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Little Rock Eye Clinic
Little Rock Eye Clinic Glaucoma Service would like to share with you a couple links to
Information on the treatment of Glaucoma.
National Eye Institute -- Facts about Glaucoma
Technology Review -- Glaucoma Test in Contact Lens
American Glaucoma Society Position Statement: Marijuana and
The Treatment of Glaucoma
All About Vision
Neuro-Ophthalmology Newsletter- April 2012 |
Neuro-Ophthalmology Newsletter
Andrew Lawton, M.D.
April 2012 - Volume IX, Number 4
The treatment of giant cell arteritis and polymyalgia rheumatica remains a tricky business. The chronic use of high dose corticosteroids has the potential for dangerous side effects. Researchers are constantly looking for alternative medications that can decrease the need for corticosteroid therapy. One medication under study is anti-tumor necrosis factor. Akawa, et al (Clin Rheumatol 2012; 31:575-579), surveyed the medical literature and found 99 patients with PMR treated with anti-tumor necrosis factor. The patients ranged from ages 63 to 84 years of age and approximately 70% were women. The duration of the disease prior to anti-TNF treatment fell between 10.5 weeks and 95 months with follow up of 2 weeks to 21 months. Specific medications used were Infliximab and Etanercept. The time to response to therapy was 2 to 8 weeks. All studies indicated a reduction in the need for corticosteroids and significant clinical improvement. Patients tended to show a significant improvement in laboratory parameters as well. The authors concluded that anti-TNF agents may have a place in reducing the need for and, in some cases, replacing corticosteroid therapy.
Patients with Parkinson’s disease suffer from a wide variety of visual complaints. Almer, et al (Ophthalmology 2012; 119:178-182), studied a cohort of 27 patients with Parkinson’s disease and 16 controls. The key issues addressed were the ability to converge and quality of life measures. Parkinson’s patients had significantly decreased convergence amplitudes and visual quality of life scores compared to controls. Treatment with dopaminergic agents resulted in a significant improvement in convergence amplitudes and quality of life scores. The authors noted that the fluctuation of function in patients with Parkinson’s disease related to blood levels of medication may complicate therapy aimed at improving visual function.
At initial presentation, neuromyelitis optica and acute retrobulbar optic neuritis may appear similar. Fernandes, et al (J Neuroophthalmol 2011; e-published December 2011), compared the outcomes in 33 patients with NMO and 30 patients with optic neuritis related to multiple sclerosis. The authors concentrated on patients who had just one episode of optic nerve involvement. Patients with NMO had visual function and average visual field mean deviation significantly worse than with MS. Two of 36 eyes with NMO had normal visual fields after final recovery compared to 17 of 36 eyes with MS. The authors concluded that NMO must be considered whenever a patient has residual visual field loss after recovering from optic neuritis.
Wegener’s granulomatosis is an extremely dangerous disease which may appear as an isolated orbital process. Baslund, et al (Clin Exp Rheumatol 2012; e-published January 2012), looked at 10 patients with isolated orbital disease. All patients were treated with Rituximab 1 gram twice separated by two weeks. A CT scan and physical exam were performed six months after treatment. 9 of 10 patients had a subjective improvement in symptoms. Four patients with visual impairment had improvement of vision that persisted at the time of follow up on average 17 months. CT scanning showed a decrease in the size of the orbital lesion in two patients while 8 patients showed no change. The authors concluded that Rituximab should be considered an option in treatment of patients with orbital Wegener’s granulomatosis.
Neuro-Ophthalmology Newsletter
Volume IX, Number 4 - April 2012
Case Study
Patient IX4 is a woman in her mid-30s who developed vertical double vision about three weeks before presentation. She noted that her left eye looked droopy. If she covered an eye, her diplopia went away. She had been generally healthy prior to this episode except for environmental allergies.
Her visual acuity was 20/20 in each eye. Her left eye was 3 mm lower than her right. She showed 2 mm of left proptosis. Both eyes moved fully in all directions. She had a 4 diopter right hypertropia in all directions of gaze. Confrontation fields were intact in both eyes. Both pupils were symmetrical and size and rate of constriction. Facial muscle strength was symmetrical. Her anterior segments appeared quiet. Her optic discs were pink and flat and spontaneous venous pulsations were present.
What is your differential diagnosis and what diagnostic testing should you perform?
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Discussion of Case IX3 from March 2012 Newsletter
Patient IX3 has an isolated right sixth cranial nerve palsy. When approaching such patients, they tend to fall into three groups. Those 40 years of age and above almost always have a microvascular etiology and may be observed without performing an MRI. Those 20 years of age and below should be imaged because of the possibility of a brainstem glioma but, in general, the MRI is negative and they recover over the course of several months. The cohort to worry about is those between 20 and 40 years of age. These patients have a high likelihood of a lesion compressing the sixth cranial nerve.
The sixth cranial nerve takes a long course that exposes it to injury in a number of locations. The nerve exits the anterior pons and then climbs upward to the edge of the petrous bone. The nerve is tethered at that point in Dorello’s canal. It traverses the petrous bone in company with the trigeminal and facial nerves before entering the cavernous sinus. Its relationship to the trigeminal and facial nerves results in Gradenigo’s syndrome when all three are affected together characterized by severe pain, loss of abduction on the affected side, and facial paralysis on the affected side.
In our above patient, the culprit was an unusual sphenoid sinus mucocele. Such mucoceles may arise due to obstruction of the sinus meatus, cyst formation in a sinus polyp, or cyst formation arising from the sinus mucosa. Because the sinus abuts on the cavernous sinus, a mucocele in this location may result in involvement of one or multiple cranial nerves.
The most common symptom of a sphenoid sinus mucocele is headache, often localized to behind the eye. One hint is that the headache tends to be relieved by becoming upright with return of the headache on reclining. The two most commonly involved cranial nerves are the third and sixth. Patients may develop visual loss including due to chiasmal compression with a bitemporal hemianopia. Patients may show features of panhypopituitarism due to involvement of the pituitary gland. Diagnosis is generally made through neuroimaging.
These patients will not respond to medical therapy. The most common treatment is a sphenoidectomy with placement of a drain into the sinus through a transnasal approach. The key to a successful outcome is a high degree of suspicion for a skull base lesion and the use of appropriate neuroimaging studies...
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Neuro-Ophthalmology Newsletter- March 2012 |
Neuro-Ophthalmology Newsletter
Andrew Lawton, M.D.
March 2012 - Volume IX, Number 3
Patients with essential blepharospasm and hemifacial spasm receive frequent and large dosages of Botox for therapy. A potential issue that could lead to insensitivity to the medication is the development of antibodies to the protein. Bakheit, et al (Int J Rehabil Res 2012; 35:36-39), used a bioassay to look for antibodies to the medication in ten consecutive treatment cycles for at least five years. The authors found that no patients had detectable levels of antibodies. The authors concluded that, although the results did not rule out the possibility that patients develop antibodies to Botox, they certainly did not support the hypothesis.
Giant cell arteritis represents the most common form of primary vasculitis in the world. Evidence suggests, however, that the frequency of GCA may vary depending upon the ethnic population. Alba, et al (J Clin Rheumatol 2012; 28:1-7), looked specifically for clinical, laboratory, and treatment aspects of the Mexican Mestizo demographic in this condition. They found 22 patients retrospectively between 1989 and 2010. 18 were women with a mean age of 73 years. The average time between development of symptoms and institution of therapy was 67 days. 90% had headaches, 86% had systemic complaints, and 59% had polymyalgia rheumatica. 36% had amaurosis fugax and 27% suffered blindness. Elevated ESR was noted in only 89%. Although patients responded to corticosteroid therapy, ten patients suffered relapses. 16 patients required additional, steroid-sparing medications. The authors concluded that giant cell arteritis is not recognized often in Latin America. They found that patients did respond to corticosteroid therapy but had a higher incidence of amaurosis fugax and blindness than other populations with a severe complication rate of 27%.
The risk for diabetic retinopathy and macular edema is increased in patients who also have obstructive sleep apnea. Mason, et al (Respiration 2011; epublished December 2011), performed a pilot study of CPAP on 28 patients who completed a six month follow up period. The mean age of patients was 66.2 years, BMI 31.7, hemoglobin A1C 7.4%, and duration of diabetes 9.5 years. 13 patients were classified as high compliers with CPAP and 15 as low compliers. The authors found that patients who used CPAP appropriately had a one-line better visual acuity measurement than those poorly compliant. Fundus photographs, however, did not show a difference in the degree of macular edema. The final conclusions were that the study provided evidence that CPAP therapy may be of value in preserving vision in patients with both diabetes and obstructive sleep apnea and that a future randomized trial should be performed.
The onset of optic neuropathy in neuromyelitis optica and in the optic neuritis seen with multiple sclerosis may be very similar. Fernandes, et al (J Neuroophthalmol 2011; epublished December 2011), found that only 2 of 36 eyes in patients with NMO recovered with a normal visual field while 17 of 35 eyes in optic neuritis did. The authors concluded that NMO should be considered in any patient with optic neuritis who have a severe residual visual field defect and significantly lowered if the visual field returns to normal.
Neuro-Ophthalmology Newsletter
Volume IX, Number 3 - March 2012
Case Study
Patient IX3 is a man in his late 20s who developed bronchitis and pneumonia about two weeks before presentation. The next day, his right eye became swollen. The eye become uncomfortable and he went to the emergency room three days later. He was told that he had a corneal abrasion. Over the next few days he developed severe headaches. He received prescriptions for eye drops and pain medications. Four days before presentation he started on a Z-pack. Right before presentation, his right eye turned in toward his nose. He had been generally health prior to this episode.
His visual acuity was 20/20 in each eye. His right eye would not abduct past midline. His left eye moved fully in all directions. Confrontation fields were intact in both eyes. Both pupils were symmetrical and size and rate of constriction. He showed no proptosis. Trigeminal sensation was symmetrical. Facial muscle strength was symmetrical. His anterior segments appeared quiet. His optic discs were pink and flat and spontaneous venous pulsations were present. Intraocular pressures were 14 mm Hg on his right and 13 mm Hg on his left.
What is your differential diagnosis and what diagnostic testing should you perform?
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Neuro-Ophthalmology Newsletter- February 2012 |
Neuro-Ophthalmology Newsletter
Andrew Lawton, M.D.
February 2012 - Volume IX, Number 2
Patients with thyroid-related eye disease regularly report ocular irritation and discomfort. Often their symptoms appear out of proportion to degree of tear deficiency or exposure. Huang, et al (Graefe’s Arch Clin Exp Ophthalmol 2011; epublished November 30), looked at the levels of cytokines in the tears of patients with Graves’ orbital disease and correlated the levels with the levels of inflammatory mediators and the clinical presentation of the patients. The subjects included 21 patients with Graves’ disease and 10 age-matched controls. The Graves’ group was subdivided into those with active disease and those with inactive disease. The authors found decreased Schirmer scores and higher tumor necrosis factor levels in all patients with Graves’ disease compared to healthy controls. Interleukin levels were significantly higher in patients with active Graves’ disease than in inactive patients or controls. Higher interleukin levels correlated with higher clinical activity scores. The differences in interleukin levels between patients with active symptoms and inactive disease suggest that active orbital inflammation contributes to corneal surface disease problems.
Downbeat nystagmus may be associated with lesions near the cervical-medullary junction. The resultant oscillopsia may cause a significant degradation of visual function. Kalla, et al (J Neuro-Ophthalmology 2011; 31:320-325), observed that aminopyridines improved downbeat nystagmus in experimental animals. The authors selected eight patients with downbeat nystagmus due to efferent sources. The subjects received a single dose of 4-aminopyridine or 3,4-diaminopyridine. They received no additional medication for 6 days and then had a single dose of the medication they hadn’t had the first time. Both chemicals resulted in significant improvement in the nystagmus but 4-aminopyridine was more effective than 3,4-diaminopyridine.
Obstructive sleep apnea is turning out to be a major risk factor in a number of ophthalmic disorders. Although glaucoma doesn’t usually fall in the territory of neuro-ophthalmology, it is, after all, an optic nerve disease. Lin, et al (J of Glaucoma 2011; 20:553-558) looked at a total of 247 subjects, 209 with obstructive sleep apnea and 38 normals, who came in for sleep studies. Each individual received a complete ophthalmologic examination including gonioscopy, automated visual field testing, and retinal nerve fiber layer thickness measurements. 12 subjects, all with obstructive sleep apnea, showed characteristic features of normal tension glaucoma. 1 had mild sleep apnea, 3 moderate, and 8 severe. Mean and minimum oxygen saturation levels correlated well with measurements of retinal nerve fiber layer thickness. The authors concluded that all patients with moderate to severe obstructive sleep apnea should be considered at increased risk for the development of normal tension glaucoma.
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Neuro-Ophthalmology Newsletter- Dec.2011/Jan.2012 |
Neuro-Ophthalmology Newsletter
Andrew Lawton, M.D.
January 2012 - Volume IX, Number 1
Benign intracranial hypertension behaves differently in children than in adults. Honorat, et al (Arch Pediatr 2011; 18:1139-1147), looked at treatment regimens for children with the condition to see what was effective. The authors found 18 children with BIH between 1995 and 2009 averaging 10 years in age. No female predilection was noted. 15 children complained of headache, 8 of diplopia due to sixth cranial nerve palsy. 16 patients had papilledema. 6 patients demonstrated decreased visual acuity and 9 patients with visual field defects at presentation. Acetazolamide was the first line treatment in 16 children averaging 11.2 mg/kg for 2.5 months. Acetazolamide alone was effective for 11 patients. 4 children received corticosteroids as initial treatment at 1.5 to 2 mg/kg for an average 1.5 months. One patient received initial treatment with both medications. Two children seemed to improve with lumbar puncture alone. None had surgical procedures. 13 patients with long-term follow up did well. The authors concluded that children with BIH tended to do better than adults and generally had good visual results with only short courses of medication.
Patients with cranial nerve palsies often must suffer with diplopia or cover one eye with resultant loss of depth perception. Tamhankar, et al (J Neuro-Ophthalmology 2011; 31:206-209), did a retrospective analysis of 83 patients with fourth cranial nerve palsies to see how effective their prism therapy was. 69 patients had congenital fourth cranial nerve palsies and 14 acquired. The average deviation in neutral position was 7.8 diopters. The mean correction with prism was 6 diopters. 92% of patients were satisfied with the prism alone. 86% of patients continued satisfied with prism alone while the remainder had strabismus surgery. Even when the primary deviation (15 patients) was more than 15 diopters, 80% of patients were comfortable with prism alone. The authors concluded that prisms represent a reasonable treatment for patients with symptomatic fourth cranial nerve palsies. The presence of a large misalignment did not preclude prism therapy. Using prism quickly in these patients may result in significant preservation of binocular function.
Weightlessness has widespread effects on human physiology. Mader, et al (Ophthalmology 2011; 118:2058-2069), reviewed the results of abnormal ophthalmic examinations in seven astronauts who spent long terms in space plus the findings of post-flight questionnaires completed by 300 astronauts. The seven astronauts with post-flight eye exams also had eye exams prior to travel. Of the seven with eye exams, five had optic disc edema, five had flattening of their eyes, five had choroidal folds, three had nerve fiber layer infarcts, six had thickening of nerve fiber layer by OCT, and six had decreased near visual acuity. Five of the patients with decreased near visual acuity had a significant hyperopic shift on refraction due to flattening of their eyes. Lumbar punctures performed on four patients with optic disc edema showed opening pressures ranging between 21 and 28.5 cm water as long as 60 days post-flight. 29% of astronauts on missions of short duration had decreases in distance and near visual acuity compared to 60% on long-term missions. In some astronauts, their shift in refractive error became permanent. The authors proposed that these findings were the result of redistribution of body fluids with a shift toward the head due to decreased gravity.
Neuro-Ophthalmology Newsletter
Volume IX, Number 1 - January 2012
Case Study
Patient IX1 is an 82-year-old woman who has noted double vision for six weeks. She described the diplopia as vertical, binocular, and constant. Her symptoms increased on right gaze. She sees clearly if she covers either eye. She reported a history of diabetes mellitus. She did not have headaches, scalp tenderness, or jaw claudication. Her medical history indicated a hysterectomy, colon surgery, back surgery, hypertension, depression, arthritis, acid reflux, and irritable bowel syndrome. Her ocular history was significant for cataract surgery in both eyes. A review of systems was otherwise non-contributory. Her family history was non-contributory. She does not consume tobacco or alcohol. Current medications include Atenolol, Lisinopril, Actos, Metformin, Cymbalta, Nexium, Tylenol, and Systane. She reported no allergies to medications.
At examination, her visual acuity was 20/30 (+2) on her right and 20/25 (-2) on her left with correction. She demonstrated a 30% decrease in adduction of her right eye. Both eyes had a marked decrease in the ability to look to her right. She fused in neutral position with an 8 diopter right exotropia and a 4 diopter right hypertropia. She had no relative afferent pupillary defect. Confrontation testing was intact in both eyes. Her adnexal structures appeared healthy. Her conjunctiva, corneas, anterior chambers, and irises were normal in both eyes. Both eyes contained posterior chamber intraocular lenses. Intraocular pressures were 12 mm Hg on her right and 10 mm Hg on her left. Her posterior segments were unremarkable.
What would be the diagnosis if the above were all the information you have? The actual diagnosis will be discussed in the next issue although it’s actually in the differential diagnosis now.
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Discussion of Case VIII12 from December 2011 Newsletter
This patient has the classic appearance of benign intracranial hypertension. Another condition may mimic BIH, however, and that is dural venous sinus thrombosis, particularly lateral sinus thrombosis. Patients with dural sinus thrombosis are at significant risk for permanent neurological injury and should be treated immediately. Many authors are now calling for performing a magnetic resonance venogram (MRV) at the same time as performing the MRI to eliminate the possibility of an intracranial mass.
The most significant neurological complication of DVST is cerebral infarction due to back pressure in cerebral veins from the obstruction. The ophthalmological parallel would be an ischemic central retinal vein occlusion. Depending on the study, mortality rates if the condition remains untreated can be as high as 48%. Although early detection leads to a good survival rate, permanent effects may include seizures, chronic headaches, memory loss, depression, and permanent visual deficits. There was a slight increased prevalence in women compared to men with the ages of the patients generally in the third and fourth decades.
The headaches reported with DVST may be of precipitous onset more so than in BIH. The location and description of the headache does not correlate with the location of the thrombosis. There is a strong association with arterial hypertension. Focal neurological deficits and cranial nerve dysfunction are common. Infection and trauma may precipitate DVST. Medical conditions associated with this problem include treatment with birth control pills, hypercoaguable state, pregnancy, collagen vascular disease, and treatment with other medications that promote clotting. If the condition is suspected, early consultation with a hematologist is advised to assure an appropriate laboratory work up.
Treatment currently involves anticoagulation although the literature contains no controlled studies definitively proving effectiveness. Case series with treatment tend to show significantly better outcomes than published in previous cohorts of untreated patients. If anticoagulation fails, open surgical removal of the clot with direct injections of thrombolytic agents may be considered. Cerebral herniation is a leading cause of death with DVST and patients may do better with brain decompressive procedures. Appropriate and prompt treatment may lower mortality rates from 48% to 12%.
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