Visual disturbance with undiagnosed etiology
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A 20-year-old woman presented for a neuro-optometric exam with complaints of headaches, asthenopia, occasional diplopia, extreme light sensitivity, dizziness and loss of balance. She reported her symptoms started about 2 years ago with day-to-day fluctuations in her symptoms.
Upon further questioning, the patient reported difficulty with reading and near work producing diplopia and headaches. She also reported feeling fatigued after reading along with experiencing brain fog. The patient had difficulty tolerating busy/crowded environments, which produced anxiety and a feeling of being overwhelmed. Her attention span and cognition decreased since her symptoms started, and she experienced difficulty in school. She started having migraines in the last 6 months and recently developed some food sensitivities. Her current prescription was 6 months old, and she reported her vision was clear through her contact lenses and glasses. She saw a neurologist for migraines.
Source: William V. Padula, OD, SFNAP, FAAO, FNORA
Her bloodwork and MRI results were unremarkable. A careful review of systems indicated no other health concerns, and she was taking Excedrin Migraine (acetaminophen/aspirin/caffeine, Novartis) as needed for migraines. She denied any history of head trauma or accidents.
Testing
The entering corrected visual acuity was 20/25 monocularly and binocularly. Extraocular muscles were full in all fields without pain, and pupils were equal and normal with no afferent pupil defect noted. She had a receded near point of convergence of 6”/10” and reduced stereoacuity of 140 seconds of arc with Randot Stereotest (StereoOptical). Fixations revealed that focal jerk and saccadic eye movements were reduced both horizontally and vertically. Her base-in vergence findings for distance and near were high in break and recovery. Base-out vergences showed suppression at distance and near ranges.
The IOPs were 11 mm Hg OD and 12 mm Hg OS via Tonopen Avia (Reichert). The anterior segment findings were unremarkable. Posterior segment examination indicated an average cup-to-disc ratio and distinct disc margins in both eyes. Close evaluation of the optic nerve head showed peripapillary ischemia in both eyes. Fundus photography and OCT angiography (OCTA) were performed. When compared to age-matched normal OCTA, there were findings of thinner retinal nerve fiber layer and a slight reduction in vessel density. It was our hypothesis that these peripapillary atrophic changes may be related to ischemia in the peripapillary capillary plexus of the nerve fiber layer surrounding the optic nerve head.
Visual evoked potential (VEP) P-100 pattern reversal performed binocularly revealed negative deflection in amplitude of the N-75. With the addition of 1 D base-in prisms over both eyes there was a decrease in the negative deflection of the N-75 value.
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Based on patient presentation, the first differential diagnosis would be a binocular vision dysfunction due to symptoms experienced after prolonged near work. Some of her symptoms are classic for a visual spatial processing dysfunction secondary to a possible neurological injury. Research showed that a compressed P-100 and an increase in amplitude with the addition of a low amount of base-in prism presented binocularly indicates a spatial visual processing dysfunction. This can be caused by concussion. The increase in the amplitude may indicate a mild traumatic brain injury.
It is also important to rule out brain tumors or other brain abnormalities by ordering an MRI or comanaging with a neurologist. We also need to rule out autoimmune or infectious disease due to prolonged symptoms that have continued to increase over time.
Diagnosis
After discussion of signs and symptoms, the patient was recommended to have bloodwork for Lyme-related disease. We provided an IGeneX testing kit (testing may take 2 weeks to 3 weeks to complete). Her test results were positive for Borrelia burgdorferi with Bartonella and Babesia coinfections.
This patient was also diagnosed with visual spatial dysfunction secondary to Lyme-related disease. A visual spatial dysfunction often presents similar to a binocular vision disorder because there is an overlap of visual complaints.
Treatment, management
The patient was referred to a physician specializing in tickborne diseases (resources are available through the International Lyme and Associated Disease Association). She was started on a course of multiple antibiotics and supplements. An overall improvement in symptoms began within a few weeks of starting treatment.
Padula and colleagues have shown that in subjects with diagnosed Lyme-related disease, the negative deflection of the binocular N-75 is statistically significant when compared to a control group of subjects without history of Lyme-related disease and may be considered a biomarker. Treatment with base-in prisms reduces the negative amplitude of the N-75, indicating a spatial visual processing compromise by the infectious disease. The compromise in spatial visual process can cause visual symptoms along with imbalance in posture and balance.
The patient was prescribed separate pairs of distance and near prism lenses; the distance prism lenses were affecting vision and posture/balance with yoked prisms, and a low plus power with base-in prisms was prescribed for near work. We also recommended a 10% blue tint in her lenses to reduce light sensitivity and dark sunglasses for outdoors.
Discussion
Many people with Lyme or tickborne disease experience difficulty with reading, eyestrain and fatigue, intermittent diplopia, loss of comprehension, loss of place, headaches, joint pain, and discomfort in the neck and shoulders. The disease can also affect balance and posture. Tickborne disease may also affect personality and learning ability and cause the onset of food allergies. There are certain hallmarks of specific coinfections, which can be used as markers to consider ruling out Lyme-related disease.
Vision is often affected by the infection, yet the symptoms are often mistaken for other problems associated with functional ocular disorders, balance, movement and cognition, as described by Padula and colleagues. Although ocular complications have been previously reported, discussion about vision problems associated with tickborne disease is sparse in the literature. It has also been reported that many people begin to experience symptoms of blurring, diplopia, photophobia, distortion of space, visual strain and headaches when performing near vision activities, difficulty with balance, dizziness, and difficulty with convergence and focusing, to name several. Researchers have reported that other eye-related complications include follicular conjunctivitis, bilateral corneal neuropathy, uveitis, vitritis, retinal vasculitis, optic atrophy and optic disc edema (Gerstenblith et al.).
The early diagnosis and detection of Lyme disease remains a challenge. Because Lyme disease is “the great mimicker,” it will often cause misdiagnosis or misdirection in medical evaluation. Lack of diagnosis and treatment in the acute phase may result in a chronic and even neurological advancement in the undiagnosed disease.
A multidimensional perspective may provide the means to screen for Lyme-related disease in conjunction with symptoms from an undiagnosed etiology, especially in areas endemic for tickborne infections.
The VEP pattern reversal analysis of the negative amplitude of the N-75 can be an effective biomarker for screening Lyme-related disease. Fundus photography of the optic nerve, as well as OCTA for determination of vessel dropout in the peripapillary area, may provide additional data supporting a diagnosis of Lyme disease even when a positive Lyme disease titer is inconclusive.
Optometrists and ophthalmologists should be alert to the sudden onset of symptoms and the characteristics of convergence and accommodative insufficiency that may appear to be of a functional cause. Dysfunction in pursuits and saccadic fixations in conjunction with convergence and accommodative disorders are characteristics of a spatial visual processing dysfunction and not of a functional cause.
The incorporation of fundus photography, VEP and OCTA potentially can enable early diagnosis of tickborne disease and provide the clinician a means to rule out Lyme-related disease by ordering a blood titer. This will enable the proper referral to a physician for medical treatment of Lyme-related disease as well as provide the clinician the opportunity to affect the dysfunction in spatial visual processing.
References:
Caulfield AJ, et al. Clin Lab Med. 2015;doi:10.1016/j.cll.2015.07.006.
Campbell JP, et al. Sci Rep. 2017;doi:10.1038/srep42201.
Gerstenblith TA, et al. Psychosomatics. 2014;doi:10.1016/j.psym.2014.02.006.
Padula WJ, et al. A visual evoked potential N-75 biomarker to predict Lyme disease and visual processing dysfunction: An experimental design. Submitted for publication. 2020.
Padula WJ, et al. Brain Injury Medicine. 2013;doi:10.1891/9781617050572.0045.
For more information:
William V. Padula, OD, SFNAP, FAAO, FNORA, is the director of the Padula Institute of Vision Rehabilitation in Guilford, Conn., and on the faculty for Western University of Health Sciences College of Optometry and Salus University of Health Sciences College of Optometry. He is also the founding president of the Neuro-Optometric Rehabilitation Association. He can be reached at: wvpadula@me.com.
Ayra I. Sayyed, OD, is a senior resident at Padula Institute of Vision, completing the R.J. Apell and C. Nelson Residency in Neuro-Optometric Rehabilitation. She can be reached at: ayrasayyed@gmail.com.
Edited by Leo P. Semes, OD, FAAO, a Primary Care Optometry News Editorial Board Member and Professor Emeritus in the Department of Optometry and Vision Science at the University of Alabama at Birmingham. He can be reached at: leopsemes@gmail.com.
Disclosures: Padula and Sayyed report no relevant financial disclosures.
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