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Bilateral phakic hypermetropic epikeratoplasty for accommodative esotropia
Bilateral phakic hypermetropic epikeratoplasty for accommodative esotropia David A. Hiles, M.D., Kenneth P. Cheng, M.D.
B TR T Optical correction of hi h h permetropia "ith la e the primary treatment fOl' accommodati e e otropia. These gla eat· often poor! accepted b adole cent and oun adult for the are co meticall und sirable hea and e otropia occur \ ith their remo al. We report an 11 1/2- eat'-old ph 'icall matUl'e female" ith high h permetropia and accommodati e e otmpia corrected to orthophoria \ ith la e who \ a unabl to be \ eaned from hel' gla ' e '. h became intolerant to gla e \ ear refu ed contact I n e and \ a treated ucce full \ ith bilateral phakic h permetropic epikeratopla ty. Two ear po tepikeratopla ty her i ual acuity i 20/40 and 20/20 uncorrected and the i ion in the ambl opic right e e ha I' mained at it · ma 'imum preoperati e Ie el. he i orthophoric at di tance and ha. a 2 pri m diopter monoR ational e ophoria at near without la e. Epikeratopla ty i an option in the treatment of accommodati e e .otropia for patient ,ho are pa t the ambl opia forming a e ha e a table an Ie of h'abi mu and \! ho r quire their full h permetropic optical correction to maintain orthophoria.
Ke
Words: He 'ommodativ "otropia m tropia I' rraeti v surg ry
Accommodative esotropia is commonly divided into two subdivisions based upon the accommodative convergence to accommodation ratio (AC/A). Dondersl described normal AC/A ratio accommodative esotropia as occurring in patients who must accommodate to clear blurred retinal images produced by high hypermetropic refractive errors. This accommodation leads to excessive convergence, which eventually exceeds the patient's fusional divergence amplitudes and esotropia results. If the esotropia measures the same at both distance and at near, the patient is described as having a normal AC/A ratio accommodative esotropia. High AC/A
pik ratopJ a t ' h~ pe r,
ratio accommodative esotropia is described by Parks 2 as being due to an abnormal synkinetic near response. Accommodation on near targets elicits an abnormally high accommodative convergence response resulting in an esotropia which is greater at near than at distance. Accommodative esotropia usually arises between two and three years of age although it may also occur during infancy or adulthood. 3 Amblyopia is frequent and patients often have a family history of an esodeviation. Children with normal AC/A ratio accommodative esotropia typically have high hypermetropic refractive errors that range from + 3.00 to
From the Department of Ophthalmology, University of Pittsburgh School of Medicine, Children's Hospital and Eye and Ear Hospital of Pittsburgh, Pennsylvania. Supported in part by grants from the Fight for Sight Childrens Eye Clinic of Childrens Hospital, Pittsburgh, Pennsylvania, and by Fight for Sight, Inc., New York, New 'fork. Reprint requests to David A. Hiles, M. Do, Eye and Ear Hospital, 230 wthrop Street, Pittsburgh, Pennsylvania 1.5213.
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+ 10.00 diopters (D) with an average of + 4.75 D. Patients with high ACIA ratio accommodative esotropia have refractive errors averaging + 2.25 D but may be myopic or more highly hypermetropic than this average value. 2 The treatment of normal ACIA ratio accommodative esotropia is based upon eliminating accommodation induced by high hypermetropic refractive errors, thus decreasing accommodative convergence. Therapeutic modalities consist of plus power glasses, contact lenses, or miotics. The standard initial treatment of a child with normal ACIA ratio accommodative esotropia and high hypermetropia consists of prescribing glasses for the full hypermetropic refractive error as determined under complete cycloplegia. Miotics facilitate myoneural junction transmission at the ciliary muscle, thereby reducing the central accommodative effort required by the patient which, in turn, reduces the associated accommodative convergence. Many patients have a decrease in their hypermetropia with growth as they approach seven years of age or more. 4 Some patients with accommodative esotropia will develop sufficient fusional divergence amplitudes to allow for the gradual reduction and eventual elimination of their glasses while maintaining orthophoria or a well-controlled esophoria during accommodation. Other patients maintain orthophoria only while wearing their full high hypermetropic glasses and have not developed sufficient fusional divergence amplitudes to control their esotropia when the power of their glasses is decreased. These older patients have a cosmetically undesirable esotropia without glasses and must remain in their high plus lenses, which are cosmetically poorly accepted by them. Contact lenses are another alternative for the optical correction of high hypermetropia, but not all patients are candidates for continued contact lens wear. In addition, the esodeviation still recurs when the contact lenses are removed. We present a patient who refused optical correction of her accommodative esotropia with glasses and contact lenses and was offered bilateral phakic hypermetropic epikeratoplasty as an alternative method for the treatment of accommodative esotropia with high hypermetropia. CASE REPORT ].S., a white female initially seen in September 1980 at 4112 years of age was orthophoric at distance, but had 40 prism D of right esotropia at near. Her visual acuity was central, steady but not maintained in the right eye, and central, steady and maintained in the left eye. The cycloplegic SE refraction was + 7.75 D in the right eye and + 5.75 + 1.00 X 40 in 362
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the left eye. Optical correction of her full hypermetropic refractive error with glasses resulted in orthophoria at distance and near. She was treated with glasses for the next six years and achieved 20/30 visual acuity in each eye. She developed an esodeviation without glasses of 45 prism D at both distance and near but she remained orthophoric with glasses. Attempts at decreasing the strength of her hypermetropic glasses at 7 years of age resulted in esotropia. In September 1986, at 10 112 years of age, her best corrected visual acuity was 20/40 in the right eye and 20/20 in the left eye. With her full cycloplegic correction in place she maintained orthophoria at distance, but had developed an esotropia of 12 prism D at near. She was treated with a + 1.25 D executive bifocal which resulted in orthophoria at near. In November 1987, at IPh years of age, the patient's parents related persistent complaints by the patient regarding the unsightly nature of her high hypermetropic glasses. Her esodeviation without correction was 40 prism D at distance and 65 prism D at near (Figures 1 and 2). Her glasses at that time measured + 7.00 D in the right eye and + 6.00 D in the left eye combined with a + 1.25 D executive bifocal. Through the upper segments, she had a monofixational esophoria of 4 prism D at distance and 12 prism D of esotropia at near (Figure 3). Through the bifocal, she had 4 prism D of right monofixational esophoria at near (Figure 4). Her best corrected visual acuity was 20/40 in the right eye and 20/20 in the left eye. The cycloplegic refractive error had increased to + 8.50 + 0.50 X 135 in the right eye and + 7.25 D in the left eye. The option of contact lenses was explored with a trial lens fit, but the patient was intolerant of this option. The risks and potential benefits of bilateral phakic hypermetropic epikeratoplasty were discussed with the patient and her parents, and informed consent was obtained. Epikeratophakia graft procedures were performed separately on each eye four days apart in December 1987. Surgery was performed on the left eye after an uncomplicated early postoperative course was observed in the right eye. The power of the epigrafts (Allergan Medical Optics KeratoLens@)) was + 8.00 D in the right eye and + 7.00 D in the left eye. The patient's postoperative course was without complication. At eight weeks postepikeratoplasty her uncorrected visual acuity was 20170 in the right eye and 20/30 in the left eye. She had a right esotropia of 6 prism D at distance and 18 prism D at near without correction. The cycloplegic refraction was -1.25 + 2.75 X 120 in the right eye and + 1.50 + 1.00 X 170 in the left eye. She was treated with echothiophate iodide 0.125% once daily in both eyes
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Fig. 1.
(Hiles) Preoperative uncorrected 40 prism D esotropia with gaze directed at a distance target.
Fig. 2.
(Hiles) Preoperative uncorrected 65 prism D esotropia with fixation directed at a near target.
for two months in an attempt to increase fusional amplitudes at near. At six months postepikeratoplasty, she was free of complaints and denied any symptoms of glare or asthenopia. The echothiophate iodide had been discontinued at the fourth postoperative month. Both the patient and her parent's denied any occurrence of esotropia during the preceding two months and both were extremely pleased with the surgery. The patient's parents reported a greatly enhanced level of self-esteem in their daughter. Her uncorrected visual acuity was 20/60 in the right eye and 20/20 in the left eye and she read Jaeger 1 plus at near without correction. She was orthophoric at distance and at near without correction. The epikeratoplasty
grafts were clear. At one year postepikeratoplasty she remained free of complaints. Her uncorrected visual acuity was 20/60 in the right eye, improving with correction ( - 2.00 + 2.00 x 25) to 20/40. This acuity was her preoperative level of best corrected visual acuity secondary to amblyopia. Her acuity in the left eye was 20/20, improving with correction ( + 0.75 + 0.25 x 40) to 20/15. She remained orthophoric at distance and demonstrated a right monoRxational esophoria of 2 prism D at near without correction. The patient required no glasses (Figures 5 and 6). At two years postepikeratoplasty her examination was essentially unchanged with uncorrected visual acuity of 20/40- in the right eye and 20/15- in the left
Fig. 3.
Fig. 4.
(Hiles) Accommodative esotropic patient with 4 prism D of right monofixational esophoria at distance with high hypermetropic glasses in place.
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(Hiles) Same patient with 4 prism D of rightmonofixational esophoria at near through a + 1.25 bifocal addition.
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Fig. 5.
(Hiles) The patient is orthophoric at distance without correction two years following bilateral epikeratoplasty.
eye. She remained orthophoric at distance with 2 prism D of monofixational esophoria at near. The epikeratoplasty grafts remain clear. Preoperative keratometry measured 43.87/43.87 in both eyes. At six months, the postoperative keratometry had increased to 52.50/52.50 and 49.75/50.00 X 95 in the right and left eye, respectively. At the first postoperative year the keratometry was 51.75/52.r-) X 175 in the right eye and 49.50/50.25 X 100 in the left eye and at two years the keratometry was 51.50/52.75 X 175 and 49.62149.87 X 100 in the right and left eye, respectively.
DISCUSSION Optical correction of high hypermetropia with glasses remains the standard treatment for normal AC/A ratio accommodative esotropia. The presence of high hypermetropia in these patients unfortunately makes their thick, high plus power lenses cosmetically undesirable by giving the patient the appearance of magnified blurred eyes to observers. Heavy glass lenses are uncomfortable and plastic lenses are frequently scratched. Both are poorly accepted by adolescents and young adults. In addition, the cosmetic blemish of esotropia is always present when the glasses are removed. Contact lenses are an alternative to glasses, but lens intolerance, high cost, and high loss rates in the adolescent population are complications well appreciated by both the ophthalmologist and the patient's parents. The use of miotics for strabismus dates back to Java1. 5 These drugs are useful as diagnostic aids in younger patients, as a substitute for glasses in uncooperative children, and for temporary use dur364
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Fig. 6.
(Hiles) Patient in Figure 5 without correction with a right monofixational esophoria of 2 prism D with fixation on a near target.
ing activities in which cosmetically straight eyes are desired and glasses are not appropriate, such as sports. 3 ,6 Miotics are not a substitute for the optical correction of high hypermetropia in the long-term management of normal AC/A ratio accommodative esotropia because visual acuity is not adequately corrected. The patient continues to accommodate to achieve an enhanced level of vision and excessive accommodative convergence and esotropia result. Strabismus surgery has been suggested in certain instances for accommodative esotropia. Albert and Hiles 7 suggested bimedial rectus muscle recessions for older children to reduce high AC/A ratios to normal in an effort to eliminate bifocal wear. DyerS recommended surgery for teenagers who must remove their glasses during activities in which glasses are not appropriate. Helveston9 reluctantly approaches older normal AC/A ratio accommodative esotropes with bimedial rectus muscle recessions in an effort to eliminate their need for glasses. Surgery, however, is not generally advocated by most surgeons. High hypermetropia still remains, andwhen the patient accommodates postoperative esotropia often results. Additionally, as patients lose the ability to accommodate with increasing age, glasses are again worn for clear vision. All the authors express concern about the eventual onset of postoperative exotropia. However, if a nonrefractive component of the esodeviation coexists, strabismus surgery for that component is recommended ..3 ,6 Epikeratoplasty is a form of onlay corneal refractive surgery in which a donor corneal lenticule is sutured onto the host cornea to alter the anterior corneal surface and its refractive power. Epikeratoplasty has been used in adults for treatment of keratoconus,lO myopia, 11 and aphakia 12; in pediatric
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patients for correction of the high hypermetropia of aphakia l3 ,14 and for myopia. 15 This paper reports the first use of bilateral phakic hypermetropic epikeratoplasty for the optical management of high hypermetropia in a patient with accommodative esotropia. The salient features of epikeratoplasty are its extraocular nature and its reversibility should complications occur. The potential complications associated with pediatric epikeratoplasty include failure of the graft to epithelialize, graft infection, and graft opacification.l 3,14 In the Allergan Medical Optics nationwide study of epikeratophakia for aphakia in children, the overall success rate of epikeratoplasty as measured by graft clarity was 89%, which improved to 95% with the addition of regrafted patients .13 In a similar nationwide study of older children receiving epikeratoplasty between the ages of 8 and 18, the initial grafting success rate was 100%.1 4 One of us (D.A.H.) has substantiated this high success rate in a separate study.16 Objections to the use of epikeratoplasty in the treatment of infantile cataracts include a delay in postoperative graft clearing, the variable refractive status during the first several postoperative months, and the relationship of these factors to the development of amblyopia. 16 These same objections apply to young patients with accommodative esotropia in the amblyopia forming age group. Their sensory status is not stable and they may develop amblyopia or a nonaccommodative component to their esodeviation. We stress that the patients selected for this procedure must have stable refractions, be beyond the age of amblyopia development, and have an ocular alignment that remains stable with their high hypermetropic optical correction in place. Concern about the predictability of the refractive changes in epikeratoplasty for myopia has been expressed. 15 In the Allergan Medical Optics nationwide studies of pediatric aphakic epikeratoplasty, 73% of the patients had postoperative refractions within ± 3.00 D of emmetropia. 13,14 In an additional study of epikeratophakia in children, Morgan et al. 17 reported a postoperative average refractive error of plano ± 5.20 D. All patients in· these studies achieved an increase in their corneal refractive powers. Our patient had an increase of8.25 D in the right eye and 6.00 D in the left eye. While some fluctuation in postepikeratoplasty keratometry has been reported for the first several postoperative weeks, the long-term keratometry determinations are reported to be stable after two to four postoperative months. IS Our patient's keratometry measurements have remained stable at six months and at one and two years postoperatively. In a study of epikeratoplasty for aphakia in adults, J CATARACT
95% of the patients had improved postoperative uncorrected visual acuity and 45% of the patients demonstrated uncorrected visual acuity better than 20/100.1 9 Further improvements in visual acuity were predicted with longer follow-ups. Ninetyseven percent of the patients between 18 and 70 years of age with more than three months postsuture removal follow-up had achieved visual acuity within one Snellen line or better of their best corrected preoperative vision. It is, therefore, reasonable to expect postoperative visual acuity to equal or very nearly equal preoperative visual acuity. This was the case in our patient. If a patient is required to wear postoperative glasses, they should be less cosmetically objectionable than the preoperative high plus power lenses. An additional factor in planning refractive surgery for children relates to the natural history of hypermetropia in childhood. Raab 4 reported that the course of hypermetropia present in children with accommodative esotropia is comparable to that found in children without strabismus. Hypermetropia increases up to 7 years of age and decreases thereafter. Repka et al. 20 have reported a small increase in hyperopia prior to age 7 (+ 0.09 D per year) with a minimal decrease in hyperopia after age 7 ( - 0.12 D per year) in accommodative esotropes treated with glasses. Our highly hypermetropic patient, at 111/2 years of age with full physical maturation, would be expected to have essentially stabilized her refractive error without a further significant reduction in power. Further refractive changes, if any, would be expected to be myopic in nature and minimal in magnitude. If visually significant, these could certainly be treated with myopic glasses which would be less objectionable than the previously required high plus power lenses. We would expect our patient's postepikeratoplasty refraction to remain stable and her uncorrected visual acuity to remain excellent. With the stable optical correction of her high hypermetropia achieved with epikeratoplasty, our patient's angle of distance deviation was reduced to orthophoria as predicted by her response to correction with her high plus power glasses preoperatively. Correction of high hypermetropia with contact lenses or epikeratoplasty has a theoretical advantage over spectacle correction in patients with high ACIA ratio accommodative esotropia. Because optical correction is achieved at the corneal plane rather than at a vertex distance of 10 mm to 15 mm, the accommodation requirements for near vision are less than with single vision glasses. 21 In our patient, the accommodation required for vision at a distance of 113 meter may be calculated to be 3.61 D while wearing her + 7.00 D glasses, vertex distance
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13 mm, versus 3.00 D with correction achieved by a + 8.00 D contact lens or epikeratophakia graft. The practical advantage of this was demonstrated in our patient. With the use of echothiophate iodide during the early postoperative period only, she was able to reduce her near deviation to a small monofixational esophoria without further pharmacologic or optical correction.
CONCLUSION This paper reports the use of bilateral phakic hypermetropic epikeratoplasty as an alternative option for the optical correction of high hypermetropia in patients with accommodative esotropia who are poor candidates for continued glasses or contact lens wear. These patients must also be unable to have the power of their high hypermetropic glasses reduced without developing esotropia. They must have a stable sensory status and angle of strabismus, be past the age of amblyopia development, and be beyond the age of a natural decrease of their hypermetropic refractive errors. REFERENCES 1. Donders FC. On the Anomalies of Accommodation and Refraction of the Eye with a Preliminary Essay on Physiological Dioptrics, trans WD Moore. London, The New Syndenham Society, 1864 2. Parks MM. Abnormal accommodative convergence in squint. Arch Ophthalmol 1958; 59:364-380 3. von Noorden GK. Burian-von Noorden's Binocular Vision and Ocular Motility; Theory and Management of Strabismus, 3rd ed. St Louis, CV Mosby, 1985; 280-281 4. Raab EL. Hypermetropia in accommodative esodeviation. J Ped Ophthalmol Strab 1984; 21:194-197 5. Javal E. Manuel Theorique et Pratique du Strabisme. Paris, G Masson, 1896 6. Parks MM, Wheeler MB. Concomitant esodeviations. In: Duane TD, ed, Clinical Ophthalmology. Philadelphia, Harper & Rowe, 1986; 1-14
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7. Albert DG, Hiles DA. Surgical treatment of accommodative esotropia with an abnormal distance/near relationship. South Med J 1967; 60:856-858 8. Dyer JA. Nonsurgical treatment of esotropia. In: Symposium on Strabismus; Transactions of the New Orleans Academy of Ophthalmology. St Louis, CV Mosby, 1971; 154-159 9. Helveston EM. Accommodative esotropia. In: Pediatric Ophthalmology and Strabismus; Transactions of the New Orleans Academy of Ophthalmology. New York, Raven Press, 1989; 111-118 10. Kaufman HE, Werblin TP. Epikeratophakia for the treatment of keratoconus. Am J Ophthalmol 1982; 93:342-347 11. McDonald MB, Klyce SD, Suarez H, et al: Epikeratophakia for myopia correction. Ophthalmology 1985; 92:14171422 12. Kaufman HE. The correction of aphakia. Am J Ophthalmol 1980; 89:1-10 13. Morgan KS, McDonald MB, Hiles DA, et al. The nationwide study of epikeratophakia for aphakia in children. Am J Ophthalmol 1987; 103:366-374 14. Morgan KS, McDonald MB, Hiles DA, et al. The nationwide study of epikeratophakia for aphakia in older children. Ophthalmology 1988; 95:526-532 15. McDonald MB, Kaufman HE, Aquavella JV, et al. The nationwide study of epikeratophakia for myopia. Am J Ophthalmol 1987; 103:375-383 16. Hiles DA. Epikeratophakia - an alternative to glasses, contact lenses and intraocular lens for optical correction of aphakia in children. Trans Pa Acad Ophthalmol Otolaryngol 1986; 38:279-285 17. Morgan KS, Stephenson GS, McDonald MB, Kaufman HE. Epikeratophakia in children. Ophthalmology 1984; 91: 780-784 18. Arffa RC, Marvelli TL, Morgan KS. Long-term follow-up of refractive and keratometric results of pediatric epikeratophakia. Arch Ophthalmol 1986; 104:668-670 19. McDonald MB, Kaufman HE, Aquavella JV, et al. The nationwide study of epikeratophakia for aphakia in adults. Am J Ophthalmol 1987; 103:358-365 20. Repka MX, Wellish K, Wisnicki HJ, Guyton DL. Changes in the refractive error of 94 spectacle-treated patients with acquired accommodative esotropia. Binoc Vision 1989; 4:15-21 21. Rubin ML. Optics for Clinicians, 2nd ed. Gainesville, Triad, 1974; 357-359
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B TR T Optical correction of hi h h permetropia "ith la e the primary treatment fOl' accommodati e e otropia. These gla eat· often poor! accepted b adole cent and oun adult for the are co meticall und sirable hea and e otropia occur \ ith their remo al. We report an 11 1/2- eat'-old ph 'icall matUl'e female" ith high h permetropia and accommodati e e otmpia corrected to orthophoria \ ith la e who \ a unabl to be \ eaned from hel' gla ' e '. h became intolerant to gla e \ ear refu ed contact I n e and \ a treated ucce full \ ith bilateral phakic h permetropic epikeratopla ty. Two ear po tepikeratopla ty her i ual acuity i 20/40 and 20/20 uncorrected and the i ion in the ambl opic right e e ha I' mained at it · ma 'imum preoperati e Ie el. he i orthophoric at di tance and ha. a 2 pri m diopter monoR ational e ophoria at near without la e. Epikeratopla ty i an option in the treatment of accommodati e e .otropia for patient ,ho are pa t the ambl opia forming a e ha e a table an Ie of h'abi mu and \! ho r quire their full h permetropic optical correction to maintain orthophoria.
Ke
Words: He 'ommodativ "otropia m tropia I' rraeti v surg ry
Accommodative esotropia is commonly divided into two subdivisions based upon the accommodative convergence to accommodation ratio (AC/A). Dondersl described normal AC/A ratio accommodative esotropia as occurring in patients who must accommodate to clear blurred retinal images produced by high hypermetropic refractive errors. This accommodation leads to excessive convergence, which eventually exceeds the patient's fusional divergence amplitudes and esotropia results. If the esotropia measures the same at both distance and at near, the patient is described as having a normal AC/A ratio accommodative esotropia. High AC/A
pik ratopJ a t ' h~ pe r,
ratio accommodative esotropia is described by Parks 2 as being due to an abnormal synkinetic near response. Accommodation on near targets elicits an abnormally high accommodative convergence response resulting in an esotropia which is greater at near than at distance. Accommodative esotropia usually arises between two and three years of age although it may also occur during infancy or adulthood. 3 Amblyopia is frequent and patients often have a family history of an esodeviation. Children with normal AC/A ratio accommodative esotropia typically have high hypermetropic refractive errors that range from + 3.00 to
From the Department of Ophthalmology, University of Pittsburgh School of Medicine, Children's Hospital and Eye and Ear Hospital of Pittsburgh, Pennsylvania. Supported in part by grants from the Fight for Sight Childrens Eye Clinic of Childrens Hospital, Pittsburgh, Pennsylvania, and by Fight for Sight, Inc., New York, New 'fork. Reprint requests to David A. Hiles, M. Do, Eye and Ear Hospital, 230 wthrop Street, Pittsburgh, Pennsylvania 1.5213.
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+ 10.00 diopters (D) with an average of + 4.75 D. Patients with high ACIA ratio accommodative esotropia have refractive errors averaging + 2.25 D but may be myopic or more highly hypermetropic than this average value. 2 The treatment of normal ACIA ratio accommodative esotropia is based upon eliminating accommodation induced by high hypermetropic refractive errors, thus decreasing accommodative convergence. Therapeutic modalities consist of plus power glasses, contact lenses, or miotics. The standard initial treatment of a child with normal ACIA ratio accommodative esotropia and high hypermetropia consists of prescribing glasses for the full hypermetropic refractive error as determined under complete cycloplegia. Miotics facilitate myoneural junction transmission at the ciliary muscle, thereby reducing the central accommodative effort required by the patient which, in turn, reduces the associated accommodative convergence. Many patients have a decrease in their hypermetropia with growth as they approach seven years of age or more. 4 Some patients with accommodative esotropia will develop sufficient fusional divergence amplitudes to allow for the gradual reduction and eventual elimination of their glasses while maintaining orthophoria or a well-controlled esophoria during accommodation. Other patients maintain orthophoria only while wearing their full high hypermetropic glasses and have not developed sufficient fusional divergence amplitudes to control their esotropia when the power of their glasses is decreased. These older patients have a cosmetically undesirable esotropia without glasses and must remain in their high plus lenses, which are cosmetically poorly accepted by them. Contact lenses are another alternative for the optical correction of high hypermetropia, but not all patients are candidates for continued contact lens wear. In addition, the esodeviation still recurs when the contact lenses are removed. We present a patient who refused optical correction of her accommodative esotropia with glasses and contact lenses and was offered bilateral phakic hypermetropic epikeratoplasty as an alternative method for the treatment of accommodative esotropia with high hypermetropia. CASE REPORT ].S., a white female initially seen in September 1980 at 4112 years of age was orthophoric at distance, but had 40 prism D of right esotropia at near. Her visual acuity was central, steady but not maintained in the right eye, and central, steady and maintained in the left eye. The cycloplegic SE refraction was + 7.75 D in the right eye and + 5.75 + 1.00 X 40 in 362
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the left eye. Optical correction of her full hypermetropic refractive error with glasses resulted in orthophoria at distance and near. She was treated with glasses for the next six years and achieved 20/30 visual acuity in each eye. She developed an esodeviation without glasses of 45 prism D at both distance and near but she remained orthophoric with glasses. Attempts at decreasing the strength of her hypermetropic glasses at 7 years of age resulted in esotropia. In September 1986, at 10 112 years of age, her best corrected visual acuity was 20/40 in the right eye and 20/20 in the left eye. With her full cycloplegic correction in place she maintained orthophoria at distance, but had developed an esotropia of 12 prism D at near. She was treated with a + 1.25 D executive bifocal which resulted in orthophoria at near. In November 1987, at IPh years of age, the patient's parents related persistent complaints by the patient regarding the unsightly nature of her high hypermetropic glasses. Her esodeviation without correction was 40 prism D at distance and 65 prism D at near (Figures 1 and 2). Her glasses at that time measured + 7.00 D in the right eye and + 6.00 D in the left eye combined with a + 1.25 D executive bifocal. Through the upper segments, she had a monofixational esophoria of 4 prism D at distance and 12 prism D of esotropia at near (Figure 3). Through the bifocal, she had 4 prism D of right monofixational esophoria at near (Figure 4). Her best corrected visual acuity was 20/40 in the right eye and 20/20 in the left eye. The cycloplegic refractive error had increased to + 8.50 + 0.50 X 135 in the right eye and + 7.25 D in the left eye. The option of contact lenses was explored with a trial lens fit, but the patient was intolerant of this option. The risks and potential benefits of bilateral phakic hypermetropic epikeratoplasty were discussed with the patient and her parents, and informed consent was obtained. Epikeratophakia graft procedures were performed separately on each eye four days apart in December 1987. Surgery was performed on the left eye after an uncomplicated early postoperative course was observed in the right eye. The power of the epigrafts (Allergan Medical Optics KeratoLens@)) was + 8.00 D in the right eye and + 7.00 D in the left eye. The patient's postoperative course was without complication. At eight weeks postepikeratoplasty her uncorrected visual acuity was 20170 in the right eye and 20/30 in the left eye. She had a right esotropia of 6 prism D at distance and 18 prism D at near without correction. The cycloplegic refraction was -1.25 + 2.75 X 120 in the right eye and + 1.50 + 1.00 X 170 in the left eye. She was treated with echothiophate iodide 0.125% once daily in both eyes
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Fig. 1.
(Hiles) Preoperative uncorrected 40 prism D esotropia with gaze directed at a distance target.
Fig. 2.
(Hiles) Preoperative uncorrected 65 prism D esotropia with fixation directed at a near target.
for two months in an attempt to increase fusional amplitudes at near. At six months postepikeratoplasty, she was free of complaints and denied any symptoms of glare or asthenopia. The echothiophate iodide had been discontinued at the fourth postoperative month. Both the patient and her parent's denied any occurrence of esotropia during the preceding two months and both were extremely pleased with the surgery. The patient's parents reported a greatly enhanced level of self-esteem in their daughter. Her uncorrected visual acuity was 20/60 in the right eye and 20/20 in the left eye and she read Jaeger 1 plus at near without correction. She was orthophoric at distance and at near without correction. The epikeratoplasty
grafts were clear. At one year postepikeratoplasty she remained free of complaints. Her uncorrected visual acuity was 20/60 in the right eye, improving with correction ( - 2.00 + 2.00 x 25) to 20/40. This acuity was her preoperative level of best corrected visual acuity secondary to amblyopia. Her acuity in the left eye was 20/20, improving with correction ( + 0.75 + 0.25 x 40) to 20/15. She remained orthophoric at distance and demonstrated a right monoRxational esophoria of 2 prism D at near without correction. The patient required no glasses (Figures 5 and 6). At two years postepikeratoplasty her examination was essentially unchanged with uncorrected visual acuity of 20/40- in the right eye and 20/15- in the left
Fig. 3.
Fig. 4.
(Hiles) Accommodative esotropic patient with 4 prism D of right monofixational esophoria at distance with high hypermetropic glasses in place.
J CATARACT REFRACT
(Hiles) Same patient with 4 prism D of rightmonofixational esophoria at near through a + 1.25 bifocal addition.
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Fig. 5.
(Hiles) The patient is orthophoric at distance without correction two years following bilateral epikeratoplasty.
eye. She remained orthophoric at distance with 2 prism D of monofixational esophoria at near. The epikeratoplasty grafts remain clear. Preoperative keratometry measured 43.87/43.87 in both eyes. At six months, the postoperative keratometry had increased to 52.50/52.50 and 49.75/50.00 X 95 in the right and left eye, respectively. At the first postoperative year the keratometry was 51.75/52.r-) X 175 in the right eye and 49.50/50.25 X 100 in the left eye and at two years the keratometry was 51.50/52.75 X 175 and 49.62149.87 X 100 in the right and left eye, respectively.
DISCUSSION Optical correction of high hypermetropia with glasses remains the standard treatment for normal AC/A ratio accommodative esotropia. The presence of high hypermetropia in these patients unfortunately makes their thick, high plus power lenses cosmetically undesirable by giving the patient the appearance of magnified blurred eyes to observers. Heavy glass lenses are uncomfortable and plastic lenses are frequently scratched. Both are poorly accepted by adolescents and young adults. In addition, the cosmetic blemish of esotropia is always present when the glasses are removed. Contact lenses are an alternative to glasses, but lens intolerance, high cost, and high loss rates in the adolescent population are complications well appreciated by both the ophthalmologist and the patient's parents. The use of miotics for strabismus dates back to Java1. 5 These drugs are useful as diagnostic aids in younger patients, as a substitute for glasses in uncooperative children, and for temporary use dur364
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Fig. 6.
(Hiles) Patient in Figure 5 without correction with a right monofixational esophoria of 2 prism D with fixation on a near target.
ing activities in which cosmetically straight eyes are desired and glasses are not appropriate, such as sports. 3 ,6 Miotics are not a substitute for the optical correction of high hypermetropia in the long-term management of normal AC/A ratio accommodative esotropia because visual acuity is not adequately corrected. The patient continues to accommodate to achieve an enhanced level of vision and excessive accommodative convergence and esotropia result. Strabismus surgery has been suggested in certain instances for accommodative esotropia. Albert and Hiles 7 suggested bimedial rectus muscle recessions for older children to reduce high AC/A ratios to normal in an effort to eliminate bifocal wear. DyerS recommended surgery for teenagers who must remove their glasses during activities in which glasses are not appropriate. Helveston9 reluctantly approaches older normal AC/A ratio accommodative esotropes with bimedial rectus muscle recessions in an effort to eliminate their need for glasses. Surgery, however, is not generally advocated by most surgeons. High hypermetropia still remains, andwhen the patient accommodates postoperative esotropia often results. Additionally, as patients lose the ability to accommodate with increasing age, glasses are again worn for clear vision. All the authors express concern about the eventual onset of postoperative exotropia. However, if a nonrefractive component of the esodeviation coexists, strabismus surgery for that component is recommended ..3 ,6 Epikeratoplasty is a form of onlay corneal refractive surgery in which a donor corneal lenticule is sutured onto the host cornea to alter the anterior corneal surface and its refractive power. Epikeratoplasty has been used in adults for treatment of keratoconus,lO myopia, 11 and aphakia 12; in pediatric
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patients for correction of the high hypermetropia of aphakia l3 ,14 and for myopia. 15 This paper reports the first use of bilateral phakic hypermetropic epikeratoplasty for the optical management of high hypermetropia in a patient with accommodative esotropia. The salient features of epikeratoplasty are its extraocular nature and its reversibility should complications occur. The potential complications associated with pediatric epikeratoplasty include failure of the graft to epithelialize, graft infection, and graft opacification.l 3,14 In the Allergan Medical Optics nationwide study of epikeratophakia for aphakia in children, the overall success rate of epikeratoplasty as measured by graft clarity was 89%, which improved to 95% with the addition of regrafted patients .13 In a similar nationwide study of older children receiving epikeratoplasty between the ages of 8 and 18, the initial grafting success rate was 100%.1 4 One of us (D.A.H.) has substantiated this high success rate in a separate study.16 Objections to the use of epikeratoplasty in the treatment of infantile cataracts include a delay in postoperative graft clearing, the variable refractive status during the first several postoperative months, and the relationship of these factors to the development of amblyopia. 16 These same objections apply to young patients with accommodative esotropia in the amblyopia forming age group. Their sensory status is not stable and they may develop amblyopia or a nonaccommodative component to their esodeviation. We stress that the patients selected for this procedure must have stable refractions, be beyond the age of amblyopia development, and have an ocular alignment that remains stable with their high hypermetropic optical correction in place. Concern about the predictability of the refractive changes in epikeratoplasty for myopia has been expressed. 15 In the Allergan Medical Optics nationwide studies of pediatric aphakic epikeratoplasty, 73% of the patients had postoperative refractions within ± 3.00 D of emmetropia. 13,14 In an additional study of epikeratophakia in children, Morgan et al. 17 reported a postoperative average refractive error of plano ± 5.20 D. All patients in· these studies achieved an increase in their corneal refractive powers. Our patient had an increase of8.25 D in the right eye and 6.00 D in the left eye. While some fluctuation in postepikeratoplasty keratometry has been reported for the first several postoperative weeks, the long-term keratometry determinations are reported to be stable after two to four postoperative months. IS Our patient's keratometry measurements have remained stable at six months and at one and two years postoperatively. In a study of epikeratoplasty for aphakia in adults, J CATARACT
95% of the patients had improved postoperative uncorrected visual acuity and 45% of the patients demonstrated uncorrected visual acuity better than 20/100.1 9 Further improvements in visual acuity were predicted with longer follow-ups. Ninetyseven percent of the patients between 18 and 70 years of age with more than three months postsuture removal follow-up had achieved visual acuity within one Snellen line or better of their best corrected preoperative vision. It is, therefore, reasonable to expect postoperative visual acuity to equal or very nearly equal preoperative visual acuity. This was the case in our patient. If a patient is required to wear postoperative glasses, they should be less cosmetically objectionable than the preoperative high plus power lenses. An additional factor in planning refractive surgery for children relates to the natural history of hypermetropia in childhood. Raab 4 reported that the course of hypermetropia present in children with accommodative esotropia is comparable to that found in children without strabismus. Hypermetropia increases up to 7 years of age and decreases thereafter. Repka et al. 20 have reported a small increase in hyperopia prior to age 7 (+ 0.09 D per year) with a minimal decrease in hyperopia after age 7 ( - 0.12 D per year) in accommodative esotropes treated with glasses. Our highly hypermetropic patient, at 111/2 years of age with full physical maturation, would be expected to have essentially stabilized her refractive error without a further significant reduction in power. Further refractive changes, if any, would be expected to be myopic in nature and minimal in magnitude. If visually significant, these could certainly be treated with myopic glasses which would be less objectionable than the previously required high plus power lenses. We would expect our patient's postepikeratoplasty refraction to remain stable and her uncorrected visual acuity to remain excellent. With the stable optical correction of her high hypermetropia achieved with epikeratoplasty, our patient's angle of distance deviation was reduced to orthophoria as predicted by her response to correction with her high plus power glasses preoperatively. Correction of high hypermetropia with contact lenses or epikeratoplasty has a theoretical advantage over spectacle correction in patients with high ACIA ratio accommodative esotropia. Because optical correction is achieved at the corneal plane rather than at a vertex distance of 10 mm to 15 mm, the accommodation requirements for near vision are less than with single vision glasses. 21 In our patient, the accommodation required for vision at a distance of 113 meter may be calculated to be 3.61 D while wearing her + 7.00 D glasses, vertex distance
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13 mm, versus 3.00 D with correction achieved by a + 8.00 D contact lens or epikeratophakia graft. The practical advantage of this was demonstrated in our patient. With the use of echothiophate iodide during the early postoperative period only, she was able to reduce her near deviation to a small monofixational esophoria without further pharmacologic or optical correction.
CONCLUSION This paper reports the use of bilateral phakic hypermetropic epikeratoplasty as an alternative option for the optical correction of high hypermetropia in patients with accommodative esotropia who are poor candidates for continued glasses or contact lens wear. These patients must also be unable to have the power of their high hypermetropic glasses reduced without developing esotropia. They must have a stable sensory status and angle of strabismus, be past the age of amblyopia development, and be beyond the age of a natural decrease of their hypermetropic refractive errors. REFERENCES 1. Donders FC. On the Anomalies of Accommodation and Refraction of the Eye with a Preliminary Essay on Physiological Dioptrics, trans WD Moore. London, The New Syndenham Society, 1864 2. Parks MM. Abnormal accommodative convergence in squint. Arch Ophthalmol 1958; 59:364-380 3. von Noorden GK. Burian-von Noorden's Binocular Vision and Ocular Motility; Theory and Management of Strabismus, 3rd ed. St Louis, CV Mosby, 1985; 280-281 4. Raab EL. Hypermetropia in accommodative esodeviation. J Ped Ophthalmol Strab 1984; 21:194-197 5. Javal E. Manuel Theorique et Pratique du Strabisme. Paris, G Masson, 1896 6. Parks MM, Wheeler MB. Concomitant esodeviations. In: Duane TD, ed, Clinical Ophthalmology. Philadelphia, Harper & Rowe, 1986; 1-14
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7. Albert DG, Hiles DA. Surgical treatment of accommodative esotropia with an abnormal distance/near relationship. South Med J 1967; 60:856-858 8. Dyer JA. Nonsurgical treatment of esotropia. In: Symposium on Strabismus; Transactions of the New Orleans Academy of Ophthalmology. St Louis, CV Mosby, 1971; 154-159 9. Helveston EM. Accommodative esotropia. In: Pediatric Ophthalmology and Strabismus; Transactions of the New Orleans Academy of Ophthalmology. New York, Raven Press, 1989; 111-118 10. Kaufman HE, Werblin TP. Epikeratophakia for the treatment of keratoconus. Am J Ophthalmol 1982; 93:342-347 11. McDonald MB, Klyce SD, Suarez H, et al: Epikeratophakia for myopia correction. Ophthalmology 1985; 92:14171422 12. Kaufman HE. The correction of aphakia. Am J Ophthalmol 1980; 89:1-10 13. Morgan KS, McDonald MB, Hiles DA, et al. The nationwide study of epikeratophakia for aphakia in children. Am J Ophthalmol 1987; 103:366-374 14. Morgan KS, McDonald MB, Hiles DA, et al. The nationwide study of epikeratophakia for aphakia in older children. Ophthalmology 1988; 95:526-532 15. McDonald MB, Kaufman HE, Aquavella JV, et al. The nationwide study of epikeratophakia for myopia. Am J Ophthalmol 1987; 103:375-383 16. Hiles DA. Epikeratophakia - an alternative to glasses, contact lenses and intraocular lens for optical correction of aphakia in children. Trans Pa Acad Ophthalmol Otolaryngol 1986; 38:279-285 17. Morgan KS, Stephenson GS, McDonald MB, Kaufman HE. Epikeratophakia in children. Ophthalmology 1984; 91: 780-784 18. Arffa RC, Marvelli TL, Morgan KS. Long-term follow-up of refractive and keratometric results of pediatric epikeratophakia. Arch Ophthalmol 1986; 104:668-670 19. McDonald MB, Kaufman HE, Aquavella JV, et al. The nationwide study of epikeratophakia for aphakia in adults. Am J Ophthalmol 1987; 103:358-365 20. Repka MX, Wellish K, Wisnicki HJ, Guyton DL. Changes in the refractive error of 94 spectacle-treated patients with acquired accommodative esotropia. Binoc Vision 1989; 4:15-21 21. Rubin ML. Optics for Clinicians, 2nd ed. Gainesville, Triad, 1974; 357-359
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