Imaging analysis of the biological parameters of the lens in patients with cortical age-related cataracts using ultrasound biomicroscopy

BACKGROUND

The spatial position of the lens in patients with cortical age-related cataract (CARC) is unclear. We investigated a basis for the assessment of visual quality after cataract surgery by analysing the ultrasound biomicroscopic characteristics of the biological parameters of the lens in patients with CARC.

METHODS

In this retrospective study, 119 patients (50 males and 69 females, totalling 238 eyes) with CARC who underwent simple cataract surgery were selected. The lens thickness (LT), axial length (AL), anterior chamber depth (ACD), lens vault (LV), trabecular-iris angle (TIA), iris-lens angle (ILA), iris-lens contact distance (ILCD) were measured by A-scan ultrasound and ultrasound biomicroscopy. The corresponding lens position (LP) and relative lens position (RLP) were calculated.

RESULTS

LP was greater in men than in women (P < 0.05), LV was smaller in men than in women (P = 0.002), ILA and ILCD were not statistically significant (P = 0.072 and P = 0.854, respectively). There were significant differences in TIA, ILA, and ILCD in the four quadrants (all P < 0.05), with a trend in the distribution of TIA: superior < inferior < nasal < temporal, ILA: nasal < inferior < temporal < superior, and ILCD: superior < temporal < inferior < nasal.

CONCLUSIONS

The lens protrudes more obviously in females than in males and the lens tilts to a certain extent with the increase of age and tends to be more upward and temporal in the supine position. Therefore, trends in lens-related parameters in patients with CARC should be taken seriously.

Comparison of Ocular Morphological Parameters Related to Lens Position by Anterior Segment Optical Coherence Tomography and Ultrasound Biomicroscopy

OBJECTIVE

The objective is to compare parameters related to lens position measured using anterior segment optical coherence tomography (AS-OCT) and ultrasound biomicroscopy (UBM) in patients with senile cataract and perform a consistency analysis.

METHODS

This prospective study included 102 patients (102 eyes) scheduled for simple cataract surgery. Among the total patients, 44 were men, and 58 were women. AS-OCT (sitting) and UBM (lying) were used to measure the anterior chamber depth (ACD) in horizontal and vertical orientations and the iris-lens contact distance (ILCD) and iris-lens angle (ILA) in inferior, superior, nasal, and temporal quadrants. Paired-sample t-test was used to compare ACD, ILCD, and ILA measurements of the two methods, while Pearson's linear correlation and Bland-Altman analyses were used to analyze the correlation and consistency of the two results.

RESULTS

The horizontal (2.499 ± 0.464 mm) and vertical (2.531 ± 0.463 mm) ACD measured using AS-OCT and the horizontal (2.556 ± 0.467 mm) and vertical (2.563 ± 0.479 mm) ACD measured using UBM were significantly different (P < 0.001); moreover, the results showed good correlation and agreement. A significant difference was observed between the two methods in terms of ILCD measured in inferior, superior, nasal, and temporal quadrants (P < 0.001), and a significant correlation was found between measurements of both methods (P < 0.001). Approximately 3.92% (4/102), 0.98% (1/102), 3.92% (4/102), and 2.94% (3/102) of points were outside the 95% limits of agreement in the four quadrants, respectively, and the agreement of the results was good. ILA measured using both methods differed in inferior, superior, nasal, and temporal quadrants (P=0.003, 0.011, 0.001, 0.001, respectively), and the correlation was good (P < 0.001). The percentage of points outside the 95% limit was higher in inferior, superior, nasal, and temporal quadrants (4.90% (5/102), 5.88% (6/102), 5.88% (6/102), and 6.86% (7/102)) with poor agreement of the results.

CONCLUSIONS

The correlation between AS-OCT and UBM in terms of measuring lens position-related parameters was good, but the agreement was unstable. The differences in measurement position (sitting and supine) and/or measurement methods (optics and ultrasound) may lead to variability in results.

Regression Patterns of Iris Melanoma after Palladium-103 (103Pd) Plaque Brachytherapy

PURPOSE

To evaluate the patterns of regression of iris melanoma after treatment with palladium-103 (¹⁰³Pd) plaque brachytherapy.

DESIGN

Retrospective, nonrandomized, interventional case series.

PARTICIPANTS

Fifty patients with primary malignant melanoma of the iris.

METHODS

Palladium-103 plaque brachytherapy.

MAIN OUTCOME MEASURES

Changes in tumor size, pigmentation, and vascularity; incidence of iris neovascularization; and radiation-related complications.

RESULTS

The mean age in the case series was 61.2±14.9 years. The mean tumor thickness was 1.4±0.6 mm. According to the American Joint Committee on Cancer, eighth edition, staging criteria for iris melanoma, 21 tumors (42%) were T1a, 5 tumors (10%) were T1b, and 24 tumors (48%) were T2a. The tumor was melanotic in 37 cases (74%) and amelanotic in 13 cases (26%); of these, 13 tumors (26%) showed variable pigmentation. After brachytherapy, mean tumor thickness decreased to 0.9±0.2 mm. Pigmentation increased in 32 tumors (64%), decreased in 11 tumors (22%), and was unchanged in 6 tumors (12%). For intrinsic vascularity (n = 19), 12 tumors (63%) showed decrease and 7 tumors (37%) showed complete resolution. Appearance of ectropion uveae showed diminution in 15 tumors (43%); newly present corectopia was observed in 6 patients (12%). On high-frequency ultrasound imaging, of the 42 tumors (84%) with low to moderate internal reflectivity, 30 tumors (60%) showed an increase in internal reflectivity on regression. Iris stromal atrophy was noted in 26 patients (52%), progression or new-onset cataract was noted in 22 patients (44%), neovascular glaucoma was noted in 1 patient (2%), and there were no cases of corneal opacity. There was no clinical evidence (0%) of radiation-induced retinopathy, maculopathy, or optic neuropathy. Mean follow-up in this series was 5.2 years (range, 0.5-17 years).

CONCLUSIONS

The most common findings related to iris melanoma regression after ¹⁰³Pd plaque brachytherapy included decreased intrinsic tumor vascularity, increased tumor pigmentation, and decreased tumor thickness with synchronous increase in internal ultrasonographic reflectivity. No irreversible sight-limiting complications were noted.

[Plaque radiotherapy for anterior uveal melanomas]

AIM

To determine the effectiveness of plaque radiation therapy for anterior uveal melanomas and to evaluate the risk and frequency of complications at different time intervals after the treatment.

MATERIAL AND METHODS

During 2010-2013 a total of 30 patients (10 male, 20 female) aged 11-73 (50 years on the average) with iris or iridociliary melanomas were treated with Ru-106 and Sr-90 ophthalmic plaques. In 8 patients the brachytherapy was preceded by local tumor excision. Morphological diagnosis was verified in 10 patients (8 iridectomies, 2 enucleations), of them 8 cases turned out to be spindle cell melanomas and the other 2--mixed cell melanomas. Follow-up period ranged from 1 to 54 months with the median of 13,5 months.

RESULTS

Tumor regression was achieved in all cases. Enucleation had to be performed in 2 patients due to cornea and sclera necrosis. In the early post-brachytherapy period (up to 1 month) the most frequent radiation-related complications were keratopathy and uveitis (8 and 6 patients correspondingly). In patients observed for up to 3 months (28 patients) these were keratopathy and cataract (8 and 5 patients correspondingly). In the long-term (over 6 months) cataract predominated (17 patients). At the end of the study all patients were alive. Metastatic disease was diagnosed in one patient 30 months after the treatment.

CONCLUSIONS

The results of the present clinical study confirm the effectiveness of brachytherapy for iris and iridociliary melanomas, which implies that tumor is well locally controlled and radiation-related complications are moderate and curable. This method of local tumor destruction can be another alternative to enucleation in cases when local tumor excision cannot be performed.

Explaining The Current Role Of High Frequency Ultrasound In Ophthalmic Diagnosis (Ophthalmic Ultrasound)

Ultrasound has become as indispensable as indirect ophthalmoscopy or slit lamp in evaluation of the eye. It is an important adjuvant for the clinical assessment of a variety of ocular and orbital diseases. Advances in instrumentation, higher frequencies and more sensitivity and resolution have resulted in continuous improvement in image quality.Very high frequency ultrasound uses frequencies in the range of 35 to 100 MHz to show greater detail of the anterior segment. Penetration is limited for these higher frequencies to only a few millimeters and thus only the anterior vitreous behind the ciliary body and lens can be imaged. High frequency ultrasound in the range of 20 to 30 MHz has a penetration of about 10 mm and can be used for posterior pole evaluation of the retina and choroid.

[Design of computerised database for clinical and basic management of uveal melanoma]

PURPOSE

The uveal melanoma is the most common primary intraocular tumour in adults. The objective of this work is to show how a computerised database has been formed with specific applications, for clinical and research use, to an extensive group of patients diagnosed with uveal melanoma.

METHOD

For the design of the database a selection of categories, attributes and values was created based on the classifications and parameters given by various authors of articles which have had great relevance in the field of uveal melanoma in recent years.

RESULTS

The database has over 250 patient entries with specific information on their clinical history, diagnosis, treatment and progress. It enables us to search any parameter of the entry and make quick and simple statistical studies of them.

CONCLUSION

The database models have been transformed into a basic tool for clinical practice, as they are an efficient way of storing, compiling and selective searching of information. When creating a database it is very important to define a common strategy and the use of a standard language.

Algorithms and results of eye tissues differentiation based on RF ultrasound

Algorithms and software were developed for analysis of B-scan ultrasonic signals acquired from commercial diagnostic ultrasound system. The algorithms process raw ultrasonic signals in backscattered spectrum domain, which is obtained using two time-frequency methods: short-time Fourier and Hilbert-Huang transformations. The signals from selected regions of eye tissues are characterized by parameters: B-scan envelope amplitude, approximated spectral slope, approximated spectral intercept, mean instantaneous frequency, mean instantaneous bandwidth, and parameters of Nakagami distribution characterizing Hilbert-Huang transformation output. The backscattered ultrasound signal parameters characterizing intraocular and orbit tissues were processed by decision tree data mining algorithm. The pilot trial proved that applied methods are able to correctly classify signals from corpus vitreum blood, extraocular muscle, and orbit tissues. In 26 cases of ocular tissues classification, one error occurred, when tissues were classified into classes of corpus vitreum blood, extraocular muscle, and orbit tissue. In this pilot classification parameters of spectral intercept and Nakagami parameter for instantaneous frequencies distribution of the 1st intrinsic mode function were found specific for corpus vitreum blood, orbit and extraocular muscle tissues. We conclude that ultrasound data should be further collected in clinical database to establish background for decision support system for ocular tissue noninvasive differentiation.

Assessment of anterior segment tumors with ultrasound biomicroscopy versus anterior segment optical coherence tomography in 200 cases

PURPOSE

To compare ultrasound biomicroscopy (UBM) versus anterior segment optical coherence tomography (AS-OCT) for imaging of tumors of the anterior segment of the eye.

DESIGN

Retrospective, noninterventional case series.

PARTICIPANTS

We included 200 patients.

METHODS

Review of medical records of patients who underwent both UBM and AS-OCT for evaluation of anterior segment tumors.

MAIN OUTCOME MEASURES

Comparison of tumor surface and internal visualization.

RESULTS

There were 200 eyes with anterior segment tumors involving the iris stroma in 96 (48%), ciliary body in 14 (7%), combined iris and ciliary body in 32 (16%), iris pigment epithelium (IPE) in 44 (22%), conjunctiva in 6 (3%), sclera in 4 (2%), and others in 6 (1% each). The diagnoses included nevus in 75 eyes (38%), melanoma in 47 (24%), cyst in 48 (24%), epithelioma (adenoma) in 5 (3%), metastasis, melanocytosis and melanocytoma in 4 eyes each (2%), and others (1% each). Image analysis (UBM vs AS-OCT) revealed adequate visualization of all tumor margins (189 [95%] vs 80 [40%]), posterior tumor shadowing (9 [5%] vs 144 [72%]), and high overall image quality (159 [80%] vs 136 [68%]). Comparison for better image resolution (UBM vs AS-OCT) disclosed UBM provided better overall tumor visualization (138 [69%] vs 62 [31%]) and better resolution of the posterior margin (147 [74%] vs 53 [27%]), whereas AS-OCT provided better resolution of the anterior margin (40 [20%] vs 160 [80%]) as well as better overall resolution of anterior segment anatomy (41 [21%] vs 159 [80%]). Better resolution was found with UBM for pigmented tumors (n = 162; 107 [66%] vs 55 [34%]) as well as for nonpigmented tumors (n = 38; 23 [61%] vs 15 [39%]). Regarding location, iris tumor resolution was similar with each technique (49 [52%] vs 45 [48%]).

CONCLUSIONS

For anterior segment tumors, UBM offers better visualization of the posterior margin and provides overall better images for entire tumor configuration compared with AS-OCT.

Long-term follow-up of 42 patients with small ciliary body tumors with ultrasound biomicroscopy

PURPOSE

To establish the growth behavior of small ciliary body tumors in a relatively large cohort of patients over an extended period.

DESIGN

Retrospective, noncomparative case series.

METHODS

Ciliary body tumors less than 4 mm in size within the penetration power of ultrasound biomicroscopy (UBM) were included. Tumor height was assessed by ultrasound biomicroscopy. Tumor growth was defined as an increase in height of at least 20% from baseline, as measured on 2 consecutive UBM readings. The data were collected longitudinally, and a statistical analysis was performed.

RESULTS

Forty-two patients were included in the study with a median follow-up of 9.0 years (range, 1.0 to 17.2 years). The median age was 59 years (range, 17 to 82 years). Median initial tumor height was 2.05 mm (range, 1.11 to 3.80 mm). The overall average rate of growth was 0.0014 mm per year (P = .68). The 5- and 10-year accumulative tumor growth rates were 12% and 29%, respectively. In the first 3 years after diagnosis, the growth rate of ciliary body lesions with an initial tumor thickness less than or equal to 2 mm was 0.054 mm per year (P = 0.0001); thereafter, tumor size appeared to stabilize. Tumors with an initial thickness greater than 2 mm showed a small but significant rate of regression of 0.0125 mm per year (P = 0.04).

CONCLUSIONS

Most small tumors of the ciliary body show little growth over an extended period and can be managed conservatively without invasive diagnostic interventions. However, long-term follow-up is required. Indications for treatment include growth in height or lateral extension, extrascleral extension or the need for cataract surgery.

Anterior segment optical coherence tomography and ultrasound biomicroscopy in the imaging of anterior segment tumors

PURPOSE

To evaluate the utility of anterior segment optical coherence tomography (OCT) in the imaging of anterior segment tumors and compare the images to ultrasound biomicroscopy (UBM).

DESIGN

Prospective observational case series.

METHODS

Eighteen eyes of 18 patients with anterior segment tumors were evaluated at Princess Margaret Hospital. The evaluation included clinical examination, clinical photography, anterior segment OCT, and UBM. Comparison of images obtained by both methods was done.

RESULTS

Anterior segment OCT imaged small hypopigmented tumors with complete penetration. Cysts were incompletely imaged behind the iris pigment epithelium. Highly pigmented tumors, large tumors, and ciliary body tumors were incompletely penetrated. Even without complete penetration it was possible to differentiate cystic lesions from solid lesions. UBM penetrated all tumors completely.

CONCLUSIONS

Anterior segment OCT can penetrate small hypopigmented tumors and supply some information on internal characteristics of other tumors. UBM is preferable for clinical anterior tumor assessment and follow-up because of its superior ability to penetrate large tumors, highly pigmented tumors, and ciliary body tumors.

High-resolution ultrasound imaging of the eye - a review

This report summarizes the physics, technology and clinical application of ultrasound biomicroscopy (UBM) of the eye, in which frequencies of 35 MHz and above provide over a threefold improvement in resolution compared with conventional ophthalmic ultrasound systems. UBM allows imaging of anatomy and pathology involving the anterior segment, including regions obscured by overlying optically opaque anatomic or pathologic structures. UBM provides diagnostically significant information in conditions such as glaucoma, cysts and neoplasms, trauma and foreign bodies. UBM also can provide crucial biometric information regarding anterior segment structures, including the cornea and its constituent layers and the anterior and posterior chambers. Although UBM has now been in use for over 15 years, new technologies, including transducer arrays, pulse encoding and combination of ultrasound with light, offer the potential for significant advances in high-resolution diagnostic imaging of the eye.

The Use of Ultrasound Biomicroscopy in the Evaluation of Anterior Segment Tumors and Simulating Conditions

PURPOSE

To report the ultrasound biomicroscopy (UBM) findings of anterior segment tumors and simulating conditions.

METHODS

Thirty-five patients underwent UBM. Of those, 16 had histopathologically or cytopathologically diagnosed tumors, and 19 had clinically diagnosed lesions.

RESULTS

The study material comprised 13 iris pigment epithelial (IPE) cysts, 7 ciliary body melanomas, 4 iris melanomas, 4 iris nevi, 3 intraocular invasions of conjunctival squamous cell carcinoma, 2 ring melanomas of the anterior chamber angle, 1 medulloepithelioma and 1 pars plana cyst. On UBM, all IPE cysts presented as cystic lesions with a thin cyst wall and no solid components. All ciliary body melanomas showed low to medium reflectivity, with cavitation in one case and extraocular extension in another. Iris melanomas presented as anterior (stromal) iris lesions with medium to high internal reflectivity. There was irregularity and convex bowing of the posterior iris plane in iris melanomas, a feature not seen in iris nevi. Intraocular invasion of conjunctival squamous cell carcinoma was evidenced as areas of medium to high reflectivity in the ciliary body and iris, loss of the acute angle shape and highly reflective spots in the anterior chamber.

CONCLUSIONS

UBM was particularly useful in the diagnosis of IPE cysts, in the visualization of small ciliary body melanomas, in the differentiation of iris melanomas from iris nevi and in the demonstration of intraocular invasion from conjunctival squamous cell carcinoma.

Advances in anterior segment imaging

PURPOSE OF REVIEW

Imaging of the crystalline lens and intraocular lens is becoming increasingly more important to optimize the refractive outcome of cataract surgery, to detect and manage complications and to ascertain advanced intraocular lens performance. This review examines recent advances in anterior segment imaging.

RECENT FINDINGS

The main techniques used for imaging the anterior segment are slit-lamp biomicroscopy, ultrasound biomicroscopy, scheimpflug imaging, phakometry, optical coherence tomography and magnetic resonance imaging. They have principally been applied to the assessment of intraocular lens centration, tilt, position relative to the iris and movement with ciliary body contraction.

SUMMARY

Despite the advances in anterior chamber imaging technology, there is still the need for a clinical, high-resolution, true anatomical, noninvasive technique to image behind the peripheral iris.