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Editor,—As the name implies, angioid streaks may resemble blood vessels.1 Initially described by Doyne in 1889 as a case presentation to the Ophthalmological Society of the United Kingdom, there was consensus that these streaks were vascular in nature, and thus aptly named. It remained for Kofler in 1916 to correctly delineate the level of the streaks at Bruch's membrane.2 Choroidal neovascularisation (CNV) has been reported as a complication of angioid streaks to occur in 70% to 86% of cases.3 Retinal telangiectasis, however, has never been described in association with angioid streaks.
A 66 year old white woman presented with gradual visual loss in her right eye for 2 months. Her best corrected visual acuity was right eye 20/40 and left eye 20/20. Slit lamp biomicroscopy of the anterior segment was normal. Fundus examination showed macular oedema in the right eye and prominent peripapillary atrophy with irregularly radiating streaks in the left eye (Fig 1). Fluorescein angiography disclosed bilateral peripapillary angioid streaks and juxtafoveolar retinal telangiectasis in the right eye. There was no evidence of CNV (Fig 2).
The development of CNV is a common finding in angioid streaks. Histopathological studies demonstrated linear breaks in Bruch's membrane in addition to extensive calcification. These cracks in Bruch's membrane may be bridged by a thin hypopigmented layer of retinal pigment epithelium, thus predisposing to the ingrowth of fibrovascular tissue from the choroid into the subpigment epithelial space in at least three out of four patients, usually occurring during the third to fifth decade of life.2 3
Despite the age of 66 years, the patient presented here did not show any evidence of CNV or related scaring. However, mild peripapillary streaks were present in both eyes. It has been reported previously that streaks with this appearance are not associated with fundus abnormalities or macular lesions typically observed in patients with pseudoxanthoma elasticum, such as reticular pigmentary changes or peau d'orange appearance.1 Regarding the different clinical appearance and the benign course, these mild peripapillary streaks were considered a separate entity and have also been termed senile atrophic lines or pseudostreaks.4 Characteristically, in senile streaks, peripapillary helicoidal choroidal atrophy is often much more prominent than the streaks themselves (Figs 1 and 2).
The macular oedema of this 66 year old woman, however, resulted from leakage of juxtafoveolar telangiectasis. A classification of idiopathic juxtafoveolar retinal telangiectasis was proposed by Gass and coworkers in 1982, and updated in 1993.5 According to the biomicroscopic and fluorescein angiographic findings, three distinct groups of patients at risk were categorised—unilateral, non-familial, biomicroscopically visible telangiectasis with intraretinal exudation; bilateral, occult telangiectasis with minimal exudation and superficial retinal crystalline deposits; bilateral, biomicroscopically visible telangiectasis with minimal exudation and capillary occlusion, associated with systemic disease.5
The aetiology of angioid streaks as well as of retinal telangiectasis remains unknown. Although hundreds of eyes with angioid streaks have been observed clinically and some of them have been studied histopathologically, the reason for calcification and for the development of cracks of Bruch's membrane remained unclear. Abnormal calcification of elastic tissue, a component of Bruch's membrane, is seen in other parts of the body in pseudoxanthoma elasticum and in Paget's disease. These two entities are the most common systemic association with angioid streaks, occurring in up to 50%. Sickle cell haemoglobinopathy and haemolytic anaemia are much less frequent.2
In Gass's studies, only bilateral, biomicroscopically visible telangiectasis was associated with systemic disease. These eyes were characterised not by exudation, but by capillary obstruction and occlusion “similar to that seen in some patients with sickle cell retinopathy”. All of these patients had systemic disease which was probably related to telangiectasis such as abnormalities of the cardiovascular or central nervous system.5 As sickle cell haemoglobinopathy is the only known systemic disease associated with both retinal telangiectasis and angioid streaks, bilateral telangiectasis and angioid streaks may theoretically present together.
In our case, unilateral juxtafoveolar telangiectasis caused macular oedema. There was no evidence of systemic disease or vascular occlusion. Therefore, regarding the various histopathological features and systemic diseases associated with angioid streaks and retinal telangiectasis, we assume that both clinical entities occurred in a coincidental way. It is important to note, however, that retinal telangiectasis can occur in an eye with angioid streaks, and it should not be confused with CNV. In elderly patients beyond the sixth decade of life, there is a senile form of angioid streaks which is unlikely to cause CNV, but may be associated with retinal telangiectasis.