Medical Care
For refractive accommodative esotropia, treatment is determined by cycloplegia. Prescription of the full amount of hyperopic correction provides adequate treatment for refractive (accommodative) esotropia in 75% of cases. [7, 8]
Patients with a high AC/A ratio accommodative esotropia can be given bifocals to reduce the need to accommodate for near fixation. The goal of bifocals is to restore normal fusion and stereopsis at both distance and near fixation.
Anticholinesterase miotic agents may also be used in children who lack cooperation with glasses wear. Echothiopate iodide 0.125% reduces the accommodative effort by acting as a parasympathomimetic on the iris sphincter and ciliary muscle. It can be given for 2 weeks and then slowly tapered to normalize the AC/A ratio . However, anticholinesterase drops or ointments are not as effective as glasses. Side effects of anticholinesterase miotic agents may also include retinal detachment, iris cysts, lens opacities, stinging, burning, and lacrimation.
In cases of concurrent amblyopia, early treatment with penalization therapy, such as with patching or atropine penalization of the normal eye, is the mainstay of treatment. This may be undertaken with the start of glasses or afterwards if amblyopia persists despite glasses wear. The choice and order of this treatment is oftentimes dependent on age and cooperation with acuity testing. If surgical treatment is needed, patients can be trialed with prism adaptation prior to surgery. Prism adaptation uses a base-out prism to manage residual esotropia after hyperopic correction.
Surgical Care
Surgery may be required if the esodeviation progresses to partially accommodative esotropia, with residual misalignment of greater than 8-10 PD despite correction with full cycloplegic refraction. This amount of misalignment prevents binocular development. Surgery often is needed when optical treatment is delayed. [9]
Surgical treatment typically entails recession or weakening of the inward-pulling medial rectus muscle in each eye. In cases involving amblyopia, surgery can be limited to only the amblyopic eye by performing a recession of the medial rectus and a resection or strengthening of the ipsilateral lateral rectus, so as to put all risk of surgery on the ‘weak’ eye. While surgery is performed for the nonaccommodative component only, the operation is not intended to discontinue use of glasses. However, surgery may allow patients to reduce hyperopic correction and discontinue wear of bifocals in the setting of a preoperatively high AC/A ratio.
Complications
The greatest risk of untreated accommodative esotropia is the development of amblyopia and loss of binocular visual development. This risk can be augmented by delay in treatment.
With surgery, there is a risk of overcorrection (< 10%) with development of consecutive exotropia, or undercorrection with persistence of residual esotropia. Additionally, surgical risks include infection, both periocular and endophthalmitis, as well as scleral perforation with associated retinal tear and detachment. More recently, there has been a lower risk of scleral perforation due to surgical technique preference with spatuled needles on the suture to reattach the muscle to the globe.
Long-Term Monitoring
For both refractive accommodative esotropia and high AC/A ratio accommodative esotropia, cycloplegic refraction should be repeated as hyperopia tends to increase until 5-7 years of age before plateauing. Follow up should be done to monitor for amblyopia and visual development.
