An Update on Eye Pain for the Neurologist

Painful Eyes in Neurology Clinic: A Guide for Neurologists

Eye pain is a common complaint among patients presenting to the neurology clinic. It can be related to neurologic diseases, but it can also be a localized eye condition. Such disorders can be misleading, as their benign appearance might mask more grave underlying conditions, potentially leading to misdiagnoses or delayed treatment. Clinicians should be aware of the specific neurologic or systemic disorders (eg, demyelinating diseases or vascular abnormalities) that might first manifest as eye pain. Formal ophthalmic consultation is recommended for patients presenting with eye pain as the predominant complaint especially when red flags for more serious pathology are present.

Characterization of patients with ocular pain evaluated with ultrasound

BACKGROUND

The cause of ocular pain in the quiet eye is challenging to diagnose. It is a common complaint in the ophthalmology clinic and there are no actual guidelines on the exams that should be ordered initially. We decided to characterize patients with eye pain and normal ophthalmological examination who underwent ocular ultrasound, their findings, and systemic work-up.

METHODS

A retrospective chart review of patients who underwent ocular ultrasound due to ocular pain and no clinical findings on initial slit-lamp examination. We evaluated patient characteristics and analyzed systemic work-up results in contrast to ocular ultrasound findings.

RESULTS

Two hundred and three patients with normal slit-lamp examination and ocular pain were evaluated using ocular ultrasound at Clinica Barraquer. Most of the patients were women (88.7%), and 55% were older than 50 years. Nearly all of the patients had echographic findings, 87.7% of patients showed evidence of scleral scars, from which 66.5% had signs of activity, and 42.9% had thickened extraocular muscles. In general, most patients with ocular pain had normal results on systemic work-up, but the patients who did have positive results tended to have echographic findings.

CONCLUSION

Posterior inflammation is present in most patients with ocular pain in a quiet eye, and echography is an optimal tool to identify this. There is a tendency towards abnormal autoimmune test results and echographic findings. This should be considered in the initial work-up of these patients, given the importance of early diagnosis and the threat of vision loss with severe inflammation.

Efficacy and safety of pregabalin in eye pain: A systematic review

BACKGROUND

The pregabalin is approved for the management of persistent pain. The aim of this study is to assess the advantages and disadvantages of the use of pregabalin in eye pain management.

METHODS

The PubMed, Cochrane Library, Embase, and Web of Science databases were searched until January 2022 for randomized controlled trials. Randomized, double-blinded trials comparing pregabalin with placebo in eye pain management were included. The primary outcome was visual analog scale or numerical rating scale at acute (24 hours) and chronic (≥7 days after surgery) timepoints. The secondary outcomes were analgesic medication requirements and pregabalin-related complications (nausea, vomiting, dizziness, and headache). We also compared the effect of pregabalin on dry-eye syndrome.

MAIN RESULTS

Six relevant articles were identified that studied the use of pregabalin as pain relief for photorefractive keratectomy (n = 2), laser epithelial keratomileusis (n = 1), laser-assisted in situ keratomileusis (n = 1), eyelid surgery (n = 1), and dacryocystorhinostomy (n = 1). Pregabalin was associated with a significant reduction in pain scores (95% confidence interval = -0.41 [-0.76--0.06]) 24 hours after surgical procedures. The data were insufficient to draw conclusions regarding dry eye symptoms. Because of the high heterogeneity of outcomes regarding adverse effects, there is no conclusion regarding the safety of pregabalin in eye pain.

CONCLUSIONS

Pregabalin reduced acute eye pain but had no significant effect on long-term analgesia after ophthalmological surgery in adults. It had no effect on dry-eye symptoms after ocular surgery. Further studies on the safety of pregabalin in eye pain management are required to draw solid conclusions.

Secondary Headache Syndromes

PURPOSE OF REVIEW

This article is intended to assist clinicians in distinguishing benign primary headache syndromes from serious headache presentations that arise from exogenous causes.

RECENT FINDINGS

Although most cases of severe headache are benign, it is essential to recognize the signs and symptoms of potentially life-threatening conditions. Patients with primary headache disorders can also acquire secondary conditions that may present as a change in their baseline headache patterns and characteristics. Clinical clues in the history and examination can help guide the diagnosis and management of secondary headache disorders. Furthermore, advances in the understanding of basic mechanisms of headache may offer insight into the proposed pathophysiology of secondary headaches.

SUMMARY

Several structural, vascular, infectious, inflammatory, and traumatic causes of headache are highlighted. Careful history taking and examination can enable prompt identification and treatment of underlying serious medical disorders causing secondary headache syndromes.

Gray Matter Volume Changes in Patients With Acute Eye Pain: A Voxel-Based Morphometry Study

Purpose

The present study was attempted to compare the differences in gray matter volume (GMV) between the acute eye pain (EP) patients and the healthy controls (HCs) using voxel-based morphometry (VBM), and to explore the relationship with clinical features and behavioral performance.

Methods

A total of 24 patients (17 males, 7 females) with acute EP and 24 (17 males, 7 females) age-, sex-, and education-matched HCs were recruited from the Ophthalmology Department of the First Affiliated Hospital of Nanchang University. Functional magnetic resonance imaging (fMRI) scans were conducted in all subjects. We analyzed the original three-dimensional (3D) T1 brain images by VBM and compared the GMV values with the HCs. The acute EP patients can be distinguished from the HCs by receiver operating characteristic (ROC) curve.

Results

Compared with HCs, the acute EP patients had significantly lower GMV values in the brain regions of the left cerebellum posterior lobe, the left limbic lobe, the right insula, the left insula, the left thalamus, the left caudate, and the right cuneus. In addition, the WMV values of the whole brain in acute EP patients decreased slightly.

Conclusions

These results demonstrated that the acute EP patients showed an abnormal reduction in GMV in some brain regions, which might provide valuable information for further exploration of underlying neural mechanisms. These abnormal brain regions may reflect the functional disorders of acute EP patients in somatosensory, motor, cognitive functions, and so on.

Translational Relevance

The VBM study provides a diagnostic method for identifying the cause of acute EP, additionally, a novel direction was presented for further exploration of underlying neural mechanisms of acute EP.

Neuroimaging in the Diagnostic Evaluation of Eye Pain

Ocular or eye pain is a frequent complaint encountered not only by eye care providers but neurologists. Isolated eye pain is non-specific and non-localizing; therefore, it poses significant differential diagnostic problems. A wide range of neurologic and ophthalmic disorders may cause pain in, around, or behind the eye. These include ocular and orbital diseases and primary and secondary headaches. In patients presenting with an isolated and chronic eye pain, neuroimaging is usually normal. However, at the beginning of a disease process or in low-grade disease, the eye may appear "quiet," misleading a provider lacking familiarity with underlying disorders and high index of clinical suspicion. Delayed diagnosis of some neuro-ophthalmic causes of eye pain could result in significant neurologic and ophthalmic morbidity, conceivably even mortality. This article reviews some recent advances in imaging of the eye, the orbit, and the brain, as well as research in which neuroimaging has advanced the discovery of the underlying pathophysiology and the complex differential diagnosis of eye pain.

Unrelenting Ocular Pain as a Masquerading Symptom of Occult Choroidal Metastasis

<b><i>Purpose:</i></b> To report a case of chronic eye pain as a presenting feature of choroidal metastasis from lung cancer. <b><i>Methods:</i></b> We report the case of a 58-year-old Caucasian woman with stage IV lung adenocarcinoma presenting with an 8-month history of left eye pain and blurred vision. <b><i>Results:</i></b> The patient had previously consulted 14 ophthalmologists with varying diagnoses including posterior scleritis and trigeminal neuralgia. Visual acuity at presentation was 20/20 in the right eye and 20/80 in the left eye. Examination of the right eye was normal, while the left eye showed ill-defined flat yellow discoloration of the choroid with overlying shifting subretinal fluid. Ultrasonography demonstrated a dense choroidal thickening measuring 2.6 mm in size and showing subretinal fluid. Enhanced depth imaging optical coherence tomography revealed choroidal thickening with a ‘lumpy bumpy' surface topography consistent with a metastatic choroidal tumor presumably from the patient's lung adenocarcinoma. Fine needle aspiration biopsy followed by treatment was recommended, but the patient declined and later succumbed to metastatic disease. <b><i>Conclusion:</i></b> We present a case of chronic eye pain associated with diffuse choroidal thickening from metastatic lung adenocarcinoma that was previously unrecognized and misdiagnosed. This case emphasizes the importance of recognizing pain as a presenting symptom of choroidal metastasis.

Does Migraine Increase the Risk of Glaucoma?: A Population-Based Cohort Study

This study investigated whether migraine influences the risk of primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG) in Taiwan.We retrieved the data analyzed in this study from the National Health Insurance Research Database in Taiwan. We included 17,606 newly diagnosed migraine patients without preexisting glaucoma and randomly selected and matched 70,423 subjects without migraine as the comparison cohort. The same exclusion criteria were also applied to comparison subjects. Multivariate Cox proportion-hazards regression model was used to assess the effects of migraines on the risk of glaucoma after adjusting for demographic characteristics and comorbidities.The cumulative incidence of POAG was higher in the migraine cohort than that in the comparison cohort (log-rank P = 0.04). The overall incidence of POAG (per 10,000 person-years) was 9.62 and 7.69, respectively, for migraine cohort and nonmigraine cohort (crude hazard ratio [HR] = 1.24, 95% confidence interval [CI] = 1.01-1.54). After adjusting the covariates, the risk of POAG was not significantly higher in the migraine cohort than in the comparison cohort (adjusted HR [aHR] = 1.15, 95% CI = 0.93-1.42). The cumulative incidence of PACG did not differ between the migraine cohort and the comparison cohort (log-rank test P = 0.53). The overall incidence of PACG was not significantly higher in the migraine cohort than that in the comparison cohort (7.42 vs 6.84 per 10,000 person-years), with an aHR of 1.04 (95% CI = 0.82-1.32).This study shows that migraines are not associated with a higher risk either in POAG or in PACG.

Headaches attributed to visual disturbances

Ocular pain due to ophthalmological diseases is most commonly associated with redness and inflammation of the ocular surface and surrounding tissues. Pain in a quiet eye can be referred as headache and can be the first sign of a number of ocular or orbital conditions. Painful symptoms may be considered non-specific if signs of targeted diseases are not identified. Collection of appropriate history of pain around the eye and associated symptoms or signs should be considered to recognize when ophthalmological examination is needed. Some painful diseases such as intermittent angle closure glaucoma, uveitis or optic neuritis, can lead to severe and permanent visual loss and require a prompt diagnosis and treatment.