Spontaneous Venous Pulsations Detected With Infrared Videography: Comment

Letters to the Editor Spontaneous Venous Pulsations Detected With Infrared Videography: Comment W e thank Mr. McHugh and his colleagues for their insightful research on the detection of spontaneous venous pulsation (SVP), using the infrared videography technique on the retinal ocular coherence tomography (OCT) (1). Indeed, as elucidated in their research, traditional SVP detection methods using the direct ophthalmoscope or slit lamp suffer from a comparatively poor sensitivity and are subjected to interobserver variability, especially if the pulsation is subtle. More objective means of SVP detection require some form of videography, whether it is the retinal OCT or a preconfigured tablet mounted onto the slit lamp (2). These highly specialized equipment, however, are unlikely to be found in a hospital's emergency department (ED), when patients suspected to have raised intracranial pressure (ICP) may typically present. Novel retinal imaging devices, such as Peek Retina (3) and D-EYE (4), act similarly to a direct ophthalmoscope when used in combination with a smartphone. We recently tested with the Peek Retina device and was successful in recording SVP in Full HD resolution (Figs. 1 and 2, See Supplemental Digital Content, Video 1, http://links.lww.com/WNO/A464). Limitations for this method include the lack of image stabilization, making it difficult to quantify the amplitude and therefore the grading of SVP. In an emergency setting where raised ICP is suspected but neuro-ophthalmic expertise is unavailable, patients may be more readily subjected to more invasive investigations, such as computed tomography scan or lumbar puncture. The devices required for a smartphone funduscopy technique are portable and relatively inexpensive. This may circumvent the aforementioned equipment availability issue and the need to train ED staff on how to use and maintain them. Derek Kwun-Hong Ho, MA(Cantab), FRCOphth, Yvonne Yeung, MSc, MOrth Department of Ophthalmology (DK-HH), University Hospital of Wales, Cardiff, Wales, United Kingdom; and Cardiff University, Cardiff, Wales, United Kingdom (YY). FIG. 1. Using the peek retina device to image the optic disc, through a pharmacologically dilated pupil. Letters to the Editor: J Neuro-Ophthalmol 2023; 43: e93-96 e93 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Letters to the Editor FIG. 2. Peek retina device was used to record spontaneous pulsation of the retinal vein, as it crosses the optic disc inferiorly. The authors report no conflicts of interest. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the full text and PDF versions of this article on the journal's Web site (www.jneuroophthalmology.com). REFERENCES 1. McHugh JA, D'Antona L, Toma AK, Bremner FD. Spontaneous venous pulsations detected with infrared videography. J Neuroophthalmol. 2020;40:174–177. Spontaneous Venous Pulsations Detected With Infrared Videography: Response W e thank Ho and Yeung for their letter, and congratulate them for obtaining a video of very clear spontaneous venous pulsations (SVPs), using a mobile phone camera and Peek adapter through a dilated pupil. Smartphone-based retinal imaging systems can be readily obtained for use in emergency departments, but currently have important limitations. In our experience, obtaining clear fundus images using a Peek adapter can be a significant technical challenge in patients with small pupils. Even with an optimal view, using a slit lamp or direct ophthalmoscope through a pharmacologically dilated pupil, SVPs can be impossible to visualize by experts in approximately a third of healthy subjects (1–3). Motion stabilized videography (e.g., using an ocular coherence tomography system) permits venous pulsations to be visualized both inside and outside the margins of the optic disc. SVPs can be observed in approximately 98% of healthy patients with this technique, including in patients with physiologically crowded discs, which can be difficult to confidently distinguish from mild papilledema by funduscopy (4). We agree that still or video photography of the fundus has immense potential value for clinicians working in emergency or remote settings, including the ability to e94 2. Shariflou S, Agar A, Rose K, Bowd C, Golzan SM. Objective quantification of spontaneous retinal venous pulsations using a novel tablet-based ophthalmoscope. Transl Vis Sci Technol. 2020;9:19. 3. Bastawrous A, Giardini ME, Bolster NM, Peto T, Shah N, Livingstone IA, Weiss HA, Hu S, Rono H, Kuper H, Burton M. Clinical validation of a smartphone-based adapter for optic disc imaging in Kenya. JAMA Ophthalmol. 2016;134: 151–158. 4. Russo A, Morescalchi F, Costagliola C, Delcassi L, Semeraro F. A novel device to exploit the smartphone camera for fundus photography. J Ophthalmol. 2015;2015:823139. obtain a rapid opinion from a distant eye unit. However, we suspect that SVPs will be observable in less than twothirds of healthy patients using Peek and comparable smartphone systems through undilated pupils. A study of smartphone camera SVP assessment in a cohort of healthy patients with presumed normal intracranial pressure would therefore be of interest. James A. McHugh, FRCOphth, Linda D'Antona, MD, MBBS, Ahmed K. Toma, MD, FRCS, Fion D. Bremner, PhD, FRCOphth Department of Ophthalmology (JAM), King's College Hospital, London, United Kingdom; Department of Neurosurgery (LD, AKT), National Hospital for Neurology and Neurosurgery, London, United Kingdom; and Department of Neuro-Ophthalmology (FDB), National Hospital for Neurology and Neurosurgery, London, United Kingdom. The authors report no conflicts of interest. REFERENCES 1. Levin BE. The clinical significance of spontaneous pulsations of the retinal vein. Arch Neurol. 1978;35:37–40. 2. Wong SH, White RP. The clinical validity of the spontaneous retinal venous pulsation. J Neuroophthalmol. 2013;33:17–20. 3. Hedges TR Jr, Baron EM, Hedges TR III, Sinclair SH. The retinal venous pulsation. Ophthalmology. 1994;101:542–547. 4. McHugh JA, D'Antona L, Toma AK, Bremner FD. Spontaneous venous pulsations detected with infrared videography. J Neuroophthalmol. 2020;40:174–177. Letters to the Editor: J Neuro-Ophthalmol 2023; 43: e93-96 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited.