Carotid endarterectomy in a patient with anterior ischemic neuropathy

Visual Outcome of Carotid Endarterectomy in Patients with Carotid Artery Stenosis

BACKGROUND

Carotid endarterectomy (CEA) is deemed to restore the blood flow of the carotid and ophthalmic arteries in patients with carotid artery stenosis. However, specific changes in visual function before and after CEA are not well understood; hence, this observational study aimed to investigate the functional and structural changes in vision after CEA in those patients.

METHODS

Patients with severe carotid artery stenosis (>70% with standard carotid duplex scanning or arteriography) scheduled to undergo CEA were consecutively recruited for the study between September 2015 and July 2016. All patients underwent a standardized ophthalmic examination, including intraocular pressure (IOP) measurement, slit-lamp examination, and fundus examination. Visual acuity, best corrected visual acuity (BCVA), and kinetic and static visual fields (VFs) were tested to evaluate subjective visual function. Flash and pattern visual evoked potentials (VEPs) and an electroretinogram (ERG) were measured for objective visual function. Retinal nerve fiber layer (RNFL) thickness was scanned using optical coherence tomography for structural evaluation.

RESULTS

The study involved 15 patients (11 male and 4 female, corresponding to 30 eyes; mean age 62.8 ± 5.0 years). After CEA, both uncorrected visual acuity and BCVA improved, and IOP significantly decreased from 17.41 ± 2.59 to 15.95 ± 2.50 mm Hg (P = 0.0022). Kinetic VF range increased significantly (P = 0.0126) as did mean sensitivity from 18.8 ± 5.5 to 20.6 ± 4.3 dB (P = 0.0208), whereas mean defect decreased from 8.2 ± 5.3 to 6.5 ± 4.2 dB (P = 0.025). RNFL thickness was not significantly altered. Latency of the P2 wave on flash VEP reduced significantly after CEA (P = 0.0151), whereas the oscillatory potential amplitude of waveform 3 in the ERG significantly increased after CEA.

CONCLUSIONS

Our results demonstrate that an improvement in carotid artery and ophthalmic artery blood flow after CEA does indeed enhance subjective and objective assessments of visual function in patients with carotid artery stenosis, including visual acuity, kinetic and static VF, P2 latency, and ocular pressure amplitude; however, it did not affect RNFL thickness.

[A case of nonarteritic anterior ischemic optic neuropathy with hypertension, diabetes mellitus, hyperlipidemia and severe stenosis of the internal carotid artery]

A 76 year-old man had had hypertension, diabetes mellitus and hyperlipidemia since 1985, and bruit in his left neck since 1993. He had abrupt decrease in left visual acuity on November 24, 2005, and visited an ophthalmologist. On November 28, his corrected visual acuity was 1.0 in the right and 0.1 in the left. The examination of optic fundi showed ear-side edema of the left optic disk. Fluorescence examination of the left optic fundus showed delay in early filling and later hyperfluorescence. Goldman visual field examination showed horizontal lower semiblindness. Since he did not complain of eye pain, his blood examination showed no reaction of inflammation, and he had hypertension, diabetes mellitus and hyperlipidemia, anterior ischemic optic neuropathy was diagnosed. The treatment with aspirin, alprostadil and prednisolone transiently improved the optic fundi and visual acuity, but his left visual acuity returned to 0.1. Carotid ultrasonography showed 95 percent stenosis in the left internal carotid artery. As there is no established treatment for ischemic optic neuropathy, the management of risk factors is most important.

Non-Arteritic Anterior Ischaemic Optic Neuropathy: A New Indication for Carotid Endarterectomy

We present a case of non-arteritic anterior ischaemic optic neuropathy (NAION) associated with ipsilateral internal carotid artery stenosis, in a patient who presented with sudden loss of vision. This patient underwent a carotid endarterectomy and reported both subjective and objective improvement in vision in the immediate postoperative period and a complete resolution of symptoms at 6 weeks follow-up. This case raises the question of a new indication for carotid endarter-ectomy in selected cases of NAION.

Ocular and systemic findings and their correlation with hemodynamically significant carotid artery stenosis: a retrospective study

BACKGROUND

Optometrists often encounter patients with ocular signs and/or symptoms suggestive of carotid artery disease, but criteria for eye care practitioners concerning when to order carotid studies are not well established. A retrospective study in an optometry clinic was performed to determine if certain ocular findings and associated systemic risk factors were associated with hemodynamically significant carotid artery stenosis (HSCAS).

METHODS

A retrospective analysis was performed on all patients examined in the optometry clinic at the Sepulveda Ambulatory Care Center from January 1, 1998 through December 31, 1999 to identify all patients who had carotid studies ordered. Charts were then reviewed to determine the ocular finding that prompted the carotid study. Statistical analysis using an odds-ratio was performed to determine whether any ocular sign/symptom or systemic risk factor was associated with HSCAS.

RESULTS

Of 3822 patients, 48 (1.26%) had carotid studies ordered. Eight (17%) had HSCAS of >50% and symptomatic patients were 1.6 times more likely to have HSCAS than asymptomatic patients. Patients with HSCAS were 1.8 times more likely to have retinal vascular occlusions, 1.9 times more likely to have normotensive glaucoma, 2.4 times more likely to have peripheral retinal hemorrhages, and 2.6 times more likely to be smokers, although none of these factors were found to be a statistically significant indicator of HSCAS. However, the number of systemic diseases tended to be greater for the HSCAS patients compared with the non-HSCAS patients (HSCAS median = 3.5 and the non-HSCAS median = 2, p = 0.049).

CONCLUSION

Although no single ocular or systemic risk factor was found to be a statistically significant indicator of HSCAS, the number of systemic disease risk factors tended to be greater for the HSCAS patients compared with the non-HSCAS patients (p = 0.049). An extensive literature review was also performed to help establish guidelines for when to order carotid studies on the basis of ocular signs and/or symptoms as well as the presence of additive associated systemic risk factors.