FIVE-YEAR FOLLOW-UP OF A SPONTANEOUSLY PROGRESSIVE RETINAL RACEMOSE HEMANGIOMA

Retinal racemose hemangioma is a rare congenital, nonhereditary, retinal vascular anomaly. The disease was once considered to be stable and nonprogressive. We report the progression of a patient with retinal racemose hemangioma followed up for 5 years.

Abstract

Purpose:

To report the progression of a patient with retinal racemose hemangioma after 5 years of follow-up.

Methods:

Observational case report.

Results:

A 14-year-old girl was diagnosed with an isolated retinal racemose hemangioma with retinal arteriovenous malformation in the posterior pole of the left eye fundus. At the fifth year of follow-up, a spontaneous enlargement of the previously normal vessel was found above the original lesion. The patient's vision remained stable, and no complication was observed.

Conclusion:

Retinal racemose hemangioma was once considered stable and nonprogressive, but progression and expansion of the lesion may also occur, so long-term follow-up is necessary.

Retinal racemose hemangioma (RRH) is a rare congenital, nonhereditary, retinal vascular anomaly, which was first described by Magnus in 1874, and it is also known as retinal arteriovenous malformation (AVM) or arteriovenous communication of the retina.^1,2 The typical manifestation is one or more retinal arteriovenous anastomoses. The anastomotic vessels are characteristically dilated and tortuous, usually arising from the optic disk toward the retinal periphery.^3,4 Approximately 30% of patients with RRH have similar AVMs along the visual pathway from the optic nerve to the ipsilateral occipital cortex and/or other parts of the central nervous system (such as thalamus, basal ganglia, and cerebellum). In addition, AVMs may occur in the maxilla and mandible, jaw, orbit, or skin in some patients. This association of retinal AVMs with ipsilateral cerebral and facial AVMs is known as Wyburn–Mason syndrome.^3,4 Retinal racemose hemangioma was thought to be nonprogressive, but research has shown that AVMs are capable of growth, hemorrhage, sclerosis, and thrombosis.⁵

Here, we present a case of an isolated RRH, evaluated by comparing color fundus photography and fluorescein fundus angiography (FFA) at the initial visit and 5 years later.

Case Report

A 14-year-old girl underwent her first ophthalmic examination in 2015 because of decreased visual acuity in her left eye (LE). She has no any other systemic diseases. Her best-corrected visual acuity was 20/40 LE and 20/20 in the right eye. The anterior segment of both eyes was unremarkable. The fundus of the LE revealed dilated and tortuous anomalous retinal vessels emanating from the optic disk and located below the foveal region, extending to approximately 2 × 3 disc diameter (DD) in size with no clear distinction between arteries and veins (Figure 1A). The fundus of the right eye showed no abnormality. FFA of the LE showed direct and rapid transit of dye through the anomalous vessels in early frames, with no fluorescein leakage (Figure 1, B and C). The brain magnetic resonance imaging did not show any vascular or neurologic malformations, and the patient was diagnosed with RRH of the LE. Because the patient had only isolated AVM, regular follow-up was recommended. The lesion remained stable during the subsequent 4-year follow-up. However, in the fifth year of follow-up, a new dilated and tortuous vessel was found in the supratemporal region of the optic disk in the LE and was in contact with the existing AVM at the fovea (Figure 1D). In addition, the vessel in front of the optic disk had become more dilated. FFA were repeated, and we found that the newly anomalous vessel filled as quickly as the original AVM, without venous laminar flow (Figure 1, E and F). Careful comparison of the two FFAs revealed that there was no anastomoses between the two malformed vessels, but the new AVM was connected with the abnormal arterial branch (Figure 1C green arrow). Therefore, we speculated that the new lesion was caused by high pressure in the arterial branch of the AVM, resulting in the arterialization of the terminal vessels. The patient's VA was unchanged, so follow-up was continued.

Fig. 1.

Color fundus photography and fluorescein fundus angiography (FFA) of the LE. A. Fundus image of the LE at baseline. B. Early phase of FFA image of the LE at baseline. C. Local enlarged view of (B) (note that at this time, the AVM have been filled completely, whereas the vein vessel above the fovea is still in the venous laminar flow phase; the vessel indicated by the green arrow is the abnormal arterial branch of the original AVM). D. Fundus image of the LE at the fifth year of follow-up. E. Early phase of FFA image of the LE at the fifth year of follow-up. F. Local enlarged view of (E) (note that the blood vessel above the fovea is filled completely together with the original AVM).

Discussion

Based on complexity and severity, Archer et al² categorized AVMs into three groups: Group I is characterized by an abnormal capillary plexus between arteries and veins. Such AVMs are usually limited to one quadrant of the retina and rarely pose a threat to vision. Group II shows direct communication between arteries and veins without capillary or arteriolar elements. This group sometimes leads to exudation, edema, thrombosis, or hemorrhage because the venous side of the communication is characterized by hyperdynamic flow and high intraluminal pressure. Group III has extensive intertwined retinal arteriovenous anastomoses, with arteries and veins almost indistinguishable, severe visual loss, and a high degree of correlation with intracranial AVM.

Retinal racemose hemangioma can be asymptomatic and is usually an unexpected finding in an ophthalmic examination.⁶ Symptomatic patients may present with decreased VA of the affected eye, the severity of which depends on whether the lesion involves the foveal area and whether it is associated with complications.¹ The incidence of complications of RRH has been reviewed in the literature, with venous occlusion being the most common, followed by hemorrhage (including vitreous and intra/subretinal hemorrhage), and to a lesser extent, macular edema, neovascular glaucoma, and retinal detachment.³ The high incidence of venous occlusion is mainly the result of the vein in the AVM being an extension of the artery and thus affected by arterial flow and arterial pressure, resulting in blood turbulence, vessel wall damage, and finally thrombosis and occlusion. In addition, the compression effect of AVMs located at the optic nerve may be responsible for the development of central retinal vein occlusion in patients with slowed blood flow in the compressed central retinal vessels, facilitating the formation of thromboses.⁵

Retinal racemose hemangioma was once considered to be stable and nonprogressive. The longest follow-up time was 27 years, with no change in retinal and cerebrovascular malformations during this period.⁷ However, some cases have confirmed that this lesion can “grow” or regress after thrombosis of the involved vessels. Two cases with 17-year follow-ups showed increased dilation of the AVMs and partially occluded degeneration.^4,8 Augsburger et al⁴ pointed out that the marked dilatation and tortuosity of the AVM indicates that these presumably mature vessels could continue to grow and develop over several years. In addition, Ehrt⁹ reported that the abnormal vascular ring gradually developed to involve the fovea within 2 years, that not all AVMs are stationary and that small changes may lead to severe visual loss. Our patient with an isolated Group II retinal AVM had no ocular complications during the follow-up period, and the lesion remained unchanged during the first 4 years, but dilatation of the previously normal vessels occurred in the fifth year. Comparison of the baseline and follow-up FFAs, with no evidence of anastomoses between two segments of the abnormal vessels, suggests that the new AVM was exposed to sustained high blood flow pressure from the arterial branches of the original AVM over time, leading to the gradual arterialization of small terminal vessels, resulting in the anomaly apparent at Year 5. It is not known whether the retinal AVM in this patient will continue to develop thereafter, so follow-up is ongoing. We report this rare case because the very clear lesion process shown in this case aids our understanding of this disease.

Conclusion

This report observes the natural course of a case with RRH from stability to progression of the AVM. Retinal racemose hemangioma can be stable, combine with complications and even enlarge, so long-term follow-up is necessary. Although we can visualize the lesion using an ophthalmoscope or fundus photography, FFA can provide more information to understand the occurrence and development of the lesion.