodes have a thinner retinal nerve fibre layer than patients with no history of these episodes. Mean macular thickness is not correlated to EDSS level.

Macular pattern dystrophy and homonymous hemianopia in MELAS syndrome

We report an unusual association of a pattern dystrophy of the retinal pigment epithelium and homonymous hemianopia in a woman diagnosed with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes syndrome.