Ocular Ischemic Syndrome due to Internal Carotid Artery Occlusion with Neurofibromatosis Type 1.

Neurofibromatosis type 1 (NF-1) is associated with multiple vascular abnormalities, including internal carotid artery (ICA) stenosis/occlusion. Depending on the site of stenosis/occlusion of the ICA, both cerebral circulation and ocular circulation can be impaired. We describe a rare pediatric case of ocular ischemic syndrome (OIS) due to ICA occlusion in NF-1. The patient diagnosed with NF-1 suffered right ICA occlusion at 12 years of age, and developed right dense vitreous hemorrhage due to OIS at 13 years of age. The patient underwent right cerebral revascularization surgery to improve cerebral and ocular ischemia, but the visual acuity of the right eye did not improve. This case suggests that attention should be paid not only to cerebral ischemia but also to ocular ischemia in patients with ICA stenosis/occlusion of NF-1. Surgical interventions such as cerebral revascularization surgery should be considered in the early stages of OIS to protect visual function, and careful follow-up is required.

Concurrent analogous organ damage in the brain, eyes, and kidneys in malignant hypertension: reversible encephalopathy, serous retinal detachment, and proteinuria.

Malignant hypertension, a form of hypertensive emergency, causes acute damage in vital organs such as the brain, eyes, and kidneys. We aimed to examine the concurrency of acute hypertensive damage across the target organs to elucidate the underlying analogous pathophysiology. This single-center retrospective study evaluated the characteristics of organ damage, short-term clinical course, and interorgan relationships in patients with malignant hypertension treated between 2008 and 2019. Baseline characteristics of 20 patients who met our inclusion criteria were mean age 48 ± 13 years and blood pressure 222 ± 18/142 ± 16 mmHg; the median estimated glomerular filtration rate and urinary protein level were 49 mL/min/1.73 m2 (interquartile range [IQR] 27-79) and 1.9 g/g creatinine (IQR 0.2-4.0), respectively. Posterior reversible encephalopathy syndrome (PRES) was found in 60% of patients with major involvement and a wide variety of distribution patterns in the brainstem. In the fundus, serous retinal detachment was found in 60% of patients. Patients with PRES and serous retinal detachment showed higher levels of urinary protein than those without symptoms (P = 0.007 and 0.02, respectively), and proteinuria >1 g/g creatinine highly complicated both PRES and serous retinal detachment (91%). Matrix analysis also showed that the three symptoms were highly associated with each other. These results demonstrate the close relationship and concurrency of hypertensive acute organ damage in the brain, eyes, and kidneys. A common analogous mechanism, such as hyperperfusion-induced capillary leakage in each organ, implies an underlying pathophysiology of PRES, serous retinal detachment, and proteinuria.

Laser speckle and hydrogen gas clearance measurements of optic nerve circulation in albino and pigmented rabbits with or without optic disc atrophy.

PURPOSE: The purpose of this study was to evaluate the correlation between laser speckle flowgraphy measurements of mean blur rate (MBR) and hydrogen gas clearance measurements of capillary blood flow (CBF) in the optic nerve head (ONH) of albino and pigmented rabbits, with or without chronic ischemia-induced ONH atrophy. METHODS: The ONH MBR and ONH CBF were measured at baseline, 30 and 60 minutes after the intravenous administration of endothelin-1 (ET-1) (10(-10) mol/kg) in six albino and six pigmented rabbit eyes. The ONH MBR and ONH CBF were also measured in nine pigmented rabbit eyes that underwent the intravitreal administration of ET-1 (20 pmol) twice per week for 4 weeks to provoke chronic ischemia-induced ONH atrophy. RESULTS: In the group that received intravenous ET-1, average measurements of ONH MBR and ONH CBF at all time points were correlated in both the albino (r = 0.88, P < 0.001, n = 18) and pigmented rabbits (r = 0.85, P < 0.001, n = 18), with no intrarabbit correlations (P = 0.524). The ONH MBR and ONH CBF were also correlated in the model of chronic ischemia-induced ONH atrophy (r = 0.78, P = 0.013, n = 9). Pooled ONH MBR and ONH CBF measurements in both the intravenous and intravitreal groups were also highly correlated (r = 0.87, P < 0.001, n = 45), with no significant intergroup differences in the relationship between ONH MBR and ONH CBF (P = 0.138). CONCLUSIONS: Regardless of the presence of fundus pigmentation or ONH atrophy, ONH MBR and ONH CBF were highly correlated, suggesting that MBR in the ONH tissue is usable for interindividual and intergroup comparisons.

Difficulty in inserting 25- and 23-gauge trocar cannula during vitrectomy.

PURPOSE: To determine the incidence of difficulty in inserting a 25- and 23-gauge trocar cannula (DITC) during 25- or 23-gauge micro-incision vitrectomy surgery (MIVS). METHODS: Retrospective, consecutive, interventional case series performed by a single surgeon at a single centre. We defined a DITC as the condition where at least 1 trocar cannula could not be inserted into the vitreous at the beginning of MIVS. The incidence of DITC was calculated from 1,525 eyes, and the pre-operative demographics of the DITC cases were compared to those of the non-DITC cases. RESULTS: The incidence of DITC for all cases was 0.6% (9 of 1,525 eyes). Overall, there were 242 eyes with a retinal detachment (RD), and 8 of the 9 eyes with DITC had an RD with an incidence of 3.3% (8 of 242 RD eyes). Seven of these 8 eyes had a total RD, 4 also had a choroidal detachment, 4 eyes were also myopic (>-8.0 dpt, high myopia), and 6 of the 8 eyes were hypotonic (<8 mm Hg). The DITC cases had larger RDs (p<0.0001), a higher incidence of choroidal detachment (p<0.0001), higher myopia (p=0.0204) and hypotony (p=0.0003) than the non-DITC eyes with an RD. CONCLUSIONS: A large RD, a choroidal detachment, high myopia and hypotony are significant risk factors for DITC. We recommend that MIVS should be performed cautiously for eyes with these risk factors.