- Email: [email protected]
Paralysis of the near-vision triad in a child
Paralysis of the near-vision triad in a child Mihir Kothari, MS,a Kruti Mody, MBBS,a Jaydeep Walinjkar, MBBS,a Jigna Madia, DOT,b and Shalini Kaul, DNBa
The near-vision triad, or complex, consists of convergence, miosis, and accommodation. Neuronal pathways that control each of these components are distinct but interrelated. Abnormalities affecting 1 or more components of the complex may present as eye pain, headache, blurred vision, or diplopia at near fixation. Although isolated abnormalities in any one of the components are common, a severe and concurrent defect in all three is rare.1,2 We describe an 11-year-old child who presented with complete paralysis of the near triad without identifiable neurological defect. The child benefited from prism and plus lenses. To our knowledge, only three previous reports have described patients with idiopathic paralysis of convergence and accommodation in healthy children.2-4 The methods we used to objectively confirm defects in the near-vision complex and rule out a psychogenic etiology may be instructive to other clinicians.
Case Report
A
n 11-year-old boy presented with a 6-year history of blurred and double vision at near fixation. Medical, perinatal, and family history was unremarkable. On examination, visual acuity without correction in each eye was 6/6 at 6 m and 6/60 on reduced Snellen chart at 40 cm, improving to 6/6 in each eye with a ⫹ 3.00 D addition. Cycloplegic refraction was ⫹0.50 –1.00 ⫻ 90 in the right eye and ⫹0.25–1.00 ⫻ 90 in the left eye. Autorefractor readings (ARK 30; Nidek Inc., Japan) were obtained with the contralateral eye fixing at 6 m and then at 30 cm on an accommodative target. No significant accommodative response was noted. Dynamic retinoscopy confirmed the autorefractor findings. Pupillary constriction on attempted reading at near was absent. The pupillary light reflex was normal. Prism and cover testing revealed orthophoria at 6 m and 8⌬ exotropia at 40 cm in the cardinal positions of gaze. The near deviation did not change with ⫹3.00 D correction. The near point of convergence was at 2 m. Each eye had full adduction.
Author affiliations: aAditya Jyot Eye Hospital, Maharashtra, India; and bMehta Eye Clinic Jayant Arcade, Maharashtra, India
Institution at which the study was conducted: Aditya Jyot Eye Hospital, Wadala. Submitted March 4, 2008. Revision accepted September 30, 2008. Published online December 15, 2008. Reprint requests: Mihir Kothari, MS, Jyotirmay Eye Clinic, 205, Ganatra Estate Pokhran Road No 1, Khopat Thane West, 400601, Maharashtra India (email: [email protected]). J AAPOS 2009;13:202-203. © 2009 Published by Elsevier Inc. on behalf of the American Association for Pediatric Ophthalmology and Strabismus. 1091-8531/2009/$36.00 ⫹ 0 doi:10.1016/j.jaapos.2008.09.002
202
A fusion response was obtained with the Worth 4-Dot test at 6 m; at near, the fusion response was obtained with 4⌬ base in prisms and ⫹3.00 D lenses in front of each eye, with no pupillary miosis evident. Prism bar measurement revealed fusional amplitudes of 14⌬ (convergence, 8⌬; divergence, 6⌬) at 40 cm. Synoptophore analysis revealed gross stereopsis for distance. With near correction, stereoacuity on TNO test was 240 arcsec. Absence of significant accommodation and pupillary miosis at near also were documented by wavefront analysis (CustomVue; VISX USA Inc., Santa Clara, CA).5 Two instillations of 0.1% pilocarpine at 5-minute intervals did not induce any miosis, whereas topical 1% pilocarpine promptly induced both accommodation and miosis. Forced eye closure while the examiner was holding the eyelids open did not induce the near reflex. The addition of ⫺1.00 D lenses for distance caused deterioration of Snellen acuity by 2 lines and did not induce any convergence (suggesting lack of significant relative positive accommodation and a flat accommodative convergence-toaccommodation ratio). There was no other neurological deficit. Ultrasound biomicroscopy revealed normal anterior segment structures. A magnetic resonance imaging scan of the brain was normal. The patient was prescribed half eye spectacles, mounted with 5⌬ base in (ground-in glass prisms) with ⫹3.00 D sphere in front of each eye. After 9 months, the diplopia and blurred vision were relieved, but with no change in convergence or accommodation. Psychiatric consultation was obtained. The child had above-normal intelligence and was found to be deriving no secondary gain from the illness. No associated psychosocial abnormality was detected.
Discussion Although the components of the near triad— convergence, miosis, and accommodation— have an independent neuronal circuitry,6,7 they are interrelated. An abnormality at the level of the midbrain or in the supranuclear area may manifest with the defect in all components. Anticholinergic drugs, closed head trauma, viral encephalopathies, postdiphtheritic neuritis, Parkinson’s disease, progressive supranuclear palsy, multiple sclerosis, midbrain hemorrhage or infarction, subdural hematoma, and metabolic abnormalities can present as accommodation failure, convergence insufficiency, or pupillary light near dissociation (reverse Argyll Robertson pupil of Purves-Stewart). In this patient, there was no accommodative response on dynamic retinoscopy, dynamic autorefraction, or dynamic wavefront analysis, with an absence of convergence and of
Journal of AAPOS
Volume 13 Number 2 / April 2009
the near pupillary reflex. Prompt accommodation and miosis after pilocarpine instillation ruled out a primary ocular defect, and absence of the response to 0.1% pilocarpine ruled out end-organ hypersensitivity, indicating a lack of damage to the terminal neurons that usually result in an up-regulation of the muscarinic receptors. In cases such as this, psychogenic cause or malingering must be ruled out. The following tests can differentiate an organic cause from a psychogenic one: (1) Demonstrating absence of the pupillary (near) reflex upon forced eyelid closure while the examiner holds the eyelids open to establish an organic cause. (2) Obtaining a psychiatric consultation to reveal (a) whether the patient has any secondary gains to derive by feigning illness; or ( b) the presence of a psychosocial anomaly, such as alexithymia.8 (3) Demonstrating normal accommodation by introducing minus lenses while the patient reads from a distance visual acuity chart. (4) Inducing a malingering patient to converge involuntarily by using base in prisms or a synoptophore.9 (5) Testing the visually evoked response to diagnose accommodation–vergence insufficiency.10 In this patient, there was no evidence that the weakness in the near-vision complex was psychological in origin; nor was there a demonstrable structural defect in the supranuclear circuitry. The onset of the symptoms after the age of 6 years suggests an acquired cause; however, there are exceptions: Trimble3 reported a 12-year-old boy who had sudden onset severe weakness of accommodation and convergence associated with loss of pupillary miosis at near for which no organic or psychological cause could be found. Chrousos and colleagues2,4 described 3 healthy adolescents who had severe deficiency of accommodation and convergence.
Journal of AAPOS
Kothari et al
203
Paralysis of the near-vision complex is rare and appears to be of supranuclear origin. Detailed neuropsychiatric examination and neuroimaging may be inconclusive in such cases. Once organic causes are ruled out, treatment should focus on improving function using a combination of base-in prism and a near add.
Acknowledgments The authors wish to thank Dr. Vinod Mehta for wavefront analysis; Dr. Deepak Bhat for ultrasonic biomicroscopy; and Dr. Om Prakash Tauri for the magnetic resonance imaging scan. References 1. Ohtsuka K. Accommodation and convergence palsy caused by lesions in the bilateral rostral superior colliculus. Am J Ophthalmol 2002; 133:425-7. 2. Chrousos GA, O’Neill JF, Cogan DG. Absence of the near reflex in a healthy adolescent. J Pediatr Ophthalmol Strabismus 1985;22:76-7. 3. Trimble RB. Loss of accommodation and convergence. Proc R Soc Med 1977;70:261. 4. Chrousos GA, O’Neill JF, Lueth BD, Parks MM. Accommodation deficiency in healthy young individuals. J Pediatr Ophthalmol Strabismus 1988;25:176-9. 5. Mrukw´a-Kominek E, Gierek-Ciaciura S, Wygledowska-Promien´ska D, Zawojska I. The evaluation of accommodation range in patients of various age groups by WASCA wavefront aberrometer. Klin Oczna 2003;105:277-81. 6. The extraocular muscles. In: Hart WM, editor. Adler’s physiology of the eye. St. Louis, MO: Mosby-Year Book Inc.; 1992. p. 172-4. 7. Campbell FW, Westheimer G. Dynamics of accommodation responses of the human eye. J Physiol 1960;151:285-95. 8. Middleton EM, Sinason MD, Davids Z. Blurred vision due to psychosocial difficulties: A case series. Eye 2008;22:316-17. 9. Hoyt CG. Pupil anomalies and reactions. In: Taylor D, editor. Pediatric ophthalmology. Boston: Blackwell Science; 1997. p. 812. 10. Lovasik JV, Wiggins R. Cortical indices of impaired ocular accommodation and associated convergence mechanisms. Am J Optom Physiol Opt 1984;61:150-59.
The near-vision triad, or complex, consists of convergence, miosis, and accommodation. Neuronal pathways that control each of these components are distinct but interrelated. Abnormalities affecting 1 or more components of the complex may present as eye pain, headache, blurred vision, or diplopia at near fixation. Although isolated abnormalities in any one of the components are common, a severe and concurrent defect in all three is rare.1,2 We describe an 11-year-old child who presented with complete paralysis of the near triad without identifiable neurological defect. The child benefited from prism and plus lenses. To our knowledge, only three previous reports have described patients with idiopathic paralysis of convergence and accommodation in healthy children.2-4 The methods we used to objectively confirm defects in the near-vision complex and rule out a psychogenic etiology may be instructive to other clinicians.
Case Report
A
n 11-year-old boy presented with a 6-year history of blurred and double vision at near fixation. Medical, perinatal, and family history was unremarkable. On examination, visual acuity without correction in each eye was 6/6 at 6 m and 6/60 on reduced Snellen chart at 40 cm, improving to 6/6 in each eye with a ⫹ 3.00 D addition. Cycloplegic refraction was ⫹0.50 –1.00 ⫻ 90 in the right eye and ⫹0.25–1.00 ⫻ 90 in the left eye. Autorefractor readings (ARK 30; Nidek Inc., Japan) were obtained with the contralateral eye fixing at 6 m and then at 30 cm on an accommodative target. No significant accommodative response was noted. Dynamic retinoscopy confirmed the autorefractor findings. Pupillary constriction on attempted reading at near was absent. The pupillary light reflex was normal. Prism and cover testing revealed orthophoria at 6 m and 8⌬ exotropia at 40 cm in the cardinal positions of gaze. The near deviation did not change with ⫹3.00 D correction. The near point of convergence was at 2 m. Each eye had full adduction.
Author affiliations: aAditya Jyot Eye Hospital, Maharashtra, India; and bMehta Eye Clinic Jayant Arcade, Maharashtra, India
Institution at which the study was conducted: Aditya Jyot Eye Hospital, Wadala. Submitted March 4, 2008. Revision accepted September 30, 2008. Published online December 15, 2008. Reprint requests: Mihir Kothari, MS, Jyotirmay Eye Clinic, 205, Ganatra Estate Pokhran Road No 1, Khopat Thane West, 400601, Maharashtra India (email: [email protected]). J AAPOS 2009;13:202-203. © 2009 Published by Elsevier Inc. on behalf of the American Association for Pediatric Ophthalmology and Strabismus. 1091-8531/2009/$36.00 ⫹ 0 doi:10.1016/j.jaapos.2008.09.002
202
A fusion response was obtained with the Worth 4-Dot test at 6 m; at near, the fusion response was obtained with 4⌬ base in prisms and ⫹3.00 D lenses in front of each eye, with no pupillary miosis evident. Prism bar measurement revealed fusional amplitudes of 14⌬ (convergence, 8⌬; divergence, 6⌬) at 40 cm. Synoptophore analysis revealed gross stereopsis for distance. With near correction, stereoacuity on TNO test was 240 arcsec. Absence of significant accommodation and pupillary miosis at near also were documented by wavefront analysis (CustomVue; VISX USA Inc., Santa Clara, CA).5 Two instillations of 0.1% pilocarpine at 5-minute intervals did not induce any miosis, whereas topical 1% pilocarpine promptly induced both accommodation and miosis. Forced eye closure while the examiner was holding the eyelids open did not induce the near reflex. The addition of ⫺1.00 D lenses for distance caused deterioration of Snellen acuity by 2 lines and did not induce any convergence (suggesting lack of significant relative positive accommodation and a flat accommodative convergence-toaccommodation ratio). There was no other neurological deficit. Ultrasound biomicroscopy revealed normal anterior segment structures. A magnetic resonance imaging scan of the brain was normal. The patient was prescribed half eye spectacles, mounted with 5⌬ base in (ground-in glass prisms) with ⫹3.00 D sphere in front of each eye. After 9 months, the diplopia and blurred vision were relieved, but with no change in convergence or accommodation. Psychiatric consultation was obtained. The child had above-normal intelligence and was found to be deriving no secondary gain from the illness. No associated psychosocial abnormality was detected.
Discussion Although the components of the near triad— convergence, miosis, and accommodation— have an independent neuronal circuitry,6,7 they are interrelated. An abnormality at the level of the midbrain or in the supranuclear area may manifest with the defect in all components. Anticholinergic drugs, closed head trauma, viral encephalopathies, postdiphtheritic neuritis, Parkinson’s disease, progressive supranuclear palsy, multiple sclerosis, midbrain hemorrhage or infarction, subdural hematoma, and metabolic abnormalities can present as accommodation failure, convergence insufficiency, or pupillary light near dissociation (reverse Argyll Robertson pupil of Purves-Stewart). In this patient, there was no accommodative response on dynamic retinoscopy, dynamic autorefraction, or dynamic wavefront analysis, with an absence of convergence and of
Journal of AAPOS
Volume 13 Number 2 / April 2009
the near pupillary reflex. Prompt accommodation and miosis after pilocarpine instillation ruled out a primary ocular defect, and absence of the response to 0.1% pilocarpine ruled out end-organ hypersensitivity, indicating a lack of damage to the terminal neurons that usually result in an up-regulation of the muscarinic receptors. In cases such as this, psychogenic cause or malingering must be ruled out. The following tests can differentiate an organic cause from a psychogenic one: (1) Demonstrating absence of the pupillary (near) reflex upon forced eyelid closure while the examiner holds the eyelids open to establish an organic cause. (2) Obtaining a psychiatric consultation to reveal (a) whether the patient has any secondary gains to derive by feigning illness; or ( b) the presence of a psychosocial anomaly, such as alexithymia.8 (3) Demonstrating normal accommodation by introducing minus lenses while the patient reads from a distance visual acuity chart. (4) Inducing a malingering patient to converge involuntarily by using base in prisms or a synoptophore.9 (5) Testing the visually evoked response to diagnose accommodation–vergence insufficiency.10 In this patient, there was no evidence that the weakness in the near-vision complex was psychological in origin; nor was there a demonstrable structural defect in the supranuclear circuitry. The onset of the symptoms after the age of 6 years suggests an acquired cause; however, there are exceptions: Trimble3 reported a 12-year-old boy who had sudden onset severe weakness of accommodation and convergence associated with loss of pupillary miosis at near for which no organic or psychological cause could be found. Chrousos and colleagues2,4 described 3 healthy adolescents who had severe deficiency of accommodation and convergence.
Journal of AAPOS
Kothari et al
203
Paralysis of the near-vision complex is rare and appears to be of supranuclear origin. Detailed neuropsychiatric examination and neuroimaging may be inconclusive in such cases. Once organic causes are ruled out, treatment should focus on improving function using a combination of base-in prism and a near add.
Acknowledgments The authors wish to thank Dr. Vinod Mehta for wavefront analysis; Dr. Deepak Bhat for ultrasonic biomicroscopy; and Dr. Om Prakash Tauri for the magnetic resonance imaging scan. References 1. Ohtsuka K. Accommodation and convergence palsy caused by lesions in the bilateral rostral superior colliculus. Am J Ophthalmol 2002; 133:425-7. 2. Chrousos GA, O’Neill JF, Cogan DG. Absence of the near reflex in a healthy adolescent. J Pediatr Ophthalmol Strabismus 1985;22:76-7. 3. Trimble RB. Loss of accommodation and convergence. Proc R Soc Med 1977;70:261. 4. Chrousos GA, O’Neill JF, Lueth BD, Parks MM. Accommodation deficiency in healthy young individuals. J Pediatr Ophthalmol Strabismus 1988;25:176-9. 5. Mrukw´a-Kominek E, Gierek-Ciaciura S, Wygledowska-Promien´ska D, Zawojska I. The evaluation of accommodation range in patients of various age groups by WASCA wavefront aberrometer. Klin Oczna 2003;105:277-81. 6. The extraocular muscles. In: Hart WM, editor. Adler’s physiology of the eye. St. Louis, MO: Mosby-Year Book Inc.; 1992. p. 172-4. 7. Campbell FW, Westheimer G. Dynamics of accommodation responses of the human eye. J Physiol 1960;151:285-95. 8. Middleton EM, Sinason MD, Davids Z. Blurred vision due to psychosocial difficulties: A case series. Eye 2008;22:316-17. 9. Hoyt CG. Pupil anomalies and reactions. In: Taylor D, editor. Pediatric ophthalmology. Boston: Blackwell Science; 1997. p. 812. 10. Lovasik JV, Wiggins R. Cortical indices of impaired ocular accommodation and associated convergence mechanisms. Am J Optom Physiol Opt 1984;61:150-59.