Ultrasound biomicroscopic diagnosis of cyclitic membranes.

PURPOSE: To evaluate the utility of ultrasound biomicroscopy in imaging cyclitic membranes. METHODS: Patients with hypotony and suspected or known cyclitic membrane underwent ultrasound biomicroscopic examination. Histopathology of cyclitic membrane was correlated with ultrasound biomicroscopy in three cases. RESULTS: Six eyes of six patients were enrolled. Mean patient age was 62.2 +/- 18.4 (SD) years. The mean intraocular pressure in the affected eye was 4.3 +/- 3.4 mmHg. Three eyes were pseudophakic and three eyes were aphakic. All eyes had undergone two or more previous intraocular surgeries. Ultrasound biomicroscopy imaged the cyclitic membrane in all six eyes. Histopathology revealed fibroproliferative cyclitic membranes with associated inflammatory cells. CONCLUSION: Ultrasound biomicroscopy is useful in detecting the presence of those cyclitic membranes that may not be identified on clinical examination.

Glaucoma drainage tube kink after pars plana insertion.

PURPOSE: To describe focal obstruction of drainage tubes by kinking at the scleral entry site after pars plana insertion. METHODS: Case study. RESULTS: Three eyes of three patients underwent uncomplicated placement of a Baerveldt implant into the vitreous cavity at the time of pars plana vitrectomy. Intraocular pressure remained increased after the procedure without evidence of flow. Surgical exploration and modification of the tube placement resulted in immediate intraocular pressure reduction. Compression of the tube at the scleral entry site was confirmed intraoperatively in all eyes by ultrasound biomicroscopy. CONCLUSION: Kinking of the tube at its scleral entry site should be recognized as a possible cause of increased intraocular pressure without bleb formation after pars plana insertion of a glaucoma drainage implant.

Ciliary body enlargement and cyst formation in uveitis.

BACKGROUND: Acute anterior uveitis has diverse causes and systemic associations. Inflammation is predominantly localised to the iris and pars plicata. Little is known about the in vivo effects of uveitis on ciliary body anatomy. METHODS: Bilateral, high frequency, high resolution, ultrasound biomicroscopy was performed on consecutive patients with unilateral anterior uveitis to evaluate ciliary body anatomy. Imaging was repeated when possible during the clinical course. The cross sectional area of the anterior ciliary body was measured using image processing and analysis software. Measurements from the uveitic eyes were compared with the fellow eyes and the effect of treatment was evaluated. RESULTS: Fourteen patients were enrolled. Ultrasound biomicroscopy demonstrated a larger ciliary body cross sectional area in the uveitic eyes compared with the fellow, clinically uninvolved eyes (2.45 (SD 0.48) mm2 versus 1.55 (SD 0.15) mm2, (p = 0.0000; paired t test)). A ciliochoroidal effusion was present in one uveitic eye. Epithelial cysts were imaged bilaterally in four uveitic patients (29%) and unilaterally in unaffected eyes of two uveitic patients. Ciliary body cross sectional area decreased following steroid therapy (p = 0.0001; paired t test). New cysts were noted in three uveitic eyes during the follow up period and in none of the fellow, unaffected eyes. CONCLUSION: Ultrasound biomicroscopy offers a new approach to the evaluation of anterior uveitis. The response to treatment can be evaluated objectively and therapeutic efficacy can be more easily assessed. It has the potential to help elucidate the pathophysiology and anatomical changes of this heterogeneous group of disorders.

Reproducibility of retinal thickness measurements in normal eyes using optical coherence tomography.

BACKGROUND AND OBJECTIVE: To determine the reproducibility of retinal thickness measurements in normal eyes using optical coherence tomography (OCT). PATIENTS AND METHODS: Multiple 3.20-mm vertical cross-sectional images through the center of fixation of consecutive patients with normal results on ocular examinations were obtained. Each image was divided into seven 320-micron segments. Regional retinal thicknesses for each section were measured using both the manually assisted (requiring observer localization of reflectivity peaks) and the automated modes (observer-independent measurement) of the computer software. RESULTS: Eighteen right eyes were studied. The mean coefficient of variation was less than 10% for all locations using the manually assisted method (average standard deviation less than 17 microns [range 9 to 16 microns]). The automated method was less reliable, with a coefficient of variation greater than 10% for locations within 500 microns of fixation. Automated measurements at fixation were the least reproducible because of poor internal limiting membrane reflectivity. CONCLUSION: OCT is capable of reproducible measurement of retinal thickness in normal eyes. Computer-driven, automated measurement of retinal thickness within 500 microns of fixation needs to be refined and its reproducibility reassessed in this region.

Diagnosis of traumatic cyclodialysis by ultrasound biomicroscopy.

BACKGROUND AND OBJECTIVE: To evaluate the ability of high-frequency ultrasound biomicroscopy to diagnose traumatic cyclodialyses not evident on clinical examination. PATIENTS AND METHODS: Six eyes to six patients with posttraumatic hypotony and/or shallow anterior chamber and suspected cyclodialysis clefts were examined with slit-lamp biomicroscopy, gonioscopy, B-scan ultrasonography, and ultrasound biomicroscopy. Ultrasound biomicroscopy provided high resolution of cross-sectional images of the anterior chamber angle, posterior chamber, and anterior uveal tissue. RESULTS: Ultrasound biomicroscopy confirmed the disinsertion of the ciliary body from the scleral spur and associated ciliary body detachment in all eyes. Gonioscopy failed to demonstrate a cyclodialysis cleft in five eyes because of hyphema (two eyes) and abnormal iris architecture (related to trauma) precluding visualization of the angle recess (three eyes). Using information from ultrasound biomicroscopy imagining, one patient underwent a ciliary body reattachment procedure and repair of the cyclodialysis cleft. CONCLUSION: Ultrasound biomicroscopy is a noninvasive method that can accurately diagnose the presence of traumatic cyclodialyses and can aid in surgical management. It is particularly useful in the presence of hazy media, hypotony, and/or abnormal anterior segment anatomy.

Ultrasound biomicroscopy in anterior ocular trauma.

BACKGROUND AND OBJECTIVE: The authors investigated the role of ultrasound biomicroscopy after ocular trauma. PATIENTS AND METHODS: Ultrasound biomicroscopy was performed in six eyes of six patients at the New York Eye and Ear Infirmary after a variety of traumatic ocular injuries. RESULTS: Eyes with angle recession, iridodialysis, cyclodialysis, hyphema, an intraocular foreign body, scleral laceration, and subluxed crystalline lens were imaged without complication. Ultrasound biomicroscopy aided in the diagnosis when visualization was limited by media opacities or distorted anterior segment anatomy. CONCLUSION: Ultrasound biomicroscopy is a safe and effective adjunctive tool for the clinical assessment and management of ocular trauma, especially when visualization is limited and multiple traumatic injuries are involved.

External limiting membrane and visual outcome in macular hole repair: spectral domain OCT analysis.

PURPOSE: To investigate the relationship between postoperative visual acuity and integrity of the external limiting membrane (ELM) and inner segment-outer segment (IS-OS) junction layers, using spectral domain optical coherence tomography (SD-OCT), in eyes with macular holes (MHs) following surgical repair. METHODS: Medical charts of MH-operated cases were retrospectively identified and reviewed. The primary outcome measures were best-corrected visual acuity (BCVA) and the status of the ELM and IS-OS lines, using SD-OCT, at 6 weeks and 6 months postoperatively. RESULTS: Sixty-two eyes of 62 patients were included. At 6 weeks following surgery, out of 56 (90.3%) eyes with successful MH closure: 0 eyes showed the combination of disrupted ELM and continuous IS-OS layers; 7 eyes (12.5%) demonstrated continuity of both ELM and IS-OS (ELM(c)/IS-OS(c) group); 29 eyes (51.8%) had continuous ELM with discontinuous IS-OS layers (ELM(c)/IS-OS(d) group); and 20 eyes (35.7%) had discontinuities in both the layers (ELM(d)/IS-OS(d) group). The ELM(d)/IS-OS(d) group had the lowest visual gain at 6 months (P = 0.03). At 6 months, a restoration of the integrity of IS-OS layer was observed in 51.7% eyes in the ELM(c)/IS-OS(d) group and in 5% in the ELM(d)/IS-OS(d) group (P = 0.001). CONCLUSIONS: When both ELM and IS-OS layers showed disruptions 6 weeks postoperatively, a significantly worse BCVA was measured at 6 months, compared with the eyes with only IS-OS disruptions, detected 6 weeks following surgery. The integrity of the ELM layer appears to be a critical factor for the restoration of the photoreceptor layer and for predicting a successful visual outcome following MH repair.

Normal electro-oculograms in two patients with malignant melanoma of the choroid.

The electro-oculogram has been applied in the diagnostic evaluation of eyes with malignant uveal melanoma. Typically, a marked reduction in the light peak to dark trough ratio has been reported. We studied two patients with histologically confirmed uveal malignant melanomas in whom the preenucleation electro-oculograms were normal. The electro-oculogram should be evaluated within the framework of the clinical examination and other ancillary tests in the diagnostic evaluation of a suspected uveal malignant melanoma.

Risk factors for ciliochoroidal effusion after panretinal photocoagulation.

PURPOSE: To determine the incidence, duration, and risk factors for ciliochoroidal effusion after panretinal photocoagulation. METHODS: Thirty-nine consecutive patients with diabetic retinopathy underwent ultrasound biomicroscopy of both eyes to image the ciliochoroidal space immediately before and 1 day after unilateral argon-green panretinal photocoagulation. Imaging was repeated on days 3, 7, and 14 in patients in whom ciliochoroidal effusion developed. RESULTS: Low-lying ciliochoroidal effusions were imaged in 23 (59%) of 39 eyes. Of 23 eyes, effusions resolved in 6 (26%), 12 (52%), and 5 (22%) eyes by 3, 7, and 14 days respectively. The number of laser applications (P = 0.02), shorter axial length (P = 0.01), and percentage of retinal surface area treated (P = 0.02) were associated with systemic hypertension, location of treatment, previous panretinal photocoagulation of cataract surgery, retinal surface area treated, and mean blood pressure before photocoagulation were not associated with effusion. All fellow, untreated eyes remained effusion-free. CONCLUSION: Ciliochoroidal effusion develops commonly after panretinal photocoagulation. Limiting the number of laser applications and the percentage of retinal surface area treated reduces the likelihood of this complication. Eyes with shorter axial lengths are at higher risk

High-resolution ultrasound biomicroscopy of the pars plana and peripheral retina.

OBJECTIVE: This study aimed to evaluate the ability and role of ultrasound biomicroscopy in imaging the peripheral retina, pars plana, and anterior choroid. DESIGN: The study design was a case series. PARTICIPANTS: Seventeen eyes of 17 patients with a variety of clinical diagnoses involving the anterior portion of the posterior segment were studied. INTERVENTION: High-frequency (50 MHz), high-resolution (50 microns) ultrasound biomicroscopy was performed. RESULTS: Ultrasound biomicroscopy was capable of imaging the peripheral retina, pars plana, and anterior choroid. Images had features consistent with known histopathology. Retinoschisis consisted of one thin hyper-reflective echo and could be differentiated from a retinal detachment, which was thicker and formed a bilayered echo. A choroidal effusion could be identified as an echolucent space within the suprachoroidea, whereas a choroidal hemorrhage was moderately echodense. Inflammatory diseases, such as a sarcoid granuloma, pars planitis, and Harada's disease, were characterized by different forms of uveal thickening. A ciliochoroidal nevus was internally hyporeflective and could be measured accurately and localized. CONCLUSIONS: Imaging of the peripheral retina, pars plana, and anterior choroid is possible with ultrasound biomicroscopy and may aid in the diagnosis and management of pathology involving this region.