Abstract
Purpose :
Optic head nerve drusen (ONHD) are less frequently detected in clinical routine, than they actually exist. The pathology of ONHD is a proceeding calcification in the optic nerve. Conventionally ophthalmoscopy, fundus autofluorescence (FAF) and B scan ultrasound are used to identify and illustrate ONHD. Transverse section enhanced depth imaging optical coherence tomography (TSV-EDI-OCT) enables imaging of deeper layers of the subretinal structures. The purpose of this study was to describe the morphologic information acquired by TSV-EDI-OCT, to compare the diagnostic information of this method to previous imaging techniques. Furthermore TSV-EDI-OCT was used to detect ONHD and acquire measurements regarding to the surrounding anatomical constitutions.
Methods :
23 eyes of 12 patients (6 women, 6 men, mean age 64 years) with diagnosed ONHD were included. A complete ophthalmological examination, perimetry, B scan ultrasound, FAF and TSV-EDI-OCT through the optic nerve were performed. Localizations of drusen in regard to Bruchs Membrane, greatest linear diameter in Bruchs Membrane Opening (BMO), choroidial thickness in different eccentricities and papilla prominence were measured.
Results :
All eyes presented ONHD in ultrasound examination. TSV-EDI-OCT identified ONHD in 22 eyes, 21 eyes with superficial and 19 eyes with buried drusen. In these 22 eyes hyperreflective plaques were demonstrated. Not only the plaques but also the different reflectivity of the drusen volume enables a clear delimitation to other structures primarily to vessels. The mean horizontal diameter of BMO was 1594 (± 189) µm. 1500 µm nasal from the central of the optic disc the choroidial thickness showed an average of 107 (± 28) µm and temporal 110 (± 27) µm. A mean maximal papilla prominence of 661 (± 149) µm was found. Importantly, TSV-EDI-OCT was able to verify buried drusen in 5 eyes, which did not show any corresponding signal in FAF.
Conclusions :
B scan ultrasound is still gold standard in patients with ONHD. But particularly regarding to the anatomically position and surrounding area TVS-EDI-OCT provides valuable detectability and monitoring of ONHD. In addition, TVS-EDI-OCT illustrates hyperreflective plaques and may permit a more sensitive proof of buried drusen than FAF.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.