Acommon dilemma for retinal surgeons in daily practice is a patient who demonstrates delayed arm-to-retina circulation time (ART) during fluorescein angiography (FA)—despite the absence of objective or subjective symptoms of ocular and/or extraocular vascular occlusive disease. We became interested in the possible clinical significance of delayed ART in otherwise asymptomatic patients.1
FA is an invaluable tool in the diagnosis and treatment of retinal disease.2 It allows clear documentation of sequential retinal blood flow through intravascular fluorescein dye injection and synchronized fundus photography. Sodium fluorescein is a relatively low-molecular-weight, highly water-soluble compound that exhibits the physical property of fluorescence. When exposed to light of a blue wavelength (465 and 490 nm) at physiologic pH, fluorescein emits light frequencies in the green-yellow range (520 to 530 nm). Properly matched exciting and barrier filters facilitate image capture of the retinal and choroidal vasculature, as well as other fundus abnormalities. Since its development nearly 50 years ago, FA continues to provide crucial clinical and pathophysiological insights and is an essential element in both medical and laser treatment of numerous chorioretinal diseases.
The average ART is 12 to 15 seconds. There are numerous potential causes for ART delay, including myocardial and pulmonary disease, changes in blood viscosity, increased age, hypertension, and glaucoma. There have been retrospective reports3 demonstrating patients with carotid disease and delayed ART. There are no prospective data, however, evaluating potential vasculopathy in this scenario. We sought to determine the proportion of patients receiving fundus FA who also had increased ART. Of these individuals, we investigated the proportion who had (1) hemodynamically significant carotid vascular disease and (2) orbital small vessel disease.
STUDY METHODS
We evaluated consecutive patients with increased ART, which was defined as >23 seconds. These patients received bilateral carotid and ipsilateral orbital Doppler ultrasound testing to determine the presence of any extraocular arterial occlusive disease. We also recorded additional data such as ocular and medical history, age, race, intraocular pressure, and lens status. We performed statistical comparisons using the one-sample Student T test and Wilcoxon sign-rank testing.
Of the 790 consecutive FA studies we evaluated, 72 (9%) had a delayed ART. Among these 72 patients, 22 (31%) agreed to undergo additional ultrasound testing. The bilaterial carotid ultrasound studies did not reveal significant arterial disease in this 22-patient cohort; however, ipsilateral orbital color Doppler imaging showed statistically significant decreases in the velocity of numerous retrobulbar arteries.
These values, compared with historical controls, were 7.2 versus 10.6 cm/sec (P=.010) for the systolic nasal-posterior ciliary artery (PCA); 2.4 versus 3.4 cm/sec (P=.054) for the diastolic nasal PCA; 7.8 vs 10.6 cm/sec (P=.016) for the systolic temporal PCA; and 2.2 versus 3.4 cm/sec (P=.019) for diastolic temporal PCA. The values, compared with controls, were 28.8 versus 33.2 cm/sec (P=.030) for the systolic ophthalmic artery (OA) and 5.2 versus 8.3 cm/sec (P=.000001) for the diastolic OA.
Interestingly, flow velocity differences were not statistically significant in the central retinal artery (8.2 vs 10.1 cm/sec [P=.069] for systolic and 2.1 vs 2.5 cm/sec [P=.262] for diastolic) (Figures 1-6).
We concluded that, in this cohort of patients with an increased ART, no hemodynamically significant underlying occlusive disease of the common or internal carotid artery was present (Figure 7). Statistically significant differences, however, in orbital vascular flow velocities were present in the OA and posterior ciliary vessels. Diabetes, hypertension, and hypercholesterolemia may play a role in this pathology. We will continue to evaluate these patients and follow their long-term morbidity and mortality rates related to systemic atherosclerotic disease.
Joseph I. Maguire, MD, is Associate Professor at Thomas Jefferson University Hospital and Attending Surgeon at Wills Eye Hospital, Philadelphia. He may be reached at jmag629@hotmail.com; phone: 610-649-1970; or fax: 610-649-8624.
Robert C. Sergott, MD, is Professor of Ophthalmology and Neurology, Thomas Jefferson University and Co-Director Neuro-Ophthalmology, Wills Eye Institute. He may be reached at 215-928-3130.
Richard Scartozzi, MD, is a Vitreoretinal Surgery Fellow, Doheny Eye Institute and Clinical Instructor, University of Southern California, Los Angeles. He may be reached at rscartozzi@doheny.org, phone: 323-442-6522; or fax: 323-442-6460.
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