Ryuya Hashimoto

Autoregulation of Optic Nerve Head Blood Flow Induced by Elevated Intraocular Pressure during Vitreous Surgery

ABSTRACT Purpose: To investigate optic nerve head (ONH) blood flow changes resulting from intraocular pressure (IOP) elevation in subjects without systemic disorders. Materials and Methods: Eighteen eyes of 18 patients who underwent vitrectomy to treat an epiretinal membrane or macular hole at Toho University Sakura Medical Center were included. Following standard 25-gauge microincision vitreous surgery, mean blur rate (MBR) in tissue (MT), an index of ONH blood flow, was measured using laser speckle flowgraphy. Measurements were taken before and 5 and 10 minutes after a 15 mmHg IOP elevation. Results: The ONH blood flow was initially lower than baseline (P = 0.001) after elevating IOP from 14.8 ± 2.8 mmHg to approximately 30 mmHg. Between 5 and 10 minutes after elevating IOP, ONH blood flow partially recovered (P = 0.004), even though ocular perfusion pressure was 20.2% lower than at baseline. Conclusions: The ONH blood flow in subjects without systemic disorders was initially lower, but began to recover 5–10 minutes after a 15 mmHg elevation in IOP. These results indicate that autoregulatory mechanisms of ONH blood flow may help to minimize the effects of IOP elevations and fluctuations during vitreous surgery.

Changes in choroidal blood flow and choroidal thickness after treatment in two cases of pediatric anisohypermetropic amblyopia

Purpose We aimed to examine the changes in choroidal blood flow (CBF) and central choroidal thickness (CCT) in children with anisohypermetropic amblyopia using laser speckle flowgraphy (LSFG) and enhanced depth imaging optical coherence tomography (EDI-OCT). Observations The patients were both 6-year-old Japanese male children with complaints of worsening right visual acuity and were diagnosed with anisohypermetropic amblyopia. The decimal best-corrected visual acuities (BCVAs) in cases 1 and 2 were both 0.5. In both cases, LSFG results demonstrated CBF impairment in amblyopic eyes compared with fellow eyes. EDI-OCT results also showed that the CCTs of amblyopic eyes were greater than those of fellow eyes at the initial visit. Several months after the first visit, the decimal BCVAs in both cases had improved to 1.0 because of treatment. Further, the CBF gradually increased along with a decrease in the CCT of the amblyopic eye. The axial lengths and spherical powers of the amblyopic eyes in the two cases were not different during follow-up. Conclusions and importance We have determined the changes in CBF and CCT in two children with anisohypermetropic amblyopia for the first time. CBF impairments may be involved in the pathogenesis of anisohypermetropic amblyopia, and LSFG may be useful in examining CBF in pediatric anisohypermetropic amblyopia.

Subfraction analysis of circulating lipoproteins in a patient with Tangier disease due to a novel ABCA1 mutation

Tangier disease, characterized by low or absent high-density lipoprotein (HDL), is a rare hereditary lipid storage disorder associated with frequent, but not obligatory, severe premature atherosclerosis due to disturbed reverse cholesterol transport from tissues. The reasons for the heterogeneity in atherogenicity in certain dyslipidemias have not been fully elucidated. Here, using high-performance liquid chromatography with a gel filtration column (HPLC-GFC), we have studied the lipoprotein profile of a 17-year old male patient with Tangier disease who to date has not developed manifest coronary atherosclerosis. The patient was shown to be homozygous for a novel mutation (Leu1097Pro) in the central cytoplasmic region of ATP-binding cassette transporter A1 (ABCA1). Serum total and HDL-cholesterol levels were 59mg/dl and 2mg/dl, respectively. Lipoprotein electrophoretic analyses on agarose and polyacrylamide gels showed the presence of massively abnormal lipoproteins. Further analysis by HPLC-GFC identified significant amounts of lipoproteins in low-density lipoprotein (LDL) subfractions. The lipoprotein particles found in the peak subfraction were smaller than normal LDL, were rich in triglycerides, but poor in cholesterol and phospholipids. These findings in an adolescent Tangier patient suggest that patients in whom these triglyceride-rich, cholesterol- and phospholipid-poor LDL-type particles accumulate over time, would experience an increased propensity for developing atherosclerosis.

Case report of subcutaneous panniculitis-like T-cell lymphoma complicated by eyelid swelling

BackgroundSubcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare, highly malignant, extranodal lymphoma that preferentially infiltrates into subcutaneous adipose tissue. No case of SPTCL with the earliest symptoms occurring in the eye region has been reported. We report a case of SPTCL complicated by eyelid swelling.Case presentationA 19-year-old Japanese man presented with worsening left eyelid swelling. The patient’s best-corrected visual acuity (BCVA) was 0.8, left intraocular pressure was 36 mm Hg, and he had prominent mucosal hyperemia and edema. His left eye had light reflex attenuation and a positive relative afferent pupillary defect, but no abnormality in the visual field or central flicker value. Magnetic resonance imaging showed left orbital adipose tissue inflammation. The blood examination was normal. He was hospitalized for an intensive examination and treatment for possible cellulitis, orbital panniculitis, and inflammatory pseudotumor. Systemic antibiotics were initiated. The following day, he underwent a sub-Tenon’s injection of triamcinolone. Left eyelid swelling gradually improved. He was discharged on the ninth day and followed up with oral prednisolone. Two months later, he visited our department because of a high fever and slight right eyelid swelling. Ocular hypertension was detected. A blood examination revealed pancytopenia. Computed tomography showed fluid retention, hydrothorax, and abdominal dropsy. Magnetic resonance imaging revealed right orbital panniculitis. Because of suspected hemodyscrasia, he was referred to the hematology department of another hospital where he was diagnosed with SPTCL.ConclusionsThe possibility of SPTCL, with attention to recurrence and systemic symptoms, should be considered in young patients with sudden eyelid swelling.

Choroidal blood flow impairment demonstrated using laser speckle flowgraphy in a case of commotio retinae

Purpose To report the time course of choroidal blood flow (CBF) in a commotio retinae case using laser speckle flowgraphy (LSFG). Observations A 58-year-old Japanese man with complaints of worsening left visual acuity after blunt eye trauma was diagnosed with commotio retinae. A funduscopic examination showed macular opacity, and LSFG results demonstrated CBF impairment in the affected eye. Optical coherence tomography also showed disruption of the photoreceptor outer segment. Seven months after the initial visit, CBF was significantly increased, along with improvement in the photoreceptor outer segment. Conclusion and importance: We revealed CBF impairment in a case of commotio retinae for the first time. CBF impairment may be involved in the pathogenesis of commotio retinae, and LSFG may be useful for examining CBF in commotio retinae.

Risk factors for requirement of filtration surgery after vitrectomy in patients with proliferative diabetic retinopathy

Purpose We retrospectively reviewed patients with postoperative neovascular glaucoma (NVG) after vitrectomy for proliferative diabetic retinopathy to investigate how variables assessed before, during, and after vitrectomy are associated with the requirement for filtration surgery. Patients and methods The subjects in this retrospective, observational, comparative study were 55 consecutive patients (61 eyes) who underwent vitrectomy for proliferative diabetic retinopathy at Toho University Sakura Medical Center between December 2011 and November 2016, were followed up for at least 6 months after surgery, and developed NVG within 2 years after surgery. They comprised 44 men and 11 women of mean age 52.4±9.1 years, who were followed up for a mean 7.1±6.1 months. We collected data on the following 16 variables: sex, age, history of panretinal photocoagulation completed within 3 months before vitrectomy, presence/absence of a lens, obvious iris/angle neovascularization, tractional retinal detachment, diabetic macular edema, vitreous hemorrhage, visual acuity and intraocular pressure before vitrectomy and at the onset of NVG, glycated hemoglobin, fasting blood glucose, estimated glomerular filtration rate, and use of intraoperative gas tamponade. Results Logistic regression analysis with the backward elimination method identified preoperative fasting hyperglycemia (P=0.08), high intraocular pressure at the onset of NVG (P=0.04), and use of gas tamponade during vitrectomy (P=0.008) to be significant risk factors for requirement of filtration surgery. Conclusion Preoperative fasting hyperglycemia, high intraocular pressure at the onset of NVG, and use of gas tamponade during vitrectomy predispose patients to require filtration surgery in the event of postoperative NVG.

Risk factors for retinal breaks during macular hole surgery

Purpose To identify risk factors for retinal breaks during macular hole (MH) surgery. Patients and methods This retrospective, observational, comparative study included the medical records of 364 consecutive patients (382 eyes) who underwent vitrectomy for MH at Toho University Sakura Medical Center between January 2012 and May 2017. The patients comprised 135 men and 229 women with mean age 67.6±8.0 years. Six eyes with a pre-existing retinal tear treated by laser photocoagulation before MH surgery were excluded. Data on sex, age, presence or absence of lattice degeneration, axial length (measured using an IOL Master®), preoperative refraction, whether or not combined lens extraction/vitrectomy had been performed, whether or not the lens was pseudophakic before vitrectomy, and whether or not a posterior vitreous detachment had been created intraoperatively were collected. The lattice degeneration status was classified as none (0), treated using laser photocoagulation (1), or untreated (2). Results The only item identified in logistic regression analysis with the backward elimination method to be a significant risk factor for retinal breaks during MH surgery was the presence of lattice degeneration (P<0.001). Conclusion Ophthalmologists should be aware of the increased risk of retinal breaks during MH surgery in eyes with lattice degeneration. Intraoperative retinal breaks may be less likely to occur in eyes with lattice degeneration treated by photocoagulation preoperatively.

Comparison of Optic Nerve Head Blood Flow Autoregulation among Quadrants Induced by Decreased Ocular Perfusion Pressure during Vitrectomy

Purpose The present study aimed to examine changes in optic nerve head (ONH) blood flow autoregulation in 4 quadrants (superior, nasal, inferior, and temporal) with decreased ocular perfusion pressure (OPP) during vitrectomy in order to determine whether there is a significant difference of autoregulatory capacity in response to OPP decrease at each ONH quadrant. Methods This study included 24 eyes with an epiretinal membrane or macular hole that underwent vitrectomy at Toho University Sakura Medical Center. Following vitrectomy, the tissue mean blur rate (MBR), which reflects ONH blood flow, was measured. Mean tissue MBRs in the four quadrants were generated automatically in the software analysis report. Measurements were conducted before and 5 and 10 min after intraocular pressure (IOP) elevation of approximately 15 mmHg in the subjects without systemic disorders. Results The baseline tissue MBR of the temporal quadrant was significantly lower than that of the other 3 quadrants (all P < 0.05). However, the time courses of tissue MBR in response to OPP decrease were not significantly different among the four quadrants during vitrectomy (P = 0.23). Conclusions There is no significant difference in the autoregulatory capacity of the four ONH quadrants in patients without systemic disorders during vitrectomy.