Changes in retinal nerve fiber layer thickness after spinal surgery in the prone position: a prospective study / Alterações da espessura da camada de fibras nervosas da retina após cirurgia da coluna vertebral em pronação: estudo prospectivo / Alteraciones del espesor de la capa de fibras nerviosas de la retina después de la cirugía de la columna vertebral en pronación: estudio prospectivo

BACKGROUND AND OBJECTIVES: Changes in ocular perfusion play an important role in the pathogenesis of ischemic optic neuropathy. Ocular perfusion pressure is equal to mean arterial pressure minus intraocular pressure. The aim of this study was to evaluate the changes in the intraocular pressure and the retinal nerve fiber layer thickness in patients undergoing spinal surgery in the prone position. METHODS: This prospective study included 30 patients undergoing spinal surgery. Retinal nerve fiber layer thickness were measured one day before and after the surgery by using optical coherence tomography. Intraocular pressure was measured by tonopen six times at different position and time-duration: supine position (baseline); 10 min after intubation (Supine 1); 10 (Prone 1), 60 (Prone 2), 120 (Prone 3) min after prone position; and just after postoperative supine position (Supine 2). RESULTS: Our study involved 10 male and 20 female patients with the median age of 57 years. When postoperative retinal nerve fiber layer thickness measurements were compared with preoperative values, a statistically significant thinning was observed in inferior and nasal quadrants (p = 0.009 and p = 0.003, respectively). We observed a statistically significant intraocular pressure decrease in Supine 1 and an increase in both Prone 2 and Prone 3 when compared to the baseline. Mean arterial pressure and ocular perfusion pressure were found to be significantly lower in Prone 1, Prone 2 and Prone 3, when compared with the baseline. CONCLUSIONS: Our study has shown increase in intraocular pressure during spinal surgery in prone position. A statistically significant retinal nerve fiber layer thickness thinning was seen in inferior and nasal quadrants one day after the spinal surgery. .

JUSTIFICATIVA E OBJETIVOS: As alterações de perfusão ocular desempenham um papel importante na patogênese da neuropatia óptica isquêmica. A pressão de perfusão ocular é igual à pressão arterial média menos a pressão intraocular. O objetivo deste estudo foi avaliar as alterações da pressão intraocular e da espessura da camada de fibras nervosas da retina em pacientes submetidos à cirurgia da coluna vertebral em pronação. MÉTODOS: Este estudo prospectivo incluiu 30 pacientes submetidos à cirurgia da coluna vertebral. A espessura da camada de fibras nervosas da retina foi medida um dia antes e um depois da cirurgia, com o uso da tomografia de coerência óptica. A pressão intraocular foi medida seis vezes com o Tonopen e o tempo de duração em posições diferentes: em supinação (basal), 10 minutos após a intubação (Supinação 1); após a pronação aos 10 minutos (Pronação 1), 60 minutos (Pronação 2) e 120 minutos (Pronação 3) e logo após a supinação no período pós-operatório (Supinação 2). RESULTADOS: Nosso estudo envolveu 10 pacientes do sexo masculino e 20 do feminino, com média de 57 anos. No pós-operatório, quando as medidas da espessura da camada de fibras nervosas da retina foram comparadas com os valores do pré-operatório, um afinamento estatisticamente significativo da retina foi observado nos quadrantes nasais e inferiores (p = 0,009 e p = 0,003, respectivamente). Observamos uma diminuição da pressão intraocular estatisticamente significante em Supinação 1 e um aumento em ambos momentos Pronação 2 e Pronação 3, em comparação com os valores basais. A pressão arterial média e a pressão de perfusão ocular foram significativamente mais baixas em Pronação 1, Pronação 2 e Pronação 3, em comparação com os valores basais. CONCLUSÕES: Nosso estudo mostrou aumento da pressão intraocular durante a cirurgia da coluna vertebral em pronação. Um afinamento estatisticamente significante da espessura da camada de fibras nervosas da retina foi observado ...

JUSTIFICACIÓN Y OBJETIVOS: Las alteraciones en la perfusión ocular desempeñan un rol importante en la patogénesis de la neuropatía óptica isquémica. La presión de perfusión ocular es igual a la presión arterial media menos la presión intraocular. El objetivo de este estudio fue evaluar las alteraciones de la presión intraocular y del espesor de la capa de fibras nerviosas de la retina en pacientes sometidos a cirugía de la columna vertebral en pronación. MÉTODOS: Este estudio prospectivo incluyó a 30 pacientes sometidos a cirugía de la columna vertebral. El espesor de la capa de fibras nerviosas de la retina se midió un día antes y uno después de la cirugía, con la tomografía de coherencia óptica. La presión intraocular se midió 6 veces con tonopen y el tiempo de duración en posiciones diferentes: en supinación (basal), 10 min después de la intubación (supinación 1); después de la pronación a los 10 min (pronación 1), 60 min (pronación 2) y 120 min (pronación 3), y justo después de la supinación en el período postoperatorio (supinación 2). RESULTADOS: Nuestro estudio contó con la participación de 10 pacientes del sexo masculino y 20 del femenino, con un promedio de edad de 57 años. En el postoperatorio, cuando las medidas del espesor de la capa de fibras nerviosas de la retina fueron comparadas con los valores del preoperatorio, se observó un adelgazamiento estadísticamente significativo de la retina en los cuadrantes nasales e inferiores (p = 0,009 y p = 0,003, respectivamente). Observamos una disminución de la presión intraocular estadísticamente significativa en supinación 1 y un aumento en pronación 2 y 3, en comparación con los valores basales. La presión arterial media y la presión de perfusión ocular fueron significativamente más bajas en pronación 1, pronación 2 y pronación 3, en comparación con los valores basales. CONCLUSIONES: Nuestro estudio mostró un aumento de la presión intraocular durante la cirugía de la columna vertebral ...

[Changes in retinal nerve fiber layer thickness after spinal surgery in the prone position: a prospective study]. / Alterações da espessura da camada de fibras nervosas da retina após cirurgia da coluna vertebral em pronação: estudo prospectivo.

BACKGROUND AND OBJECTIVES: Changes in ocular perfusion play an important role in the pathogenesis of ischemic optic neuropathy. Ocular perfusion pressure is equal to mean arterial pressure minus intraocular pressure. The aim of this study was to evaluate the changes in the intraocular pressure and the retinal nerve fiber layer thickness in patients undergoing spinal surgery in the prone position. METHODS: This prospective study included 30 patients undergoing spinal surgery. Retinal nerve fiber layer thickness were measured one day before and after the surgery by using optical coherence tomography. Intraocular pressure was measured by tonopen six times at different position and time-duration: supine position (baseline); 10min after intubation (Supine 1); 10 (Prone 1), 60 (Prone 2), 120 (Prone 3)min after prone position; and just after postoperative supine position (Supine 2). RESULTS: Our study involved 10 male and 20 female patients with the median age of 57 years. When postoperative retinal nerve fiber layer thickness measurements were compared with preoperative values, a statistically significant thinning was observed in inferior and nasal quadrants (p=0.009 and p=0.003, respectively). We observed a statistically significant intraocular pressure decrease in Supine 1 and an increase in both Prone 2 and Prone 3 when compared to the baseline. Mean arterial pressure and ocular perfusion pressure were found to be significantly lower in Prone 1, Prone 2 and Prone 3, when compared with the baseline. CONCLUSIONS: Our study has shown increase in intraocular pressure during spinal surgery in prone position. A statistically significant retinal nerve fiber layer thickness thinning was seen in inferior and nasal quadrants one day after the spinal surgery.

The neuroprotective effect of Sulindac after ischemia-reperfusion injury in rats.

PURPOSE: To investigate the neuroprotective effects of Sulindac on the hippocampal complex after global cerebral ischemia/reperfusion (I/R) injury in rats. METHODS: Thirty one Sprague-Dawley rats were used, distributed into group I (sham) n:7 were used as control. For group II (n:8), III (n:8) and IV (n:8) rats, cerebral ischemia was performed via the occlusion of bilateral internal carotid artery for 45 minutes and continued with reperfusion process. 0.3 mL/kg/h 0.9 % sodium chloride was infused intraperitoneally to the Group II rats before ischemia, 5µg/kg/h/0.3 ml sulindac was infused intraperitoneally to the Group III rats before ischemia and 5µg/kg/h/0.3 ml sulindac was infused intraperitoneally to the Group IV rats after ischemia and before reperfusion process. The levels of MDA, GSH and MPO activity were measured in the left hippocampus tissue. The hippocampal tissue of all group members were taken for histopathological study. RESULTS: The MDA and MPO levels increased from group I (control) to group II (I/R) (P<0.05) and decreased from group II (I/R) to group III (presulindac + I/R) and IV (postsulindac + I/R) (P<0.05). Beside these, the GSH levels decreased from group I (control) to group II (I/R) (P<0.05) and increased from group II (I/R) to group III (presulindac + I/R) and IV (postsulindac + I/R) (P<0.05).The number of apoptotic neurons increased from group I (control) to group II (I/R) (P<0.05) and decreased from group II (I/R) to group III (presulindac + I/R) and IV (postsulindac + I/R) (P<0.05). CONCLUSION: The Sulindac may have neuroprotective effects on ischemic neural tissue to prevent the reperfusion injury after ischemia.

The neuroprotective effect of Sulindac after ischemia-reperfusion injury in rats

To investigate the neuroprotective effects of Sulindac on the hippocampal complex after global cerebral ischemia/reperfusion (I/R) injury in rats. Thirty one Sprague-Dawley rats were used, distributed into group I (sham) n:7 were used as control. For group II (n:8), III (n:8) and IV (n:8) rats, cerebral ischemia was performed via the occlusion of bilateral internal carotid artery for 45 minutes and continued with reperfusion process. 0.3 mL/kg/h 0.9 % sodium chloride was infused intraperitoneally to the Group II rats before ischemia, 5μg/kg/h/0.3 ml sulindac was infused intraperitoneally to the Group III rats before ischemia and 5μg/kg/h/0.3 ml sulindac was infused intraperitoneally to the Group IV rats after ischemia and before reperfusion process. The levels of MDA, GSH and MPO activity were measured in the left hippocampus tissue. The hippocampal tissue of all group members were taken for histopathological study. The MDA and MPO levels increased from group I (control) to group II (I/R) (P<0.05) and decreased from group II (I/R) to group III (presulindac + I/R) and IV (postsulindac + I/R) (P<0.05). Beside these, the GSH levels decreased from group I (control) to group II (I/R) (P<0.05) and increased from group II (I/R) to group III (presulindac + I/R) and IV (postsulindac + I/R) (P<0.05).The number of apoptotic neurons increased from group I (control) to group II (I/R) (P<0.05) and decreased from group II (I/R) to group III (presulindac + I/R) and IV (postsulindac + I/R) (P<0.05). The Sulindac may have neuroprotective effects on ischemic neural tissue to prevent the reperfusion injury after ischemia.

The neuroprotective effect of Sulindac after ischemia-reperfusion injury in rats

To investigate the neuroprotective effects of Sulindac on the hippocampal complex after global cerebral ischemia/reperfusion (I/R) injury in rats. Thirty one Sprague-Dawley rats were used, distributed into group I (sham) n:7 were used as control. For group II (n:8), III (n:8) and IV (n:8) rats, cerebral ischemia was performed via the occlusion of bilateral internal carotid artery for 45 minutes and continued with reperfusion process. 0.3 mL/kg/h 0.9 % sodium chloride was infused intraperitoneally to the Group II rats before ischemia, 5μg/kg/h/0.3 ml sulindac was infused intraperitoneally to the Group III rats before ischemia and 5μg/kg/h/0.3 ml sulindac was infused intraperitoneally to the Group IV rats after ischemia and before reperfusion process. The levels of MDA, GSH and MPO activity were measured in the left hippocampus tissue. The hippocampal tissue of all group members were taken for histopathological study. The MDA and MPO levels increased from group I (control) to group II (I/R) (P<0.05) and decreased from group II (I/R) to group III (presulindac + I/R) and IV (postsulindac + I/R) (P<0.05). Beside these, the GSH levels decreased from group I (control) to group II (I/R) (P<0.05) and increased from group II (I/R) to group III (presulindac + I/R) and IV (postsulindac + I/R) (P<0.05).The number of apoptotic neurons increased from group I (control) to group II (I/R) (P<0.05) and decreased from group II (I/R) to group III (presulindac + I/R) and IV (postsulindac + I/R) (P<0.05). The Sulindac may have neuroprotective effects on ischemic neural tissue to prevent the reperfusion injury after ischemia.(AU)