Pathogenesis Of Ischemic Optic Neuropathy Research Articles

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 objectivesChanges 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. MethodsThis 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); 10min (prone 1), 60min (prone 2), 120min (prone 3) after prone position; and just after postoperative supine position (supine 2). ResultsOur 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=.009 and P=.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. ConclusionsOur 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.

Alterações da espessura da camada de fibras nervosas da retina após cirurgia da coluna vertebral em pronação: estudo prospectivo

Background and objectivesChanges 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. MethodsThis 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). ResultsOur 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. ConclusionsOur 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.

Changes in retinal nerve fiber layer thickness after spinal surgery in the prone position: a prospective study

Background and objectivesChanges 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. MethodsThis 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). ResultsOur 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. ConclusionsOur 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.

Pseudo Foster Kennedy Syndrome secondary to uncontrolled hypertension and diabetes mellitus: A case report

Pseudo-Foster Kennedy Syndrome is described as unilateral optic disc swelling with contra lateral optic atrophy in the absence of an intracranial mass causing compression of the optic nerve. This occurs typically due to bilateral sequential optic neuritis or ischemic optic neuropathy. We describe a case of pseudo-Foster Kennedy Syndrome in a 37-year-old male with unilateral papilledema secondary to malignant hypertension and pre-existing ischemic optic neuropathy in other eye preventing transmission of raised intracranial pressure to the optic nerve. Hypertension and diabetes mellitus (DM) play a significant role in pathogenesis of ischemic optic neuropathy. There is a greater correlation in patients with small disc and little to no cupping. The disorder commonly occurs in the 40-65 yrs age group. Our case is an example of Pseudo-Foster Kennedy syndrome where papilledema in one eye was associated with uncontrolled hypertension and disc pallor in fellow eye was secondary to ischemic optic neuropathy.

Structural Factors in the Pathogenesis of Ischemic Optic Neuropathy

Some patients with nonarteritic ischemic optic neuropathy have no signs or symptoms of systemic vascular disease; therefore, nonvascular factors may play a role in the pathogenesis of this syndrome. We observed that the average cup-disk ratio of the unaffected optic disks in a group of patients with ischemic optic neuropathy was significantly (P = .005) smaller than the average ratio in a group of age-matched controls (0.36 +/- 0.19 vs 0.21 +/- 0.16). Fourteen of 30 patients but only two of 29 controls had cup-disk ratios equal to or less than 0.1. Mechanical factors, such as constriction of axons as they traverse the scleral canal, may contribute to the pathogenesis of ischemic optic neuropathy.