Prospective comparison of ultrasound biomicroscopy and anterior segment optical coherence tomography for evaluation of anterior chamber dimensions in European eyes with primary angle closure

Assessment by Optical Coherence Tomography of Short-Term Changes in IOP-Related Structures Caused by Wearing Scleral Lenses

BACKGROUND

The mechanism that could increase intraocular pressure (IOP) during scleral lens (SL) wear is not fully understood, although it may be related to compression of the landing zone on structures involved in aqueous humor drainage.

METHODS

Thirty healthy subjects were fitted with two SLs of different sizes (L1 = 15.8 mm, L2 = 16.8 mm) for 2 h in the right eye and left eye as a control. Central corneal thickness (CCT), parameters of iridocorneal angle (ICA), Schlemm's canal (SC), and optic nerve head were measured before and after wearing both SLs. IOP was measured with a Perkins applanation tonometer before and after lens removal and with a transpalpebral tonometer before, during (0 h, 1 h, and 2 h), and after lens wear.

RESULTS

CCT increased after wearing L1 (8.10 ± 4.21 µm; p < 0.01) and L2 (9.17 ± 4.41 µm; p < 0.01). After L1 removal, the ICA parameters decreased significantly (p < 0.05). With L2 removal, nasal and temporal SC area and length were reduced (p < 0.05). An increased IOP with transpalpebral tonometry was observed at 2 h of wearing L1 (2.55 ± 2.04 mmHg; p < 0.01) and L2 (2.53 ± 2.22 mmHg; p < 0.01), as well as an increased IOP with Perkins applanation tonometry after wearing L1 (0.43 ± 1.07 mmHg; p = 0.02).

CONCLUSIONS

In the short term, SL resulted in a slight increase in IOP in addition to small changes in ICA and SC parameters, although it did not seem to be clinically relevant in healthy subjects.

[Angle-closure glaucoma]

Angle-closure glaucoma is a rare form of glaucoma characterized by a narrow or an occlusion of the anterior chamber angle and subsequently an obstruction of the outflow of aqueous humor resulting in an increase in intraocular pressure. Symptoms can include severe eye pain and/or headache, blurred vision, a medium-sized and rigid pupil, conjunctival hyperemia, and nausea. Treatment options include pressure-lowering topical and systemic medications as well as surgical interventions, especially cataract surgery and laser iridotomy. Besides parasympathomimetics (pilocarpine), all topical antiglaucoma medications can principally be used (beta-receptor antagonists, carbonic anhydrase inhibitors, alpha‑2 selective adrenergic antagonists, prostaglandins and prostaglandin analogues). Carbonic anhydrase inhibitors and osmotic agents (e.g., mannitol) can be systemically used.

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.

Corneal Structural Changes in Congenital Glaucoma

OBJECTIVE

To identify corneal structure differences on quantitative high-frequency ultrasound biomicroscopy (UBM) among subjects with congenital glaucoma compared with controls.

METHODS

This prospective case-control study evaluated 180 UBM images from 44 eyes of 30 subjects (18 control and 12 glaucoma, mean age 5.2±8.0 years, range 0.2-25.8 years) enrolled in the Pediatric Anterior Segment Imaging and Innovation Study (PASIIS). ImageJ was used to quantify a comprehensive set of corneal structures according to 21 quantitative parameters. Statistical analysis compared corneal measurements in glaucoma subtypes and age-matched controls with significance testing and mixed effects models.

RESULTS

Significant differences between congenital glaucoma cases and controls were identified in 16 of 21 measured parameters including angle-to-angle, central and peripheral corneal thicknesses, scleral integrated pixel density, anterior corneal radius of curvature, and posterior corneal radius of curvature. Eight parameters differed significantly between primary congenital glaucoma and glaucoma following congenital cataract surgery.

CONCLUSION

Multiple measurable corneal structural differences exist between congenital glaucoma and control eyes, and between primary and secondary congenital glaucoma, including but not limited to corneal width and thickness. The structural differences can be quantified from UBM image analysis. Further studies are needed to determine whether corneal features associated with glaucoma can be used to diagnose or monitor progression of congenital glaucoma.

Iris Cysts: Clinical Features, Imaging Findings, and Treatment Results

Objectives:

To report the clinical and demographic characteristics, imaging findings, treatment results, and follow-up data of patients with iris cysts.

Materials and Methods:

The medical records of 37 patients with iris cysts were retrospectively analyzed. Ultrasound biomicroscopy (UBM), swept-source optical coherence tomography (SS-OCT), and SS-OCT angiography (SS-OCTA) were performed to examine the iris cysts.

Results:

The mean age of the patients was 34.4 years, ranging from 5 to 85 years. Twenty-four patients (65%) were female and 13 (35%) were male. Mean follow-up period was 21.3 months, ranging from 4 months to 8 years. Thirty-five (94.5%) of the cysts were classified as primary and 2 (4.5%) were classified as secondary. Thirty-one (83.7%) of the primary cysts were pigment epithelial and 4 were stromal. Primary iris pigment epithelial cysts were classified as peripheral in 26 patients (72.2%), midzonal in 4 (11.1%), and dislodged in 1 (2.7%). Stromal cysts were classified as acquired in 3 patients (8.1%) and congenital in 1 patient (2.7%). Secondary iris cysts were caused by perforating eye injury. UBM could visualize both the anterior and posterior surfaces of the cysts (26 patients). Anterior segment SSOCT could visualize the anterior but not the posterior surface of the cysts (4 patients). Iris cysts did not display intrinsic vascularity on SS-OCTA (4 patients). All pigment epithelial cysts were managed by observation. Of the 4 primary stromal cysts, 3 were managed by surgical excision and 1 by observation. Two secondary cysts required surgical removal.

Conclusion:

Pigment epithelial cysts generally remain stable without need for treatment. However, iris stromal cysts frequently require surgical intervention. UBM and SS-OCT were valuable in the diagnosis of iris cysts. On UBM, iris cysts appear with a thin, hyperechoic wall with hypoechoic internal content. Iris cysts did not have intrinsic vascularity on anterior segment SS-OCTA.

Repeatability and Reliability of Quantified Ultrasound Biomicroscopy Image Analysis of the Ciliary Body at the Pars Plicata

Most of the ciliary body and ciliary processes of the eye cannot be directly visualized in vivo because of the posterior location of the pars plicata to the posterior chamber and iris. However, ciliary anatomy can be effectively imaged using ultrasound biomicroscopy (UBM) by placing the probe close to the limbus, perpendicular to this structure. Previous studies measuring ciliary body parameters in meridian UBM images found that these parameters were measured with poor reliability and repeatability. This study evaluates the intra-observer reliability and inter-observer agreement of a standardized protocol for measuring six ciliary parameters in transverse or quadrant UBM images that capture an entire row of ciliary processes. All six ciliary parameters have high intra-observer reliability, with ciliary body thickness, ciliary process length and ciliary process density measurements being the most consistent for each observer. The coefficient of variation for each observer ranged from 1.4%-15%. Inter-observer agreement was also high for all six parameters, with an intra-class correlation coefficient >0.8. Utilizing transverse UBM images of the pars plicata allows for consistent quantitative analysis in control subjects.

Semiautomated Assessment of Anterior Segment Structures in Pediatric Glaucoma Using Quantitative Ultrasound Biomicroscopy

The study was a prospective observational study comparing semiautomated to manual quantitative ultrasound biomicroscopy image analysis among 82 images from 41 eyes of 32 subjects (21 controls and 11 glaucoma) enrolled in the Pediatric Anterior Segment Imaging Innovation Study. Intraclass correlation coefficients and correlation coefficients were >0.8 for all parameters, and comparison of respective analysis speed was 7 times faster for the semiautomated method compared with manual image quantification.

Exploring the Occurrence Mechanisms of Acute Primary Angle Closure by Comparative Analysis of Ultrasound Biomicroscopic Data of the Attack and Fellow Eyes

Purpose

To explore the anatomical characteristics and occurrence mechanisms of acute primary angle closure (APAC) by comparing the quantitative data of UBM images of the APAC and fellow eyes.

Methods

131 patients (262 eyes) were studied over five years by retrospective analysis. The quantitative data from UBM images including angle opening distance at 500 μm (AOD500), trabecular-iris angle (TIA), iris convexity (IC), iris span (IS), iris-lens angle (ILA), iris-lens contact distance (ILCD), iris-ciliary process angle (ICPA), and limbus-ciliary body angle (LCBA) were retrospectively recorded; comparative analysis of the APAC and fellow eyes was performed.

Results

The superior, inferior, nasal, temporal, and mean AOD500, TIA, IC, and LCBA (P < 0.001) were significantly smaller in APAC than in fellow eyes. Values of the lens thickness (LT), lens/axial length factor (LAF), lens position (LP), and relative lens position (RLP) were lower in APAC than in fellow eyes (P = 0.021; P = 0.025; P < 0.001; and P < 0.001). In APAC eyes, AOD500 was significantly positively correlated with IC, ILCD, and LCBA; TIA was significantly positively significantly correlated with IC, ILCD, and LCBA. In fellow eyes, AOD500 was significantly negatively correlated with ILA and significantly positively correlated with ILCD, ICPA, LCBA, axial length (AL), central anterior chamber depth (CACD), and LP; TIA was significantly negatively correlated with ILA and significantly positively correlated with IS, ILCD, ICPA, LCBA, AL, CACD, LP, and RLP.

Conclusions

Multiple nonpupillary block factors (plateau iris, anterior attachment and insertion of the iris root, anterior shift of the lens, and anterior rotation of the ciliary body) promote the occurrence of APAC, and abnormal positional relationships of the iris, ciliary body, and lens may contribute to APAC.

Comparison of measurements of anterior chamber angle via anterior segment optical coherence tomography and ultrasound biomicroscopy

BACKGROUND

Glaucoma is an irreversible optic neuropathy with the loss of visual field and decrease of vision. The variable clinical manifestations may result in differential diagnostic difficulties. The early screening and diagnosis of glaucoma are currently experiencing a demand for anterior segment analysis tools that can gather more information with one short measurement. Therefore, we analyzed the agreement, difference, and correlation of chamber angle parameters such as angel opening distance at 500 μm (AOD500) and trabeculo-iris space area at 500 μm² (TISA500) measured by anterior segment optical coherence tomography (AS-OCT) and ultrasound biomicroscopy (UBM).

AIM

To compare the differences, correlation, and agreement in measuring AOD500 and TISA500 by AS-OCT and UBM.

METHODS

Both AS-OCT and UBM were performed to measure AOD500 and TISA500 in 45 subjects (72 eyes). All subjects without glaucoma were collected from October 2015 to August 2016 at the Ophthalmology Department of the Fourth Affiliated Hospital of China Medical University. Data of the two groups (AOD500 and TISA500) were compared by nonparametric tests. Pearson correlative analysis and Bland–Altman analysis were used to compare the correlation and agreement.

RESULTS

There were no significant differences between AS-OCT and UBM in measuring AOD500 (P1 = 0.110, P2 = 0.633, P3 = 0.078, and P4 = 0.474) and TISA500 (P1 = 0.584, P2 = 0.889, P3 = 0.297, and P4 = 0.550) of the four quadrants of the anterior chamber angle. There was a high correlation in measuring AOD500 (r1 = 0.562, r2 = 0.671, r3 = 0.635, and r4 = 0.720; P < 0.001) and TISA500 (r1 = 0.584, r2 = 0.889, r3 = 0.297, and r4 = 0.550; P < 0.001). There was a good agreement in measuring AOD500 and TISA500 by the two modalities.

CONCLUSION

There is a high correlation and agreement between AOD500 and TISA500 measurements by AS-OCT and UBM. They are interchangeable under some circumstances. AS-OCT proves to be a better early screening tool for glaucoma.

Assessment of Anterior Chamber by Ultrasound Biomicroscopy and Anterior Segment Optical Coherence Tomography in Patients with Inflammatory Glaucoma

Objective

To investigate the clinical indications of ultrasound biomicroscopy (UBM) and anterior segment optical coherence tomography (AS-OCT) in eyes with inflammatory glaucoma.

Methods

Sixteen patients (16 eyes) with inflammatory glaucoma were analysed retrospectively. All of the subjects underwent UBM and AS-OCT scans, measuring the following parameters: central corneal thickness (CCT), central anterior chamber depth (ACD), angle-opening distance (AOD500), and trabecular-iris angle (TIA500) in four quadrants.

Results

Both the UBM and AS-OCT generated detailed, high-resolution images of the anterior segments of the eyes with inflammatory glaucoma. Moreover, the UBM and AS-OCT exhibited statistically similar measurement results for all of the indices. A Bland–Altman analysis showed a high level of agreement between the two imaging techniques. Additionally, the UBM was able to visualize the ciliary body and pars plana, while the cells and the flare in the anterior chamber appeared more pronounced in the UBM images.

Conclusions

Both the UBM and AS-OCT are useful tools for anterior segment imaging and taking measurements needed for evaluating inflammatory glaucoma. The AS-OCT has the advantages of being noninvasive and fast, whereas the UBM is presently unparalleled in the visualization of the ciliary body and pars plana.

Update on the usefulness of optical coherence tomography in assessing the iridocorneal angle

The iridocorneal angle, due to its implications in the physiopathology of aqueous humour drainage, is a fundamental structure of the anterior chamber. Anterior segment optical coherence tomography is a rapid and non-invasive technique that obtains images in vivo. The high resolution allows it to analyse the normal anatomy of the angle, any alterations, and the changes that occur after different therapeutic interventions. Anterior segment optical coherence tomography technology has evolved to provide images that allow the identification and quantification of the angular structures in healthy subjects and in glaucoma patients, and especially the trabecular meshwork and the Schlemm's canal. It also enables the angle width to be quantified, with some objective parameters that have been standardised in recent years, such as the trabecular-iris angle, the angle opening distance, and the trabecular-iris area. This technique has multiple uses in the study of the different mechanisms of angle closure, the evaluation of changes after a laser peripheral iridotomy or iridoplasty after cataract surgery, as well as after the implantation of phakic lenses.

Assessment of Circumferential Angle Closure with Swept-Source Optical Coherence Tomography: a Community Based Study

PURPOSE

To evaluate the diagnostic performance of swept-source optical coherence tomography (SS-OCT, CASIA SS-1000; Tomey Corporation, Nagoya, Japan) for angle closure detection, in comparison with gonioscopy, in a community setting.

DESIGN

Reliability analysis.

METHODS

A total of 2027 phakic subjects aged ≥50 years, with no previous history of glaucoma, laser (including peripheral iridotomy), intraocular surgery, or ocular trauma, were consecutively recruited from a community polyclinic in Singapore. Gonioscopy was performed by a single trained ophthalmologist. SS-OCT angle scans, which obtain radial scans for the entire circumference of the angle, were analyzed by a single examiner, masked to the subject's clinical details. On SS-OCT images, angle closure was defined as contact between the iris and any part of the angle wall anterior to the scleral spur. Different cutoff values of the degree of circumferential angle closure (≥35%, ≥50%, and ≥75%) were taken for analysis to assess SS-OCT performance in detecting angle closure.

RESULTS

A total of 1857 subjects (91.6%) were included in the final analysis after excluding poor-quality SS-OCT scans. Almost 90% of the subjects were Chinese, with a mean age of 61.8 ± 6.7 years, and more than half were women (63.5%). The overall AUC of SS-OCT manual grading against gonioscopy was 0.84 (95% confidence interval, 0.81-0.88). The prevalence of angle closure on SS-OCT was 26.1% for the ≥35% definition, with an area under the curve of 0.80 (0.77-0.84), sensitivity of 82.5% (75.3%-88.4%), and specificity of 78.5% (76.5%-80.4%). The first-order agreement coefficient statistics for the 2-quadrant gonioscopic definition of angle-closure with corresponding ≥35%, ≥50%, and ≥75% angle closure definitions for SS-OCT were good at 0.89 (0.83-0.93), 0.88 (0.842-0.93), and 0.88 (0.831-0.99), respectively.

CONCLUSIONS

In this large community-based study, SS-OCT exhibited moderate performance for angle closure detection compared to gonioscopy as the reference standard.

Comparison of ultrasound biomicroscopy and spectral-domain anterior segment optical coherence tomography in evaluation of anterior segment after laser peripheral iridotomy

AIM

To quantitatively assess narrow anterior chamber angle using spectral-domain anterior segment optical coherence tomography (SD-AS-OCT) and ultrasound biomicroscopy (UBM), and to evaluate the correlations and consistency between SD-AS-OCT and UBM.

METHODS

Fifty-five eyes from 40 patients were examined. Patients were diagnosed with primary angle-closure glaucoma (PACG) remission (11 eyes from 8 patients), primary angle closure (PAC, 20 eyes from 20 patients) and PAC suspect (24 eyes from 12 patients). Each eye was examined by SD-AS-OCT and UBM after laser peripheral iridotomy (LPI). The measurements of SD-AS-OCT were angle open distance (AOD), anterior chamber angle (ACA), trabecular iris angle (TIA), and trabecular iris space area (TISA). UBM measurements were AOD and TIA. Correlations of AOD500 and TIA500 between UBM and AS-OCT were assessed. All parameters were analysed by SPSS 16.0 and MedCalc.

RESULTS

ACA, TIA and AOD measured by SD-AS-OCT reached a maximum at the temporal quadrant and minimum at the nasal quadrant. TISA reached the maximum at the inferior and minimum at the superior quadrant. Group parameters of AOD500 and AOD750 showed a linear positive correlation, and AOD750 had less variability. UBM outcomes of AOD500 and TIA500 were significantly smaller than those of SD-AS-OCT. The results of the two techniques were correlated at the superior, nasal and inferior quadrants.

CONCLUSION

Both UBM and SD-AS-OCT are efficient tools for follow-up during the course of PACG. We recommended using parameters at 750 µm anterior to the sclera spur for the screening and follow-up of PACG and PAC. The two methods might be alternatives to each other.

Application of anterior segment optical coherence tomography in glaucoma

Optical coherence tomography (OCT) is a cross-sectional, three-dimensional, high-resolution imaging modality that uses low coherence interferometry to achieve axial resolution in the range of 3-20 μm. Two OCT platforms have been developed: time domain (TD-OCT) and spectral (or Fourier) domain (SD/FD-OCT). Visante anterior segment OCT (Carl Zeiss Meditec) is a TD-OCT widely used for anterior segment imaging. The SD-OCT systems with both posterior and anterior segment imaging capabilities include the RTVue, iVue (Optovue), the Cirrus (Carl Zeiss Meditec), and the Spectralis (Heidelberg Engineering, Inc.). Each of the SD-OCTs has a wavelength in the range of 820-879 nm. Anterior segment OCT is a non-contact method providing high resolution tomographic cross-sectional imaging of anterior segment structures. Anterior segment OCT provides qualitative and quantitative assessment of the anterior segment structures important to the pathogenesis and the anatomical variations of glaucoma, and the approach to and success of treatment. We summarize the clinical applications of anterior segment OCT in glaucoma.

Ultrasound biomicroscopic evaluation of anterior segment cysts as a risk factor for ocular hypertension and closure angle glaucoma

AIM

To investigate the relationship between the ultrasound biomicroscopic (UBM) features of anterior-segment cysts (ASCs) and increased intraocular pressure (IOP) as a risk factor for closed-angle glaucoma (CAG).

METHODS

Totally 24 eyes with recently diagnosed ASCs were divided into two groups. First group with ASC and ocular normotension (n=13), second group with ASC and ocular hypertension (n=11). An ophthalmologic examination, including tonometry, slit-lamp biomicroscopy (SLBM), gonioscopy, fundoscopy, pentacam, and UBM, was performed. The features of the ASCs were compared with the IOP.

RESULTS

ASCs were accurately diagnosed and delineated in 24 eyes using UBM. IOP was elevated in those ASCs with a secondary aetiology (P=0.027), iridociliary location (P=0.006), deformed shape (P=0.013), increased size (P=0.001) and elongated pupillary aperture (P=0.009). However, the count (P=0.343) of ASCs, anterior chamber depth (ACD; P=0.22) and axial lenght (AL; P=0.31) were not associated with ocular hypertension. Correlations were found between the IOP and ASC size (r=-0.712; P=0.003), anterior chamber angle (ACA; r=-0.985; P<0.001), angle opening area (AOA; r=0.885; P<0.001), angulation of iris (r=-0.776, P<0.001), and affected iris quadrant (r =-0.655, P=0.002).

CONCLUSION

Ocular hypertension in some eyes with ASC might be associated with various mechanisms, including secondary aetiology, iridociliary location, deformed shape, increased size and elongated pupill, which can be determined by UBM.

Fibrin membrane pupillary-block glaucoma after uneventful cataract surgery treated with intracameral tissue plasminogen activator: a case report

Background

Fibrin pupillary-block glaucoma is a rare complication after cataract surgery. The treatment for this condition is still controversial, since Nd:YAG laser fibrin membranotomy tends to reocclude and laser peripheral iridotomy entails the risk of damaging the corneal endothelium in the presence of corneal edema associated with elevated intraocular pressure.

Case presentation

A 62-year-old man with diabetes mellitus developed acute elevation of intraocular pressure with a shallow anterior chamber five days after uneventful cataract surgery. Initially, slit lamp examination provided only limited information due to severe corneal edema. After resolution of corneal edema with systemic glaucoma therapy, a complete fibrin membrane was observed across the pupil by slit lamp examination. Anterior segment optic coherence tomography clearly revealed a thin fibrin membrane covering the entire pupillary space, a shallow anterior chamber, and a deep posterior chamber. The intraocular lens was not observed by anterior segment optic coherence tomography. In contrast, ultrasound biomicroscopy, which has superior penetration depth, was able to visualize the intraocular lens deep in the posterior chamber. Injection of tissue plasminogen activator into the anterior chamber resulted in complete fibrinolysis and released the pupillary block.

Conclusion

This case suggests that ocular anterior segment imaging modalities, especially ultrasound biomicroscopy, serve as powerful diagnostic tools to identify mechanisms of acute angle closure glaucoma, which is often accompanied by poor intraocular visibility. This is the first reported case of fibrin pupillary-block glaucoma after cataract surgery successfully treated with intracameral tissue plasminogen activator.

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.