Early diagnosis of Horner syndrome using topical apraclonidine

Neuro-Ophthalmological Manifestations of Horner's Syndrome: Current Perspectives

Horner's syndrome (HS) is caused by a damage to the oculosympathetic pathway. HS may be congenital, but it is usually acquired and may reveal a life-threatening condition. According to the anatomic location of the underlying pathologic process, HS is classified as central, pre- or postganglionic, when the lesion affects the first, second or third-order neuron, respectively. Pharmacological testing, if available, can be used to differentiate HS from « pseudo-HS » in patients with mild symptoms. Given the financial burden that imaging of the entire oculosympathetic pathway represents, a targeted imaging approach is advised. Although in the majority of cases, clinical examination may predict etiology, in other cases pharmacological testing can help in the localization process. We searched PubMed data base for papers published before December 2022 that concerned Horner's syndrome, its neuro-ophthalmological manifestations and diagnosis. In this article, we describe the main neuro-ophthalmological manifestations of the three types of HS, the most common etiologies, and a targeted diagnostic strategy in each type.

Safety of apraclonidine eye drops in diagnosis of Horner syndrome in an outpatient pediatric ophthalmology clinic

PURPOSE

To describe the efficacy and systemic side effects of apraclonidine drops 0.5% in children clinically suspected of having Horner syndrome.

METHODS

The medical records of patients with clinically suspected Horner syndrome who underwent testing with apraclonidine 0.5% eyedrops were reviewed retrospectively. The following data were retrieved from the record: allergic reactions, somnolence, shallow respiration, pallor, or excessive fussiness noted by the examiner or parents.

RESULTS

A total of 46 patients presenting with anisocoria and tested with apraclonidine 0.5% were included. Of these, 15 had a positive result, with reversal of anisocoria. The mean age of patients was 3.2 years (median, 0.91; mode, 0.25 years). Twenty-four patients were ≤1 year of age; 19 were ≤6 months. No systemic side effects were noted during the examination or reported by parents in any patients.

CONCLUSIONS

The use of topical apraclonidine eyedrops has been described as an effective test for Horner syndrome. However, concerns have been raised regarding the potential systemic side effects in children, especially those under the age of 6 months. In our cohort, no systemic side effects were reported, including in those under 6 months of age.

Apraclonidine for the pharmacologic confirmation of acute Horner syndrome

Apraclonidine is the most widely used pharmacologic agent to confirm Horner syndrome. It is a strong α-2 and a weak α-1 adrenergic agonist and reversal of anisocoria is considered a positive test. The utility of apraclonidine in acute Horner syndrome remains controversial as the exact timing for denervation sensitivity to develop remains unknown. The goal of this study was to describe the use of apraclonidine in the diagnosis of acute Horner syndrome in patients with an unequivocal onset within 7 days. We identified 3 patients who were referred to ophthalmology/neuro-ophthalmology service and had reversal of anisocoria within 7 days. Two cases of second-order Horner syndrome after cardiac surgery and a case of a third-order Horner syndrome from a carotid cavernous sinus fistula resulted in reversal of anisocoria 72 h, 48 h, and 5 days after onset. Photographic documentation was provided for all cases. Our results suggest that apraclonidine has utility in the acute period and positive results can be seen as early as 48 h after onset. Apraclonidine should therefore still be considered to confirm the presence of acute Horner syndrome before extensive neuroimaging is performed.

Apraclonidine Is Better Than Cocaine for Detection of Horner Syndrome

Background: In suspected cases of Horner syndrome pharmacological confirmation is often required before embarking on further investigations. There are two drugs currently used for this purpose that are commercially available for topical administration: cocaine (2–10%) and apraclonidine (0.5–1.0%).

Aims: To evaluate and compare the effects of both drugs in normal eyes and eyes with Horner syndrome

Methods: This is a retrospective study looking at the outcome of 660 consecutive pharmacological tests with these two drugs in one tertiary referral center over 14 years. Eyes were categorized as “normal” or “Horner syndrome” based on non-pharmacological criteria (pupillometric and clinical evidence). Pupil diameters in the dark and in bright light were measured by pupillometry before and 40 min after administration of the test drug (either 4% cocaine or 0.5% apraclonidine).

Results: Cocaine dilated the normal pupil (measured in bright light: mean +2.1 mm, range −0.4 to +3.9 mm; 95% lower limit +0.5 mm); the extent of this response was not significantly affected by patient age or pupil size, but was 50% less in brown eyes compared with blue or green eyes, and 20% less if the measurements were made in the dark. In eyes with Horner syndrome cocaine had significantly less mydriatic effect (mean +0.7 mm, range −0.7 to +2.9 mm). Apraclonidine constricted the normal pupil (measured in the dark: mean −0.4 mm, range −1.3 to +0.8 mm; 95% upper limit +0.1 mm); eye color made no difference but the response was significantly greater in younger patients and larger pupils and significantly less if measured in bright lighting conditions. In eyes with Horner syndrome apraclonidine dilated the pupil (mean +0.6, range −0.4 to +2.3 mm). Applying the 95% limits identified from my normative data, I estimate the sensitivity of each drug test for detection of Horner syndrome at 40% for cocaine (criterion for abnormal: mydriasis ≤0.5 mm when measured in the dark) compared with 93% for apraclonidine (criterion for abnormal: mydriasis ≥0.1 mm when measured in the dark).

Conclusions: Apraclonidine is a more sensitive test than cocaine for detection of Horner syndrome, and should be adopted as the new gold standard in routine clinical practice. However, caution is needed when using this drug within hours of a suspected sympathetic lesion, or in infants under 1 year of age.

Efficacy of digital pupillometry for diagnosis of Horner syndrome

Objectives

To evaluate the efficacy of digital pupillometry in the diagnosis of anisocoria related to Horner syndrome in adult patients.

Design

Retrospective, observational, case control study.

Methods

Nineteen patients with unilateral Horner syndrome (Horner group) and age-matched controls of 30 healthy individuals with normal vision and neither optic nerve dysfunction nor pupillary abnormalities were included. Pupillary light reflex (PLR) of the Horner group and controls were measured by a dynamic pupillometer (PLR-200; NeurOptics Inc., Irvine, USA). Minimal and maximal (min/max) pupil diameters, latency, constriction ratio, constriction velocity, dilation velocity, and total time taken by the pupil to recover 75% of maximal pupil diameter (T75) were noted. PLR were measured at baseline in both groups and at 30–45 minutes later after 0.5% apraclonidine (Iopidine^®; Alcon Laboratories, Fort Worth, TX, USA) instillation in the Horner group.

Main outcome measures

The PLR parameters in the affected eye and inter-eye difference before and after 0.5% apraclonidine instillation.

Results

In the Horner group, pupil diameters and T75 showed significant difference between the affected eye and unaffected contralateral eye at baseline (all P<0.00625). Compared to controls, inter-eye difference values of pupil diameters and T75 were significantly larger in the Horner group (all P<0.001). After 0.5% apraclonidine instillation, changes in pupil diameter and constriction ratio were significantly larger in the affected eye compared to the unaffected contralateral eye (all P<0.00625). The area under the receiver operating characteristic curves for diagnosing Horner syndrome were largest for baseline inter-eye difference in min/max pupil sizes (AUC = 0.975, 0.994), T75 (AUC = 0.838), and change in min/max pupil sizes after apraclonidine instillation (AUC = 0.923, 0.929, respectively). The diagnostic criteria for Horner syndrome relying on baseline pupillary measurements was defined as one of the two major findings; 1) smaller maximal pupil diameter in the affected eye with an inter-eye difference of > 0.5 mm, or 2) T75 > 2.61 seconds in the affected eye, which showed a sensitivity of 94.7% and specificity of 93.3%. The diagnostic accuracy of apraclonidine testing showed a sensitivity of 84.6% and specificity of 92.3%.

Conclusions

Digital pupillometry is an objective method for quantifying PLR. Baseline inter-eye difference in maximal pupil sizes and dilation lag measured by T75 was equally effective in the diagnosis of Horner syndrome compared to the reversal of anisocoria after apraclonidine instillation.

[What would you do in front of a patient with a Horner syndrome?]

Horner's syndrome (HS) occurs when there is disruption to the oculosympathetic pathway. Its features include eyelid ptosis, miosis and anhidrosis. The aetiology of this syndrome is varied and includes tumours, trauma, vascular disease and iatrogenic. Different pharmacologic tests are used for diagnosis, such as cocaine, hydroxyamphetamine and apraclonidine; while neuroimaging helps elucidating the aetiology. We present a case of a 63-year-old female referred to our service with a 4-month history of right eyelid ptosis. During examination right miosis was noted. The patient reported a history of multinodular goiter. Pharmacologic tests and neuroimaging confirmed the diagnosis of HS secondary to thyroid disease.

Horner's syndrome in patients admitted to the intensive care unit that have undergone central venous catheterization: a prospective study

PurposeCentral venous catheterization (CVC) is estimated to be performed in millions of patients per year. Swan-Ganz catheters used for CVC are most often inserted into the internal jugular vein and during this procedure they may come into contact with the sympathetic chain. This study aims to determine the incidence of Horner's syndrome in patients admitted to intensive care unit that have undergone internal jugular CVC insertion during their admission and to determine whether ultrasonography-assisted insertion has decreased the frequency of this complication.Patients and methodsA total of 100 prospective patients admitted to the ICU were examined for the presence of anisocoria and ptosis after undergoing recent CVC. Presence of Horner's syndrome was confirmed by testing with 0.5% apraclonidine and looking for the reversal of anisocoria.ResultsFrequency of Horner's syndrome after CVC was 2% in a sample of 100 prospectively examined patients.ConclusionHorner's syndrome remains a relatively rare but definitive complication of CVC. ICU physicians should be educated about its existence and prevalence and ophthalmologists should inquire about any history of ICU admission necessitating CVC insertion in any patient presenting with Horner's syndrome.

Horner syndrome: clinical perspectives

Horner syndrome consists of unilateral ptosis, an ipsilateral miotic but normally reactive pupil, and in some cases, ipsilateral facial anhidrosis, all resulting from damage to the ipsilateral oculosympathetic pathway. Herein, we review the clinical signs and symptoms that can aid in the diagnosis and localization of a Horner syndrome as well as the causes of the condition. We emphasize that pharmacologic testing can confirm its presence and direct further testing and management.

Eye drop neurology

Eye drops can help to diagnose and prevent complications of neurological disorders. Guttae ophthalmicae (eye drops) are generally safe because the drugs rarely achieve significant systemic concentrations, although there are rare exceptions. This article covers contemporary pharmacological pupil testing; how to dilate a pupil safely; common reasons why pupils do not respond to drops; and corneal lubrication to prevent complications of weak eye closure.

Neuro-ophthalmology Annual Review

PURPOSE

To provide a clinical update of the neuro-ophthalmology literature over the last twelve months.

DESIGN

This is an annual review of current literature from August 1, 2011 to August 1, 2012.

METHODS

The authors conducted a one year English language neuro-ophthalmology literature search using PubMed from August 1, 2011 to August 1, 2012 using the following search terms: pupil abnormalities, eye movements, diseases of muscle and musculoskeletal junction, optic nerve disorders, optic neuritis and multiple sclerosis, chiasm and posterior primary visual pathway lesions, increased intracranial pressure and related entities, tumors (e.g., meningioma) and aneurysm affecting the visual pathways, vascular diseases, higher visual functions, advances in neuroimaging, and miscellaneous topics in neuro-ophthalmology. The authors included original articles, review articles, and case reports, which revealed the new aspects and updates in neuro-ophthalmology. Letters to the editor, unpublished work, and abstracts were not included in this annual literature review. We propose to update the practicing clinical ophthalmologist on the most clinically relevant literature from the past year. However, this review is not meant to be all-inclusive and highlights only the literature most applicable to the practicing clinical ophthalmologist.

RESULTS

We reviewed the literature over the past year in neuro-ophthalmology of potential interest and relevance to the comprehensive ophthalmologist.

CONCLUSION

This annual review provides a brief update on a number of neuroophthalmic conditions that might be of interest to the practicing clinical ophthalmologist.