RETINAL ONCOLOGY CASE REPORTS IN OCULAR ONCOLOGY SECTION EDITOR: CAROL L. SHIELDS, MD Enhanced Depth Imaging Optical Coherence Tomography for Choroidal Tumors BY SHAZIA NAKHODA, BS; CARLOS BIANCIOTTO, MD; AND CAROL L. SHIELDS, MD
nhanced depth imaging optical coherence A B tomography (EDI OCT) was first described by Spaide and associates1 in 2008 as a technique for E imaging the superficial and deep layers of the ocular fundus. The method involves placing a conven- tional optical coherence tomography (OCT) device closer to the eye and thereby producing an inverted image of both the retina and choroid.1 Conventional OCT technology visualizes the retinal and retinal pig- ment epithelial (RPE) layers but little of the underlying C choroidal tissue.2 This novel method allows improved resolution of and sensitivity to deeper fundus structures such as the choroid and inner sclera using noncontact technology.2 D A standard OCT device uses near infrared light at approximately 800 nm. This form of light allows visuali- zation of the retina and subretinal space but becomes scattered by the RPE and choroidal structures. Moving the device closer to the eye allows the choroidal layers to receive a more focused stream of light, providing enhanced visualization of choroidal details. This devel- Figure 1. Color fundus photograph of right eye, showing a opment has facilitated descriptive findings of choroidal partially pigmented choroidal nevus with overlying drusen tumors and precision in measurement of choroidal in the temporal macular region (A). B-scan ultrasonography tumor thickness.1 demonstrating slightly elevated choroidal lesion correspon- ding to the nevus (B) with measurement of 1.5 mm thick- CASE DESCRIPTION ness (retina plus choroid thickness). Standard OCT depict- A 61-year-old white woman was found to have a pig- ing the subtle choroidal elevation devoid of features but mented fundus lesion on routine eye examination. Visual with excellent detail of overlying retina and retinal pigment acuity was 20/20 in each eye (OU). Intraocular pressures epithelium (C). Enhanced depth imaging OCT showing full and anterior segments were normal OU. The left fundus thickness of choroidal nevus with some degree of choroidal was normal. The right fundus disclosed a lightly pigment- detail showing compression of the choriocapillaris overly- ed choroidal nevus temporal to the foveola measuring ing the deeper nevus; in this image, the nevus measured 6 x 5 mm at the base and 1.5 mm in thickness; overlying 660 µm in thickness (D).
48 IRETINA TODAYIJANUARY/FEBRUARY 2012 RETINAL ONCOLOGY CASE REPORTS IN OCULAR ONCOLOGY
drusen were noted (Figure 1A, 1B). Autofluorescence showed absence of orange pigment. Standard OCT depicted the slightly elevated choroidal mass with no EDI OCT has played a vital role details except for slight deep optical shadowing (Figure in the analysis of multiple ocular 1C). The overlying retina was attached, and there were fundus conditions affecting micronodular changes at the level of the RPE consistent with drusen. EDI OCT confirmed the above findings but the retina and the choroid. revealed more detail regarding the internal features of the choroidal nevus, demonstrating the location of the nevus in the outer choroid with compression of the choriocap- explore the pathogenesis of related RPE detachment. illaris, intact scleral wall, and thickness of 660 µm (Figure EDI OCT imaging allowed visualization of choroidal 1D). A diagnosis of choroidal nevus was rendered, and neovascularization on the back surface of the detached observation was advised. RPE, possibly representing retinal vascular anastomosis and leading to RPE tears following contraction. DISCUSSION Imamura and associates5 used EDI OCT to demonstrate EDI OCT has played a vital role in the analysis of mul- the increase in choroidal thickness in 19 patients with tiple ocular fundus conditions affecting the retina and central serous chorioretinopathy (CSC); the investiga- the choroid. Fujiwara and associates3 utilized this tech- tors suggested that accumulation of choroidal fluid or nique to image highly myopic eyes in 31 patients. EDI thickness with elevated hydrostatic pressure could be a OCT displayed significant choroidal thinning, and the step in the pathogenesis of CSC. investigators calculated that subfoveal choroidal thick- A recent PubMed search identified 2 reports of EDI ness decreased by 8.7 µm per diopter of myopia and by OCT on choroidal tumors in the literature. 12.7 µm per decade of life. Spaide and associates4 stud- Basdekidou and associates6 presented a case report in ied age-related macular degeneration in 22 patients to which a choroidal nevus inaccessible to ultrasonography !-$ GENETIC TESTING
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was measured and evaluated in the superior macula using CONCLUSION EDI OCT. Thickness was measured based on the hyper- EDI OCT enables improved examination of choroidal reflectivity between the Bruch membrane and the inner nevus and small melanoma, in comparison with standard scleral surface. The tumor was identified despite absence OCT, by providing higher resolution of and sensitivity to of RPE detachment and retinal photoreceptor damage. choroidal detail and allowing precise measurement of Torres and coworkers2 described the EDI OCT fea- intrachoroidal tumor thickness, which has historically tures of choroidal tumors less than 1 mm in thickness, often been possible only in thin amelanotic tumors. EDI which were previously unable to be identified using OCT is an additional resource for tumor detection of ultrasonography, in 23 patients. Various clinical features inconspicuous flat tumors that might remain hidden were identified on EDI OCT based on the tumor type. from ultrasonography. As in the case presented here, EDI Amelanotic choroidal nevus showed a homogeneous OCT can occasionally provide complete visualization of a appearance, with medium reflective band and visible choroidal tumor, which is critical for patient follow-up. ■ intrinsic choroidal vessels. Melanotic choroidal nevus displayed a highly reflective band at the choriocapillaris Shazia Nakhoda, BS, is a Medical Student in Ocular layer with posterior optical shadowing. Choroidal Oncology at Wills Eye Institute, Thomas Jefferson University, melanoma displayed a highly reflective band anteriorly Philadelphia. and did not allow visualization of choroidal vessels or Carlos G. Bianciotto, MD, is a Staff Member in sclera. EDI OCT was able to identify the anterior and Ocular Oncology at Wills Eye Institute, Thomas lateral tumor boundaries using recognized landmarks of Jefferson University, Philadelphia. Bruch membrane, RPE, and surrounding normal Carol L. Shields, MD, is the Co-Director of choroid. However, the junction of the posterior bound- the Ocular Oncology Service, Wills Eye ary of the tumor with the inner scleral layer was visible Institute, Thomas Jefferson University. She is only in tumors measuring less than 0.9 mm in thickness. a Retina Today Editorial Board member. Dr. Consequently, tumors with thickness greater than 1 mm Shields can be reached at +1 215 928 3105; in height or 9 mm in diameter could not be clearly fax: +1 215 928 1140; or via email at identified from surrounding structures. [email protected]. Shah and coworkers7 evaluated 104 patients with choroidal nevus to determine the optimal characteris- Support for this article was provided by Eye Tumor tics for EDI OCT imaging. Lesion and patient factors for Research Foundation, Philadelphia, PA (CLS). The funders ideal EDI OCT imaging included patient age less than had no role in the design and conduct of the study, in the 60 years (for best cooperation), nevus location within collection, analysis and interpretation of the data, or in the or close to macula (for most direct imaging), and small preparation, review or approval of the manuscript. Carol L. lesion diameter (for identification of landmark sur- Shields, MD, has had full access to all the data in the study rounding structures). The investigators evaluated retina and takes responsibility for the integrity of the data and the and choroid in exquisite detail and reported that the accuracy of the data analysis. most common findings for choroidal nevus imaged No conflicting relationship exists for any author. with EDI OCT included choroidal shadowing deep to 1. Spaide RF, Koizumi H, Pozzoni MC. Enhanced depth imaging spectral-domain optical the nevus (92%), choriocapillaris thinning overlying the coherence tomography. Am J Ophthalmol. 2008;146:496-500. nevus (94%), RPE atrophy (43%), RPE nodularity (8%), 2. Torres V, Brugnoni N, Kaiser P, Singh A. Optical coherence tomography enhanced depth imaging of choroidal tumors. Am J Ophthalmol. 2011;151:586-593. photoreceptor loss (43%), inner segment-outer seg- 3. Fujiwara T, Imamura Y, Margolis R, et al. Enhanced depth imaging optical coherence ment irregularity or loss (43%), external limiting mem- tomography of the choroid in highly myopic eyes. Am J Ophthalmol. 2009;148:445-450. 4. Spaide RF. Enhanced depth imaging optical coherence tomography of retinal pigment epithe- brane irregularity (18%), outer nuclear and outer plexi- lial detachment in age-related macular degeneration. Am J Ophthalmol. 2009;147:644-652. form layer irregularity (8%), inner nuclear layer irregu- 5. Imamura Y, Fujiwara T, Margolis R, Spaide RF. Enhanced depth imaging optical coherence tomography of the choroid in central serous chorioretinopathy. Retina. 2009;29:1469-1473. larity (6%), and subretinal fluid detected by EDI OCT 6. Basdekidou C, Wolff B, Vasseur V, Mer YL, Sahel JA. Flat choroidal nevus inaccessible to (16%). The authors commented that EDI OCT meas- ultrasound sonography evaluated by enhanced depth imaging optical coherence tomography. Case Report Ophthalmol. 2011;2:185-188. urement of a choroidal nevus at 0.66 mm was smaller 7. Shah S, Kaliki S, Shields CL, Ferenczy SR, Harmon SA, Shields JA. Enhanced depth imag- than the ultrasound measurement of 1.5 mm. This ing optical coherence tomography of choroidal nevus in 104 cases. Ophthalmology. In press. probably relates to the more precise “choroid-only” measurement of the nevus and higher resolution of CONTACT US true anterior and posterior margins, but it could also Send us your thoughts via e-mail to represent miscalibration of either the OCT or the ultra- [email protected]. sound unit.
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