Clinical Characteristics and Surgical Outcomes in Patients With Intermittent Exotropia

Abstract

The clinical characteristics and surgical outcomes in a large sample of patients with intermittent exotropia (IXT) as well as an analysis of risk factors associated with surgical failures are presented in this article. Data from IXT patients who received surgical management at the Eye Hospital, in the Zhongshan Ophthalmic Center, of Sun Yat-Sen University, China from January 2009 to December 2013 were reviewed retrospectively. Included within this analysis were data from pre- and postoperative ocular motility, primary alignment, and binocular vision.A total of 1228 patients with IXT were reviewed. Males (50.4%) and females (49.6%) were nearly equally represented in this sample. Thirty-two patients (2.6%) had a family history of strabismus. The mean age at onset was 6.77 ± 6.43 years (range 7 months –48.5 years), mean duration at presentation was 7.35 ± 6.68 years (range 6 months–47 years), and mean age at surgery was 13.7 ± 8.8 years (range 3–49 years). The mean refractive error was −0.84 ± 2.69 diopter in the right eye and −0.72 ± 2.58 diopter in the left eye. Amblyopia (4.2%), oblique muscle dysfunction (7.0%), and dissociated vertical deviation (4.7%) were also present in these patients. The most common subtype of IXT was the basic type (88.1%). Orthophoria was observed in 80.5% of patients and the ratios of surgical undercorrection and overcorrection were 14.7% and 4.8%, respectively, as determined with a mean follow-up time of 7.8 ± 3.7 months. When combining ocular alignment with binocular vision as the success criteria, the success rate decreased to 35.6%. Multivariate risk factor analysis showed that only the loss of stereoacuity (P = 0.002) was associated with a poor outcome. There were no differences in the long-term results between bilateral lateral rectus recession and unilateral lateral rectus recession with medial rectus resection.Most IXT patients displayed normal vision, with few having positive family histories, amblyopia, oblique muscle dysfunction, and dissociated vertical deviation. The most common subtype of IXT was the basic type. Long-term surgical results were less favorable when sensory status was included in the criteria for success. Patients with stereoacuity loss were at an increased risk for poor outcomes.

Visual outcome and factors influencing surgical outcome of horizontal strabismus surgery in a teaching hospital in Malaysia: a 5-year experience

“…The outcome of strabismus surgery in Asian countries has been reported by researchers in Thailand, Korea, Hong Kong and China [3][4][5][6][7][8]. However, apart from Thailand, we found no other data from South East Asian countries [3].…”

“…Reported success rates of strabismus surgery vary widely, ranging from 35.6 to 80.5% [3][4][5][6][7][8].…”

“…Our outcome criteria were similar to criteria used by Kampanartsanyakorn et al from Thailand [3]. Success rates of strabismus surgery tend to be higher (60 to 80%) when satisfactory alignment is the sole criterion for a successful outcome [3][4][5][6][7][8]. We did not include measurement of sensory outcome during the postoperative period.…”

An Attempt to Explore various factors involved in the Treatment of Strabismus Eye Surgery and pre as well as Post-surgery Optometric Eye Care

“…Therefore, delaying the surgery should not influence the sensory and visual outcomes to a great extent, and many studies have advocated for a delayed approach as it may also allow for more accurate measurements and better results. [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33]: Distance stereopsis is affected earlier in X(T) compared with near stereopsis. Some investigators advocate the use of distance stereoacuity to monitor the progression of distance, indication for surgery and as an outcome measure.…”

Neural plasticity following surgical correction of strabismus in monkeys

“…The most common treatment strategy for strabismus is the surgical manipulation of specific extraocular muscles to re-align the eyes. Although popular and practiced widely, studies have shown that surgical approaches have varying levels of success and permanence, and often the patients tend to regain misalignment leading to multiple surgeries (Pineles et al 2010, Yang et al 2016). Ekdawi and colleagues suggested that the failure rate of surgical correction in children with intermittent exotropia rises to 84% by 15 years (Ekdawi et al 2009).…”