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A Kakehashi

Publications and source records attributed to A Kakehashi.

At least 19 recordsLinked to original sources
PubMed1999

Combined system of biomicroscopic vitreous videography and photography.

PURPOSE: To combine the techniques of biomicroscopic vitreous videography and vitreous photography when examining patients with age- or disease-related vitreous changes. METHODS: We performed biomicroscopic vitreous videography and photography using the newly developed digital photo camera (one-half-inch three-charged coupled device camera with high resolution of 800 x 800 television lines) connected to a slit-lamp biomicroscope and compared it with conventional 35-mm slit-lamp photography in 24 consecutive eyes of 19 patients with idiopathic macular breaks. RESULTS: Stage 1 macular breaks were found in three eyes, stage 2 in four eyes, stage 3 in 11 eyes, and stage 4 in six eyes. Both vitreous videographs and still photographs were recorded and reviewed rapidly in one system. Using this system, dynamic vitreous changes and still vitreous images were documented clearly with real-time television monitoring without using flash illumination. The still images obtained from this system were better than those obtained using conventional 35-mm slit-lamp photography in cases with stage 1, 2, and 3 macular breaks (P = 0.0000000001 by Fisher's exact test). CONCLUSION: This combined system of biomicroscopic vitreous videography and photography may become the standard system of biomicroscopic vitreous examination.

Aged↗
PubMed1998

Predictive value of floaters in the diagnosis of posterior vitreous detachment.

PURPOSE: To evaluate Weiss ring and floaters as indexes of posterior vitreous detachment. METHODS: Using biomicroscopy and indirect ophthalmoscopy, we examined the posterior vitreous in 200 consecutive eyes with posterior vitreous detachment. RESULTS: In 200 eyes with posterior vitreous detachment, biomicroscopy disclosed complete, incomplete, and no Weiss ring in 102 (51%), 72 (36%), and 26 (13%) eyes, respectively. Indirect ophthalmoscopy showed the glial ring in 58 (56.9%) and 16 (22.2%) of the eyes, with a complete (102 eyes) and incomplete (72 eyes) Weiss ring, respectively. Although the incidence of floaters was significantly correlated with the presence of the glial ring (P = .0014), 60 (58.8%) and 49 (68.1%) of the eyes with a complete (102 eyes) and incomplete (72 eyes) glial ring, respectively, had no floaters. CONCLUSION: Detecting the detached posterior vitreous cortex by biomicroscopy is essential regardless of the presence of Weiss ring or floaters.

Aged↗
PubMed1997

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 occlusions (8 eyes, 20.5%); in partial PVD with TPVC (64 eyes), proliferative diabetic retinopathy (30 eyes, 46.9%); and inpartial 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, chi 2 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.

Adult↗
PubMed1997

Copper-ion-catalyzed vitreous liquefaction in vivo.

To investigate copper-ion (Cu2+)-catalyzed vitreous liquefaction in vivo, Cu2+ solution (10 mumol) was injected into the vitreous cavity of rabbits. At 24 h after the injection, the gel and liquid vitreous were weighed, and the percent of vitreous liquefaction was calculated. Cu2+ injection resulted in liquefaction of 58% of the vitreous, although control eyes had 12% liquefaction (p < 0.1). The vitreous liquefaction was more pronounced in the presence of exogenous ascorbic acid. However, the addition of mannitol, a hydroxyl-radical-specific scavenger, significantly suppressed the Cu(2+)-catalyzed vitreous liquefaction. The free radicals generated by the Cu(2+)-catalyzed oxidation system may cause vitreous liquefaction in vivo.

Animals↗
PubMed1996

Vitreomacular observations. II. Data on the pathogenesis of idiopathic macular breaks.

BACKGROUND: The pathogenesis of idiopathic macular breaks is still uncertain. Their formation has been ascribed to anteriorly oriented intravitreous traction and to shrinkage of the prefoveal cortical vitreous. The validity of both hypotheses is considered in this paper. METHODS: In order to clarify the pathogenesis of idiopathic macular breaks 127 consecutive patients had their vitreous examined and photographed with the El Bayadi-Kajiura precorneal lens and a slit-lamp microscope. RESULTS: A comparison with 127 matched controls demonstrated that the vitreous was significantly more often attached in eyes with a macular break than in controls (P < 0.01). In eyes with a macular break the vitreous was significantly more often attached in early cases (Gass stage 1) than in Gass stages 3 and 4 (P < 0.01). Still photographs and observation of the movements of the operculum demonstrated that, in some cases of stage 3 and also in stage 4, it moved inside the partially liquefied posterior vitreous, anteriorly to the retinal surface and frequently without evidence of posterior vitreous detachment over the macular area. The following anatomical features characterize the vitreomacular area: extremely thin hyaloid membrane (< 100 microns) and inner limiting lamina (10 nm) that adhere strongly to each other and to the underlying Mueller cells. There is no evidence that these structures can shrink selectively to cause a macular break. The premacular vitreous gel contains collagen fibers that attach posteriorly to the macula and anteriorly to the vitreous base. CONCLUSIONS: Our working hypothesis is that when detachment of the posterior vitreous is abnormally delayed, anteroposterior traction by collagen fibers may pull a foveal operculum off the retina. Our observations make this hypothesis attractive. However, the generally accepted hypothesis of Johnson and Gass cannot be entirely dismissed. In reality, since the two hypotheses are not mutually exclusive, they may both the partially correct.

Aged↗
PubMed1996

Differential diagnosis of macular breaks by microperimetry using the scanning laser ophthalmoscope.

To improve the differential diagnosis of macular breaks by microperimetry using the scanning laser ophthalmoscope (SLO), we studied 50 consecutive breaks detected by biomicroscopy and indirect ophthalmoscopy. The full-thickness macular break was easily diagnosed using only biomicroscopy and indirect ophthalmoscopy because the macular break had a cuff in 22 of the eyes. SLO microperimetry also showed an absolute scotoma within the macular break and a relative scotoma on the cuff in these 22 eyes. However, in the other 28 eyes it was impossible to distinguish between the full-thickness macular breaks and pseudo-macular breaks or lamellar macular breaks using only biomicroscopy and indirect ophthalmoscopy because of the absence of a cuff. However, SLO microperimetry differentiated full-thickness macular breaks from pseudomacular breaks or lamellar macular breaks in these 28 eyes. SLO microperimetry is indispensable for determining the prognosis of and the surgical indication requirements for idiopathic macular breaks.

Diagnosis, Differential↗
PubMed1996

Clinical characteristics of traumatic macular holes.

The clinical characteristics of 20 eyes of 20 consecutive patients with traumatic macular hole were studied retrospectively. The macular holes were elliptical with irregular edges in 19 eyes (95%) and ranged in size from 0.2 to 0.5 DD (disc diameter). Posterior vitreous detachment (PVD) was found in only 3 eyes (15%); the vitreous was detached from the macula in only one of these 3. Other conditions found in the 20 patients included commotio retinae, vitreous hemorrhage, hyphema, and choroidal rupture. These findings strongly suggest that most traumatic macular holes develop in the absence of PVD and that the pathogenesis is independent of the occurrence of PVD. We believe that the macular rupture (hole) is caused mechanically by the force of the impact on the posterior pole and the ocular deformity which result from blunt trauma.

Accidents↗
PubMed1995

Serum-induced collagen gel contraction.

PURPOSE: To understand the molecular events underlying disease-related vitreous gel contraction, the effect of serum components on collagen was investigated. METHODS: Bovine vitreous or dermal collagen was incubated with a mixture of transglutaminase (TG; factor XIIIa) and fibronectin (FN), and the biochemical changes of collagen were monitored by gel electrophoresis. In addition, serum-induced changes in the volume of the collagen gel were monitored. RESULTS: Gel electrophoresis revealed a new high-molecular-weight band (M(r) 240,000) presumably due to intermolecular cross-links of collagen peptides and FN. The serum components also were shown to cause a significant decrease in the volume of the collagen gel. CONCLUSION. Collagen gel contraction could be attributed to the collagen-FN-collagen cross-links catalyzed by TG.

Animals↗
PubMed1995

Spontaneous resolution of foveal detachments and macular breaks.

PURPOSE: To evaluate the mechanism of spontaneous resolution of foveal detachments and idiopathic macular breaks. METHODS: We reviewed the records of 139 consecutive eyes (94 patients) with either a foveal detachment or a macular break in patients who were examined between 1989 and 1992. There were 26 men and 68 women (mean age, 66.9 +/- 6.9 years). They were either unoperated on or observed during the period that preceded surgery. Each patient underwent complete ophthalmic examination in addition to slit-lamp photography of the vitreomacular interface and microperimetry with the scanning laser ophthalmoscope. RESULTS: Eight eyes demonstrated spontaneous resolution. A foveal detachment was noted in five eyes (five patients) and a stage 2 macular break in three eyes (three patients). The mean duration of observation was 33 months (range, one to 144 months). Resolution of the foveal detachments occurred without the development of posterior vitreous detachment. In each eye, the presence of a pseudo-operculum, indicating vitreofoveal separation, was accompanied by flattening of the foveal detachment without detectable posterior vitreous detachment. The three eyes with stage 2 macular break resolved after premature development of a posterior vitreous detachment. CONCLUSIONS: Foveal detachment and macular break resolution seem to result from the release or weakening of vitreous traction on the fovea. Reattachment of the foveal retina preserves fair to good visual acuity. Surgical intervention is contraindicated (1) in eyes in which foveal detachment flattens and develops a pseudo-operculum and (2) when a posterior vitreous detachment develops in an eye with a stage 2 macular break. Careful biomicroscopic vitreous examination and microperimetry with the scanning laser ophthalmoscope are extremely useful methods for adequate examination of these patients.

Aged↗
PubMed1995

Vitreous observation using a CCD camera and a computerized unit for image processing and storage.

PURPOSE: This study was conducted to evaluate a new technique of vitreous observation. METHODS: The authors used commercially available devices, including a slit-lamp, monochromatic charge coupled device (CCD) camera, and a computerized unit for image processing and storage, to observe the vitreous and the vitreoretinal relationship. RESULTS: The authors obtained good images of the vitreous and the vitreoretinal relationship using the new technique. Furthermore, the image stored in the computer could be accessed and used for patient explanations instantly. CONCLUSION: This technique is useful for documenting the vitreous and can help determine the role of the vitreous in many vitreoretinal disorders.

Aged↗
PubMed1995

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.

Adult↗
PubMed1995

[Traumatic macular hole and posterior vitreous].

We studied retrospectively the clinical features of 18 eyes of 18 patients with traumatic macular hole. The macular hole was elliptical with irregular edges in 17 eyes (94%) and its size ranged from 1/5 to 1/2 of the disc diameter. Posterior vitreous detachment was found in 3 eyes (17%); the vitreous was detached from the macula in only one of these 3 eyes. Commotio retinae, vitreous hemorrhage, hyphema, or choroidal rupture was also found in several eyes. These findings suggest that traumatic macular hole develops usually in the absence of posterior vitreous detachment and its pathogenesis is independent of the occurrence of posterior vitreous detachment. We speculate that blunt trauma-induced deformity of the eyeball or impact on the posterior pole provides a mechanical cause for the macular rupture.

Adolescent↗
PubMed1995

[Vitreous videography with a scanning laser ophthalmoscope].

We used a scanning laser ophthalmoscope (SLO) to attempt better visualization of the posterior vitreous than conventional biomicroscopy. We observed the posterior vitreous using the SLO in patients with age- or disease-related vitreous changes. We compared the results using lasers of several wavelengths. The detailed structure of the posterior hyaloid membrane, its collagen mesh structure with premacular defect, and the prepapillary glial ring were clearly visualized by direct laser illumination. Persistent attachment of the vitreous gel to the macula through the oval defect in the posterior hyaloid membrane was seen even with repeated eye rotations. Short wavelength laser was preferable to a long wavelength one for observing the posterior hyaloid membrane. Vitreous opacities were clearly visualized with all lasers as dark spots with fundus monitoring by retro illumination. Thus in vivo visualization of the posterior hyaloid membrane and vitreous gel was achieved using this new technique, which is more advantageous than the conventional biomicroscopy because of its monochromatic laser delivery system with confocal light detection.

Adolescent↗
PubMed1995

[Differential diagnosis of macular breaks by microperimetry with a scanning laser ophthalmoscope].

To improve differential diagnosis of macular breaks, microperimetry with a scanning laser ophthalmoscope (SLO) was performed. Fifty consecutive macular breaks were detected by biomicroscopy and indirect ophthalmoscopy, and SLO microperimetry was performed on each. Of the 50 eyes, 22 eyes were diagnosed with idiopathic macular breaks by biopmicroscopy and indirect ophthalmoscopy because of a cuff. SLO microperimetry also showed dense scotoma within the macular break and relative scotoma on the cuff in the 22 eyes. However, diagnosis was not done only by biomicroscopy and indirect ophthalmoscopy in the other 28 eyes because of the absence of a cuff. SLO microperimetry differentiated the full thickness macular breaks from pseudo-or lamellar breaks in these eyes. SLO microperimetry is useful for differentiating their prognosis, and determining the need for surgical treatment.

Aged↗
PubMed1995

[Biomicroscopic findings of premacular posterior vitreous].

The presence of vitreous gel in front of the macular area is still controversial. In order to understand the anatomy of the premacular vitreous, the posterior vitreous was observed biomicroscopically and slit-lamp photographs were taken in 100 eyes without posterior vitreous detachment. We defined the premacular vitreous as the lacuna seen when optically empty space, a demarcated oval shaped dark area without Tyndall phenomenon, was observed in front of the macula. Although the premacular vitreous showed liquefaction, the Tyndall-phenomenon, indicating the presence of formed vitreous gel, was observed in most cases. Premacular lacuna was observed in 3 cases with high myopia, and in one case with vitreoretinal degeneration syndrome. The bursa premacularis or premacular precortical vitreous pocket observed in autopsy eyes could barely be observed in living eyes.

Adolescent↗
PubMed1995

[Observing idiopathic macular break by scanning laser ophthalmoscope vitreous videography].

We used vitreous videography in conjunction with the scanning laser ophthalmoscope (SLO) to evaluate the pathogenesis of idiopathic macular breaks. The fundamental aspect of this method is videographic documentation of the mobile posterior vitreous and an operculum. The high reflectivity from the vitreous gel using the SLO clearly showed the mobility of the operculum and the posterior vitreous in the idiopathic macular breaks. In some cases without posterior vitreous detachment, the operculum initially was suspended superior to the macular break and anterior to the retinal surface. Upon ocular movement, the operculum moved down smoothly in front of the macular break. The findings of these vitreous videographs using the SLO suggest that anteriorly oriented vitreous traction is one cause of idiopathic macular breaks.

Aged↗
PubMed1995

Vitreous videography using the scanning laser ophthalmoscope.

To establish the method of vitreous videography using the scanning laser ophthalmoscope, we observed the vitreous in patients with age- or disease-related vitreous changes. We compared the results using four laser wavelengths. The detailed structures of the posterior vitreous cortex, a premacular defect, and a prepapillary glial ring were clearly shown under direct laser illumination. A short wavelength laser was found to be superior to a long wavelength laser for observing the posterior vitreous cortex. Vitreous opacities were clearly shown as dark spots under retroillumination using any of the four laser wavelengths. In vivo visualization of the vitreous was achieved using this new technique, which is superior to conventional biomicroscopy because of its monochromatic laser delivery system and confocal light detection capacity.

Adolescent↗