J. Randall Hughes

Intraoperative Echographic Localization Of Iodine 125 Episcleral Radioactive Plaques For Posterior Uveal Melanoma

Purpose Plaque radiotherapy has been reported to have a higher relapse rate than charged-particle radiotherapy for posteriorly located uveal melanomas, which also are more technically difficult to localize accurately. The authors used intraoperative echography in patients with posterior uveal melanoma to determine the rate of inaccurate localization of iodine 125 (125I) episcleral plaques using standard localization techniques. Methods The authors reviewed the records of 29 consecutive patients with medium-sized posterior uveal melanomas who underwent 125I episcleral plaque radiotherapy with intraoperative echographic verification of plaque placement. Results After careful plaque placement using standard localization techniques, 4 of 29 plaques (14%) did not cover at least one tumor margin. All four of these plaques were associated with posterior tumors with at least one margin posterior to the temporal arcades. Two (7%) additional juxtapapillary plaques were displaced away from the sclera by the optic nerve. In all six cases, it was possible to immediately reposition the plaque to achieve coverage of all tumor margins. Conclusions Placement of 125I episcleral radioactive plaques for posteriorly located uveal melanomas using standard localization techniques occasionally results in suboptimal plaque positioning. Intraoperative echography can identify plaques that are localized poorly and allows immediate adjustment to achieve optimal plaque positioning.

Echographic and histologic tumor height measurements in uveal melanoma.

We studied the relation between echographic tumor elevation (measured by standardized A-scan echography) and histologic tumor thickness (measured from histologic slides with an ocular micrometer) in a series of 53 choroidal and ciliary body melanomas enucleated within one month of the most recent echographic measurement. Histologic height was less than echographic height for all sizes and locations studied, with a correlation coefficient of r = .926. The following equations for straight lines described the relationship: Echographic height = 1.964 + (1.042 X histologic height). Histologic height = -0.660 + (0.823 X echographic height). Thus, current thickness criteria for small (less than 3 mm), medium (3 to 5 mm), and large (more than 5 mm) melanomas, based on histologic measurements, may be translated to the following echographic terms: small, less than 5.2 mm; medium, 5.2 to 7.2 mm; and large, more than 7.2 mm. The source of this difference is a variable degree of tumor shrinkage induced by fixation and histologic preparation.

Echographic features of medulloepithelioma

PURPOSE To evaluate the echographic features of medulloepithelioma that may assist in establishing the diagnosis. METHODS Retrospective review identified four eyes with medulloepithelioma studied with echography. Clinical records, echographic findings, histopathologic tumor features, and the clinical course were reviewed. RESULTS The initial preoperative diagnosis of medulloepithelioma was uncertain, based on clinical findings alone in three cases but was accurate when echographic findings were combined with clinical findings in all four cases. Cysts posterior to the iris were detected on clinical examination in only two cases, but were revealed on echography in all four cases. Additional echographic findings included irregular high internal reflectivity (n = 4), irregular tumor surface (n = 3), molding around intraocular structures (n = 3), and internal vascularity (n = 2). CONCLUSIONS The diagnosis of medulloepithelioma is not always apparent on clinical examination alone. Echographic findings of a highly reflective, irregularly structured tumor with associated cystic changes involving the ciliary body region may help establish a presumed diagnosis of medulloepithelioma.

Macular hole syndromes. Echographic findings with clinical correlation.

BACKGROUND Anatomic characteristics of macular holes may be difficult to define, even with contact lens biomicroscopy. With the advent of successful macular hole surgical techniques, accurate diagnosis has become increasingly important to avoid unnecessary or incorrect surgery. Echography may provide additional diagnostic information in some cases. The purpose of this study is to correlate echographic and intraoperative clinical features of macular holes. METHODS The echographic features and intraoperative findings in 25 patients were compared. The spectrum of identifiable echographic features included (1) a thin, smooth, membrane-like surface minimally elevated over the macula (limited posterior vitreous face separation); (2) macular thickening; (3) an operculum; and (4) a complete posterior vitreous face separation. Intraoperative clinical findings included the presence or absence of (1) a thin, limited posterior vitreous face separation, (2) a subretinal fluid cuff, (3) an operculum, and (4) a complete posterior vitreous face separation. RESULTS Echographic and intraoperative findings correlated regarding the limited posterior face separation in 23 of 25 patients, a surrounding subretinal fluid cuff (macular thickening) in 24 of 25 patients, an operculum in 19 of 25 patients, and complete posterior vitreous face separation in 24 of 25 patients. Thus, echography was very effective in detecting the position of the posterior vitreous face. Overall, echography correlated accurately with 90 (90%) of 100 of these four features. CONCLUSION Echographic features correlate accurately with clinical features.

Echography of retinoblastoma: Histopathologic correlation and serial evaluation after globe-conserving radiotherapy or chemotherapy

PURPOSE To assess the sensitivity of echography in detecting retinoblastoma, compare tumor features observed by echography with histopathology data, and assess the usefulness of echography in serially following retinoblastoma tumors after globe-conserving treatments. METHODS The medical and echography records of all patients treated for retinoblastoma at the Bascom Palmer Eye Institute between 1991 and 1997 were reviewed. All eyes underwent pretreatment echographic evaluation, and eyes treated with external beam radiotherapy, brachytherapy, or chemotherapy underwent serial follow-up echography. RESULTS Sixty-nine eyes of 48 patients were identified. Echography demonstrated evidence of retinoblastoma in 69 of 69 (100%) eyes and calcification in 63 (91.3%) eyes. Histopathology was superior to echography in detecting optic nerve invasion, extraocular extension, and presence of calcification. CONCLUSION Echography is a useful adjunct to indirect ophthalmoscopy in establishing the diagnosis of retinoblastoma. While not as specific as histopathology, echographic evaluation before and after treatment of retinoblastoma permits monitoring of treatment response and may aid in detecting recurrent tumor growth or failure to respond to treatment.

Contact B-Scan Echography in the Assessment of Optic Nerve Cupping

We determined the reliability of high-resolution contact B-scan echography for estimating the optic cup size in 56 eyes of 28 patients with glaucoma or ocular hypertension. Two trained observers independently evaluated horizontal and vertical cup/disk ratios in stereophotographs, and two skilled echographers independently estimated optic cup size in photoechograms in a masked fashion. The reliability of echographic interpretation varied (kappa 0.29 to 0.71), but it always exceeded that expected by chance alone, even for cups of 0.3 disk diameter or less. Subtly saucer-shaped cups (three of 50 eyes) and deep cups with intact neuroretinal rims (two of 50 eyes) were misinterpreted echographically. High-resolution contact B-scan echography may provide a useful and reliable estimate of the optic cup size in eyes with opaque media.

Echographic evaluation of a patient with diabetes and dense vitreous hemorrhage: an avulsed retinal vessel may mimic a tractional retinal detachment.

PURPOSE To report that an avulsed retinal vessel may appear as a tractional retinal detachment on echographic evaluation. METHODS Case report. RESULTS A 57-year-old diabetic woman presented with a nonclearing vitreous hemorrhage of 2 months duration in the left eye. Echography was consistent with a localized tractional retinal detachment on longitudinal sections; transverse sections demonstrated a pinpoint opacity in the vitreous cavity. Intraoperatively, an avulsed retinal vessel was noted in the area of echographic abnormality. CONCLUSION An avulsed retinal vessel may mimic tractional retinal detachment on echography. Although trained ophthalmic echographers routinely perform both longitudinal and transverse sections during an echographic evaluation, less skilled observers must be aware of the importance of performing both longitudinal and transverse sections for accurate echographic diagnosis.