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Nonaccommodative esotropia after cataract extraction in a patient with previous accommodative esotropia
Nonaccommodative esotropia after cataract extraction in a patient with previous accommodative esotropia Kammi B. Gunton, MD, Leonard B. Nelson, MD, Janine G. Tabas, MD ABSTRACT We report a case of nonaccommodative esotropia developing after bilateral cataract surgery that corrected the preexisting hyperopia in a patient with accommodative esotropia since childhood. The esotropia required surgical correction despite the good visual acuity after the cataract surgery. In patients with preexisting strabismus, there is a possibility of decompensation of adaptive binocular mechanisms after cataract surgery and refractive procedures. J Cataract Refract Surg 2002; 28:566 –568 © 2002 ASCRS and ESCRS
T
he persistence of refractive accommodative esotropia into adulthood is well documented.1–3 These patients are orthophoric or have cosmetically acceptable esotropia with their refractive correction. We present a patient with refractive accommodative esotropia who developed nonaccommodative esotropia after bilateral cataract extraction with intraocular lens (IOL) implantation.
Case Report A 68-year-old man presented to an ophthalmologist reporting hazy vision and glare of gradual onset in the left eye. He had a history of accommodative esotropia treated with hyperopic correction since the age of 3 years. He denied previous ocular surgery or diplopia. On examination, the best corrected visual acuity was 20/25– in both eyes with ⫹7.00 ⫹1.25 ⫻ 100 in the right eye and ⫹7.75 ⫹1.25 ⫻ 81 in the left eye. The bifocal add was Accepted for publication June 20, 2001. From the Department of Pediatric Ophthalmology and General Ophthalmology Service, Wills Eye Hospital, Philadelphia, Pennsylvania, USA. Reprint requests to Leonard B. Nelson, MD, Department of Pediatric Ophthalmology, Wills Eye Hospital, 900 Walnut Street, Philadelphia, Pennsylvania 19107, USA. © 2002 ASCRS and ESCRS Published by Elsevier Science Inc.
⫹2.50 diopters (D) in both eyes. No cycloplegic refraction was performed. With medium light intensity on the brightness acuity tester, visual acuity fell to 20/60 in each eye. The patient had significant nuclear sclerotic cataract in both eyes. He was orthotropic with spectacles but developed a “moderate” right esotropia without spectacles that was not further quantitated. He had normal ocular rotations. No sensory studies were performed. The patient had uneventful cataract extraction under topical anesthesia in the left eye with implantation of a Chiron LI61U 29.5 D IOL in the capsular bag. Immediately after surgery, visual acuity was 20/20 with a refraction of plano ⫹1.00 ⫻ 90. The patient also developed an esotropia of 25⌬ in the right eye. Three weeks later, the patient had uneventful cataract extraction under topical anesthesia in the right eye with implantation of a Chiron LI61U 29.5 D IOL in the capsular bag. Postoperatively, the visual acuity in the right eye was 20/20 with a refraction of – 0.50 ⫹1.25 ⫻ 100. He continued to have an esotropia of 25 and diplopia. One week after the second cataract surgery, the patient had a 25⌬ base-out prism placed in the spectacle correction and was referred to a strabismologist. One month after cataract extraction, the patient continued to have a comitant esotropia of 25 to 30⌬. Refraction was unchanged with a visual acuity of 20/20– in each eye. Because of the persistent esotropia and the patient’s inability to wear prism spectacles, he had a right medial rectus recession of 6.0 mm. Postoperatively, he had residual esotropia of 2⌬. On follow-up 3 months later, he denied having diplopia and appeared orthotropic. 0886-3350/02/$–see front matter PII S0886-3350(01)01037-9
CASE REPORTS: GUNTON
Discussion Strabismus is a known but relatively uncommon complication of cataract extraction. Diplopia occurs after cataract surgery at a frequency of 2.0% to 2.7%.4,5 Reported causes of diplopia after cataract surgery fall into 4 basic categories1: trauma to the extraocular muscles during the surgical procedure or anesthetic administration,2 a vasculopathic event at the time of surgery or a preexisting disorder rendered asymptomatic by an occluding cataract,3 disorders specifically related to IOL implantation,4 and decompensated prior strabismus syndromes.5–7 Peribulbar or retrobulbar injection of anesthetic agents into the inferior rectus can cause ischemic contracture of the muscle that presents as muscle restriction or paralysis.8 The resulting strabismus occurs immediately postoperatively and may require strabismus surgery, the use of prism to alleviate symptoms, or both. Vertical muscle strabismus can occur after bridle suture placement.9 In our case, topical anesthesia was used without bridle suture placement. The comitant nature of the esotropia in our patient makes surgery-related trauma to a specific extraocular muscle unlikely. Although vasculopathic nerve palsies, decompensated thyroid eye disease, and myasthenia gravis can result in strabismus after cataract extraction, our patient did not develop a specific cranial nerve palsy. He had no history of diabetes or hypertension to put him at additional risk for vasculopathic disease at the time of surgery. Patients with a preexisting condition such as thyroid eye disease present with diplopia after cataract surgery because the visual acuity preoperatively precludes awareness of the diplopia.6 Disorders related to IOL implantation include color or brightness disparity, anisometropia, and ocular dominance reversal.6 Anisometropia with unequal accommodative demand may have contributed to our patient’s diplopia; however, surgical correction of the anisometropia did not alleviate the symptoms. Reversal of ocular dominance was not adequately evaluated in this patient. The most relevant cause of diplopia after cataract surgery in this case is decompensation of a preexisting strabismus syndrome. If accommodative esotropia is not treated soon after its onset, a decompensated nonaccommodative esotropia results. Although this patient was orthotropic when measured with spectacles preopera-
tively, the high hyperopic correction may have masked a small nonaccommodative esotropia. Hyperopic correction diminishes the measurement of strabismus. In this patient’s preoperative spectacle correction, this would result in an 18.7% (2.50 ⫻ 7.50) to 20.6% (2.50 ⫻ 8.25) reduction depending on the method of measurement. A small esotropia reduced by 20% may have lead to the appearance of no deviation. Speculating that the patient had the monofixation syndrome with a small nonaccommodative esotropia and a larger accommodative esotropia preoperatively, the 3-week delay without optical correction before the second eye had cataract extraction may have contributed to the decompensation of the preexisting strabismus. Postoperative accommodative esotropia resulting from the cataract surgery would cause diplopia. Although cycloplegic refraction was not done preoperatively in this patient, an accommodative esotropia remains unlikely because further hyperopic refraction did not correct the esotropia. An IOL would preclude the possibility of latent hyperopia, making residual accommodative esotropia unlikely as the etiology in this patient. Treatment for strabismus after cataract extraction can be problematic. Prisms are initially used to correct the diplopia. In 1 study, 48 of 81 patients with strabismus after cataract extraction regained binocularity with prisms.5 In another study, 20 of 24 patients required strabismus surgery to improve the deviation.4 Most studies suggest that a combination of strabismus surgery, prisms, or some type of penalization to 1 eye is necessary to regain binocularity.6,7 This case illustrates the complexities of ocular alignment in adults with refractive accommodative esotropia who may have cataract surgery. Patients may gain excellent visual results after the cataract surgery, but prior strabismus may persist. In discussing possible outcomes of both cataract and refractive procedures, persistence of strabismus with onset of diplopia should be considered in patients with a history of accommodative esotropia.
References 1. Swan KC. Accommodative esotropia long range followup. Ophthalmology 1983; 90:1141–1145 2. Shippmann S, Weseley AC, Cohen KR. Accommodative
J CATARACT REFRACT SURG—VOL 28, MARCH 2002
567
CASE REPORTS: GUNTON
esotropia in adults. J Pediatr Ophthalmol Strabismus 1993; 30:368 –371 3. Rutstein RP, Marsh-Tootle W. Clinical course of accommodative esotropia. Optom Vis Sci 1998; 75:97– 102 4. Schwarz EC, Gerdemann M, Hoffmann R, Hartmann C. Kataraktoperation mit Linsenimplantation; Strabismus und Diplopie als Komplikation. Ophthalmologe 1999; 96:635– 639 5. Wylie J, Henderson M, Doyle M, Hickey-Dwyer M. Persistent binocular diplopia following cataract surgery: aetiology and management. Eye 1994; 8:543– 546
568
6. Hamed LM. Strabismus presenting after cataract surgery. Ophthalmology 1991; 98:247–252 7. Domingo Gordo B, Merino Sanz P, Arrevola Velasco L, et al. Diplopı´a post-cirugı´a de catarata: causas y tratamiento. Arch Soc Esp Oftalmol 2000; 75:581– 587 8. Pearce IA, McCready PM, Watson MP, Taylor RH. Vertical diplopia following local anaesthetic cataract surgery: predominantly a left eye problem? Eye 2000; 14:180 – 184 9. Catalano RA, Nelson LB, Calhoun JH, et al. Persistent strabismus presenting after cataract surgery. Ophthalmology 1987; 94:491– 494
J CATARACT REFRACT SURG—VOL 28, MARCH 2002
T
he persistence of refractive accommodative esotropia into adulthood is well documented.1–3 These patients are orthophoric or have cosmetically acceptable esotropia with their refractive correction. We present a patient with refractive accommodative esotropia who developed nonaccommodative esotropia after bilateral cataract extraction with intraocular lens (IOL) implantation.
Case Report A 68-year-old man presented to an ophthalmologist reporting hazy vision and glare of gradual onset in the left eye. He had a history of accommodative esotropia treated with hyperopic correction since the age of 3 years. He denied previous ocular surgery or diplopia. On examination, the best corrected visual acuity was 20/25– in both eyes with ⫹7.00 ⫹1.25 ⫻ 100 in the right eye and ⫹7.75 ⫹1.25 ⫻ 81 in the left eye. The bifocal add was Accepted for publication June 20, 2001. From the Department of Pediatric Ophthalmology and General Ophthalmology Service, Wills Eye Hospital, Philadelphia, Pennsylvania, USA. Reprint requests to Leonard B. Nelson, MD, Department of Pediatric Ophthalmology, Wills Eye Hospital, 900 Walnut Street, Philadelphia, Pennsylvania 19107, USA. © 2002 ASCRS and ESCRS Published by Elsevier Science Inc.
⫹2.50 diopters (D) in both eyes. No cycloplegic refraction was performed. With medium light intensity on the brightness acuity tester, visual acuity fell to 20/60 in each eye. The patient had significant nuclear sclerotic cataract in both eyes. He was orthotropic with spectacles but developed a “moderate” right esotropia without spectacles that was not further quantitated. He had normal ocular rotations. No sensory studies were performed. The patient had uneventful cataract extraction under topical anesthesia in the left eye with implantation of a Chiron LI61U 29.5 D IOL in the capsular bag. Immediately after surgery, visual acuity was 20/20 with a refraction of plano ⫹1.00 ⫻ 90. The patient also developed an esotropia of 25⌬ in the right eye. Three weeks later, the patient had uneventful cataract extraction under topical anesthesia in the right eye with implantation of a Chiron LI61U 29.5 D IOL in the capsular bag. Postoperatively, the visual acuity in the right eye was 20/20 with a refraction of – 0.50 ⫹1.25 ⫻ 100. He continued to have an esotropia of 25 and diplopia. One week after the second cataract surgery, the patient had a 25⌬ base-out prism placed in the spectacle correction and was referred to a strabismologist. One month after cataract extraction, the patient continued to have a comitant esotropia of 25 to 30⌬. Refraction was unchanged with a visual acuity of 20/20– in each eye. Because of the persistent esotropia and the patient’s inability to wear prism spectacles, he had a right medial rectus recession of 6.0 mm. Postoperatively, he had residual esotropia of 2⌬. On follow-up 3 months later, he denied having diplopia and appeared orthotropic. 0886-3350/02/$–see front matter PII S0886-3350(01)01037-9
CASE REPORTS: GUNTON
Discussion Strabismus is a known but relatively uncommon complication of cataract extraction. Diplopia occurs after cataract surgery at a frequency of 2.0% to 2.7%.4,5 Reported causes of diplopia after cataract surgery fall into 4 basic categories1: trauma to the extraocular muscles during the surgical procedure or anesthetic administration,2 a vasculopathic event at the time of surgery or a preexisting disorder rendered asymptomatic by an occluding cataract,3 disorders specifically related to IOL implantation,4 and decompensated prior strabismus syndromes.5–7 Peribulbar or retrobulbar injection of anesthetic agents into the inferior rectus can cause ischemic contracture of the muscle that presents as muscle restriction or paralysis.8 The resulting strabismus occurs immediately postoperatively and may require strabismus surgery, the use of prism to alleviate symptoms, or both. Vertical muscle strabismus can occur after bridle suture placement.9 In our case, topical anesthesia was used without bridle suture placement. The comitant nature of the esotropia in our patient makes surgery-related trauma to a specific extraocular muscle unlikely. Although vasculopathic nerve palsies, decompensated thyroid eye disease, and myasthenia gravis can result in strabismus after cataract extraction, our patient did not develop a specific cranial nerve palsy. He had no history of diabetes or hypertension to put him at additional risk for vasculopathic disease at the time of surgery. Patients with a preexisting condition such as thyroid eye disease present with diplopia after cataract surgery because the visual acuity preoperatively precludes awareness of the diplopia.6 Disorders related to IOL implantation include color or brightness disparity, anisometropia, and ocular dominance reversal.6 Anisometropia with unequal accommodative demand may have contributed to our patient’s diplopia; however, surgical correction of the anisometropia did not alleviate the symptoms. Reversal of ocular dominance was not adequately evaluated in this patient. The most relevant cause of diplopia after cataract surgery in this case is decompensation of a preexisting strabismus syndrome. If accommodative esotropia is not treated soon after its onset, a decompensated nonaccommodative esotropia results. Although this patient was orthotropic when measured with spectacles preopera-
tively, the high hyperopic correction may have masked a small nonaccommodative esotropia. Hyperopic correction diminishes the measurement of strabismus. In this patient’s preoperative spectacle correction, this would result in an 18.7% (2.50 ⫻ 7.50) to 20.6% (2.50 ⫻ 8.25) reduction depending on the method of measurement. A small esotropia reduced by 20% may have lead to the appearance of no deviation. Speculating that the patient had the monofixation syndrome with a small nonaccommodative esotropia and a larger accommodative esotropia preoperatively, the 3-week delay without optical correction before the second eye had cataract extraction may have contributed to the decompensation of the preexisting strabismus. Postoperative accommodative esotropia resulting from the cataract surgery would cause diplopia. Although cycloplegic refraction was not done preoperatively in this patient, an accommodative esotropia remains unlikely because further hyperopic refraction did not correct the esotropia. An IOL would preclude the possibility of latent hyperopia, making residual accommodative esotropia unlikely as the etiology in this patient. Treatment for strabismus after cataract extraction can be problematic. Prisms are initially used to correct the diplopia. In 1 study, 48 of 81 patients with strabismus after cataract extraction regained binocularity with prisms.5 In another study, 20 of 24 patients required strabismus surgery to improve the deviation.4 Most studies suggest that a combination of strabismus surgery, prisms, or some type of penalization to 1 eye is necessary to regain binocularity.6,7 This case illustrates the complexities of ocular alignment in adults with refractive accommodative esotropia who may have cataract surgery. Patients may gain excellent visual results after the cataract surgery, but prior strabismus may persist. In discussing possible outcomes of both cataract and refractive procedures, persistence of strabismus with onset of diplopia should be considered in patients with a history of accommodative esotropia.
References 1. Swan KC. Accommodative esotropia long range followup. Ophthalmology 1983; 90:1141–1145 2. Shippmann S, Weseley AC, Cohen KR. Accommodative
J CATARACT REFRACT SURG—VOL 28, MARCH 2002
567
CASE REPORTS: GUNTON
esotropia in adults. J Pediatr Ophthalmol Strabismus 1993; 30:368 –371 3. Rutstein RP, Marsh-Tootle W. Clinical course of accommodative esotropia. Optom Vis Sci 1998; 75:97– 102 4. Schwarz EC, Gerdemann M, Hoffmann R, Hartmann C. Kataraktoperation mit Linsenimplantation; Strabismus und Diplopie als Komplikation. Ophthalmologe 1999; 96:635– 639 5. Wylie J, Henderson M, Doyle M, Hickey-Dwyer M. Persistent binocular diplopia following cataract surgery: aetiology and management. Eye 1994; 8:543– 546
568
6. Hamed LM. Strabismus presenting after cataract surgery. Ophthalmology 1991; 98:247–252 7. Domingo Gordo B, Merino Sanz P, Arrevola Velasco L, et al. Diplopı´a post-cirugı´a de catarata: causas y tratamiento. Arch Soc Esp Oftalmol 2000; 75:581– 587 8. Pearce IA, McCready PM, Watson MP, Taylor RH. Vertical diplopia following local anaesthetic cataract surgery: predominantly a left eye problem? Eye 2000; 14:180 – 184 9. Catalano RA, Nelson LB, Calhoun JH, et al. Persistent strabismus presenting after cataract surgery. Ophthalmology 1987; 94:491– 494
J CATARACT REFRACT SURG—VOL 28, MARCH 2002