Quejas visuales durante la pandemia de COVID-19 en España y Portugal / Visual complaints during the COVID-19 pandemic in Spain and Portugal

Objetivo Este estudio reporta los hábitos de la población y las quejas oculares relacionadas con la salud visual en el contexto de la pandemia de COVID-19 a partir de visitas realizadas durante 2021 en España y en Portugal. Material y métodos Invitación por correo electrónico a una encuesta transversal online y también realizada en persona a pacientes de clínicas de oftalmología de España y de Portugal de septiembre a noviembre de 2021. Participaron 3.833 encuestados mayores de 18años con respuestas anónimas válidas. Resultados El 60% de los encuestados explicó mucha incomodidad causada por el aumento de los síntomas de ojo seco debido al trabajo digital más intenso y el empañamiento de los lentes al usar mascarillas. El 81,6% de los encuestados usaba dispositivos digitales al menos 3horas en promedio por día, y el 40% comenzó a usar dispositivos digitales más de 8horas en promedio por día. Además, el 44% de los encuestados sintió que su visión de cerca había empeorado en este período. El primer síntoma importante de la presbicia estaba relacionado con la dificultad para leer las letras más pequeñas de los paquetes. El 86% presentó los primeros síntomas a los 40años. Las ametropías más frecuentes identificadas fueron miopía (40,2%) y astigmatismo (36,7%). Para los padres, tener buena vista (87,2%) era el aspecto más valorado en la vida de sus hijos. Conclusiones Los hallazgos brindan una idea de los desafíos durante la COVID-19 para las prácticas oftalmológicas. En una sociedad altamente dependiente de la visión, es fundamental centrarse en los signos y los síntomas que conducen a afecciones oftalmológicas. El uso excesivo de dispositivos digitales y el uso de mascarillas durante esta pandemia han agravado algunos, señalando la importancia de la referencia para planificar una atención ocular eficiente en situaciones similares (AU)

Purpose This study reports visual health during the COVID-19 pandemic in 2021 in Spain and Portugal, focusing on eye complaints and population habits. Material and methods Cross-sectional survey through an online email invitation to patients attending ophthalmology clinics in Spain and Portugal from September to November 2021. Around 3833 participants offered valid anonymous responses in a questionnaire. Results Sixty percent of respondents identified significant discomfort related to dry eye symptoms for increased screen time and lens fogging using facemasks. 81.6% of the participants used digital devices for more than 3h per day and 40% for more than 8h. In addition, 44% of participants referred to worsening near vision. The most frequent ametropias were myopia (40.2%) and astigmatism (36.7%). Parents considered eyesight the most important aspect of their children (87.2%). Conclusions The results show the challenges for eye practices during the initial COVID-19 pandemic. Focusing on signs and symptoms that lead to ophthalmologic conditions is an essential concern, especially in our digital society highly dependent on vision. At the same time, the excessive use of digital devices during this pandemic has aggravated dry eye and myopia (AU)

[Visual complaints during the COVID-19 pandemic in Spain and Portugal]. / Quejas visuales durante la pandemia de COVID-19 en España y Portugal.

Purpose: This study reports visual health during the COVID-19 pandemic in 2021 in Spain and Portugal, focusing on eye complaints and population habits. Material and methods: Cross-sectional survey through an online email invitation to patients attending ophthalmology clinics in Spain and Portugal from September to November 2021. Around 3833 participants offered valid anonymous responses in a questionnaire. Results: Sixty percent of respondents identified significant discomfort related to dry eye symptoms for increased screen time and lens fogging using facemasks. 81.6% of the participants used digital devices for more than 3 h per day and 40% for more than 8 h. In addition, 44% of participants referred to worsening near vision. The most frequent ametropias were myopia (40.2%) and astigmatism (36.7%). Parents considered eyesight the most important aspect of their children (87.2%). Conclusions: The results show the challenges for eye practices during the initial COVID-19 pandemic. Focusing on signs and symptoms that lead to ophthalmologic conditions is an essential concern, especially in our digital society highly dependent on vision. At the same time, the excessive use of digital devices during this pandemic has aggravated dry eye and myopia.

Visual complaints during the COVID-19 pandemic in Spain and Portugal.

PURPOSE: This study reports visual health during the COVID-19 pandemic in 2021 in Spain and Portugal, focusing on eye complaints and population habits. MATERIAL AND METHODS: Cross-sectional survey through an online email invitation to patients attending ophthalmology clinics in Spain and Portugal from September to November 2021. Around 3833 participants offered valid anonymous responses in a questionnaire. RESULTS: Sixty percent of respondents identified significant discomfort related to dry eye symptoms for increased screen time and lens fogging using facemasks. 81.6% of the participants used digital devices for more than 3 h per day and 40% for more than 8 h. In addition, 44% of participants referred to worsening near vision. The most frequent ametropias were myopia (40.2%) and astigmatism (36.7%). Parents considered eyesight the most important aspect of their children (87.2%). CONCLUSIONS: The results show the challenges for eye practices during the initial COVID-19 pandemic. Focusing on signs and symptoms that lead to ophthalmologic conditions is an essential concern, especially in our digital society highly dependent on vision. At the same time, the excessive use of digital devices during this pandemic has aggravated dry eye and myopia.

Assessment of Corneal Epithelial Thickness in Asymmetric Keratoconic Eyes and Normal Eyes Using Fourier Domain Optical Coherence Tomography.

Purpose. To compare the characteristics of asymmetric keratoconic eyes and normal eyes by Fourier domain optical coherence tomography (OCT) corneal mapping. Methods. Retrospective corneal and epithelial thickness OCT data for 74 patients were compared in three groups of eyes: keratoconic (n = 22) and normal fellow eyes (n = 22) in patients with asymmetric keratoconus and normal eyes (n = 104) in healthy subjects. Areas under the curve (AUC) of receiver operator characteristic (ROC) curves for each variable were compared across groups to indicate their discrimination capacity. Results. Three variables were found to differ significantly between fellow eyes and normal eyes (all p < 0.05): minimum corneal thickness, thinnest corneal point, and central corneal thickness. These variables combined showed a high discrimination power to differentiate fellow eyes from normal eyes indicated by an AUC of 0.840 (95% CI: 0.762-0.918). Conclusions. Our findings indicate that topographically normal fellow eyes in patients with very asymmetric keratoconus differ from the eyes of healthy individuals in terms of their corneal epithelial and pachymetry maps. This type of information could be useful for an early diagnosis of keratoconus in topographically normal eyes.

Sistemas genéticos para un nuevo abordaje del riesgo de progresión de la retinopatía diabética / Genetic systems for a new approach to risk of progression of diabetic retinopathy

OBJETIVO: Evaluar el riesgo de progresión de la retinopatía diabética (RD) utilizando nuevas estrategias para obtener información genética en diabéticos tipo 2 (DT2) basadas en interferencia por ácido ribonucleico (ARN). MATERIAL Y MÉTODOS: Estudio multicéntrico, prospectivo de casos-controles en 132 participantes divididos en: grupo DT2 (GDT2) con RD (+RD) y sin RD (-RD) (n = 77) y grupo control (GC) (n = 55). Tras entrevista personal y examen oftalmológico, se extrajeron lágrimas para análisis molecular (expresión de micro-ARN [miARN] [miRCURY™ ARN Isolation Kit, Qiagen]). En 18 muestras (GDT2+RD = 6; GDT2-RD = 6; GC = 6) obtuvimos librerías de 137 vs. 140 pares de bases (GeneMapper, Applied Biosystems) y realizamos secuenciación de próxima generación (NGS). El programa SPSS 15.0 vehiculizó el análisis estadístico. RESULTADOS: Edad media: 67 ± 12 años en GDT2 vs. 55 ± 21 años en GC. Distribución hombres/mujeres: 51/28 en GDT2 vs. 25/30 en GC. Los antecedentes familiares de DM, cumplir dieta, fumar, beber y realizar ejercicio mostraron diferencias significativas entre grupos (p < 0,001). Con 20-25 μL de lágrimas extrajimos 9,42 ± 3,30 ng/mL de ARN purificado, con diferencias significativas entre GDT2/GC (p = 0,002) y GDT2+RD/GC (p = 0,004). La expresión lagrimal de miARN en GDT2 correlacionó directamente con: edad/obesidad/duración de DM (p < 0,05), e indirectamente con: agudeza visual (p < 0,05). Hemos identificado 14 miARN relacionados con la presencia, mecanismos patogénicos y factores de riesgo para la progresión de la RD. CONCLUSIONES: Proponemos utilizar lágrimas como fuente de información genética para la DM. Los miARN específicos implicados en desarrollo o progresión de la RD pueden utilizarse como biomarcadores moleculares y, a partir de ellos, desarrollar futuras bioterapias

OBJECTIVE: To evaluate the risk of progression of diabetic retinopathy (DR) using new strategies to obtain genetic information in type 2 diabetes (T2D) based on interfering ribonucleic acid (RNA). MATERIAL AND METHODS: A prospective multicentre case-control study of 132 participants was distributed into: T2D with (+DR) or without (-DR) (T2DG; n = 77), and a control group (CG; n = 55). After an eye examination and personal interview, tears were collected for molecular analysis (expression of microRNAs [miRNAs] (miRCURY(TM) ARN Isolation Kit, Qiagen)]. Libraries, 137 vs. 140 bp (GeneMapper, Applied Biosystems), were obtained in 18 samples (T2DG+DR = 6; T2DG-DR = 6; CG = 6) by performing next-generation sequencing (NGS). SPSS 15.0 statistical program was used to perform data analysis. RESULTS: The mean age was 67 ± 12 years in the T2DG vs. 55 ± 21 years in the CG. Distribution men/women: 25/30 in T2DG vs. 51/28 in CG. A family history of DM, diet compliance, smoking, drinking and exercise, showed significant differences between groups (P<.001). A 20-25 microlitre sample of tears contained a mean of 9.42 ± 3.30 ng/mL of purified ARN, with significant differences between T2DG/CG (P=.002) and T2DG+RD/CG (P=.004). Tear expression of miARNs in T2DG directly correlated with age/obesity/T2D duration (P<.05), and indirectly with visual acuity (P<.05). A total of 14 miRNAs related to the presence, pathogenic mechanisms and risk factors for the progression of diabetic retinopathy, were identified. CONCLUSIONS: We propose to use tears as a source of genetic information for DM. Specific miRNAs involved in DR development and/or progression can be used as molecular biomarkers, and based on these, for developing future biotherapies

Genetic systems for a new approach to risk of progression of diabetic retinopathy. / Sistemas genéticos para un nuevo abordaje del riesgo de progresión de la retinopatía diabética.

OBJECTIVE: To evaluate the risk of progression of diabetic retinopathy (DR) using new strategies to obtain genetic information in type 2 diabetes (T2D) based on interfering ribonucleic acid (RNA). MATERIAL AND METHODS: A prospective multicentre case-control study of 132 participants was distributed into: T2D with (+DR) or without (-DR) (T2DG; n=77), and a control group (CG; n=55). After an eye examination and personal interview, tears were collected for molecular analysis (expression of microRNAs [miRNAs] (miRCURY ™ ARN Isolation Kit, Qiagen)]. Libraries, 137 vs. 140bp (GeneMapper, Applied Biosystems), were obtained in 18 samples (T2DG+DR=6; T2DG-DR=6; CG=6) by performing next-generation sequencing (NGS). SPSS 15.0 statistical program was used to perform data analysis. RESULTS: The mean age was 67±12 years in the T2DG vs. 55±21 years in the CG. Distribution men/women: 25/30 in T2DG vs. 51/28 in CG. A family history of DM, diet compliance, smoking, drinking and exercise, showed significant differences between groups (P<.001). A 20-25 microlitre sample of tears contained a mean of 9.42±3.30 ng/mL of purified ARN, with significant differences between T2DG/CG (P=.002) and T2DG+RD/CG (P=.004). Tear expression of miARNs in T2DG directly correlated with age/obesity/T2D duration (P<.05), and indirectly with visual acuity (P<.05). A total of 14 miRNAs related to the presence, pathogenic mechanisms and risk factors for the progression of diabetic retinopathy, were identified. CONCLUSIONS: We propose to use tears as a source of genetic information for DM. Specific miRNAs involved in DR development and/or progression can be used as molecular biomarkers, and based on these, for developing future biotherapies.

Propiedades biomecánicas de la cornea con corvis ST y ocular response analyser después de diferentes procedimientos quirúrgicos en pacientes con queratocono / Corneal biomechanical properties with corvis ST and ocular response analyser in eyes with keratoconus which were submitted to different surgical procedures

Introducción. Las opciones quirúrgicas disponibles para el tratamiento del queratocono (QC) se han ampliado y mejorado. Nuestro objetivo es comparar las propiedades biomecánicas de la córnea con dos instrumentos de uso clínico en ojos con QC sin cirugía o intervenidos con diferentes tipos de cirugía corneal (cross-linking (CXL), segmentos intra-corneales (ICSR) y queratoplastia penetrante(QP)). Material e Métodos. Se analizaron 91 ojos de paciente con KC no operados, 22 ojos con ICSR, 16 ojos con QP y 6 ojos con CXL. Se analizó el espesor corneal central (ECC), presión intra-ocular y los parámetros obtenidos con ORA (clásicos, y análisis de señal) y Corvis. Resultados. Tanto los valores de presión intra-ocular (PIO) obtenidos directamente con ORA y Corvis como los valores de PIO corregidos por el ORA (PIOcc) fueron significativamente diferentes entre los distintos grupos. Hasta 9 de los parámetros resultantes del análisis de señal de medida del ORA (p1area, p2area, h2, dive2, path1, aplhf, p1area1, p2area1 y w11) mostraron diferencias estadísticamente significativas entre los grupos. En cuanto al Corvis, A1 Time, A2 Time y Peak Distance fueron significativamente diferentes entre los grupos considerados. Conclusiones. Las nuevas tecnologías de evaluación y análisis de datos de la respuesta biomecánica de la cornea permiten cuantificar y diferenciar el comportamiento biomecánico tras diferentes tipos de cirugía para la estabilización, regularización o substitución corneal en pacientes con queratocono (AU)

Background. Surgical options for the treatment of keratoconus (KC) have been expanded and improved. Our goal is to evaluate the changes in biomechanical properties of the cornea measured with two instruments for clinical use in KC eyes not operated or which undergoing different surgical procedures (cross-linking (CXL), intra-corneal ring segment (ICSR) and penetrating keratoplasty (QP)). Material and methods. The population consisted of 91 eyes with KC not operated, 22 eyes that underwent ICRS implant, 16 eyes that were submitted to PK and 6 eyes that underwent CXL. We analyzed corneal thickness, intraocular pressure and the parameters obtained with ORA (classic and signal analysis) and Corvis. Results. Both the values of intraocular pressure (IOP) obtained directly from ORA and Corvis, as IOP values corrected by the ORA (IOPcc) were significantly different between groups. For 9 of the parameters resulting from ORA analysis of signal (p1area, p2area, h2, Dive2, path1, aplhf, p1area1, p2area1 and w11) showed statistically significant differences between groups. Regarding Corvis, A1 Time, A2 Time and Peak Distance were significantly different between the groups. Conclusions. The new technology assessment and analysis of the biomechanical response of the cornea to quantify and differentiate the biomechanical behavior after different types of surgery for stabilization, regularization or corneal replacement in patients with keratoconus (AU)

[Circumferential viscocanalostomy with suture tensioning in Schlemm canal (canaloplasty)-one year experience]. / Viscocanalostomía circunferencial con sutura de tensión en el canal de Schlemm (canaloplastia): un año de experiencia.

PURPOSE: To study the efficacy and the safety of ultrasound biomicroscopy assisted canaloplasty in the treatment of open-angle glaucoma (OAG) METHODS: A prospective study of uncontrolled open-angle glaucoma patients, or patients with cataracts associated with controlled or uncontrolled OAG under maximal medical therapy who had been subjected to canaloplasty alone or combined with cataract surgery, respectively. Complications, Goldmann intraocular pressure (IOP) and mean number of drugs (ND) were evaluated at 1 day, 1 week, 1 month, and every 3 months. RESULTS: Thirty five surgeries were performed (11 canaloplasties, 24 phaco-canaloplasties). The mean IOP (mmHg) dropped from 24.5±5.1, in canaloplasty, and from 19.8±6.4, in phacocanaloplasty, preoperatively, to medium-low levels at all follow-up periods (13.5±1.0 and 11.0±4.2, at 1 year in canaloplasty and phaco-canaloplasty, respectively). The number of grugs used dropped from 3.3±0.5 before surgery to less than of 1 in all follow-up periods (0.5±0.8 at 1 year). The complications were 2 microruptures of the trabeculodescemetic window, 5 entries in the collector channels, 5 choroidal space/anterior chamber passages, 10 hyphemas, 3 hypotonies, one peripheral Descemet detachment, one intracorneal hematoma, two peripheral anterior synechia, one internal iris prolapse, and two suture extrusions to the anterior chamber. CONCLUSIONS: Ultrasound biomicroscopy assisted Canaloplasty, alone or combined, provided a sustained IOP reduction to medium-low levels, led to a decrease in the number of drugs and had a good safety profile, making this a good alternative to trabeculectomy.

Viscocanalostomía circunferencial con sutura de tensión en el canal de Schlemm (canaloplastia): un año de experiencia / Circumferential viscocanalostomy with suture tensioning in Schlemm canal (canaloplasty)–one year experience

Propósito: Estudiar la eficacia y la seguridad de la canaloplastia asistida por biomicroscopia ultrasónica en el tratamiento de glaucoma de ángulo abierto Métodos: Estudio prospectivo de pacientes con glaucoma de ángulo abierto no controlado o pacientes con catarata asociada a glaucoma descontrolado o controlado con tratamiento médico máximo, sometidos a canaloplastia simple o combinada. Fueron evaluados las complicaciones, la presión intraocular Goldmann (PIO) y el número medio de fármacos (NMF) en primer día, primera semana, primer mes y de 3 en 3 meses. Resultados: Se realizaron 35 cirugías (11 canaloplastias, 24 facocanaloplastias). La PIO media (mmHg) disminuyó de 24,5 ± 1,0 en canaloplastia y de 19,8 ± 6,8 en facocanaloplastia, en el preoperatorio, a niveles medio-bajos en todos los periodos de seguimiento (13,5 ± 1,0 y 11,0 ± 4,2, al año, en canaloplastia y facocanaloplastia, respectivamente). El NMF ha bajado de 3,3 ± 0,5 antes de la cirugía para niveles menores que uno en todos los tiempos de seguimiento (0,5 ± 0,8, al año). Como complicaciones se obtuvieron 2 microrroturas de la ventana trabeculodescemética, 5 entradas en los colectores, 5 trayectos coroideo/cámara anterior, 10 hipemas, 3 hipotonías, un desgarro periférico de la Descemet, un hematoma intracorneano, 2 sinequias anteriores periféricas, un prolapso interno de iris y 2 extrusiones de la sutura a la cámara anterior. Conclusiones: La canaloplastia asistida por biomicroscopia ultrasónica simple o combinada obtuvo reducciones sustentadas de la PIO para niveles medio-bajos así como en el NMF y con un buen perfil de seguridad, lo que la hacen una buena alternativa a la trabeculectomía (AU)

Purpose: To study the efficacy and the safety of ultrasound biomicroscopy assisted canaloplasty in the treatment of open-angle glaucoma (OAG). Methods: A prospective study of uncontrolled open-angle glaucoma patients, or patients with cataracts associated with controlled or uncontrolled OAG under maximal medical therapy who had been subjected to canaloplasty alone or combined with cataract surgery, respectively. Complications, Goldmann intraocular pressure (IOP) and mean number of drugs (ND) were evaluated at 1 day, 1 week, 1 month, and every 3 months. Results: Thirty five surgeries were performed (11 canaloplasties, 24 phaco-canaloplasties). The mean IOP (mmHg) dropped from 24.5 ± 5.1, in canaloplasty, and from 19.8 ± 6.4, in phacocanaloplasty, preoperatively, to medium-low levels at all follow-up periods (13.5 ± 1.0 and 11.0 ± 4.2, at 1 year in canaloplasty and phaco-canaloplasty, respectively). The number of grugs used dropped from 3.3 ± 0.5 before surgery to less than of 1 in all follow-up periods (0.5 ± 0.8 at 1 year). The complications were 2 microruptures of the trabeculodescemetic window, 5 entries in the collector channels, 5 choroidal space/anterior chamber passages, 10 hyphemas, 3 hypotonies, one peripheral Descemet detachment, one intracorneal hematoma, two peripheral anterior synechia, one internal iris prolapse, and two suture extrusions to the anterior chamber. Conclusions: Ultrasound biomicroscopy assisted Canaloplasty, alone or combined, provided a sustained IOP reduction to medium-low levels, led to a decrease in the number of drugs and had a good safety profile, making this a good alternative to trabeculectomy (AU)

Evaluation of a new scleral fixation foldable IOL in the absence of capsule support.

PURPOSE: The purpose of this study was to compare a new scleral fixation foldable intraocular lens (IOL), the Ophtec PC 425Y 6/13.5, with the scleral fixation rigid IOL Alcon CZ 70 BD, as regards efficacy, surgical complications, advantages, disadvantages, and surgery costs in cases with no capsule support. MATERIAL AND METHODS: This was a retrospective study conducted on 24 patients (24 eyes), 14 of whom had traumatic cataract, six had postphacoemulsification complications, two were aphakic, and two had lens luxation. The patients were divided into two groups: group l, scleral fixation foldable IOL, and group ll, scleral fixation rigid IOL, made up of 12 patients each, during a study period lasting 20 months. The procedures were performed under topical plus subconjunctival anesthesia in group l, under general anesthesia in group ll, all by the same surgeon. The IOL scleral fixation technique used in both groups was the scleral incision technique. RESULTS: The mean age of group I patients was 57.8 years (range, 24-75 years), and in group II patients 50.3 years (range, 7-75 years). The average duration of the surgical intervention was significantly lower in the group I: 32.5 min (+/-0.19) versus 43.4 min (+/-0.4.2) in the group II (p<0,001). The incision required for the Ophtec PC 425Y 6/13.5 foldable intraocular lens was less than half the length needed for the other rigid intraocular lens (3.2 mm versus 7.0 mm). In group I, the patients reported no discomfort intraoperatively or postoperatively, and none required intravenous sedation. The mean duration of the convalescence period showed a statistically significant difference between the two groups: 3.8 (+/-0.45) weeks for group I and 12.5 (+/-0.90) weeks for group II (p<0.001). Group I achieved a Best optical Correction Visual Acuity (BCVA) of 0.57 (+/-0.17) at the 1st week postoperatively, whereas group II achieved a BCVA of 0.44 (+/-0.19). The difference was statistically significant (p<0.05). In the 1st postoperative month, group I presented a mean postoperative astigmatism of -0.88 D (+/-0.42) and group II presented a mean postoperative astigmatism of -2.42 D (+/-0.60). The difference was statistically significant (p<0.05). CONCLUSION: In this study, the scleral fixation of the foldable IOL Ophtec PC 425Y 6/13.5 with the scleral incision technique took less time, needed a smaller incision and provided a better visual outcome, suggesting that this could be the alternative to the conventional scleral fixation rigid IOL.

Morphological and biochemical assessment of the cornea in a Gaucher disease carrier with keratoconus.

Ocular abnormalities such as corneal opacities and some specific alterations in ocular movements have been described in the neuropathic forms of Gaucher disease. This study was designed to correlate the clinical, morphological and biochemical findings in the corneal button obtained after keratoplasty in a Gaucher disease carrier with keratoconus. Morphologically, the cornea showed keratocytes with marked dilatations of the rough endoplasmic reticulum and intracytoplasmic "dark inclusions"; the acidic lipid profiles presented alterations in the cornea of the Gaucher disease carrier when compared with healthy controls and a clear deficiency in beta-glucosidase activity was detected as well. Our data suggest that the cornea may serve as a good marker of an early target organ in lipid metabolism disorders such as Gaucher's disease.

Retinal changes induced by neonatal cocaine exposure in the rat.

Retinal abnormalities have been described in both animals and humans exposed to cocaine during development. The present study was designed to examine the morphological repercussions of neonatal exposure to cocaine on the developing retina of the rat. Male Wistar rats were given 15 mg/kg body weight per day of cocaine hydrochloride subcutaneously on postnatal days (PND) 0-6, 13 and 29 and sacrificed at PND 7, 14 or 30; controls were given saline. The retinas were processed for electron microscopy. Retinal quadrants were embedded flat and vertical semithin and ultrathin sections obtained. PND 7 sections showed discrete intraretinal hemorrhages, PND 14 sections showed massive intraretinal hemorrhages and images of ischemic necrosis in the nerve fiber layer and PND 30 sections showed cavity lesions in the hemorrhagic areas, gliosis and pigmented macrophage-rich epiretinal membranes; photoreceptor rosettes were also found. These results are the first morphological demonstration of retinal hemorrhages and associated epiretinal membranes following neonatal exposure to cocaine in the rat. These changes are probably related to the ischemia/hypoxia induced by cocaine.

Changes in the retinal ganglion cell layer and optic nerve of rats exposed neonatally to cocaine.

The effects of neonatal exposure to cocaine upon the structure of the visual system are poorly understood despite the evidence of eye abnormalities in infants exposed in utero to cocaine. We previously demonstrated alterations in the optic nerve of rats exposed neonatally to cocaine, although no changes were detected in the number of its axons. This study was undertaken to investigate the retinal ganglion cell layer and the size distribution of the optic axons, in an attempt to assess further changes in the visual pathways. Groups of rats (Wistar strain) were given subcutaneous injections of cocaine hydrochloride (15 mg kg-1 body weight day-1) divided into two daily doses, from the day following birth until postnatal day 30 Controls were given subcutaneous saline throughout the same experimental period. Per group, five animals from three different litters were evaluated morphometrically. Following perfusion with aldehydes, samples from the median ventral and dorsal parts of the retina and the optic nerves were processed for electron microscopy. Morphometric techniques at light and electron microscopic levels allowed us to determine the following. (a) In the optic nerve: (1) frequency size-distribution of myelinated nerve fibres; and (2) number of myelin sheaths per fibre. (b) In the retina: (1) thickness of the layers; (2) frequency size-distribution of ganglion layer neurons; (3) mean cell nuclear size; and (4) packing density of ganglion cell layer neurons.(ABSTRACT TRUNCATED AT 250 WORDS)

Morphological changes in the optic nerve after chronic exposure of neonatal rats to cocaine and amphetamine.

We determined the effects of cocaine hydrochloride (15 mg/kg body weight/day) or amphetamine sulfate (25 mg/kg body weight/day) on the optic nerve in groups of rats exposed from postnatal day 1 to 30. Qualitative and quantitative studies of cross-sections of the optic nerves showed different patterns of organization, namely the presence of degenerative features in drug-treated animals and significant differences in the proportion of the nerve occupied by glial cells and their processes and nerve fiber bundles. No significant differences of the total number of fibers were found. Taken together, these data indicate that the optic nerve is vulnerable to early exposure to cocaine and amphetamine which cause developmental changes in this link of the visual pathways.