Yasushi Ikuno

Choroidal thickness in healthy Japanese subjects.

Purpose. To study posterior choroidal thickness and its profile based on location in healthy Japanese subjects and the correlation with axial length, refractive error (RE), and age. Methods. Eighty-six eyes of 43 healthy volunteers with no ophthalmic or systemic symptoms were examined with prototype high-penetration optical coherence tomography using a 1060-nm light source. Eyes with high myopia (exceeding -6 D) or with retinal/choroidal disease were excluded. The spherical equivalent RE was measured by autorefractometry, and the axial length was measured by partial coherence inferometry. Results. Mean choroidal thicknesses were 354 +/- 111 mum at the fovea, 364 +/- 86 mum superiorly, 345 +/- 108 mum inferiorly, 227 +/- 532 mum nasally, and 337 +/- 102 mum temporally. Subfoveal choroidal thickness was significantly greater than nasal (P < 0.01) and temporal (P < 0.05) choroidal thickness; however, there was no significant difference compared with superior (P = 0.20) and inferior (P = 0.17) choroidal thickness. The temporal choroid was significantly (P < 0.01) thicker than the nasal choroid, and the inferior choroid was significantly (P < 0.01) thinner than the superior choroid. There was a significant negative correlation between foveal choroidal thickness and axial length (P < 0.05) but a borderline correlation with the RE (P = 0.086) and age (P = 0.07). Age was the factor that was most associated with the choroidal thickness (F = 20.86; P < 0.001), followed by RE (F = 5.37; P < 0.05); axial length was not a significant factor (F = 1.47; P = 0.22) by stepwise analysis. Conclusions. The profile of choroidal thickness depends on its location. RE, axial length, and especially age are critical for evaluation of choroidal thickness.

Retinal and Choroidal Biometry in Highly Myopic Eyes with Spectral-Domain Optical Coherence Tomography

PURPOSE Morphologic changes in the retina and choroid are closely related with high myopia-related diseases. This study was conducted to evaluate the morphologic characteristics of normal highly myopic eyes. METHODS Thirty-one phakic highly myopic eyes with no posterior abnormalities (18 patients; mean +/- SD age, 51.7 +/- 11.4 years) were enrolled. Retinal-choroidal thickness at the fovea 1.5 mm superiorly, inferiorly, nasally, and temporally and the choroidal curvature were measured in the 512 x 128 three-dimensional scan mode with spectral-domain optical coherence tomography. The degree of posterior staphyloma was determined as the sum of the vertical distance from the retinal pigment epithelial line beneath the fovea to the nasal, temporal, superior, and inferior edge of the image, including the fovea. The association of clinical data with these parameters was evaluated. RESULTS The mean +/- SD central retinal thickness was 200.9 +/- 39.3 microm. The mean choroidal thickness at the fovea (100.5 +/- 56.9 microm) was significantly different from the temporal (125.4 +/- 59.7 microm), nasal (81.9 +/- 35.0 microm), and superior (129.4 +/- 57.5 microm) thicknesses (P < 0.01). Central retinal thickness did not correlate with age, sex, refractive error, axial length, or central choroidal thickness. Central choroidal thickness was significantly associated with refractive error (P < 0.05) and posterior staphyloma height (P < 0.01). Posterior staphyloma height was significantly correlated with refractive error and axial length (P < 0.01). Stepwise analysis indicated that choroidal thickness correlated significantly with age and posterior staphyloma height (P < 0.01). CONCLUSIONS Posterior staphyloma formation was a key factor in choroidal thinning in highly myopic eyes. Choroidal thickness had a greater effect than retinal thickness in highly myopic eyes.

Reproducibility of Retinal and Choroidal Thickness Measurements in Enhanced Depth Imaging and High-Penetration Optical Coherence Tomography

PURPOSE Two optical coherence tomography (OCT) modalities can visualize the choroid: high-penetration OCT (HP-OCT) using a long wavelength, and enhanced depth imaging technique using Heidelberg OCT (EDI-OCT). The purpose of this study was to compare and investigate the agreement among the retinal/choroidal thickness parameters. METHODS Twenty-four eyes of 12 healthy volunteers were examined simultaneously using the prototype swept-source HP-OCT and EDI-OCT. Six independent examiners measured the central retinal/choroidal thicknesses on horizontal B-scan images. The reliability was evaluated by intraclass correlation coefficient (ICC). Intervisit reproducibility was assessed by examining 10 of the volunteers 4 months later. RESULTS Using HP-OCT, the average of all measurements was 209.1 ± 12.9 μm in the retina and 292.7 ± 77.3 μm in the choroid, and using EDI-OCT, 212.5 ± 13.3 μm in the retina and 283.7 ± 84.1 μm in the choroid. An intersystem comparison showed that the ICCs were 0.661 (95% confidence interval [CI], 0.535-0.754) for the retina and 0.921 (95% CI, 0.875-0.948) for the choroid. Using HP-OCT, the interexaminer ICC reproducibility values were 0.630 (95% CI, 0.447-0.791) for the retinal thickness and 0.912 (95% CI, 0.835-0.958) for the choroidal thickness; using EDI-OCT, the values for the retinal and choroidal thicknesses were 0.788 (95% CI, 0.607-0.898) and 0.970 (95% CI, 0.948-0.985), respectively. The intervisit ICC values for the retinal and choroidal thicknesses were 0.504 (95% CI, 0.376-0.609) and 0.893 (95% CI, 0.864-0.916). CONCLUSIONS The retinal and choroidal thicknesses were well-correlated between the instruments. Higher reliability and reproducibility are expected for the choroidal thickness measurements despite with higher morphologic interindividual variations.

Complications in patients after intravitreal injection of bevacizumab

Purpose:  To report complications in patients after intravitreal injection of bevacizumab to treat ocular diseases associated with vascular endothelial growth factor.

Intravitreal Bevacizumab to Treat Iris Neovascularization and Neovascular Glaucoma Secondary to Ischemic Retinal Diseases in 41 Consecutive Cases

PURPOSE To evaluate the biologic efficacy of intravitreal bevacizumab (IVB) for iris neovascularization (INV) or neovascular glaucoma (NVG) in patients with ischemic retinal disorders. DESIGN Retrospective, consecutive, interventional case series. PARTICIPANTS Thirty patients (41 eyes) with INV or NVG secondary to ischemic retinal disorders. METHODS Patients received IVB (1 mg) as the initial treatment for INV or NVG and were followed up for at least 6 months. Ophthalmic evaluations included measurement of visual acuity and intraocular pressure (IOP), a complete ophthalmic examination, and fluorescein angiography. Patients were divided into 3 subgroups: INV without elevated IOP (INV group), NVG with an open angle (O-NVG group), and NVG with angle closure (C-NVG group) for outcomes analysis. MAIN OUTCOME MEASURES The controllability of IOP by IVB, incidence of recurrence, and requirement for surgery to treat NVG. RESULTS No significant ocular or systemic adverse events developed during follow-up (range, 6-22 months; mean, 13.3 months). The mean IOP levels were 14.7, 31.2, and 44.9 mmHg at baseline in the INV, O-NVG, and C-NVG groups, respectively. In the INV group (9 eyes), the INV regressed or resolved after 1 injection. Iris neovascularization recurred in 4 eyes by 6 months and stabilized after repeated injections without IOP elevation. In the O-NVG group (17 eyes), rapid neovascular regression with successful IOP normalization (<or=21 mmHg) occurred in 12 eyes (71%) within 1 week after 1 injection. Five (29%) of the 17 eyes required surgery by 6 months despite repeated IVB injections, and a total of 7 eyes (41%) underwent surgery during follow-up. In the C-NVG group (15 eyes), IVB caused INV resolution but failed to lower the IOP. Fourteen (93%) of 15 eyes required surgery by 2 months after initial IVB and achieved IOP stabilization. The mean interval between IVB and surgery was significantly shorter in the C-NVG group than in the O-NVG group (P<0.001). CONCLUSIONS Intravitreal bevacizumab is well tolerated, effectively stabilized INV activity, and controlled IOP in patients with INV alone and early-stage NVG without angle closure. In advanced NVG, IVB cannot control IOP but may be used adjunctively to improve subsequent surgical results. Further evaluation in controlled randomized studies is warranted.

Testing of semichronically implanted retinal prosthesis by suprachoroidal-transretinal stimulation in patients with retinitis pigmentosa.

PURPOSE To examine the safety and effectiveness of a retinal prosthesis that is implanted semichronically in two patients with advanced retinitis pigmentosa (RP). METHODS Two eyes of two patients with advanced RP had a retinal prosthesis implanted in a sclera pocket of one eye. The visual acuity of both eyes before the implantation was bare light perception. Phosphenes were elicited by suprachoroidal-transretinal stimulation (STS). The internal devices of the STS were implanted under the skin on the temporal side of the head, and the 49 electrode-array was implanted in the scleral pocket of one eye. Biphasic electrical pulses (duration, 0.5 ms; frequency, 20 Hz) were delivered through nine active electrodes. The threshold current was determined by currents ≤1 mA. Behavioral tasks were used to determine the functioning of the prosthesis. RESULTS The surgery was completed without a retinal detachment and retinal/vitreous hemorrhage. The implanted STS system remained functional for the 4-week test period. Phosphenes were elicited by currents delivered through six electrodes in Patient 1 and through four electrodes in Patient 2. The success of discriminating two bars was better than the chance level in both patients. In Patient 2, the success of a grasping task was better than the chance level, and the success rate of identifying a white bar on a touch panel increased with repeated testing. CONCLUSIONS Semichronic implantation of a microelectrode-STS system showed that it was safe and remained functional for at least 4 weeks in two patients with advanced RP. (www.umin.ac.jp/ctr number, R000002690.).

Intravitreal Bevacizumab for Choroidal Neovascularization Attributable to Pathological Myopia: One-Year Results

PURPOSE To assess the potential effect of intravitreal bevacizumab (IVB) (Avastin) on retinal function and anatomic recovery in eyes with choroidal neovascularization attributable to pathological myopia (mCNV). DESIGN Retrospective case series. METHODS setting: Institutional. patient population: Sixty-three eyes of 63 patients were treated with IVB for mCNV. intervention procedure: 1 mg of bevacizumab was injected into the vitreous via the pars plana. IVB was repeated after two to three months if there was fluorescein leakage in fluorescein angiogram (FA), apparent subretinal fluid in optical coherence tomography (OCT) persisted, or both. main outcome measurement: Best-corrected visual acuity (BCVA) and CNV size measured on FA. RESULTS IVB was performed one to six times during the first 12 months (mean, 2.4 +/- 1.4 times). The size of the mCNV decreased and the BCVA improved significantly (P < .01 for both comparisons). The BCVA improved more than three lines in 25 eyes (40%), worsened more than three lines in three eyes (5%), and was unchanged in 35 (56%) eyes 12 months after. Fluorescein leakage from the mCNV ceased in 30 eyes (48%), diminished in 28 (44%), and was unchanged in five (8%) eyes. Stepwise analysis showed that the number of IVB (P < .01), macular atrophy associated with mCNV (P < .05), and myopic atrophy (P < .05) were significant predictive factors for BCVA at 12 months. CONCLUSIONS Although the current study lacked a control group, IVB seems to be an effective treatment for mCNV after a long-term. The absence of chorioretinal atrophy and that of recurrence and persistency of mCNV are positive predictive factors.

Ocular risk factors for choroidal neovascularization in pathologic myopia.

UNLABELLED PURPOSE. To identify the risk factors for development of myopic choroidal neovascularization (mCNV), a major cause of visual impairment. METHODS. Enrolled in the study were 23 consecutive patients with bilateral high myopia (axial length, > or =26.5 mm or refractive error, < or =8 D) and unilateral newly developed mCNV who presented to the Myopia Clinic, Osaka University Hospital. Spectral-domain optical coherence tomography (SD-OCT) showed that the fellow eyes had a normal macula. The parameters in the affected and fellow eyes were compared between the individual patients, including best-corrected visual acuity (BCVA), intraocular pressure (IOP), refractive error, axial length, choroidal thickness (CT) (subfoveal, 1.5 mm superiorly and inferiorly), posterior staphyloma height 3 mm from the fovea, length of retinal pigment epithelium (RPE) curvature within 6 mm measured on SD-OCT images, and choroidal degeneration and lacquer crack formation, graded according to a published METHOD RESULTS. The IOP, axial length, refractive error, and chorioretinal degeneration did not differ significantly. Affected eyes had a significantly higher lacquer crack grade (P < 0.05). The superior CT was not significantly different; the subfoveal and inferior CTs were significantly lower in the affected eyes (P < 0.05 and P < 0.001, respectively). The absolute value of the nasal posterior staphyloma height from the fovea was significantly greater in the affected eyes (P < 0.05), and the affected eyes had a significantly (P < 0.05) longer RPE curvature. CONCLUSIONS. Choroidal thinning resulting from increased RPE/choroid curvature is a risk factor for unilateral mCNV.

Transretinal Electrical Stimulation with a Suprachoroidal Multichannel Electrode in Rabbit Eyes

PurposeSeveral approaches for placing an electrode device for visual prosthesis have been previously proposed. In this study, we investigated if transretinal stimulation from the suprachoroidal space can elicit an electrical evoked potential (EEP) in albino rabbits.MethodsA flat electrode array (polyimide plate, platinum electrode) was developed and used for this study. After performing a scleral incision at 2–2.5 mm from the limbus and placing an anchoring suture, the array was inserted into the suprachoroidal space in the posterior portion of the eye by direct observation under a microscope. A platinum wire was implanted into the vitreous space as a reference electrode. For electrical stimulation, a biphasic pulse was used. When the electrode was stimulated, the EEP was recorded.ResultsWhen the electrical stimulation from the suprachoroidal space was applied, the EEP could be recorded with an epidural electrode, and the threshold was 66.0 ± 32.1μA (42.0μC/cm2). Histological examination indicated the absence of major damage to the retina and choroid from the insertion and placement of the array and the electrical stimulation.ConclusionsTransretinal electrical stimulation from the suprachoroidal space could elicit EEP, suggesting that this approach may be useful for a retinal prosthesis system.

Two-Year Visual Results for Older Asian Women Treated With Photodynamic Therapy or Bevacizumab for Myopic Choroidal Neovascularization

PURPOSE To compare the long-term visual and anatomic outcome of treatment with photodynamic therapy (PDT) or intravitreal bevacizumab (IVB; Avastin; Genentech Inc, South San Francisco, California, USA) for choroidal neovascularization attributable to pathologic myopia (mCNV). DESIGN An open-label, interventional case series. METHODS SETTING Multi-institutional. PATIENTS Thirty-one eyes of Japanese women who received either PDT or IVB for mCNV. Inclusion criteria were age 50 years or older, greatest linear dimension (GLD) 1200 to 3000 microm, and baseline best-corrected visual acuity (BCVA) 20/200 to 20/40. INTERVENTION PROCEDURES: Patients received either PDT or IVB (1 mg/40 microL) throughout the study, with re-treatment when necessary. MAIN OUTCOME MEASURES BCVA and visual gain/loss at 3, 6, 12, 18, and 24 months after the initial treatment. RESULTS Age, BCVA, location of CNV, refractive error, and symptom duration at baseline did not differ significantly between groups. BCVA was significantly improved at 3 to 12 months (P < .05); however, the significance was lost at 18 and 24 months in the IVB group. The PDT group showed no significant improvement within the first year, and vision slowly worsened after 12 months, becoming significantly worse at 18 and 24 months compared to baseline (P< .01). BCVA was significantly higher in the IVB group at 6 months (P< .05), and 12 months or further (P < .01). Visual gain was significantly greater in the IVB group at 6, 12, 18, and 24 months (P < .05 for 6, 18, and 24 months and P < .01 for 12 months). CONCLUSIONS These findings indicate that the effects of PDT and IVB have a different time course, and that IVB provides a significantly better BCVA than PDT for mCNV over the long-term.