Standardized A-scan Echography Research Articles

Large ciliary body melanocytoma with pseudocysts: a case report

BackgroundTo describe the correlation between standardized A-scan echography and histopathology in a ciliary body melanocytoma.Case presentationWe present a case of a large ciliary body melanocytoma with significant growth, vision loss, and elevated intraocular pressure that was diagnosed clinically as a melanoma, but the standardized A-scan findings correlated to the histopathological description of a melanocytoma with multiple pseudocysts.ConclusionsThe reflectivity of this melanocytoma by standardized A-scan was consistent with multiple pseudocysts on pathological evaluation. This echographic pattern guided the differential diagnosis. Standardized A-scan is an important diagnostic tool in the differentiation of ciliary body melanocytomas from melanomas.

Evaluation of vascular changes with optical coherence tomography angiography after ruthenium-106 brachytherapy of circumscribed choroidal hemangioma.

To describe the vascular changes of circumscribed choroidal hemangioma (CCH) after ruthenium-106 brachytherapy using optical coherence tomography angiography (angio-OCT). Seven eyes of 7 patients diagnosed with symptomatic CCH who underwent ruthenium-106 plaque radiotherapy were included in the study. Patients underwent complete ophthalmic examination, bulbar echography and angio-OCT. The same protocol was applied 1 year after ruthenium-106 brachytherapy. At baseline, the mean best-corrected visual acuity (BCVA) in affected eyes was 0.67 ± 0.14 logMAR, and the mean tumor thickness was 4.46 ± 0.91 mm measured by standardized A-scan echography. After ruthenium-106 plaque treatment, the mean BCVA increased to 0.17 ± 0.10 logMAR (p = 0.001) and the mean tumor thickness to 2.29 ± 0.71 mm (p = 0.003). Moreover, there was a significant reduction of the tumor basal diameter (p= 0.009). Intra-tumor angio-OCT measurements revealed a statistically significant reduction of the vessel and flow areas (p = 0.006 and p = 0.002, respectively) 1 year after brachytherapy. Angio-OCT is a non-invasive reliable method with which to evaluate the vascular features of CCH and consequently to monitor changes after conservative treatment.

Possible role of standardized echography complementing ultrasound biomicroscopy in tumors of the anterior eye segment: a study in a series of 13 patients

To evaluate the efficacy of standardized A-scan echography (ASE) complementing ultrasound biomicroscopy (UBM) to propose the most efficient method as grounds for the diagnosis, treatment, and follow-up of anterior eye-segment tumors. The inclusion criteria were tumors of the ciliary body and peripheral choroidal tumors, whose anterior border could not be visualized with a 10MHz ultrasound probe. The largest basal dimension and the highest prominence of the tumor were measured with a UBM Lin 50 probe. A standardized A-scan examination determined the tumor's thickness and internal reflectivity. Thus, tissue differentiation led to a standardized echography-based diagnosis (SED). The study included 13 patients. SED was achieved in all examined tumors. The smallest thickness of the tumor of the ciliary body enabling SED was only 1.78mm. The highest prominence of the tumor (3.66 ± 1.39mm) was generally larger than its thickness (3.30 ± 1.71mm). When approaching ciliary body tumors, both ASE and UBM should be performed, the former to accurately differentiate the tumor and measure its height, and the latter to delineate anterior tumor margins and iris involvement. Standardized echography-based diagnosis was grounds for further evaluation and/or treatment in this case series. The highest prominence of the ciliary body tumor perpendicular to the sclera as evidenced by UBM was generally higher than the thickness obtained with standardized echography. Hence, we propose ASE thickness to be the grounds for staging the severity of ciliary body tumors in the algorithm for their management.

Invasion intracornéenne par un mélanome du corps ciliaire

The authors report a case of a slow reduction of vision in the left eye of a 69-year-old woman. The slit-lamp examination of the eye showed a vascularized achromic subconjunctival mass close to the nasal limbus, invading the inferonasal corneal quadrant. At B-scan and standardized A-scan echography, the mass was shown to be localized to the ciliary body, with characteristics of a malignant melanoma. The patient did not want to undergo conservative treatment. Therefore, enucleation was performed and light microscopy revealed a pigmented malignant melanoma of the ciliary body with extrascleral growth and infiltration of the anterior third of the corneal stroma. No alteration of Bowman's membrane was present. The corneal infiltration, limited to the anterior third of the stroma, could be due to the fact that at this level the collagen fibers are disposed less regularly than those of the posterior two-thirds, with this different disposition responsible for the weak resistance opposed to the tumoral invasion.

Biometry and refractive outcome of eyes filled with silicone oil by standardized echography and partial coherence interferometry

We evaluated the validity of calculations for refractive outcome in cataract surgery in silicone oil-filled eyes. The retrosilicone space (RSS) was included in these calculations. In a prospective study the axial length (AL) of silicone oil-filled eyes was measured. with standardized A-scan echography (SAE) and partial coherence interferometry (PCI). Meldrum's formula was used to transform the velocity of ultrasound within the vitreous cavity. To investigate whether refractive outcome can be calculated accurately, we assessed the difference between precalculated and final refractive outcome. Furthermore, we determined the advantages and disadvantages of SAE and PCI. A minor aim was to assess whether the AL of the two eyes differed significantly. In 85% of 117 eyes the difference between precalculated and postsurgical refraction was smaller than 1 diopter spherical and statistically not significant (p>0.2). The mean AL was 24.1 mm (range 20.0-31.4 mm). The difference in outcome between the two methods was without statistical significance: the AL difference was 0.4 (+/-2.6) mm on measurement with SAE and 0.04 (+/-0.46) mm with PCI. PCI has the advantage that it can be performed more easily, without contact, while echography is advantageous in the presence of advanced cataracts. In supine position an oil-free fluid space behind the silicone oil was detected with echography. The mean dimension of this space was 1.9 (+/-0.67) mm and it was taken into consideration for IOL calculation. The mean AL difference between the two eyes was 0.4 mm, but the difference was greater than 1 mm in 26% of the patients. The AL of eyes filled with silicone oil can be measured reliably with SAE and PCI. In supine position the RSS has to be considered to obtain more accurate IOL calculations.

Ultrasonographic classification and phacoemulsification of white senile cataracts

Objective To classify the white senile cataracts and report the results of phacoemulsification of white cataracts. Design Prospective, noncomparative case series. Participants One hundred eyes were included. Intervention White cataracts were examined biomicroscopically before surgery, and their acoustic structure was analyzed with standardized A-scan echography. White cataract surgery was performed with phacoemulsification via a superior temporal near-limbus corneal approach using a bimanual divide-and-conquer or stop-and-chop technique. Patients were followed after surgery for a period of 9 months. Main outcomes measures The A-scan acoustic structure of white cataracts; successful accomplishment of capsulorrhexis; mean phacoemulsification time, power, and energy; intraoperative and postoperative complications of phacoemulsification; and visual acuity at 9 months after surgery. Results White senile cataracts were categorized into three different types. Type I included intumescent, white cataracts with cortex liquefaction and high internal acoustic reflections (44 eyes), type II included white cataracts with voluminous nuclei, little amount of whitish solid cortex, and low internal acoustic reflections (49 eyes), and type III included white cataracts with fibrosed anterior capsule and low internal echospikes (7 eyes). Circular capsulorrhexis was completed in 79 eyes and was significantly less successful in eyes with type I intumescent, white cataracts compared with type II white cataracts ( P = 0.0034). Mean phacoemulsification time and energy were higher in type II and type III white cataracts. Posterior capsule rupture occurred in ten eyes, and three of these eyes were complicated by vitreous loss. In 95 eyes, the posterior chamber lens was implanted in the capsular bag and in five eyes in the sulcus. After surgery, a transient corneal edema developed in 31 eyes. At the final 6-month examination, the mean postoperative visual acuity was 20/30. Conclusion Current phacoemulsification techniques can safely manage eyes with senile white cataracts. The increased risk of difficulty with continuous capsulorrhexis in type-I and type-III white cataracts and the substantial nuclear hardness in type-II and mainly type-III white cataracts would suggest that current phacoemulsification techniques might not be as successful in these patients as they are in ordinary earlier cataracts.

Echographic Measurement of Optic Nerve Thickness Correlated With Neuroretinal Rim Area and Visual Field Defect in Glaucoma

To determine whether echographic measurements of the pial diameter of the optic nerve are significantly correlated with glaucomatous changes of the optic disk and retinal nerve fiber layer. In 31 patients with primary open-angle glaucoma and 16 normal control subjects, optic nerve thickness was determined by measuring the maximal pial diameter of the optic nerve using standardized A-scan echography. The optic disks were morphometrically examined using color stereo photographs, and the retinal nerve fiber layer was assessed using wide-angle red-free fundus photographs. Optic nerve thickness as measured echographically decreased significantly (P < .001) with decreasing neuroretinal rim area, diminishing visibility of the retinal nerve fiber layer, narrowing of the retinal arterioles, enlarging parapapillary atrophy, and increasing mean visual field defect. In an intraindividual bilateral comparison, side differences in the optic nerve thickness were significantly correlated with side differences in neuroretinal rim area (P < .0001), diameter of retinal arterioles (P = .003), and visual field defect (P < .0001). In the differentiation of normal and glaucomatous eyes, sensitivity and specificity were higher for echographic measurements of the optic nerve thickness than for parapapillary atrophy and diameter of retinal arterioles but worse than for determination of the neuroretinal rim area. Echographic measurements of optic nerve thickness are significantly correlated with glaucomatous changes of the optic disk and retinal nerve fiber layer. In patients with opaque media, echographic measurement of optic nerve thickness may be helpful in distinguishing among normal eyes, eyes with medium advanced glaucoma, and eyes with markedly progressed glaucoma.

Macula study with standardized echography.

At an early clinical stage, patients with cystoid macular oedema show no significant changes in their vision. This phase is described as angiographic cystoid macular oedema. Echographic macular studies have in the past years shown that the macular thickness is increased in the early stages of cystoid macular oedema. In these patients there was no evidence of cystoid macular oedema with the visual acuity test, B-scan echography and fluorescein angiography. In this paper an echographic macular study by standardized A-scan echography was performed in 537 patients before extracapsular cataract extraction and intraocular lens implantation in posterior chamber (ciliary sulcus). The results showed that this method is very sensitive in detecting patients with high risk of cystoid macular oedema.

Comparison of Standardized Echography with Magnetic Resonance Imaging to Measure Extraocular Muscle Size

Using both standardized echography and high-resolution, surface coil magnetic resonance imaging, we measured the transverse diameter of recti extraocular muscles to evaluate comparative accuracy. Maximum transverse diameter of each rectus muscle in primary gaze was measured in 39 orbits of 20 subjects by using standardized A-scan echography. In the same orbits, we obtained multiple coronal magnetic resonance imaging planes by using a surface coil to span the anteroposterior extent of each orbit. Digital image analysis with the National Institutes of Health Image program was used to measure transverse muscle diameter. Average size for each rectus muscle was similar for the echographic and magnetic resonance imaging techniques. However, linear regressions of individual ultrasound against magnetic resonance imaging measurements showed coefficients of determination (R 2 ) moderate (0.29) for inferior recti muscles and low (≤0.11) for other recti muscles. For most recti muscles, significant variability in echographic estimates of muscle width results from factors other than true muscle size. Results indicate that ultrasound measurements of muscle size in individual patients should be interpreted cautiously.

Comparison of Standardized Echography With Magnetic Resonance Imaging to Measure Extraocular Muscle Size

Using both standardized echography and high-resolution, surface coil magnetic resonance imaging, we measured the transverse diameter of recti extraocular muscles to evaluate comparative accuracy. Maximum transverse diameter of each rectus muscle in primary gaze was measured in 39 orbits of 20 subjects by using standardized A-scan echography. In the same orbits, we obtained multiple coronal magnetic resonance imaging planes by using a surface coil to span the anteroposterior extent of each orbit. Digital image analysis with the National Institutes of Health Image program was used to measure transverse muscle diameter. Average size for each rectus muscle was similar for the echographic and magnetic resonance imaging techniques. However, linear regressions of individual ultrasound against magnetic resonance imaging measurements showed coefficients of determination (R2) moderate (0.29) for inferior recti muscles and low (< or = 0.11) for other recti muscles. For most recti muscles, significant variability in echographic estimates of muscle width results from factors other than true muscle size. Results indicate that ultrasound measurements of muscle size in individual patients should be interpreted cautiously.

Optic Nerve Sheath Fenestration for Treatment of Progressive Ischemic Optic Neuropathy-Reply

In reply McHenry and Spoor raise an interesting point that fluid accumulation in theperioptic meninges may be associated with a progressive course of visual loss and better surgical outcome following ONSD in patients with AION. In our series of 26 eyes with progressive AION,1only one of 17 eyes showed meager increased fluid in the subarachnoid space. In fact, in the Echography Laboratory of the Bascom Palmer Eye Institute, Miami, Fla, using standardized A-scan echography, we do not find increased sheath fluid in cases of AION, whether progressive or static. The surgical series of Spoor et al2was recently published, including sonographic data on 12 eyes with progressive AION and 27 eyes with static AION. Mean optic nerve diameter in the progressive group was 3.47 mm, with afluid shift (30° test) rangingfrom 5% to 25%, and mean optic nerve diameter in the static group was 3.19 mm, with afluid shift

Standardized A-scan echography and the normal optic nerve. Experience with the new Mini A equipment.

The potential of making differential diagnosis in optic nerve disease with standardized A-Scan echography has been well established. With this technique it is possible to differentiate 'solid' and 'fluid' thickening. A few years ago a new standardized A-scan equipment was built: The Mini A. With this equipment, it is possible to distinguish spikes coming from the pia, the arachnoid, and the dura around the optic nerve, and to measure the thickness of these structures with a precision of 0.03 mm. We found dura distance 4.0-5.3 mm, arachnoid 3.2-4.0 mm, an pial diameter 2.8-3.4 mm. In this paper the authors discuss their preliminary findings in a normal population.

Classification of Eye Changes of Graves' Disease

Classification of Eye Changes of Graves' Disease

Diameter of Normal Extraocular Recti Muscles With Echography

To establish the range of diameters of normal extraocular muscles, we used standardized A-scan echography to measure the superior recti/levator complex, medial, lateral, and inferior recti muscles in 38 subjects with healthy orbital tissues. The relationships of age, gender, height, and weight to axial length of the globe were considered. These factors and extraocular muscle diameters were not consistently associated. Our normative data were compared with previously reported studies of extraocular muscle diameter performed with standardized A-scan and contact B-scan echography and computed tomographic scanning.

Standardized A-Scan Echography in Optic Nerve Disease

• This study documents the results of standardized A-scan examinations performed in 59 cases of optic nerve lesions (15 perioptic meningiomas, four gliomas, 15 acute neuritides, ten optic atrophies, five ischemic optic neuropathies, five acute central retinal vein occlusions, five traumatic optic neuropathies), as compared with 73 normal optic nerves. Analysis included the assessment of reflectivity (spike height) and nerve width (maximal diameter) with the patient fixating in primary gaze and 30° of eccentric gaze; measurements were obtained from the anterior one third and posterior one third of the optic nerves. Increased nerve diameters could be distinguished as noncompressible (a negative 30° test) when due to tumor, or compressible (a positive 30° test) when due to increased subarachnoid fluid, as exemplified by inflammatory optic neuritis or traumatic neuropathy. Moreover, reflectivity patterns regularly differentiated meningioma (medium reflectivity) from optic glioma (low reflectivity). Neither ischemic neuropathy nor vein occlusion altered optic nerve diameter. These results indicate that echographically defined optic nerve diameter, compressibility in eccentric gaze, and reflectivity patterns can be used to effectively distinguish among causes of chronic optic atrophy (tumor vs remote neuropathy) and disc edema (tumor vs neuritis vs ischemic neuropathy).

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 study of the optic nerve during anesthesia

At present an exact measurement of intraorbital optic nerve diameter is possible by using standardized A-scan echography. Measurements are made with an accuracy of 0.4 µsec for the anterior orbit and ± 0.6 µsec for the posterior orbit. In addition, it is known that some types of anesthetic cause modifications in the intracranial pressure. The authors evaluated the effect of a number of anesthesiological techniques on the intracranial pressure by measuring the optic nerve diameter within the orbit. The results demonstrate a significant increase in the optic nerve diameter in patients subjected to anesthesia with premedication of atropine and diazepam in combination with intravenously administered ketamine. The type of anesthetic should be specified in case of biometry of the optic nerve if these measurements are performed under general anesthesia.

Echographic optic nerve study in Graves’ ophthalmopathy

A and B-Scan echography, CT scanning and pathological studies have clearly shown that the extraocular muscles are the primary focus in orbital Graves’ disease. The presence of optic neuropathy is probably secondary to apical orbital compression by congested muscles. At present the Standardized A-Scan echography is a reliable method for precise biometrical estimation of the thickness of the optic nerve. The purpose of this work is to evaluate the diameter of the optic nerve in patients with Graves’ disease in relation to the involvement of this structure in this disease.The results show that the optic nerve can be affected in Graves’ disease already in the very first stage of the disease. There is moreover a discrepancy between the thickening of the optic nerve and the progression of Graves’ disease.A hypothesis is given to explain these data.