Kenzo Hokazono

Evaluation of Inner Retinal Layers in Eyes With Temporal Hemianopic Visual Loss From Chiasmal Compression Using Optical Coherence Tomography

PURPOSE We measured macular inner retinal layer thicknesses using frequency-domain optical coherence tomography (fd-OCT) and correlated these measures with visual field (VF) in eyes with temporal hemianopia from chiasmal compression and band atrophy (BA) of the optic nerve. METHODS Macular fd-OCT scans and VFs were obtained from 33 eyes of 33 patients with temporal hemianopia and 36 control eyes. The macular retinal nerve fiber layer (mRNFL), combined retinal ganglion cell and inner plexiform layers (RGCL+), and the inner nuclear layer (INL) were segmented. Measurements were averaged for each macula quadrant. Scans were assessed qualitatively for microcysts in the INL. The VF was estimated from the central 16 test points. The two groups were compared. Correlations between VF and OCT measurements were assessed. RESULTS The mRNFL, RGCL+, and total retinal (TR) macular thickness measurements were significantly smaller in BA eyes than controls. In the nasal quadrants, INL measurements were significantly greater in BA eyes than controls. The mRNFL and RGCL+ measurements had greater discrimination ability than TR measurements in the temporal quadrants. A significant correlation was found between most OCT parameters and their corresponding VF parameters. The strongest association was observed between RNFL and RGCL+ thickness, and VF loss in the corresponding area. The INL microcysts were found in seven eyes with BA, but not in controls. CONCLUSIONS Band atrophy leads to mRNFL and RGCL+ thinning, and INL thickening, and mRNFL and RGCL+ measurements are correlated strongly with VF loss. Segmented macular thickness measurements may be useful for quantifying neuronal loss in chiasmal compression.

Correlation between multifocal pattern electroretinography and Fourier-domain OCT in eyes with temporal hemianopia from chiasmal compression

PurposeTo evaluate the correlation between multifocal pattern electroretinography (mfPERG) and Fourier-domain optical coherence tomography (FD-OCT) with regard to macular and retinal nerve fiber layer (RNFL) thickness in eyes with temporal hemianopia from chiasmal compression.MethodsTwenty-five eyes from 25 patients with permanent temporal visual field defects from chiasmal compression and 25 healthy eyes were submitted to mfPERG using a stimulus pattern of 19 rectangles, standard automated perimetry and FD-OCT measurements. The mfPERG response was determined for groups of three rectangles for the nasal and temporal hemifields and for each quadrant. Macular thickness measurements were registered according to an overlaid OCT-generated checkerboard with 36 checks and averaged for the central area, and for each scanned quadrant and hemifield. RNFL thickness was determined for all twelve 30-degree segments around the disc, and averaged for the segments corresponding to the 6, 7, 8, 9, 10, 11 and 12 o’clock position. Correlations were verified with Pearson’s correlation coefficients and linear regression analysis.ResultsBoth mfPERG amplitudes and OCT measurements were significantly smaller in eyes with temporal visual field defects than in normals. A significant and strong correlation was found between most mfPERG and macular or RNFL thickness OCT parameters.ConclusionsmfPERG amplitudes and OCT measurements are significantly correlated in patients with chiasmal compression. Both technologies can quantify neuronal loss and, if used in combination, may help clarify structure–function relationships in this patient population.

Relationship between Pattern electroretinogram, Frequency Domain-OCT and Automated perimetry in Chronic papilledema from Pseudotumor Cerebri Syndrome

PURPOSE We evaluated the ability of transient pattern electroretinogram (PERG) parameters to differentiate between eyes with visual field (VF) loss and resolved papilledema from pseudotumor cerebri syndrome (PTC) and controls, to compare PERG and optical coherence tomography (OCT) with regard to discrimination ability, and to assess the correlation between PERG, frequency domain OCT (FD-OCT), and VF measurements. METHODS The VFs and full-field stimulation PERGs based on 48 and 14-min checks were obtained from patients with PTC (n = 24, 38 eyes) and controls (n = 26, 34 eyes). In addition, FD-OCT peripapillary retinal nerve fiber layer (RNFL) and segmented macular layer measurements were obtained and correlation coefficients were determined. RESULTS Compared to controls, PERG N95 and P50+N95 amplitude measurements with 48-minute checks were significantly reduced in eyes with resolved papilledema from PTC. Both PERG N95 amplitude and OCT parameters were able to discriminate papilledema eyes from controls with a similar performance. Significant correlations, ranging from 0.25 (P < 0.05) to 0.43 (P < 0.01) were found between PERG amplitude values and OCT-measured macular ganglion cell layer thickness, RNFL thickness, and total retinal thickness. The PERG amplitude also was significantly associated with VF sensitivity loss with correlation coefficients ranging from 0.24 (P < 0.05) and 0.35 (P < 0.01). CONCLUSIONS The PERG measurements were able to detect neural loss in PTC eyes with resolved papilledema and were reasonably well correlated with OCT measurements and VF parameters. Thus, PERG may be a useful tool in the monitoring of retinal neural loss in eyes with active papilledema from PTC.

Pattern-reversal electroretinograms for the diagnosis and management of disorders of the anterior visual pathway

The pattern electroretinogram is an electrophysiological test that assesses the function of inner retinal layers, particularly the ganglion cells layer of retina, using a reversing checkerboard or grating pattern that produces no change in average luminance over time. The normal pattern electroretinogram is composed of a proeminent positive component (P50) and a large later negative component (N95). Since structural damage that compromises the retinal ganglion cell layer can lead to pattern electroretinogram changes, particularly in the N95 amplitude, the test can be useful in the treatment of a number of anterior visual pathway diseases. In this article, we review the methods for recording pattern electroretinogram and its usefulness in the diagnosis and management of diseases including inflammatory, hereditary, ischemic and compressive lesions of the anterior visual pathway.

Perfluoroctano em cavidade orbitária após vitrectomia posterior e sutura de perfurante ocular: relato de caso

A case of a perfluoro-n-octane leakage into the orbital cavity after corneoscleral suture, scleral buckling and pars plana vitrectomy in an eye with perforating injury after trauma is reported for the first time. A previously healthy 39-year-old man was sent for ophthalmic evaluation one day after suffering a penetrating ocular trauma in his right eye while hammering a nail. On the initial evaluation, the patient presented sudden reduction of visual acuity on his right eye with a perforating corneoscleral injury, intraocular foreign body and retinal detachment. The patient was submitted to corneoscleral suture, pars plana vitrectomy with perfluoro-n-octane administration to flatten the retina and scleral buckling, when it was found transfixation of the globe by the intraocular foreign body. Postoperatively, computed tomography scans of the orbit were ordered due to proptosis, which showed the presence of hyperdense images, suggesting leakage of perfluoro-n-octane into the orbital cavity. Thus, in cases of perforating eye injury, one should be suspicious about the possibility of intraocular foreign body, as well as possible occurrence of transfixation of the globe when scheduling the surgery.

Sensibilidade ao contraste na retinopatia diabética tratada por panfotocoagulação com laser de argônio

PURPOSE To evaluate contrast sensitivity in patients with diabetic retinopathy (DR) treated with argon laser panphotocoagulation. METHODS Prospective study of patients with diabetic retinopathy and 20/20 visual acuity, treated with retinal panphotocoagulation, following ETDRS criteria. The patients were submitted, initially, to complete ophthalmologic evaluation and contrast sensitivity testing (Vision Contrast Test System). After 3 months of treatment, they were reevaluated by means of visual acuity and contrast sensitivity. RESULTS The sample comprised 28 patients (28 eyes), all with type II diabetes. A ranged from 45 to 77 years (mean 57.8+/-8.0), 19 (67.9%) patients were male and 9 (32.1%) female. Regarding the type of retinopathy, 18 (64.3%) had proliferative DR and 10 (35.7%) very severe non proliferative RD. No visual acuity alteration was observed after treatment. In relation to contrast sensitivity, there were no alterations between pre and post-treatment in all evaluated spacial frequencies 1.5 (p=0.191); 3.0 (p=0.850); 6.0 (p=0.374); 12.0 (p=0.674) e 18.0 (p=0.443). CONCLUSION There was no significant alteration in the contrast sensitivity of patients with diabetic retinopathy after panphotocoagulation with argon laser in the studied period.

Tratamento da retinopatia por radiação com injeção intravítrea de bevacizumab (Avastin®): relato de caso

PURPOSE To report a case of radiation retinopathy treatment with intravitreal injection of bevacizumab (Avastin®) in a patient undergoing radiotherapy for lymphoma in the right orbit. Patient of 55 years-old male, diabetic, diagnosed with an orbital MALT lymphoma three years ago, treated with local radiotherapy (dose: 35Gy) two years ago, complaining of reduced visual acuity of the right eye for about four months. During the ophthalmologic evaluation, he had an exam suggestive of radiation retinopathy. Macular thickness at the optical coherence tomography was 480 µm. Patient was referred to intravitreal injection (0.05 ml) of bevacizumab (Avastin®) in the right eye, showing reduction of macular edema and mild improvement of visual acuity. In this case, the treatment of radiation retinopathy with intravitreal injection of bevacizumab (Avastin®) was relatively useful, with mild improvement of visual acuity due to the regression of macular edema.

Síndrome do ápice orbitário causada por herpes zóster oftálmico: relato de caso e revisão da literatura

Herpes Zoster ophthalmicus (HZO) is caused by a varicella-zoster virus infection which remains latent in the ganglion of Gasser until it is reactivated and compromise the ophthalmic division of the trigeminal nerve. HZO commonly causes neuro-ophthalmic complications such as vesicular lesions in the eyelids, keratoconjunctivitis, sclertis, uveitis, ocular palsy, orbital miositis and optic neuritis. HZO rarely presents as an orbital apex syndrome. This paper describes a patient with of orbital apex syndrome associate and meningitis caused by HZO which was treated with systemic steroids and acyclovir.

Meningioma do nervo óptico simulando progressão de dano axonal glaucomatoso: relato de caso

To report a case of an optic nerve sheath meningioma located at the optic canal area mimicking the progression of a glaucomatous axonal damage. A 60-year-old female patient developed progressive visual field loss and enlargement of the optic disc cup in the left eye while in treatment for primary open-angle glaucoma. Because of the rapid progression of axonal loss, the asymmetry of the visual field defect and the fact that intraocular pressure had been under control, a compressive optic neuropathy was suspected. A computerized tomography scan of the orbit was normal but a high-resolution magnetic resonance imaging demonstrated an optic nerve sheath meningioma located at the optic canal area. Compressive lesions of the anterior visual pathways are uncommon causes of optic disc cupping but should be considered in patients suspected of or undergoing treatment for glaucoma that present with atypical progression of visual loss.