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Show Journal of Cli/lical Neuro-ophthalmology 7(3):132-134, 1987. Editorial Comment © 1987 Raven Press, Ltd., New York Accommodative Spasm Versus Spasm of the Near Reflex In this issue of The Journal, Bohlmann and France report on a young woman who developed accommodative spasm in both eyes, first noted 3 months after a head injury at the age of 19 years. Her pupils and motility examination were normal. Nine years later, she failed a driver's vision test, and had distance vision of 20/300 in the right eye and 20/200 in the left eye without correction. After administration of 1% atropine to both eyes, her distance vision again improved to 20/20 in both eyes without correction. The authors then discuss the differential diagnosis of spasm of the near reflex as well as the pathogenesis of accommodative spasm in their papers. I believe that the action "behind the scenes" on reviewing this paper by various editorial board reviewers and consultants would be of interest to the readers of this journal. One reviewer considered it unusual that a patient have "post-traumatic spasm of the near reflex" years after the presumed precipitating event. This reviewer pointed out that spasm of convergence can be seen in early stages of periaqueductal lesions, and that he had seen this with pineal tumors in the early stages. He thought there was no means, however, of establishing a relationship between a brain stem lesion and the pseudomyopia in this patient. A senior neuro-ophthalmologist of world repute objected to a lack of distinction between "spasm of accommodation" and "spasm of the near reflex" in this paper. He requested that this be clarified, and the authors responded appropriately with a revision of the manuscript. The same consultant then reviewed the revised paper, and considered the paper acceptable but still felt there was some confusion between accommodative spasm and convergence spasm of the near reflex. The editor then tried to have an editorial written about this paper by two of the most noted ophthalmologists who deal with refractive, optical, and accommo- . _.: '" nroLd('Ill'i, but both passed, and therefore .n'ments will be made hoping that ,,'., ;0 clinicians who occa- 132 sionally encounter these unusual types of problems. First of all, let's consider the entity called "spasm of the near reflex" as originally reported by Cogan and Freese (Arch Ophthalmol 1955: 54:752-9). This is an entity which typically mimicks a motility problem, and presents with a unilateral or bilateral abduction deficit in a patient complaining of double vision, and is misdiagnosed as sixth nerve disease. Usually the patient has had a mild head injury or bump or other stressful event, and a day or two later when being examined by a physician is asked as to whether or not they have had double vision. While being examined, they often reply "Yes", and from then on have recurrent bouts of blurred or double vision. The diagnostic tip-off to this entity is that when the patient attempts to abduct the involved eye, the pupil immediately constricts on the attempt, which proves that the patient is simultaneously innervating a horizontal lateral gaze attempt with concomitant convergence, and the end result is that when one asks the patient to look to her left, that the right eye adducts normally, but the left eye makes a notably incomplete abduction movement. A variability of response is consistently found in these patients, and reassurance, treating them for 2-3 weeks with mild cydoplegics (e.g., a drop of 5% scopalamine to both eyes at bed time), andlor giving them -1.00 lenses, usually will handle the problem. The important point is to make the diagnosis and avoid the usually extensive and expensive neuroimaging, and neurodiagnostic workups otherwise done if this is thought to be true sixth nerve disease. Thus, the commonest things seen in the differential diagnosis of a "pseudoabducens palsy" are: 1. spasm of the near reflex, 2. Duane's retraction syndrome, 3. thyroid eye disease (with a tight medial rectus muscle), 4. old esotropia with secondary medial rectus limitation, and 5. a medial wall orbital fracture or other form of medial rectus entrapment. These can be differentiated by his- EDITORIAL COMMENT 133 tory, careful examination of the pupil on attempted abduction, and a forced ductions and a forced generations test in nearly all instances. Accommodative spasm probably consists of two formal types-a more common form which may be called "functional accommodative spasm" or "ciliary spasm", and a rarer type which might be called "organic accommodative spasm" or "central accommodative spasm". I have seen several patients who complain of blurred vision, are wearing perhaps - 3.00 glasses in both eyes, and, under full cycloplegia plus fogging, have either a basically emmetropic correction or even a slight hypermetropic state. Thus, under full cycloplegia plus fogging, they may have a prescription of +0.25 + 0.87 cx 105 or something like that. Very often these patients will have an extremely large amplitude of accommodation if adequately tested, in order to sustain the amount of accommodative effort needed to wear minus lenses at a distance quite in excess of their true refractive need for good vision. The test I like to use to make this diagnosis I call the "Nail test", which was named for Dr. James B. Nail, the resident at Wilmer Institute, who told me how to use it. It can be used whether the patient is seen without drops or when the patient is under full cycloplegia, whichever is preferred. For example, let's say the patient is seen with 20/40 best corrected vision with their present glasses. One can then perform dry retinoscopy under the refractor, and let's say they show a - 2.00 streak with each eye. One thing that should be done early in examining these patients is to check their visual acuity at distance and at near with their present glasses, and also to do the same thing without any correction at all. It is common in neuro-ophthalmologic practice to see a patient complaining of blurred vision in the right eye who wears glasses all the time, and to find that their acuity in the right eye is 20/30-2 with their present lenses. However, if the glasses are removed, and the distance acuity is tested again, it may be 20/20-3 now in the same eye. That obviously proves that the glasses are the problem in that patient! In other words, if the acuity is worse with the glasses on and the patient is complaining about blurred vision, one doesn't need to rush that individual off for a $400 CT scan or other exotic test, but simply to do a good DKR (doctor killing refraction) in that circumstance. Now, however, let's return to the "Nail test". If you get a retinoscopic correction of - 2.00, and with that the patient can read 20/20 at distance, the next thing to do is to click up six clicks (of + 0.25 diopters each) on both sides of the re-fractor. Then take the vision again. If you are at a proper correction in the first place (i.e., the patient is a true - 2.00 myope), you will find the patient is now notably blurred at distance. A general rule of thumb is that the vision decreases one line at distance with each + 0.25 diopter of "fog" that is given. However, if you find that with only - 0.50 before each eye, your patient still is reading down to about 20/30 or so, you have proven that the patient is not a true myope at all, but has pseudomyopia due to excessive accommodative tone. The thing that should be done at that point is to binocularly increase the plus on both sides, and have the patient continue to read down the chart, pushing them by encouraging them to try and look through the blur and read as far down as they can, and when one finally increases the plus to the point where they can just binocularly read on the 20/20 line, you are approaching the true basic refractive error, as not influenced by excessive accommodative tone. The same test should now be n.peated again after full cycloplegia, using at least 1% Cyclogyl in an adult, and not Mydriacyl which usually gives notably incomplete cycloplegia, particularly in the type of cases we are discussing. In Walsh and Hoyt, third edition, volume one, on page 550, a patient is described who is somewhat reminiscent of the individual here reported by Bohlmann and France. A 17-year-old young man complained of defective vision, glare, and double vision following an uncertain history of mild head trauma. His distance acuity was 5/200 in each eye, but corrected to 20/20 with -7.00 spheres before both eyes. Retinoscopy was - 0.25 in the right eye and plano in the left eye under atropine, and with that he corrected to 20/20 in each eye. After the atropine wore off, his symptoms of blurred vision returned, and for several years he used atropine and bifocal glasses. However, on a followup 7 years later, the patient was now found to be essentially free of both muscle imbalance and accommodative spasm for at least 6 months, and no longer required a bifocal. In my experience, organic accommodative spasm as reported with periaqueductal lesions, syphilis, and the like is quite rare. However, peripheral ciliary spasm is not infrequent at all, particularly as is seen with corneal abrasions, contusion injuries of the globe, ocular inflammation, and the like. All of these things can be ruled out, however, by a careful ophthalmologic examination. The patients with white eyes and pseudomyopia, who complain of progressive visual blurring, and who get more and more minus correction added to their glasses year by year, however, JCli,/ Neuro-oplzthalmol, Vol. 7, No.3. 1987 134 EDITORIAL COMMENT can be difficult to detect and more so to treat. Usually they have a previously uncorrected rather significant astigmia, in my experience, and may have had the problem precipitated by intense near work. The ''bottom line" here is that one can see excessive accommodation, excessive convergence, and excessive effort of the entire near synkinesis (i.e., blurring due to excessive accommodation, abduction deficit or diplopia due to increased convergence, and miosis due to increased pupillary sphincter tone), all as separate and distinct entities. All of them are far less common than the opposite situation of convergence insufficiency, which is probably the most common problem bringing a young adult with good acuity to the ophthalmologist, but that is not the topic being addressed here. I believe the patient reported by JCli,/ Neuro-oplzthalmol, Vol. 7, No.3, 1987 Bohlmann and France is a true instance of accommodative spasm, and that one should differentiate that entity unequivocally from spasm of the near reflex, for the management of these two clinical situations is quite different. Finally, one must remember that in many academic ophthalmology departments, it is much easier to get a computed tomographic scan of the orbits, magnetic resonance imaging with surface coil techniques, fluorescein angiography, and the like, than to get a meticulously performed refraction. Many, many patients receive neuro-ophthalmologic investigations that could be avoided by a careful pin-hole test, dry retinoscopy, and consideration of the functional interactions of the near synkinesis. J. Lawton Smith, MD |