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 devia- tion 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 ab- duction, and diplopia following unilateral pterygium ex- Conclusions: Incomitant esotropia is an uncommon but cision surgery. serious complication following pterygium excision sur- gery. 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 connec- tive 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 Drectus 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 pte- rygium 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- (REPRINTED) ARCH OPHTHALMOL / VOL 125, MAR 2007 WWW.ARCHOPHTHALMOL.COM 369 ©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 in- creases the chances of postoperative diplopia.2,9,10 In sub- jects 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 rota- tions. 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.