Factors associated with serous retinal detachment in highly myopic eyes with inferior posterior staphyloma. / Factores asociados con el desprendimiento neurosensorial macular en pacientes miopes magnos con estafiloma inferior.

PURPOSE: To investigate the factors associated with persistent serous retinal detachment in highly myopic eyes with inferior posterior staphyloma. METHODS: A total of 27 highly myopic patients (44 eyes) with an inferior posterior staphyloma were recruited. Serous retinal detachment was investigated; 13 eyes had persistent sub-macular fluid (study group), and 31 eyes lacked sub-macular fluid (control group). All patients underwent complete ophthalmologic examinations, including axial length measurement and fluorescein angiography (FA). Triton Deep Range Imaging (DRI) optical coherence tomography (OCT) (Topcon Corp., Tokyo, Japan) scans through the fovea measured choroidal thicknesses, macular bend height, and vitreoretinal interface factors. RESULTS: Of the 44 eyes, 13 had neurosensory retinal detachment and 31 did not. No significant differences were found in any of the studied variables (age, gender, spherical equivalence, axial length, vitreomacular traction, epiretinal membrane, internal limiting membrane detachment), except a higher macular bend height (p = 0.01), and a reduced macular choroidal thickness (p = 0.02), which were associated with the risk of serous retinal detachment. No statistically significant differences in best-corrected visual acuity (BCVA) were observed between the study and control groups. Serous retinal detachment always occurred at the bisected retinal pigment epithelium of the macula corresponding to the upper edge of the staphyloma, and was characterised by multiple hyperfluorescent granular patches on fluorescein angiography. CONCLUSIONS: A higher macular bend height and a reduced macular choroidal thickness may be important factors in the development of serous retinal detachment in patients with inferior posterior staphyloma.

Prospective analysis of macular and optic disc changes after non-arteritic anterior ischemic optic neuropathy.

PURPOSE: To prospectively analyse macular and optic disc changes after the occurrence of non-arteritic anterior ischemic optic neuropathy (NAION) and study possible predictors of final visual outcome. METHODS: Patients with NAION underwent a complete ophthalmic examination, including spectral-domain optical coherence tomography of the macula and optic nerve head. The examination was repeated 1, 3, 6, 9 and 12 months after onset. Final visual prognosis was evaluated by visual field (VF) and best-corrected visual acuity (BCVA) at the final visit. Data within the NAION group were analysed over the course of the disease and compared to a disease-free control group at each visit. RESULTS: Twenty-two eyes with NAION and 43 eyes from a control group were included. The retinal nerve fiber layer (RNFL) was significantly thicker in NAION eyes than controls at presentation (P=0.00), and significantly decreased during the next 3 months after presentation (P=0.02). The ganglion cell+inner plexiform layer (GCIPL) was thinner in the NAION group throughout the course of the disease (all P<0.05). Although the acute NAION eyes had significantly lower cup/disc ratios and higher neuroretinal and disc sizes (all P=0.00), there were no significant differences between groups from the third month onwards (all P>0.05). The best predictors of BCVA and VF were GCIPL at 3 months of follow-up (r2=0.32; P=0.03) and RNFL at 6 months of follow-up (r2=0.41; P=0.01) respectively. CONCLUSIONS: RNFL and optic disc changes occur during the first 3 months after the onset of NAION, whereas GCIPL is affected soon after the onset of symptoms. GCIPL and RNFL are useful predictors of final visual outcome.

Longitudinal study of visual function in patients with relapsing-remitting multiple sclerosis with and without a history of optic neuritis. / Estudio longitudinal de la función visual en pacientes con esclerosis múltiple remitente-recurrente con y sin antecedentes de neuritis óptica.

INTRODUCTION: The contrast sensitivity test determines the quality of visual function in patients with multiple sclerosis (MS). The purpose of this study is to analyse changes in visual function in patients with relapsing-remitting MS with and without a history of optic neuritis (ON). METHODS: We conducted a longitudinal study including 61 patients classified into 3 groups as follows: a) disease-free patients (control group); b) patients with MS and no history of ON; and c) patients with MS and a history of unilateral ON. All patients underwent baseline and 6-year follow-up ophthalmologic examinations, which included visual acuity and monocular and binocular Pelli-Robson contrast sensitivity tests. RESULTS: Monocular contrast sensitivity was significantly lower in MS patients with and without a history of ON than in controls both at baseline (P=.00 and P=.01, respectively) and at 6 years (P=.01 and P=.02). Patients with MS and no history of ON remained stable throughout follow-up whereas those with a history of ON displayed a significant loss of contrast sensitivity (P=.01). Visual acuity and binocular contrast sensitivity at baseline and at 6 years was significantly lower in the group of patients with a history of ON than in the control group (P=.003 and P=.002 vs P=.006 and P=.005) and the group with no history of ON (P=.04 and P=.038 vs P=.008 and P=.01). However, no significant differences were found in follow-up results (P=.1 and P=.5). CONCLUSIONS: Monocular Pelli-Robson contrast sensitivity test may be used to detect changes in visual function in patients with ON.

[Analysis of the quantitative differences in the thickness of the retinal nerve fibre layer between time-domain and spectral-domain optical coherence tomography in patients with relapsing-remitting multiple sclerosis]. / Analisis de las diferencias cuantitativas en el grosor de la capa de fibras nerviosas retiniana entre la tomografia de coherencia optica de dominio-tiempo y de dominio-espectral en pacientes con esclerosis multiple remitente recurrente.

INTRODUCTION: Optical coherence tomography (OCT) is a tool that is increasingly more commonly used in the study of neuro-degenerative diseases. AIMS: To analyse and correlate the thickness of the retinal nerve fibre layer (RNFL) by means of time-domain and spectral-domain OCT in patients with relapsing-remitting multiple sclerosis (MS), with and without a history of optic neuritis (ON). SUBJECTS AND METHODS: We conducted a cross-sectional study of the thickness (mean and by quadrants) of the RNFL of 15 disease-free subjects, 28 with MS with no prior history of ON and 18 with a history of ON. The full ophthalmologic examination included measurement of the RNFL by means of time-domain and spectral-domain tomography. RESULTS: Statistically significant differences are found between the two tomography scans on comparing the mean thickness of the RNFL of the control group (p = 0.000), the group with a history of ON (p = 0.000) and the group without ON (p = 0.000). We obtained a strong, statistically significant and directly proportional correlation between the mean thickness of the RNFL measured with the two types of tomography in the control group (rho = 0.842; p = 0.000), and the groups of eyes without ON (rho = 0.91; p = 0.000) and with ON (rho = 0.902; p = 0.000). CONCLUSIONS: There is a strong correlation between the two tomography scans in the measurement of the thickness of the RNFL in patients with MS, with and without a history of ON. Time-domain OCT quantifies greater thicknesses, and therefore both types of tomography have proven to be effective in the study of MS, although the results cannot be interchanged or extrapolated.

TITLE: Analisis de las diferencias cuantitativas en el grosor de la capa de fibras nerviosas retiniana entre la tomografia de coherencia optica de dominio-tiempo y de dominio-espectral en pacientes con esclerosis multiple remitente recurrente.Introduccion. La tomografia de coherencia optica (OCT) es una herramienta cada vez mas extendida en el estudio de las enfermedades neurodegenerativas. Objetivos. Analizar y correlacionar el grosor de la capa de fibras nerviosas retiniana (CFNR) mediante OCT de dominio-tiempo y dominio-espectral en pacientes con esclerosis multiple (EM) remitente recurrente, con y sin antecedente de neuritis optica (NO). Sujetos y metodos. Estudio transversal del grosor medio y por cuadrantes de la CFNR en 15 sujetos libres de enfermedad, 28 con EM sin historia previa de NO y 18 con antecedentes de NO. La exploracion oftalmologica completa incluia la medicion de la CFNR mediante tomografos de dominio-tiempo y dominio-espectral. Resultados. Existen diferencias estadisticamente significativas entre ambos tomografos al comparar el grosor medio de la CFNR en el grupo control (p = 0,000), el grupo con antecedentes de NO (p = 0,000) y el grupo sin NO (p = 0,000). Hemos obtenido una fuerte correlacion, estadisticamente significativa y directamente proporcional entre el grosor medio de la CFNR medido con ambos tomografos en el grupo control (rho = 0,842; p = 0,000), y los grupos de ojos sin NO (rho = 0,91; p = 0,000) y con NO (rho = 0,902; p = 0,000). Conclusiones. Existe una fuerte correlacion en la medicion del grosor de la CFNR entre ambos tomografos en pacientes con EM, con y sin antecedente de NO. La OCT de dominio-tiempo cuantifica grosores mayores, por lo que ambos tomografos se demuestran eficaces en el estudio de la EM, aunque los resultados no son intercambiables ni extrapolables.

Macular choroidal thickness in non-arteritic ischemic optic neuropathy. / Grosor coroideo macular en la neuropatía óptica isquémica anterior no arterítica.

OBJECTIVE: To analyse macular choroidal thickness (MCT) in non-arteritic ischaemic optic neuropathy (NAION). MATERIALS AND METHODS: An analysis was made on 22 patients diagnosed with NAION (22 eyes) and 42 healthy controls (42 eyes) using enhanced-depth imaging of spectral-domain optical coherence tomography. A horizontal raster scan centred on the fovea was obtained per eye 3 months after the onset of NAION. Three measurements of MCT were obtained from the posterior edge of the retinal pigment epithelium to the choroid-sclera junction at 500µm intervals. Statistical analysis was used to compare the mean MCT and to correlate MCT with other ocular and systemic parameters. RESULTS: Except for refractive error (P=.01), there were no statistically significant differences between both groups in axial length (P=.53), age (P=.88) and other epidemiological and ocular parameters. Mean MCT in NAION eyes and control group was 236.21±63.29µm and 269.13±52.28, respectively. Mean MCT was significantly thinner in NAION eyes than in healthy eyes (P=.03). Thinner MCT, adjusted for refractive error, was associated with the diagnosis of NAION (P=.04). CONCLUSIONS: Eyes affected by NAION showed significantly thinner MCT compared with healthy control eyes after adjusting for refractive error.

Analysis of macular and nerve fiber layer thickness in multiple sclerosis patients according to severity level and optic neuritis episodes. / 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.

Dexamethasone intravitreal implant for treatment of persistent macular oedema in Birdshot retinochoroidopathy.

CLINICAL CASE: The case is reported of a 32 year-old man with a bilateral cystoid macular oedema and serous macular detachment due to birdshot retinochoroidopathy. An intravitreal implant of 0.7 mg dexamethasone (Ozurdex®, Allergan) was performed on both eyes, after a partial response of the macular oedema to oral and subtenon corticosteroids. Anatomical and visual improvements were observed and maintained after six months of follow up. DISCUSSION: Intravitreal dexamethasone implant may be a good therapeutic option in patients with macular oedema due to Birdshot retinochoroidopathy, and who were refractory or had intolerance to previous therapies.

Relationship between paravascular abnormalities and foveoschisis in highly myopic patients.

PURPOSE: To describe the prevalence of paravascular abnormalities in highly myopic patients and its relationship with myopic foveoschisis (MF). METHODS: Cross-sectional study of 250 highly myopic eyes. All of the patients underwent a complete ophthalmologic examination that included optical coherence tomography . RESULTS: Optical coherence tomography images showed 170 eyes (68%) with paravascular microfolds (PM), 121 eyes (48.4%) presented paravascular retinal cysts (PC), and 35 eyes (14%) with paravascular lamellar holes . All the eyes with PCs had PMs. Out of the 250 eyes, 48 (19.2%) had paravascular retinoschisis (PR). All the eyes (100%) with PR had paravascular cysts and PMs. Sixteen eyes (6.4%) had foveoschis. The spherical equivalent (P<0.00), PR (P=0.01), and the presence of tractional structures (P<0.00) were associated with increased risk for foveoschsis in the multivariate study. CONCLUSIONS: PMs were the lesions most often observed in the paravascular area in highly myopic eyes. MF would be a result of the action of different forces (intra- and extra-ocular forces), specially tractional structures, on precursor lesions (paravascular cyst and paravascular restinoschisis). Further studies are needed to confirm these results.

[Multiple retinal pigment epithelial detachments: a case report]. / Múltiples desprendimientos de epitelio pigmentario idiopático: a propósito de un caso.

CASE REPORT: A 47 year-old female who presented with a bilateral idiopathic multiple pigment epithelial detachment (PED) in a routine visit. This pathology is shown as a rare clinical manifestation, where the outcome is resolution of localized atrophy of the pigment epithelium, with a good functional prognosis. DISCUSSION: PED is a common clinical manifestation in several chorioretinal diseases, particularly in macular degeneration associated with age. Idiopathic PED can be considered as a kind of central type II serous chorioretinopathy. Fundus fluorescein angiography (FFA) and optical coherence tomography (OCT) are complementary tests to study the number, extension, and nature of these PED.

[Bevacizumab treatment for acquired vitelliform detachment in patient with cuticular drusen]. / Desprendimiento viteliforme adquirido en paciente con drusas cuticulares tratado con bevacizumab.

CASE REPORT: We report a case of a 30-year-old male with acquired vitelliform detachment (AVD) secondary to cuticular drusen and suffering from metamorphopsia in his right eye. Intravitreal bevacizumab (Avastin) was administered, achieving successful results. DISCUSSION: An independent disease, of unknown genetic phenotype, caused by a generalized dysfunction of the retinal pigment epithelium (RPE). About 50% of patients develop AVD, and a correct diagnosis can be made with the help of new complementary tests. With no effective treatment currently available, and because of the incidence of developing choroidal neovascularization (NVC), treatment with anti-VEGF could help stabilize or improve the disease functionally and/or anatomically.

[Von Hippel-Lindau disease: family study]. / Enfermedad de Von Hippel Lindau: estudio familiar.

CASE REPORT: The case of 5 members of a family who suffer from Von Hippel-Lindau disease (VHL) is presented. It is shown that retinal capillary hemangioma was the main ophthalmic symptom, with hemovitreous and tractional retinal detachment as the main complications. DISCUSSION: VHL disease is rare, but very serious, even fatal, thus it is important to obtain an early diagnosis by ophthalmoscopy, in order to change the visual prognosis and life expectancy, not only for the patient, but also for the family.

[Choroidal neovascularization secondary to pseudoxanthoma elasticum treated with ranibizumab: a report of 2 cases]. / Neovascularización coroidea secundaria a seudoxantoma elástico tratada con ranibizumab: a propósito de dos casos.

CASE REPORT: We report 2 cases of pseudoxanthoma elasticum with angioid streaks and choroidal neovascularization (CNV) in both eyes. Intravitreal ranibizumab (Lucentis) was administered with successful results in both cases. DISCUSSION: CNV has been reported to occur in 72% to 86% of patients with angioid streaks. Although uncommon, the impact of CNV is important because it tends to affect people of working age. Based on the effectiveness of ranibizumab in other secondary CNVs, we decided to use it in our patients, observing the functional and anatomical improvement.

[From scientific evidence to clinical practice: treatment protocols for diabetic macular edema]. / De la evidencia científica a la práctica clínica: pautas de tratamiento del edema macular diabético.

Diabetic macular edema (DME) is now considered the leading cause of moderate vision loss in type 2 diabetic patients and has a high socioeconomic burden. In recent years, the therapeutic approach to this entity has changed. The role of laser treatment, considered the gold standard in clinical practice worldwide for more than 25 years, has been redefined. To understand current treatment algorithms, the pathophysiology of diabetic macular edema and the role played by vascular endothelial growth factor must be elucidated. Many clinical trials have emerged showing that intravitreal ranibizumab provides effective therapy with an acceptable safety profile. Based in these data, the European Medicines Agency has approved ranibizumab for the treatment of diabetic macular edema. This article aims to discuss new treatment options and the recently developed evidence-based algorithms.

[Retinal autofluorescence imaging in patients with pseudoxanthoma elasticum]. / Imágenes funduscópicas con autofluorescencia en pacientes con pseudoxantoma elástico.

PURPOSE: To evaluate the autofluorescence findings in patients diagnosed with pseudoxanthoma elasticum. MATERIAL AND METHODS: A prospective study was conducted on 18 eyes of 9 patients who had ocular pathology andfollowed up in the pseudoxanthoma elasticum (PSX) unit of our hospital. We evaluated the best corrected visual acuity (BCVA), colour and autofluorescence photography (AF), and fluorescein angiography (FA) in patients with choroidal neovascularitation. RESULTS: Of the 9 patients, 7 were women and 2 were men. The mean age was 40 +/- 14 years. The BCVA ranged from 1 to 0.01 (Mean 0.65 +/- 0.4). All patients showed PSX injuries. Angioid streaks (AS) 18 (100%), peau d'orange 16 (87.5%) and pigmented fibrotic plates 5 (31,5%). We observed different hypoautofluorescence patterns (RPE atrophy), of which 2 of them were AS patterns (irregular lines with hyperautofluorescence speckled in its interior and edges, or bands with lobulated lesions inside and hyperautofluorescence at the edges), and finally widespread areas of hypoautofluorescence, larger than observed by ophthalmoscope. CONCLUSIONS: Autofluorescence in patients with PSX is an easy method to evaluate the initial level of ophthalmoscopic involvement and its subsequent progression. The extensive changes in the retinal pigment epithelium (RPE) suggests the important role of this in the physiopathology of the disease.

[Relationship between central corneal thickness, intraocular pressure and severity of glaucomatous visual field loss]. / Correlación entre grosor corneal central, presión intraocular y afectación glaucomatosa del campo visual.

OBJECTIVE: to determine central corneal thickness in normal subjects, glaucomatous patients and ocular hypertension patients, to evaluate if the central corneal thickness is related to the presence of glaucoma or ocular hypertension. Furthermore, we aim to verify the relationship between central corneal thickness and severity of glaucomatous visual field loss. METHODS: comparative study including 150 eyes of 150 subjects, separated into three groups: normal (47 eyes), ocular hypertension (35) and glaucomatous (68). This last group was subdividided in three subgroups depending on the Hodapp-Parrish-Anderson criteria for scoring Humphrey visual field defects (initial, moderate and advanced). We evaluated the visual field, the central corneal thickness measured by pachymetry and the intraocular pressure measured by Goldmann tonometry. Results were analysed using the Student's t-test for normally distributed independent samples. RESULTS: the central corneal thickness was 526+/-25 microns (mean +/-standard deviation (SD)) in glaucomatous patients, 560+/-27 microns in ocular hypertension patients, and 556+/-27 microns in the normal group. Statistical significance could be found between the glaucomatous group of patients and the other groups (p< 0.01), but not between the ocular hypertension group and normal subjects (p= 0.4). The comparison between central corneal thickness of the subgroup with advanced damage of the visual field and the two other subgroups was also statistically significant (p< 0.01), but not between the subgroups of initial damage and moderate damage (p= 0.7). CONCLUSIONS: the central corneal thickness in glaucomatous patients is lower than in normal subjects and in ocular hypertension patients. Patients classified as having advanced damage in their visual field have significantly lower central corneal thickness measurements than patients classified as having initial or moderate damage.

[Use of optical coherence tomography to study variations of normal parameters with age]. / Estudio de parámetros de normalidad en relación a la edad con el tomógrafo óptico de coherencia.

PURPOSE: To determine by Optical Coherence Tomography (OCT) the variation of a variety of measurable parameters (macular thickness, retinal parapapillary fiber layer thickness and optic disc morphology) with age. METHOD: We carried out OCT in 40 normal subjects (80 eyes) aged between 20 and 60 years, divided into 4 groups according to the age decades. RESULTS: Statistically significant differences were found in the macular thickness in the comparative study groups but the differences varied according to the sector assessed; the superior outer sector (p=0.00), temporal outer sector (p=0.01), temporal inner sector (p=0.04), nasal inner sector (p=0.03) and inferior inner sector (p=0.00). In the study of retinal parapapillary fiber layer thickness, statistically significant differences were found between groups in the inferior sector only (p=0.04). No statistically significant differences were found between groups in the study of optic disc morphology. CONCLUSIONS: Both the macular thickness and the nerve fiber layer in the inferior sector decrease with age. These differences in thickness are statistically significant between the extremes of age decades.

[Retinal pigment epithelial atrophic tracks secondary to central serous pigment epitheliopathy]. / Epiteliopatía en reguero.

PURPOSE AND METHODS: We report the cases of three patients with retinal pigment epithelial atrophic tracks secondary to central serous pigment epitheliopathy specially focusing on fluorescein angiographic findings. This entity is considered an atipical manifestation of central serous chorioretinopathy called chronic diffuse retinal pigment epitheliopathy. RESULTS AND CONCLUSIONS: We have studied 69 patients with the diagnose of central serous pigment epiteliopathy in our unit; 10.14% manifested diffuse retinal pigment epitheliopathy and 5.79% showed retinal pigment epithelial atrophic tracks. Both eyes were involved in 100% and all of them were males with a median age of 53.33 years. We can conclude that this entity usually affects adult males and it is frequently bilateral.

[Study on hypotensive effect of latanoprost vs timolol-dorzolamide association]. / Estudio del efecto hipotensor del latanoprost frente a la asociación timolol-dorzolamida.

PURPOSE: To compare hypotensive effect of latanoprost versus timolol-dorzolamide association on patients with glaucoma. MATERIAL AND METHOD: We studied 102 eyes in 52 patients with intraocular pressure (IOP) higher than 21 mmHg, previously treated with a betablocker. Patients were divided in two groups. Treatment was changed on group 1 (51 eyes in 27 patients) to a timolol-dorzolamide association. Group 2 (51 eyes in 27 patients) changed treatment to latanoprost. After determination of previous IOP, readings were taken at 1, 3 and 8 months later. RESULTS: Both groups showed a decrease in IOP levels: Group 1, 5.6 mmHg and Group 2, 8.5 mmHg. Association between timolol and dorzolamide reached the highest hypotensive effect after the first month of treatment and remained constant during the rest of the study period. Latanoprost showed a maximal effect after the third month of treatment and maintained its effect all through the study as well. Latanoprost behaved similar to associated timolol-dorzolamide not showing significant differences during the first month of treatment. Significant differences appeared at third and eighth month favoring latanoprost (p<0.005 and p<0.001 respectively). CONCLUSION: There was a similarity in efficacy of both treatments. However, after the third month latanoprost became more effective than the timolol-dorzolamide association.

[Study of subretinal neovascular membranes secondary to degenerative myopia]. / Estudio de membranas neovasculares subretinianas secundarias a miopía degenerativa.

PURPOSE: To study the type, size, location and posterior time evolution of the subretinal neovascular membranes (SRNM) secondary to degenerative myopia (DM) and its relationship with the degree of myopic ametropia. METHODS: We studied 65 patients (130 eyes) with MD who were divided into three groups according to their refraction. A complete ophthalmologic examination, including a fluorescein angiography (FAG), was performed for all the patients. Based on this test, 55 SRNA were identified, and were classified into two types according to the fluorescein angiography results. Their position was described in relationship to the foveal avascular zone (FAZ) and their size was measured. RESULTS: 55 (42.3%) of the 130 eyes presented SRNM, which was bilateral in 16.32% of the patients. Based on the FAG criteria, 41 eyes (74.54%) presented type 1 SRNM, 60% (33 eyes) presented subfoveal membranes and the size was greater than 1,500 microns in more than 75%. The development of the SRNM showed no relationship with the myopic ametropia degree (P<0.2500). The follow-up time was 24.61+/-7.63. CONCLUSIONS: No relationship between the appearance of the development of the SRNM and the myopia degree has been found. These are generally small sized, have poor dye diffusion and are frequently located in the foveal zone. The visual acuity loss is often sudden and maintained over time.

Effect of aspirin plus dipyridamole on the retinal vascular pattern in experimental diabetes mellitus.

Platelet hyperactivity has been one of the mechanisms implicated in the pathogenesis of diabetic retinopathy. Antiplatelet agents have been shown, in experimental models, to prevent the development of retinal vascular abnormalities when given from the first day after the onset of diabetes. We assessed the effect of aspirin plus dipyridamole (6 + 12 mg/kg daily) on the retinal vascular pattern in experimental streptozotocin-induced diabetes in rats, when the treatment was given at different intervals after the induction of diabetes, over a 3-month study period. Saline-pretreated diabetic rats showed a time-dependent increases in the platelet production of thromboxane B2 (r = 0.981, P < .0001) and a decrease in the aortic production of 6-keto-PGF1 alpha. The percentage of retinal area occupied by horseradish peroxidase-labeled vessels decreased progressively in relation to the length of time of the evolution of diabetes (r = 0.983, P < .00001) and the thromboxane/prostacyclin ratio. Treatment with aspirin plus dipyridamole caused an inhibition of the platelet production of thromboxane B2 and a decrease in the vascular synthesis of prostacyclin. Treatment with antiplatelet agents slowed down the decrease in the percentage of retinal area occupied by horseradish peroxidase-labeled vessels. These data provide further evidence to support the results of previous clinical trials in which antiplatelet agents had a beneficial effect on the evolution of retinal lesions in early diabetic retinopathy.