Incomitant Esotropia Following Pterygium Excision Surgery

CLINICAL SCIENCES Incomitant Esotropia Following Pterygium Excision Surgery

Noa Ela-Dalman, MD; Federico G. Velez, MD; Arthur L. Rosenbaum, MD

Objective: To report the clinical characteristics and treat- subject had conjunctival-perimuscular connective tis- ment of subjects with incomitant esotropia following uni- sue complex surgery alone. Postoperatively, all patients lateral pterygium excision. had orthotropia in the primary position and the deviation in the abducting field was improved to 5.2 PD (range, Methods: A retrospective review of 6 consecutive pa- 0-14 PD). tients who developed incomitant esotropia, limited abduction, and diplopia following unilateral pterygium ex- Conclusions: Incomitant esotropia is an uncommon but cision surgery. serious complication following pterygium excision surgery. Medial rectus muscle recession combined with scar Results: The mean preoperative deviation was 6 prism tissue removal is required to eliminate diplopia in the pri- diopters (PD) (range, 0-25 PD) in the primary position mary position. Conjunctiva-perimuscular scar tissue re- and 13.8 PD (range, 6-25 PD) in the abducting field of moval may suffice to improve diplopia in the abduction the involved eye. Four patients underwent simulta- gaze position. neous surgery on the conjunctiva-perimuscular connective tissue complex and the medial rectus muscle. One Arch Ophthalmol. 2007;125:369-373

IPLOPIA AND STRABISMUS eral millimeters onto the cornea. This may are uncommon compli- result in conjunctival loss, scar tissue for- cations following pte- mation, obliteration of the fornix, and me- rygium excision sur- chanical restriction of extraocular move- gery. Direct trauma to ments. Recurrent pterygium excision has rectusD muscles, scarring of the conjunctiva- a higher chance of resulting in trauma or perimuscular connective tissue complex, fibrosis of the rectus extraocular muscle pterygium recurrence, and symblepha- adjacent to the pterygium and the con- ron formation may result in incomitant nective tissue surrounding the affected rec- strabismus.1-5 Pterygium may be associ- tus muscle.1-4 Surgical treatment is chal- ated with monocular diplopia secondary lenging because it requires a combination to irregular astigmatism and horizontal of surgery on the conjunctival-perimus- flattening of the cornea in attempted con- cular connective tissue complex and the tralateral gaze rotation.6 medial rectus muscle.6-8 Extraocular muscle disinsertion dur- The aim of this study was to report the ing pterygium excision surgery is more clinical characteristics and treatment of likely to occur when removing large, deep, subjects with incomitant esotropia follow- and/or recurrent pterygium. Medial rec- ing unilateral pterygium excision. tus muscle disinsertion following pterygium surgery is characterized by a small METHODS to moderate amount of exodeviation in the primary position, mild to moderate limi- tation of ocular rotations, and positive force This is a retrospective review of 6 consecutive generation test results because the muscle patients who were seen in the strabismus clinic usually reinserts on the sclera, creating a complaining of diplopia following nasal pte- pseudotendon.3-5 rygium excision surgery between 1993 and 2005. Institutional review board approval was Restricted full abduction is usually re- obtained from the institution. lated to scar tissue formation and cicatri- All subjects underwent complete ophthal- Author Affiliations: Jules Stein zation of the operated area, limiting ocu- mological examination, including distance and Eye Institute, University of lar rotation in the contralateral gaze. near visual acuity, cycloplegic refraction ( 1% California, Los Angeles. Recurrent pterygium usually extends sev- cyclopentolate hydrochloride), slitlamp ex-

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©2007 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/27/2021 amination, and dilated fundus examination. Motor alignment eye, and 5 PD (range, 0-25 PD) in the adducting field of was determined by prism cover testing while the subject was gaze of the involved eye. The near angle of deviation fixing at a 20/70 target at 20 ft 30 cm. A prism bar (Astron In- ranged from exophoria of 6 PD to 20 PD of intermittent ternational, Mount Dora, Fla) was held in front of the affected esotropia (mean, 3 PD). eye. An optical occluder was placed to cover the prism over the Five subjects underwent surgery to correct diplopia. nonfixing eye. The patient was asked to fix at the target with the nonaffected eye. The optical occluder was moved away from One subject chose not to have surgery despite 20 PD of the affected eye to cover the nonaffected eye. The angle of de- esotropia in the abducting field of the affected eye viation was determined by the amount of prism required to neu- (Figure 1). In all subjects, the operation involved re- tralize the abducting movement of the nonfixing eye. In 1 sub- lease of restriction by excision of scar tissue between the ject with bilateral nasal pterygium, the prism bar was held in limbus and the plica semilunaris. Three subjects re- front of the eye with more limited abduction. quired ipsilateral medial rectus muscle recession using Surgery was performed using a standard conjunctival lim- adjustable suture. We used 0.3% mitomycin C in 1 sub- bal incision with 2 relaxing radial incisions to gain maximal ject to prevent scar tissue reformation (Figure 2). One exposure. Scar tissue was excised as dissection progressed pos- subject who had extensive scar tissue formation involv- teriorly. The medial rectus muscle was isolated on a muscle hook ing the medial rectus muscle required exploration of the as soon as dissection progressed to a distance of 6 mm poste- rior to the limbus. With tension placed on the muscle hook by medial rectus muscle and scar tissue removal to release the assistant, scar tissue dissection continued as the surface of restriction. the medial rectus muscle was exposed. The first goal of the dis- The mean postoperative follow-up was 5 months section was to expose the medial rectus muscle insertion and (range, 2-6 months). All patients were orthotropic in the the muscle belly to prevent muscle transection. A headlight is primary position and the adducting field of gaze post- useful for better visualization. We used 0.3% mitomycin C to operatively. Esotropia in the abducting field of gaze im- prevent recurring scarring in 1 case with the most severe scar- proved to 5 PD (range, 0-14 PD). At the last postopera- ring from 3 previous pterygium excision operations. Pieces of tive follow-up, all subjects were diplopia-free in the cellulose sponge were soaked in mitomycin C and placed on primary position. Two subjects had residual horizontal the sclera for 2 minutes in the area where scar tissue had been diplopia in lateral extreme gaze, 1 of them had bilateral removed. The sponges were removed and the area was irri- gated with 60 mL3 of balanced saline solution. All surgeries were nasal pterygium and improved from 25 PD to 8 PD of performed by an eye muscle surgeon. In 1 case, a cornea sur- esotropia in the abducting field of gaze, and 1 subject had geon was present at the time of surgery; in all the other cases, 2 PD of exophoria in the adducting field of gaze. a cornea surgeon was available at the time of the surgery for consultation if needed. Subject data were tabulated using Excel (Microsoft Office COMMENT Excel 2003 [11.5612.6360]; Microsoft, Redmond, Wash). A 2-tailed paired t test was used to compare preoperative and post- Strabismus and diplopia are serious complications rarely operative data. reported following pterygium excision surgery. The in- cidence of strabismus and diplopia following pterygium RESULTS excision surgery is unknown. Pterygium recurrence increases the chances of postoperative diplopia.2,9,10 In subjects with postoperative diplopia following pterygium re- Three male and 3 female subjects were included in the currence, the number of previous pterygium excision study (Table). The mean age at the time of initial ex- surgeries has been reported as 1.8 (range, 1-3).9 In our amination was 39 years (range, 26-69 years). All sub- study, all subjects had pterygium recurrence and the mean jects had recurrent pterygium; 5 of 6 subjects had un- number of previous pterygium excision surgeries was 2 dergone more than 1 previous pterygium excision surgery, (range, 1-3). 4 subjects (66%) had 2 previous pterygium operations, Postoperative diplopia in patients undergoing pte- and 1 subject underwent 3 previous pterygium opera- rygium surgery may result from restricted ocular rotations. All pterygium were nasal. Five of 6 subjects had tions, direct trauma to the extraocular muscle, and ir- unilateral pterygium. Previous pterygium surgery con- regular astigmatism.1-6 Conjunctival damage, scar tissue sisted of excision and graft in 4 subjects (66%) and ex- formation, cicatrization of the operated area, conjuncti- cision and radiation therapy in 2 subjects (33%). The in- val loss, and obliteration of the fornix result in re- terval between the pterygium surgery and the onset of stricted contralateral gaze rotation of the eye.1,2,6-9 Re- diplopia was 40 days (range, 4-90 days). current pterygium increases the chances of trauma and All subjects had incomitant esotropia, limited abduc- fibrosis of the rectus extraocular muscle adjacent to the tion, and horizontal binocular diplopia. No patient had pterygium and the connective tissue surrounding the af- vertical or monocular diplopia. All subjects had diplo- fected rectus extraocular muscle. Conjunctival auto- pia in the abducting field of gaze of the affected eye. Two graft transplantation reduces the rate of recurrence after subjects (33%) had diplopia in the primary position, 2 pterygium excision.7,8 However, fibrosis of the graft har- subjects (33%) had diplopia in the adducting field of the vest site may result in significantly restricted ocular mo- affected eye, and 1 subject (16%) complained of diplo- tility. Vrabec et al8 reported 2 subjects who had adduc- pia in the reading position. tion deficiency due to scar formation at the graft harvest The mean angle of deviation was 6 prism diopters (PD) site on the superior lateral conjunctiva. In our study, all (range, 0-25 PD) in the primary position, 13.8 PD (range, subjects had incomitant esotropia larger in the field of 6-25 PD) in the abducting field of gaze of the affected action of the ipsilateral lateral rectus muscle.

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Case

1234 5 6 Age, y 26 37 46 26 32 69 No. of previous 2123 2 2 pterygium surgeries Associated treatment Amniotic Conjunctival graft Radiation Amniotic membrane Conjunctival graft Radiation membrane graft graft Side OS OS OD OD OU OS Onset of diplopia, 4 d Several days Several days Several days 6 wk Several days postoperatively Diplopic field LG PP, LG Reading, RG, RG, LG PP, RG, LG LG DG Alignment PP Flick EP ET 14 PD Orthotropia Orthotropia ET 25 PD Orthotropia RG Orthotropia ET 2 PD ET 6 PD ET 10 PD ET 25 PD Orthotropia LG ET 20 PD ET 20 PD Orthotropia ET 4 PD ET 25 PD ET 8 PD Reading EP 4 PD ET 3 PD XP 6 PD Orthotropia ET 20 PD Orthotropia UG Orthotropia ET 2 PD Orthotropia Orthotropia ET 14 PD Orthotropia DG Orthotropia ET 4 PD XP 8 PD Orthotropia ET 18 PD Orthotropia Version (scale range, Limited LMR 0, LLR −1.0 RMR 0, RLR RMR −0.5, RLR −1.5 LMR 0, LLR −1.5 Limited abduction ϩ4to−4 abduction −1.5 Surgery No Pterygium removal Scar tissue Scar tissue removal Scar tissue removal Excision OS; LMR scar removal OD OD; mitomycin C OS; plicaplasty pterygium OS; removal; LMR application OD; OS; LMR conjunctival recession, 4-mm plicaplasty OD; recession, 5-mm graft OS; scar adj sut conjunctival adj sut; LLR tissue removal recession OD; resection, 4-mm OS; LMR scar RMR recession, adj sut tissue removal 2-mm adj sut Follow-up 6 mo 6 mo 2 mo 6 wk 6 mo Pterygium recurrence No No No No No Alignment PP Orthotropia Flick XP Orthotropia Orthotropia Orthotropia RG Orthotropia ET 4 PD ET 4 PD Orthotropia Orthotropia LG ET 14 PD XP 2 PD Orthotropia ET 8 PD Orthotropia Reading ET 4 PD Flick XP Orthotropia Orthotropia Orthotropia UG Orthotropia Flick XP Orthotropia Orthotropia Orthotropia DG Orthotropia Flick XP Orthotropia Orthotropia Orthotropia Version (scale range, LMR 0, LLR −0.5 RMR −0.5, RMR 0, RLR −0.5 LMR 0, LLR −0.5 RMR 0, RLR −0.5 ϩ4to−4 RLR −0.5 Diplopia Extreme LG No No LG No

Abbreviations: adj sut, adjustable sutures; DG, downgaze; EP, esophoria; ET, esotropia; LG, left gaze; LLR, left lateral rectus; LMR, left medial rectus; OD, right eye; OS, left eye; OU, both eyes; PD, prism diopters; PP, primary position; RG, right gaze; RLR, right lateral rectus; RMR, right medial rectus; UG, upgaze; XP, exophoria.

Surgical treatment to release restriction following pte- reported. In our study, all subjects operated on required rygium excision is challenging because it requires a com- conjunctival surgery and 60% required surgery on the bination of surgery on the conjunctival-perimuscular con- adjacent medial rectus muscle. No patient required cor- nective tissue complex and the medial rectus muscle. neal surgery. Only 1 subject underwent conjunctival au- Kenyon et al2 reported a series of patients with ad- tograft. Two subjects underwent pterygium removal with- vanced and recurrent pterygium who were treated with out conjunctival autograft. Both subjects had simultaneous conjunctival autograft transplantation. Prior to the au- medial rectus muscle recession with adjustable suture. tograft transplantation, about 25% of these patients had Therefore, the conjunctiva was recessed to access the ad- limited abduction. Autograft transplantation and fornix justable suture. None had pterygium recurrence at their reconstruction improved abduction. Walland et al6 re- last follow-up. ported 1 case of recurrent pterygium following simple Previous authors have reported trauma to the medial excision, causing horizontal diplopia in the lateral gaze. rectus muscle during pterygium excision surgery, result- There was extensive medial scarring dragging the car- ing in exotropia. Raab et al3 reported 3 subjects who had uncle and plica semilunaris. Abduction was limited to noncomitant exotropia, marked adduction deficiency, and 20°. Surgery consisted of pterygium removal from the area horizontal diplopia following nasal pterygium excision overlying the medial rectus muscle to the cornea and a surgery. Two of the 3 subjects had recurrent pterygium. conjunctival autograft covering the nasal limbus and the Trauma to the medial rectus muscle resulted in disin- medial rectus muscle. No postoperative abduction was sertion, transection with partial extirpation, or slip-

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©2007 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/27/2021 Figure 1. Diplopia onset 4 days after the second pterygium excision surgery with amniotic membrane graft on the left eye (case 1). Note the limited abduction (−2 [scale range, ϩ4 to −4]) in the left eye (arrow). The patient refused any further surgery.

A B

D C

Figure 2. Diplopia following the third pterygium excision surgery in the right eye (case 4). Note scar tissue formation (A) (arrow) and esotropia with limited abduction in the right gaze (B) (arrow). Diplopia and abduction improved (C) (arrow) after scar tissue removal, mitomycin c application, plicaplasty, conjunctival recession, and right medial rectus recession (D).

page. All medial rectus muscles were reattached near the subjects who had recurrent pterygium surgery. Ugrin and original insertion with or without resection and ipsilat- Molinari4 reported 2 subjects with recurrent pterygium eral lateral rectus muscle recession. Postoperatively, all who had incomitant exotropia, diplopia, and limited ad- subjects had orthotropia in the primary position. More duction. In both cases, the medial rectus muscles were severe trauma to the medial rectus muscle was seen in found inserted on the sclera near the equator of the eye.

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©2007 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/27/2021 Fibrous tissue was observed between the original inser- Correspondence: Arthur L. Rosenbaum, MD, Depart- tion and the new insertion of the muscle. Surgery con- ment of Ophthalmology, Jules Stein Eye Institute, 100 sisted of scar tissue removal and reinsertion of the me- Stein Plaza, UCLA, Los Angeles, CA, 90024 (rosenbaum dial rectus muscle to its original insertion. Alignment and @jsei.ucla.edu). adduction improved. However, no data on the postop- Financial Disclosure: None reported. erative abduction was reported. In our study, all sub- Funding/Support: Dr Rosenbaum is a recipient of a Re- jects had fibrosis and scar tissue formation surrounding search to Prevent Blindness Physician Scientist Merit the medial rectus muscle but no subject was found to have Award. direct trauma to this muscle. Release of scar tissue with Previous Presentation: This study was presented at the or without medial rectus muscle recession was required Annual Meeting of the American Association for Pedi- to improve abduction rotation and ocular alignment. atric Ophthalmology and Strabismus; March 17, 2006; In our study, we found that patients with diplopia in Keystone, Colo. the primary gaze position required medial rectus muscle Acknowledgment: Gary N. Holland, MD, was the cor- recession combined with scar tissue removal to elimi- nea consultant present in 1 case. nate diplopia, whereas for patients with diplopia only in the abduction gaze position, conjunctiva-perimuscular scar tissue removal may suffice to improve diplopia. If there is severe scarring medially, especially after 2 or more REFERENCES previous surgeries, a conjunctival graft from the oppo- site, uninvolved eye may be considered as part of the sur- 1. Jenkins PF, Stavis MI, Jenkins DE III. Esotropia following pterygium surgery. Binocul Vis Strabismus Q. 2002;17:227-228. gical treatment. 2. Kenyon KR, Wagoner MD, Hettinger ME. Conjunctival autograft transplantation This study has the limitations of a retrospective re- for advanced and recurrent pterygium. Ophthalmology. 1985;92:1461-1470. view. It is a small group sample. A longer follow-up is 3. Raab EL, Metz HS, Ellis FD. Medial rectus injury after pterygium excision. Arch required to evaluate possible late recurrence. The surgi- Ophthalmol. 1989;107:1428. 4. Ugrin MC, Molinari A. Disinsertion of the medial rectus following pterygium sur- cal technique was not standardized and varied with the gery: signs and management. Strabismus. 1999;7:147-152. type of scar tissue formation and the deviation. 5. Xia Q, Huang Z, Shen DA, Dai H. Clinical analysis of the diplopia and strabismus In conclusion, combination of conjunctiva- after ophthalmic surgeries. Zhonghua Yan Ke Za Zhi. 2003;39:727-730. perimuscular connective tissue complex and muscle sur- 6. Walland MJ, Stevens JD, Steele AD. The effect of recurrent pterygium on cor- gery is required to improve ocular alignment and motil- neal topography. Cornea. 1994;13:463-464. 7. Miyai T, Hara R, Nejima R, Miyata K, Yonemura T, Amano S. Limbal allograft, ity in subjects with incomitant esotropia following amniotic membrane transplantation, and intraoperative mitomycin C for recur- pterygium excision surgery. Surgery is effective in im- rent pterygium. Ophthalmology. 2005;112:1263-1267. proving the primary position deviation, though some re- 8. Vrabec MP, Weisenthal RW, Elsing SH. Subconjunctival fibrosis after conjunc- stricted abduction may persist. tival autograft. Cornea. 1993;12:181-183. 9. Dake CL, Crone RA, de Keizer RJ. Treatment of (recurrent) pterygium oculi by lamellar keratoplasty. Doc Ophthalmol. 1980;48:223-230. Submitted for Publication: April 16, 2006; final revi- 10. de Keizer RJ. Pterygium excision with or without postoperative irradiation, a double sion received June 21, 2006; accepted July 4, 2006. blind study. Doc Ophthalmol. 1982;52:309-315.

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