Occlusion of the posterior ciliary artery. II. Chorio-retinal lesions.

Abstract

The clinical picture of central retinal artery occlusion is well-known. Little is known, however, about the clinical picture of occlusion of the posterior ciliary arteries (PCAs). We have, therefore, carried out experimental occlusion of the various PCAs individually or together in rhesus monkeys. The effects of such occlusions have been investigated in the choroid, pigment epithelium (PE), and retina of these monkeys over a period of time, ophthalmoscopically, by intravenous fluorescence fundus angiography (IVFA), and (after death) by histology. The study has revealed fundus lesions the nature of which has hitherto been obscure.There are usually two to three PCAs, arising from the ophthalmic artery, which supply the posterior half of the choroid up to the equator of the eye. These are designated medial (MPCA) and lateral (LPCA), depending upon their relationship to the optic nerve near their site of entry into the sclera. A detailed account of the anatomy of the PCAs is given elsewhere (Hayreh, i962, 1970).The effects of occlusion of the various PCAs on the choroidal circulation have already been described in detail (Hayreh and Baines, 1972). Briefly, the distribution of the PCAs in the choroid was seen to be segmental, so that occlusion of one PCA resulted in nonperfusion of the choroid in that region during the transit of the dye in IVFA. However, a very late and sluggish patchy filling of the choroid via the various collaterals took place; this improved with time, so that in 2 to 4 weeks the choroidal circulation was restored. MaterialThe study was carried out in 85 rhesus monkey eyes. MethodsBy lateral orbitotomy, the PCAs were cauterized near their site of entry into the eyeball, leaving a small arterial stump close to the globe as follows:Lateral PCAs (LPCAs) in 3' eyes.Medial PCAs (MPCAs) in I 7 eyes. All PCAs (APCAs) in 37 eyes.

Acute multifocal ischaemic choroidopathy and the choriocapillaris

“…This may be visible in the early and late phases of angiography. We can conclude that in many fluorescein angiograms of human patients, the specific mosaic pattern of the choriocapillaris can be observed which was described in monkeys by Hayreh & Baines (7).…”

Arterial Hypertension and the Eye

“…The RPE lesions seen in this study were similar to those in my study in experimental posterior ciliary artery occlusion [ 66 ].…”

Localized Chorioretinal Degeneration in Patients Receiving Hemodialysis

“…These latter lesions were similar to those patchy fundus changes and pigment epithelial areas of atro phy observed after experimental occlusion of the posterior ciliary arteries in rhesus mon keys [5]. The ERG changes appeared to be more sensitive than ophthalmoscopy in re vealing ischemic damage to the outer retina [12], In cases 2 through 6, the deterioration of the ERG and EOG responses suggested diffuse chorioretinal lesions.…”

“…Since fluorescein angiography has been widely accepted in ophthalmology, several patterns of fundus alterations due to choroi dal vascular disturbances have been de scribed; a triangular pattern [1], segmental or peripapillary chorioretinal lesions [5], and Elschnig's spots [10] or localized pig ment epithelial changes [2. 13].…”