Researchers are now calling for the preoperative evaluation of surgical patients seeking spectacle/contact lens independence to include a complete binocular and accommodation assessment after finding such issues could develop post-op. While they found corneal refractive surgery was not a relevant source of binocular/accommodative problems, most of the issues that arose after refractive and cataract surgery turned out to be preexisting conditions or dysfunctions. Thorough preoperative screening evaluations would help to identify dysfunctional eyes prone to destabilization after surgery that could potentially develop asthenopic symptoms.

The review included 95 works selected from 40 publications. A decrease in fusional vergence amplitude in near vision was the most frequently reported alteration. Other alterations were less common and were transient in most of the cases. The researchers suggested that, for binocular vision complaints, all treatment decisions must be postponed until at least three months after surgery.

The review also highlighted preoperative anisometropia as an important source of postoperative binocular alterations. The researchers suggested carrying out a careful examination before surgery to either correct this refraction difference or to induce it, if opting for monovision. They also called for a careful evaluation of strabismus or large phorias before surgery to prevent postoperative decompression that could lead to diplopia.

The preoperative evaluation that the review calls for should include a complete binocular and accommodation assessment that measures parameters such as the phoric posture, accommodative amplitude and facility, near point of convergence, fusional reserves and accommodative convergence/accommodation coefficient. Researchers also recommend having the patient wear contact lenses during the evaluation—to simulate the surgical outcome—if there were any doubts about the refractive indication.