Session Title: Imaging II
Session Date/Time: Friday 18/09/2015 | 16:30-18:00
Paper Time: 16:30
First Author: : M.Nowara EGYPT
Co Author(s): : A. Habib E. Elsawy H. Hassan I. A Mohamed A. Soliman R. Ismail
PURPOSE:Choroidal tumors are the most common intraocular tumours. Indirect ophthalmoscopy, fundus photoography, and ultrasonography remain the main methods of diagnosis. Other ancillary tests such as fundus fluorescein angiography and Optical Coherence Tomography (OCT) can also be helpful. OCT imaging of choroidal tumours has been challenged by its limited penetration into the choroid. With the improvement of OCT machines with shorter acquisition-times and enhanced resolution, better quality images could be taken. Currently, there are no pathognomonic OCT findings for choroidal tumours. Our study aims to evaluate SD-OCT using choroidal enhancement technique in detecting diagnostic criteria of choroidal tumours.
This is a multicentre study where three centres in Cairo have been involved in recruitment of patients and conducting the study.
A multicenter observational study was conducted between 2008 to 2012. Twenty-six eyes (25 patients-9 males, 16 females) with recently diagnosed choroidal tumours were imaged by three SD-OCT machines. Patients meeting the enrolment criteria (recent diagnosis of choroidal tumours and no previous intervention) were only included in this study. OCT images were taken at the time of their initial diagnosis. The study and its probable safety and efficacy of the interventions were explained to all participants before enrolment. An informed consent was obtained from all patients. All investigators adhered to the ethical standards of Good Clinical Practice. Fifteen eyes were imaged by OTI SLO/OCT (2 eyes by C-scan, 6 eyes by choroidal enhancement technique, 7 by regular technique) ((OTI®, Toronto Canada), five eyes were examined by Spectralis (1 by choroidal enhancement technique, 4 by EDI) (Heidelberg Engineering, Heidelberg, Germany) and 6 eyes by Cirrus (regular technique). (Carl Zeiss Meditec Inc, Newark, California, USA). Qualitative analysis included the overlying retina, tumour surface, light penetration (intra lesion reflectivity) and discrimination from surrounding choroidal tissue was run.
Twenty-six eyes (9 males, 16 females) were clinically classified into: choroidal metastasis (10 eyes); choroidal haemangioma (diffuse1 eye, circumscribed 3 eyes); choroidal melanoma (4 eyes); choroidal naevus (melanotic 6 eyes, amelanotic 2 eyes). SD-OCT identified precise criteria for each tumour type, and distinguished tumour landmarks from the surrounding normal choroid. Qualitative analysis revealed amelanotic naevi and amelanotic melanomas as homogenous low to medium reflective band with visible compressed choroidal vessels- amelanotic melanomas portrayed adjacent choroidal congestion. Melanotic naevi and choroidal melanomas appeared as highly a reflective band in the anterior choroid with shadowing and obscuration of choroidal vessels and inner sclera, with signs of activity intrinsic to melanomas. Active stages of choroidal haemangiomas displayed a mammillated surface and a smooth surface was evident in quiescent stages. They appeared as a medium/low reflective interrupted band with shadowing and obscuration of choroidal vessels and inner sclera. Choroidal metastasis appeared as lobulated masses of low reflectivity, allowing deep penetration of light, with signs of activity and loss of the normal choroidal pattern.
This observational study demonstrated feasibility of directly imaging a variety of frequently encountered benign and malignant choroidal tumors with SD-OCT techniques. This can be particularly useful in detection of small choroidal tumors such as choroidal naevi that are undetectable by ultrasonography. Development of Choroidal enhancement technique / Enhancement depth image used in 8 eyes of this study was useful in obtaining deeper images of choroidal tumours and defining specific features with characteristic changes for each. This will help early diagnosis of life threatening conditions in a timely manner without the need of invasive procedures. We recommend using specific SD-OCT analysis criteria in diagnosis choroidal tumours. Improvements in OCT devices and development of new technology like swept source OCT may help in better visualization of choroidal tumors. In conclusion, SD-OCT is efficient in detecting pathognomonic criteria for different types of choroidal tumors, and can be used as a non-invasive diagnostic tool. Our study has identified specific qualitative SD-OCT features for a variety of commonly encountered benign and malignant choroidal tumours.