ABSTRACT
AIM: To determine the anatomical site and extent of electrophysiological dysfunction in patients with ethambutol associated visual loss. METHODS: A comparative case series. Four patients with ethambutol associated visual loss underwent multifocal electroretinography (mERG). Two patients had advanced visual loss while two had early signs of toxicity. The N1-P1, N1, P1 amplitudes, N1, and P1 latencies were compared to 10 age and sex matched controls. RESULTS: mERG abnormalities were detected in the ethambutol treated patients. The N1 amplitude was significantly lower in the ethambutol treated patients than in the control group. CONCLUSION: Ethambutol is possibly toxic to the retina, and not only the optic nerve. The multifocal ERG may be of value to diagnose and monitor patients taking ethambutol.
Subject(s)
Antitubercular Agents/adverse effects , Electroretinography , Ethambutol/adverse effects , Vision Disorders/chemically induced , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Retina/physiopathology , Vision Disorders/diagnosis , Vision Disorders/pathologyABSTRACT
The 20-MHz ultrasound probe was compared with ultrasound biomicroscopy to determine its usefulness in imaging various glaucomatous conditions. Ten patients with glaucoma underwent anterior segment imaging with both the 20-MHz probe, which attaches to the I3 B-scan (Innovative Imaging Inc., Sacramento, CA), and the Ultrasonic BioMicroscope (UBM; Paradigm Medical Industries, Salt Lake City, UT). All pathology was easily demonstrable using the 20-MHz probe, in one case showing a retinal detachment not seen with the UBM. However, anterior findings such as fluid in the suprachoroidal space and sclerostomy sites in postoperative trabeculectomy cases were more difficult to view with the 20-MHz probe. The use of coupling enhanced the quality of the latter images. The 20-MHz ultrasound probe may be a viable aid in diagnosis and follow-up of certain glaucomatous conditions, and the use of a coupling device enhances its images.
Subject(s)
Anterior Eye Segment/diagnostic imaging , Glaucoma/diagnostic imaging , Humans , Prospective Studies , Ultrasonography/instrumentationABSTRACT
PURPOSE: We present a clinicopathologic case report of sclerocornea with the intent of showing the usefulness of ultrasound biomicroscopy (UBM) and the correlation of histopathologic findings. METHODS: An infant with congenital bilateral sclerocornea was seen for an evaluation under anesthesia. Dense opacification of both corneas prevented adequate examination of both anterior and posterior segments of the eye. UBM was performed preoperatively with subsequent corneal transplantation of the left eye. The corneal button was submitted for histopathologic examination. RESULTS: Preoperative UBM proved helpful in assessing the status of the cornea as well as the anterior chamber and its structures. Findings on histopathologic examination correlated well with the results on UBM and confirmed the diagnosis of sclerocornea. CONCLUSION: We recommend the use of UBM in assessing opacified corneas to assist in obtaining a diagnosis, to highlight potential associated structural anomalies, and to help guide decisions regarding surgical management.
Subject(s)
Cornea/abnormalities , Corneal Opacity/diagnostic imaging , Corneal Opacity/pathology , Cornea/diagnostic imaging , Cornea/pathology , Corneal Opacity/congenital , Corneal Opacity/surgery , Female , Follow-Up Studies , Humans , Infant , Keratoplasty, Penetrating , UltrasonographyABSTRACT
Ophthalmic ultrasound measures and visualizes the posterior pole; an A-scan produces a one dimensional display and the B-scan is two dimensional. A-scan measurements are indicated prior to cataract surgery because of their accuracy and repeatability. It measures the length of the eye along the visual axis from the cornea to the retina. B-scans are performed as a check for the A-scan or for extremely long or short eyes.
