Hiroyuki Hirokawa

Role of the Vitreous in Idiopathic Preretinal Macular Fibrosis

Of 250 eyes with idiopathic preretinal macular fibrosis, 56 had no posterior vitreous detachment (Group 1), ten had partial posterior vitreous detachments without vitreous traction to the macula (Group 2), 29 had partial posterior vitreous detachments with vitreous traction to the macula (Group 3), and 155 had complete posterior vitreous detachments (Group 4). There were significantly more eyes with visual acuities of 20/60 or worse, cystoid macular changes, or macular fluorescein leakage in Group 3 than in Group 1 or Group 4. Thus, the presence of vitreous traction to the macula was associated with worse anatomic and functional findings.

Variations of posterior vitreous detachment

AIMS To identify variations in posterior vitreous detachment (PVD) and establish a clinical classification system for PVD. METHODS 400 consecutive eyes were examined using biomicroscopy and vitreous photography and classified the PVD variations—complete PVD with collapse, complete PVD without collapse, partial PVD with thickened posterior vitreous cortex (TPVC), or partial PVD without TPVC. RESULTS In each PVD type, the most frequently seen ocular pathologies were as follows: in complete PVD with collapse (186 eyes), age related changes without vitreoretinal diseases (77 eyes, 41.4%) and high myopia (55 eyes, 29.6%); in complete PVD without collapse (39 eyes), uveitis (23 eyes, 59.0%) and central retinal vein occlusion (8 eyes, 20.5%); in partial PVD with TPVC (64 eyes), proliferative diabetic retinopathy (30 eyes, 46.9%); and in partial PVD without TPVC (111 eyes), age related changes without vitreoretinal diseases (62 eyes, 55.9%). This PVD categorisation was significantly associated with the prevalence of each vitreoretinal disease (p<0.0001, χ2 test on contingency table). CONCLUSIONS PVD variations can be classified into four types, which is clinically useful because each type corresponds well to specific vitreoretinal changes.

Oral fluorescein angiography with the confocal scanning laser ophthalmoscope

OBJECTIVE To evaluate the efficacy of oral fluorescein angiography with a confocal scanning laser ophthalmoscope (SLO) system. DESIGN Comparative case series. PARTICIPANTS The authors used a confocal SLO (Heidelberg Retina Angiograph [HRA]) to perform oral fluorescein angiography in 47 patients, 13 of whom were without any retinal disease and 34 with a variety of retinal diseases including macular holes and pucker, inflammatory diseases, retinal vascular diseases, and age-related macular degeneration. The images were also compared to images taken with a fundus camera after intravenous fluorescein injections in patients on whom both studies were done. INTERVENTION Color fundus photographs were taken of each eye (30 degrees fundus camera) before drinking 4 ml of 25% sodium fluorescein mixed with 60 ml of orange juice. After oral fluorescein ingestion, images of each eye were taken with a fundus camera (TriX film) and the HRA (using 512- x 512-pixel resolution). The images were repeated at 0-, 2.5-, 5-, 7.5-, 10-, 12.5-, 15-, 20-, 25-, and 30-minute intervals. Twenty of the 47 patients underwent intravenous fluorescein angiography performed with the fundus camera. MAIN OUTCOME MEASURE Images were analyzed by a masked reader, and foveal avascular zone visualization, branch retinal vessel identification, and image quality were scored. Statistical analysis was performed with a t test for paired data with a two-tailed test of significance (alpha = 0.05). RESULTS Foveal avascular zone was 100% as seen in 16 eyes (47%) in the HRA machine versus 1 eye (2%) in the conventional fundus camera (P < 0.0001). The third-order branch retinal vessels were identified in 59% of eyes in the HRA versus 26% in the fundus camera group (P < 0.0001), and the image quality was considered comparable to an intravenous angiogram in 47% with the HRA versus 9% with the conventional fundus camera (P < 0.0001). CONCLUSIONS Oral fluorescein angiography using the HRA produces sufficiently detailed images to diagnose, treat, and follow many types of retinal pathology.

Examination of the Vitreous: A Comparison of Biomicroscopy Using the Goldmann and El Bayadi-Kajiura Lenses

Vitreous examinations using the three-mirror Goldmann and the preset El Bayadi-Kajiura lenses were performed on 222 eyes. The presence of posterior vitreous detachment, vitreous traction, liquefaction, lacunae, and cells was noted. Clinical findings using the two lenses differed in 10% of the variables studied. The accuracy of the El Bayadi-Kajiura technique was confirmed by clinical and histological examination of 20 animal eyes with experimentally altered vitreous. The Goldmann lens afforded examination of peripheral vitreous and better identification of cells in the vitreous, whereas the El Bayadi-Kajiura lens permitted better visualization of complex vitreoretinal relationships.

Ocular circulatory changes following scleral buckling procedures.

The effect of segmental scleral buckling (SB) on ocular circulation was evaluated by measurements of the ocular pulse amplitude (PA) and the ophthalmic artery pressure (OAP). In this study the OAP was defined as the intraocular pressure (IOP) at which the PA disappeared during increasing IOP. Twenty four patients with unilateral rhegmatogenous retinal detachment who underwent SB of varying extent were studied; the unoperated fellow eyes served as controls. Both the OAP and the ophthalmic perfusion pressures (OAP minus IOP) decreased significantly (p < 0.01) as the area of SB treatment increased. Follow-up measurements showed that the OAP was relatively lower up to 3 months postoperatively than after 3 months, and then remained stable. Our results indicated that SB affects the ocular pulse measurements and may decrease ocular blood flow because of decreased ophthalmic perfusion pressure, probably due to increased choroidal vascular resistance, and that the greater the extent of the SB treatment, the greater the possibility of decreased ocular blood flow.

Abnormal vitreous structure in optic nerve pit

A 37-year-old man presented with an optic nerve pit and serous macular detachment of the left eye. Scanning laser ophthalmoscopy revealed a cyst-like structure terminating at the pit in the premacular vitreous. During ocular movement, this structure moved vigorously and seemed to exert traction on the pit. We believe that it is part of an anomalous Cloquets canal, and that traction on the pit may be a significant factor in the development of serous macular detachment in this patient.

BIOMICROSCOPIC VITREOUS VIDEOGRAPHY

Purpose The authors report on the technique of biomicroscopic vitreous videography using the recently developed charge coupled device (CCD) video camera. Methods The authors performed biomicroscopic vitreous videography using the CCD video camera connected to a slit-lamp biomicroscope to examine 50 eyes with age-or disease-related vitreous changes in 50 patients. The cases were categorized as follows: 20 normal senile eyes; 10 eyes with retinal breaks; 10 eyes with diabetic retinopathy; 5 eyes with uveitis; and 5 eyes with high myopia. Noncontact positive preset lenses were used for observing the posterior vitreous; a wide-angle funduscopic contact lens and a three-mirror contact lens were used to observe the peripheral vitreoretinal changes. Results Using the CCD video camera, dynamic vitreous changes were documented clearly using real-time television monitoring. The video system also allowed rapid review of the vitreous changes. Conclusion This new biomicroscopic vitreous videography system will contribute to the study of vitreoretinal diseases and be valuable as an educational tool.

Immunohistochemical Study of Idiopathic and Secondary Epiretinal Membrane

PURPOSE We investigated the immunohistochemical features of surgically resected idiopathic epiretinal membranes(ERMs) and secondary ERMs with regard to posterior vitreous detachment(PVD). METHODS Six specimens of idiopathic epiretinal membranes(3 eyes with complete PVD, 2 eyes with partial PVD, and one eye with no PVD) and 3 specimens of secondary ERMs(all eyes with complete PVD) were immunohistochemically studied. We used type I, II, III, IV collagen and fibronectin to study extracellular components, and glial fibrillary acidic protein(GFAP), S 100 protein, vimentin, and so forth to study cellular components. RESULTS All the specimens of idiopathic ERMs had the major components of the lamellar stained by type II collagen antibody, and one out of 3 specimens of secondary ERMs had a minor component stained by type II collagen antibody. Compared with idiopathic ERMs with complete PVD, 2 out of 3 specimens of idiopathic ERMs with partial PVD or no PVD contained rather thick collagen lamellar. CONCLUSION There was difference between specimens of idiopathic ERMs and specimens of secondary ERMs in staining by type II collagen antibody, supposed by vitreous, in this study. Idiopathic ERM with attached posterior vitreous membrane may cause growth of collagen.