Partially Accommodative Esotropia Clinical Trial
Official title:
Augmented Medial Rectus Muscle Recession Versus Medial Rectus Recession With Posterior Scleral Fixation in Partially Accommodative Esotropia
Prospective randomized interventional comparative study
A prospective controlled interventional study will be performed on patients with partially
accommodative esotropia. An informed consent for the surgery will be obtained from all
patients. All patients' guardians will receive a thorough explanation of the study design and
aims, and sign a written informed consent.
An estimation of sample size was performed considering a study power of 0.8 with an alpha
error of 0.05 aiming to detect a difference of 5 Δ in the postoperative angle disparity
between the 2 groups, assuming a postoperative standard deviation of 6 Δ 9. Based on this
estimation, a total of 24 eyes were found to be adequate in each group, and considering a 25%
dropout during the follow-up, recruitment of 30 study subjects in each group will be targeted
All patients will receive a full ophthalmological assessment including history taking,
measurement of uncorrected and best-corrected visual acuity, cycloplegic refraction, anterior
segment examination, as well as a dilated fundus examination.
In addition, all patients will have a detailed motor examination during the initial
evaluation and at each follow-up period. The angle of misalignment will be measured by the
prism and alternating cover tests for both distance and near with and without glasses. The
angle of horizontal misalignment will also be measured in side gazes and in straight up and
down gazes. Measurement of the angle of deviation in up and down gazes will be done by
tilting the head, approximately 25 degrees down and up respectively, with the patient fixing
on a distance target. The difference between the angles of horizontal misalignment in up and
down gazes will be used to calculate the amount of pattern strabismus if present.
The ductions and versions in all cardinal directions of gaze will be analyzed before surgery
and thereafter during the postoperative follow up visits. Underaction will be measured on a
4-point scale ranging from -1 to -4. Similarly overaction will be measured on a 4-point scale
ranging from +1 to +4.
In all patients cycloplegic refraction will be performed using cyclopentolate 1% eye drops
instilled 3 times 10 minutes apart with the last time 30 minutes before refraction. Patients
with hypermetropia with a spherical equivalent >= +1.5 D will then prescribed the full
cycloplegic refraction and then re-evaluated with spectacles one month later. Patients who
appear to have a partially accommodative esotropia defined as residual esotropia >8 PD for
distance with spectacles will have repeat refraction using atropine 1% drops 3 times a days
for 3 days before refraction.
After ensuring that full cycloplegic refraction was prescribed, patients will then evaluated
with glasses to identify those with partially accommodative esotropia without convergence
excess. Patients will be included in the study if the residual distance angle with
cycloplegic prescription was > 15PD. Patients with convergence excess esotropia, defined as
the angle of deviation with glasses for near exceeding that for distance by 15 PD or more
will be excluded from the study.
Amblyopia, defined as a difference of 0.3 logMAR in verbal children (3 lines on the standard
logMAR visual acuity chart) or a strong unilateral fixation preference using an accommodative
target in infants and preverbal children will be treated before surgery following the
standard clinical practice using part-time occlusion and in concordance with the PEDIG
guidelines.
The smallest angle of deviation will be defined as the corrected angle for distance. The
largest angle is defined as the angle for near measured without correction. The angle
disparity is defined as the difference between the largest and smallest angles.
Patients were randomly allocated using a random table to one of two groups. In one group
bilateral augmented MR muscle recession will be performed (augmented group). In the other
group bilateral MR muscle recession combined with posterior scleral fixation sutures will be
performed (Faden group).
The surgeries were performed using the same surgical technique. In both groups the medial
rectus muscle will be exposed and hooked through a limbal approach. The muscle will then
secured with 6-0 polyglactin sutures.
In the augmented group, the medial rectus muscles will be recessed using standard tables with
the surgical dose targeting the average of the largest and smallest angles.
In the Faden group, medial rectus muscle recession will be performed as described above with
the surgical dose targeting the smallest pre-operative angle. The muscle will then be fixated
to the sclera using 6/0 polyester sutures placed in a mattress like with the anterior and the
posterior sutures passing through both the edge of muscle and the sclera 12 mm and 14 mm from
the muscle insertion, respectively.
Patients will be followed up at 1 week, 1 month, 3 months and 6 months after surgery. The
distance and near angles of deviation, with and without glasses, and the angle disparity were
measured at each follow up visit and the ductions and versions will be assessed in all
patients.
Patients will be considered to have successful outcome if both the distance and near angles
with spectacles were less than 8 PD esotropia/phoria. Patients who develop any
exophoria/tropia, or in whom hyperopic correction needed to be reduced for treatment of a
consecutive exotropia will be considered to be unsuccessful. In addition, patients will be
further subdivided into 2 groups according to the preoperative angle disparity into those
with angle disparity 20 PD or less and those with angle disparity more than 20 PD. The
success rate in each subgroup was calculated.
For categorical variables (e.g., gender), percent distribution will be used. For continuous
variables (e.g. age, angle of deviation), mean, range and standard deviation will be used.
Comparisons between the two groups were done using t-test for independent samples for
continuous variables and chi square test for categorical variables. Statistical analysis will
be performed with SPSS for Windows (SPSS Inc., Chicago, IL).
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| Status | Clinical Trial | Phase | |
|---|---|---|---|
| Recruiting |
NCT06298929 -
Medial Rectus Fenestration vs Recession for PAET
|
N/A |