Autofluorescence and Infrared Retinal Imaging in patients and obligate carriers with Neuronal Ceroid Lipofuscinosis

Abstract

Purpose: To measure fundus autofluorescence (FAF) in patients and obligate carriers with Neuronal Ceroid Lipofuscinosis (NCL) and document fundus abnormalities in NCL patients using standard retinal photography and confocal infra-red (IR) imaging.

Methods: Twenty-seven patients with NCL, 50 obligate carriers of NCL, and 19 controls were imaged in IR and FAF modes by a confocal scanning laser opthalmoscope (HRA II, Heidelberg-Engineering, Inc). FAF intensities were referenced to the mean and standard deviation at the optic disk to remove inter-subject variance and then quantified along the horizontal and vertical meridians.

Results: For NCL subjects, FAF images were successfully obtained in 16 eyes (9 of 27 subjects). Of these, 11 eyes had severely reduced or extinguished FAF and 5 eyes (3 subjects) could be analyzed along the meridians. An NCL subject with bilateral bull’s eye maculopathy showed overall increased FAF, the remaining 3 eyes had advanced retinal degeneration and showed reduced FAF. Four patterns of macular disease were observed: 1) bull’s eye atrophy 2) retinal pigment epithelium (RPE) dropout without pigmentary alterations, 3) RPE dropout with pigmentary alterations, 4) RPE dropout with pigmentary alterations and retinal flecks. Standard photography revealed focal retinal flecks in addition to severe retinal atrophy, RPE dropout, pigmentary clumping, and constricted vessels. Linear striations near the optic disc were highlighted by IR imaging. Topographical comparison of images demonstrated the focal flecks were not hyperfluorescent while the linear striations showed slight increases in FAF. For obligate carriers, FAF profiles were similar to controls with a mild increase in mean FAF intensity.

Conclusions: Patients with NCL show increases in retinal fluorophores in early stages and decreases in FAF in late stages of the disease. Obligate carriers of NCL have mildly elevated FAF but this finding is not a specific measure of the carrier state.

KEYWORDS::

• Fundus autofluorescence (FAF)
• Neuronal Ceroid Lipofuscinosis (NCL)
• Infra-red (IR) imaging
• Obligate carriers

ACKNOWLEDGMENTS

The authors would like to thank Dennis A. Orlock for performing the retinal photography in these patients, as well as Lance Johnston of the Batten Disease Support and Research Association for assistance with our study at the annual meeting.

This study was supported by the Thrasher Research Fund, as well as a departmental challenge grant from Research to Prevent Blindness (RPB) and a Sybil Harrington Research Scholar Award from RPB to GMS. The authors thank Heidelberg, Inc. and Topcon, Inc. for their generous in-kind contribution of retinal imaging equipment for this study.

Declaration of interest: G. Rowell is a former employee of Heidelberg-Engineering, Inc., providers of the HRAII confocal scanning ophthalmoscope used in this study. Mr. Rowell no longer has a commercial interest in Heidelberg-Engineering, Inc. He has a commercial interest in Precision Approach Ophthalmics, Inc., Kansas City, Kansas, USA.

The remaining authors have no proprietary or commercial interest in any materials discussed in this article.