Retrobulbar blood flow and visual organ function disturbance in the course of giant cell arteritis coexisting with optic disc drusen - a case report.

The review presented ophthalmologic syndrome connected with visual organ function disorder in giant cell arteritis patient concomitant with optic nerve disc drusen. Diagnostic difficulties were shown in relation to incidence of both similar ophthalmic symptoms as well as interpretation of specialists examinations results (pattern visual evoked potential test, scanning laser polarimetry, and perimetric tests - kinetic and static). Apart from ophthalmic investigations, significant role of radiological examinations was considered, especially color Doppler ultrasonography of retrobulbar circulation - optic artery, central retinal artery, long posterior ciliary arteries. Adequate interpretation of results seems to be crucial to establish scheme and timing of treatment in case of co-occurrence of the abovementioned disorders. In the presented case early implementation of steroid therapy resulted in improvement of blood flow parameters and the regression of ophthalmological complaints. Visual field deficiency in kinetic perimetry, reduced wave amplitude p100 in visual evoked potential test as well as decrease in number of optic nerve fibers in optic nerve disc region in scanning laser polarimetry exam can be diagnostic features in diagnosis of visual impairment in the course of giant cell arteritis and optic nerve disc drusen. Evaluation of blood flow velocity parameters in retrobulbar arteries in color Doppler ultrasonography is the most valuable screening in monitoring ophthalmic dysregulation in presented disorders.

Introduction

Giant cell arteritis (GCA) is the most frequent inflammation of large and medium arteries in individuals after 50 years of life. Anterior ischemic optic neuropathy (AION), amaurosis fugax and retinal vessels occlusion are the most often ophthalmic symptoms in this disorder. Visual acuity deterioration and visual field defects are the main complaints noted by the patients. Similar ophthalmic symptoms can be observed in optic nerve disc drusen (ONDD) – a calcification material localized in optic nerve disc region. Most often they appear bilaterally (75–85%) and their occurrence in population ranges from 0.3 to 2%(, contrary to the GCA, which frequency reaches up to 0.03% of the population aged over 50 years in some countries(.

The case presented below is interesting, according to the authors, due to diagnostic difficulties concerning the establishing of the causes for similar visual defects symptoms occurrence, which could have been observed both in GCA and ONDD. Adequate interpretation of results seems to be crucial to establish scheme and timing of treatment. Moreover, there has not been a single publication found on the discussed subject in the available medical browsers.

Patient description

The subject of description is an 80-year-old patient with GCA coexisting with diabetes mellitus (DM2), arterial hypertension (AH), coronary artery disease (CAD) and atrial fibrillation (AF). Patient fulfilled all the GCA classification criteria of American Society of Rheumatology (ACR)(: age ≥ 50 years, headaches of a new character, tenderness on palpation of the superficial temporal artery, accelerated ESR above 50 mm/h, predominance of inflammatory infiltration of mononuclear cells in histopathology superficial temporal artery.

Complaints related to limited visual field in the left eye (OS) were the major causes of ophthalmic examination with funduscopy in which optic nerve disc (nerve II) edema and hypertonic angiopathy features were observed (fig. 1). Kinetic (fig. 2 A) and static perimetry (fig. 3 A) tests revealed lowest-temporal and lowest-nasal quadrants defect of visual field. Hyperechogenic foci in ultrasonography B were noted which can correspond to optic nerve disc drusen. Cerebral computed tomography (CCT) did not confirm the increase of intracranial pressure. Due to the high risk of ischemic etiology of the presented symptoms (coexistence of GCA, CAD, DM2), color Doppler ultrasonography (CDU) of internal carotid arteries was performed, where 30% and 20% narrowing of the right and left internal carotid arteries (ICAs) was confirmed, respectively, without significant hemodynamic disturbance. Posterior wall intima-media thickness (IMT) for the right and left ICAs was 0.8 and 0.5 mm, respectively. In CDU of the affected eye (OS), the decrease of systolic and diastolic velocities in the ophthalmic artery, reversal of amplitude spectrum of wave and the increase of resistance index in CDU were noted (PSV – 22.27 cm/s; EDV – 8.29 cm/s; RI 0.89) (fig. 4 A). Significant lowering of blood flow velocity in central retinal artery (CRA) with PSV 4.31 cm/s, EDV 0.48 cm/s and elevation of resistance index RI 0.72 was measured (fig. 4 B). Similar blood flow velocity parameters were observed in this side in temporal and nasal posterior ciliary artery (TPCA/NPCA) (fig. 4 C, D). In the right eye, which was not affected by the disease process, the lowering of blood flow velocity parameters and the rise of RI in retrobulbar arteries was also noted. However, those values were less pathological in comparison to the affected eye.

Fig. 1

Optic nerve drusen and hypertonic angiopathy in funduscopy of affected eye

Fig. 2

Kinetic perimetry of affected eye (black color): A. before treatment – visual field defects in the lower hemisphere; B. after treatment – regression of visual field defects widening of visual field

Fig. 3

A. Static perimetry affected eye. Visual field defects in the lower hemisphere. B. Scanning laser polarimetry affected eye. Apparent loss of nerve fibers in the upper part of the optic disc both before and after treatment. C. Pattern visual evoked potentials in affected eye (PVEP) with reduction in amplitude p100 wave

Fig. 4

Blood flow velocity spectrum of retrobulbar arteries in affected eye before and after treatment in CDU: A. ophthalmic artery (OA); B. central retinal artery (CRA); C. nasal posterior ciliary artery (NPCA); D. temporal posterior ciliary artery (TPCA)

Decreasing number of nerve fibers in the superior quadrant of optic disc was noted bilaterally, OP – 46, OL – 49 (normal range NFI < 30) (fig. 3 B). To assess the function of visual tract, pattern visual evoked potential (PVEP) test was done revealing reduction of wave amplitude p100 (fig. 2 C).

Systemic glucocorticosteroids therapy (GCS) (intravenous methylprednisolone for 3 days, 500 mg per day) was used in conservative management. Prednisone administered orally (15–20 mg/day) was a continuation of the treatment until beneficial ophthalmic results were obtained.

After 2-month therapy, in kinetic perimetry regression of visual field defects, that were noted previously, was observed (fig. 2 B). Significant improvement of blood flow velocity parameters in retrobulbar circulation and normal direction of amplitude spectrum both in ophthalmic and in posterior ciliary arteries was presented by CDU (fig. 4 A–D): in OA PSV – 31.44 cm/s, EDV – 7.69 cm/s, RI – 0.76, in CRA PSV – 8.63 cm/s, EDV – 3.35 cm/s, RI – 0.61 cm/s.

Discussion

The ophthalmic complaints most often given by the patients in course of GCA or in isolated ONDD are peripheral narrowing or defect of visual field and weakening of visual acuity. In GCA, lowering of visual acuity is usually sudden (several days or weeks), in drusen it occurs rarely and then it is chronic. In course of GCA ophthalmic symptoms have originated from short posterior ciliary arteries (sPCAs) or their main trunk occlusion leading to ischemia of optic nerve head (AION) in 30–50% GCA and retinal vessels occlusion (< 10% GCA). In case of drusen, decreasing of visual acuity can result directly from their compression on the central retinal artery causing blood flow disturbance in nerve fibers region(.

In the presented case, CDU was the best way to assess retrobulbar circulation impairment and to show the most sensitive index of treatment efficacy of those both ophthalmic disorders. Improvement of blood flow velocity parameters (PSV, EDV) and decreasing of RI in all the examined arteries (CRA, OA and PCA) was observed in course of steroids therapy in both eyes. Until now, there have not been done Doppler examinations on a large group of patients with GCA. It can not be excluded that, according to the references, a limitation of the abovementioned examination was difficulty in measurements of blood flow parameters in single short posterior ciliary arteries (sPCAs) which are responsible for the main complications of GCA-AION(.

Besides rheumatologic and ophthalmic diseases, other risk factors diagnosed in the patient could have some impact on CDU measurements. Stenosis of carotid arteries or diabetes can affect both blood PSV/EDV and RI(. Amaurosis fugax diagnosed in both diseases most often concerns vessel spasm leading to the elevation of RI(. It should be emphasized that in CDU optic nerve disc drusen can also be artifacts source of the so-called “flicker effect”(. Angiography magnetic resonance which shows contrast enhancement of ophthalmic arteries in 50% patients with GCA can be a addition to CDU(. Cerebral computed tomography confirmed optic nerve disc drusen calcification and eliminated elevation of intracranial pressure. In this test ischemic foci of central nervous system, which are noted in 3–4% subjects with GCA, were not documented(.

Glucocorticoids therapy is acknowledged form of GCA treatment. Short time from diagnosis to application of treatment (about 7 days) relevantly decreased risk of visual acuity deterioration, what is in compliance with literature(. Improvement of visual acuity takes place in about 10–15% of the patients treated for GCA but only in 0–5% of the subjects widening of visual field is additionally noted(. Glucocorticoids do not decrease the number of ONDD or their clinical presentation. In the described case, evaluation of visual field was a reliable tool for efficacy assessment of GCA therapy.

Moreover, reduced p100 wave amplitude in VEP test can be responsible for ischemic changes confirmed by CCT in CNS visual tract. Additionally reduced number of nerves fibers in the superior quadrant of optic disc in both eyes in GDX examination could have connection with direct drusen compression on optic nerve axons in disc region. Ophthalmic outcomes evidence their important role in evaluation of visual organ condition both in GCA patients as well as in optic nerve disc drusen.

Conclusions

Visual field deficiency in kinetic perimetry, reduced wave amplitude p100 in VEP test as well as decrease in number of optic nerve fibers in optic nerve disc region in GDX exam can be diagnostic features in diagnosis of visual impairment in the course of giant cell arteritis and optic nerve disc drusen. Evaluation of blood flow velocity parameters in retrobulbar arteries in CDU is the most valuable screening in monitoring ophthalmic dysregulation in presented disorders.