Accuracy of Optical Coherence Tomography Measurements of Rectus Muscle Insertions in Adult Patients Undergoing Strabismus Surgery.
OBJECTIVE
To assess the accuracy of anterior segment optical coherence tomography (AS-OCT) in measuring the distance of extraocular muscle (EOM) insertion to the limbus to improve preoperative assessment of adult patients undergoing strabismus surgery.


METHODS
Reliability analysis.


METHODS
setting: An institutional practice.


METHODS
Seventy-four adult patients scheduled for strabismus surgery on rectus muscles.


METHODS
The distance between the EOM insertion and the limbus was measured preoperatively with AS-OCT. The value was compared with the intraoperative measurement obtained with calipers. Additional measurements included the limbus-anterior chamber angle distance with AS-OCT and the axial length with IOLMaster.


METHODS
Agreement between preoperative AS-OCT and intraoperative measurements. A difference of ≤1 mm was "clinically acceptable."


RESULTS
A total of 144 muscles were analyzed. Thirty-one of 33 reoperated muscles were successfully imaged. AS-OCT measurements were within 1 mm of intraoperative measurements in 77% of all muscles. The accuracy was higher for muscles with no prior surgery (83%), as compared with reoperated muscles (58%). Although the accuracy decreased when comparing reoperations to primary surgeries for the medial (79% to 63%; P = .09; 95% confidence interval [CI], -1.38 to 0.11) and the lateral rectus (81% to 49%; P = .11; 95% CI, -2.06 to 0.22), the difference was not significant. No correlation between limbus-anterior chamber angle distance and axial length was established.


CONCLUSIONS
AS-OCT is valuable in identifying EOM insertions in primary strabismus surgeries, but the accuracy decreases in reoperations.
Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida; Department of Ophthalmology and Visual Sciences, Federal University of São Paulo, São Paulo, Brazil.
Julia D
JD
Rossetto
Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida.
Kara M
KM
Cavuoto
Department of Ophthalmology and Visual Sciences, Federal University of São Paulo, São Paulo, Brazil.
Norma
N
Allemann
Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida.
Craig A
CA
McKeown
Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida. Electronic address: hcapo@med.miami.edu.
Hilda
H
Capó
D000293:Adolescent; D000328:Adult; D000368:Aged; D000869:Anterior Eye Segment / Q000000981:diagnostic imaging*; D005133:Eye Movements / Q000502:physiology*; D006801:Humans; D008875:Middle Aged; D009801:Oculomotor Muscles / Q000601:surgery*; D013508:Ophthalmologic Surgical Procedures / Q000379:methods*; D057234:Preoperative Period; D012086:Reoperation; D015203:Reproducibility of Results; D013285:Strabismus / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D011795:Surveys and Questionnaires; D041623:Tomography, Optical Coherence / Q000379:methods*; D016896:Treatment Outcome; D055815:Young Adult