Koji Esaki

Ultrasound Biomicroscopy Dark Room Provocative Testing: ☆ ☆☆: A Quantitative Method for Estimating Anterior Chamber Angle Width

PURPOSE To describe a quantitative method for measuring the iridocorneal angle recess area, and, using this, to evaluate factors associated with appositional angle-closure during dark room provocative testing using ultrasound biomicroscopy (UBM). METHODS All patients (178 patients, 178 eyes) with clinically narrow angles referred for UBM dark room provocative testing between September 1996 and March 1998 were enrolled in this study. Images of the inferior quadrant of the angle taken under standardized dark and light conditions were analyzed. The angle recess area (ARA) was defined as the triangular area demarcated by the anterior iris surface, corneal endothelium, and a line perpendicular to the corneal endothelium drawn from a point 750 microm anterior to the scleral spur to the iris surface. ARA, and acceleration and gamma-intercept of the linear regression analysis of the ARA were calculated. In the linear regression formula, y = ax + b, the acceleration a describes the rate at which the angle widens from the scleral spur; the y-intercept b describes the distance from the scleral spur to the iris. RESULTS Under dark conditions, the angles in 99 patients (55.6%) showed evidence of appositional angle-closure during testing. ARA (0.11 +/- 0.04 vs. 0.15 +/- 0.05 mm2, P < .0001, Student t-test), acceleration a (0.22 +/- 0.15 vs. 0.26 +/- 0.17, P = .068), and y-intercept b (66 +/- 46 vs. 92 +/- 47 microm, P = .0003) were smaller in eyes that were occluded. In the eyes that were not occluded, y-intercept b showed no significant difference between light and dark conditions (P = .1, paired t-test), while acceleration a did (P < .0001). In the eyes that were occluded, both decreased significantly under dark conditions (P < .0001). CONCLUSIONS The ARA linear regression formula provides useful quantitative information about angle recess anatomy. The more posterior the iris insertion on the ciliary face, the less likely the provocative test will be positive.

Differential diagnosis of anterior segment cysts by ultrasound biomicroscopy

BACKGROUND To describe the ultrasound biomicroscopic (UBM) features of anterior segment cysts. DESIGN A retrospective case series. PARTICIPANTS One hundred eighteen eyes with anterior segment cysts examined by UBM at The New York Eye and Ear Infirmary between August 1992 and November 1997 were included in this study. INTERVENTION The authors reviewed demographic and diagnostic data from the medical record including ocular and medical history, age, race, gender, and intraocular pressure. Ultrasound data concerning the type, number, position, and acoustic characteristics of cysts were recorded. The authors then correlated the written, clinical, and UBM characteristics. RESULTS One hundred eyes (92.6%) had neuroepithelial cysts. Ninety (83.3%) of these had primary neuroepithelial cysts, 10 (9.3%) had cysts associated with uveitis, 7 (6.5%) had implantation cysts, and 1 (0.9%) had a cavitated ciliary body tumor. Neuroepithelial cysts typically were round or ovoid, thin-walled, and echolucent. Of the 90 eyes with primary neuroepithelial cysts, 56 (62.2%) had 3 or fewer cysts; multiple cysts (>3 per eye) were found in 34 eyes (37.8%). The multiple cysts occupied more than 180 degrees in 12 patients (13.3%). Primary neuroepithelial cysts were located at the iridociliary junction (74.2%), pars plicata (14.0%), pars plana (6.8%), and iris (5.0%). Implantation cysts (seven eyes) tended to have thicker walls and two contained a copious, echogenic material. CONCLUSION The UBM results provide important information regarding location and extent of anterior segment cystic lesions. Ultrasound characteristics may help differentiate between neuroepithelial, implantation, and neoplastic cysts.

Evaluation and comparison of indentation ultrasound biomicroscopy gonioscopy in relative pupillary block, peripheral anterior synechia, and plateau iris configuration

Purpose:To evaluate and compare the findings and changes of the anterior chamber angle configuration with indentation ultrasound biomicroscopy (UBM) gonioscopy in relative pupillary block (RPB), peripheral anterior synechia (PAS), and plateau iris configuration (PIC). Methods:This study included 73 eyes of 52 patients with RPB (n = 26), PAS (n = 21), or PIC (n = 26). First, a conventional UBM scan was performed using a normal size standard eye cup before indentation. Then, for indentation UBM gonioscopy, scans were performed using a new eye cup that we designed. For evaluation of the angle, angle opening distance 500 and angle recess area were recorded and evaluated with regard to the effect of expansion on the anterior chamber angle. Results:Indentation UBM gonioscopy showed the characteristic images in each of the eyes. The angle of all examined eyes was significantly widened with indentation (P < 0.01). The angle changes in eyes with RPB were significantly greater than in eyes with PAS or PIC (P < 0.01). Conclusion:Indentation UBM gonioscopy is a very useful method for observing the angle and diagnosis of RPB, PAS, and PIC.

Supraciliochoroidal Fluid at an Early Stage After Trabeculectomy

PURPOSE To examine the supraciliochoroidal fluid(SCF) by ultrasound biomicroscopy(UBM) at an early stage after trabeculectomy. SUBJECTS AND METHODS Fifteen eyes without post-operative complications were examined by UBM before the operation and less than 2 weeks after trabeculectomy with mitomycin C. RESULTS SCF was detected postoperatively in 6 eyes. One eye had choroidal detachment under indirect-ophthalmoscope and 5 eyes(33%) had SCF without choroidal detachment. The SCF in 4 eyes disappeared within 4 weeks after trabeculectomy. The intraocular pressure was 6.4 +/- 3.4 mmHg(mean +/- standard deviation) when SCF was detected and it rose to 13.2 +/- 7.2 mmHg when SCF disappeared. The intraocular pressure was 11.4 +/- 4.0 mmHg in the eyes without SCF, which was significantly higher than in the eyes with SCF. CONCLUSION At an early stage after trabeculectomy, SCF was detected by UBM in some cases without ophthalmoscopic choroidal detachment. Compared with the reported frequency of SCF after 3 or 6 months, our study revealed that SCF was present more frequently at an early stage after trabeculectomy. Our results may indicate that the presence of SCF is related to early low intraocular pressure and that disappearance of SCF induces the elevation of intraocular pressure.

Angle recess area decreases with age in normal Japanese.

PURPOSE To investigate prospectively the relationships between anterior chamber angle configuration and refractive error, axial length, age, and body height in the Japanese. METHODS We studied 65 eyes of 65 subjects (30 men, 35 women) who were either patients at the Ophthalmology Department of Mie University or volunteers. The 65 subjects underwent a complete eye examination, A-scan biometry, and ultrasound biomicroscopy. Images were exported to an IBM-compatible personal computer in PCX format. The angle recess area (ARA) was measured using a software program of our own design. RESULTS The ARA decreased with age in all quadrants of all eyes. In older individuals, the angle in the superior quadrant was significantly narrower than in the other quadrants. The ARA correlated directly with anterior chamber depth (P < .001), axial length (P < .001), and body height (P = .003), and inversely with age (P < .001) and refractive error (P = .003) in pairwise analysis. Multivariate analysis revealed a significant association between ARA and anterior chamber depth (P < .001), axial length (P = .016), and younger age (P = .043). CONCLUSIONS The anterior chamber area narrows with age, especially in the superior quadrant. Narrowing of the angle in Japanese is associated with older age, shorter axial length, and shallower anterior chamber depth. We hypothesize that because of the increasing prevalence of axial myopia in younger Japanese, angle-closure glaucoma could become less common in Japan in the future.

Extrusion and fragmentation of hydrogel exoplant 11 years after scleral buckling surgery

MAI or MIRAgel is a hydrogel developed as a scleral buckling material. We identified upper lid masses and a limitation of supraduction in the left eye of a patient who was associated with extrusion and fragmentation of the MIRAgel episcleral exoplant 11 years after scleral buckling surgery. The material could not be removed completely because of fragmentation. Fragmentation and extrusion of MIRAgel may be rare, but periodic long-term follow-up examinations should be performed after this product has been used.

Anterior chamber structural change in postural variation in pseudoexfoliation syndrome

PURPOSE The anterior chamber structure in the supine position and the prone position was investigated with ultrasound biomicroscopy (UBM) in pseudoexfoliation syndrome (PE). METHODS We studied 12 eyes of 12 PE subjects. Patients were placed in the supine position for 30 minutes, after which UBM was performed. The UBM was repeated after 30 minutes in the prone position. Anterior chamber depth (ACD), angle opening distance 500 microns (AOD 500), and angle recess area (ARA) in 4 quadrants were measured. RESULTS Following the postural change from the supine position to the prone position, ACD decreased significantly (p < 0.0001). AOD 500 and ARA decreased significantly in the superior (AOD 500: p < 0.05, ARA: p = 0.03) and temporal quadrants (AOD 500: p < 0.0001, ARA: p < 0.0001). CONCLUSIONS The anterior chamber structural change was greater in the temporal and superior quadrants in the PE eyes. This corresponds with previous reports that zonular involvement by pseudoexfoliation material is more pronounced temporally and superiorly.

New gonioscopy system using only infrared light.

Purpose:To describe an infrared gonioscopy system designed to observe the anterior chamber angle under natural mydriasis in a completely darkened room. Methods:An infrared light filter was used to modify the light source of the slit-lamp microscope. A television monitor connected to a CCD monochrome camera was used to indirectly observe the angle. Results:Use of the infrared system enabled observation of the angle under natural mydriasis in a completely darkened room. Conclusion:Infrared gonioscopy is a useful procedure for the observation of the angle under natural mydriasis.

Changes in Localization of Amino Acids in the Detached Cat Retina

Purpose: To investigate the distribution of amino acids (glutamate, aspartate, glutamine, GABA, glycine) in detached retinas with minimum postmortem artifact and to clarify the relation between amino acid distribution and histopathological change in the outer portion of detached retinas. Methods: Unilateral retinal detachment was produced in cats by injecting 0.25% sodium hyaluronate into the subretinal space using a glass micropipet. The eyes were fixed by perfusion for 10 min, 1, 3, 6 and 24 h, 2, 3 and 7 days after detachment and then examined under conventional light- and electron-microscopic immunocytochemistry. Results: For glutamate, aspartate and glutamine, the inner segments and perikarya of the photoreceptor cells, which were not immunopositive in the normal retinas, showed various degrees of immunoreactivity immediately after retinal detachment. Photoreceptor cells with the strong immunoreactivity developed necrosis. The staining pattern of GABA and glycine scarcely changed during the course of retinal detachment. Conclusions: Excess intracellular glutamate, aspartate and glutamine in photoreceptor cells may cause a part of neuronal death after retinal detachment.

A Slit-lamp Needling Filtration Procedure for Uncontrolled Glaucoma in Pseudophakic and Aphakic Eyes

In one aphakic and one pseudophakic patient without previous filtration surgery, a transconjunctival needling procedure similar to that used for failed filtration procedures was performed to create a filtering bleb. In both cases, intraocular pressure was successfully lowered for 6 months until the occurrence of bleb encapsulation, which was relieved by transconjunctival needling. There were no complications. In selected cases, this minimally invasive slit-lamp needling procedure provides successful filtration.