The changes and causes of asthenopia after ICL implantation

OBJECTIVE

To detect the presence of asthenopia after implantation of Implantable Collamer Lens (ICL).

METHOD

Design: prospective observational case series. Patients with myopia and/or astigmatism who underwent ICL surgeries and completed 3-month follow-up were enrolled. Asthenopia scores, amplitude of accommodation (AA), positive/negative relative accommodation (PRA/NRA), accommodative facility (AF), the ratio of accommodative convergence and accommodation (AC/A), Schirmer test, noninvasive breakup time (NBUT), and HOA were examined before surgeries and at 1 week, 1 month and 3 months postoperatively then statistically analyzed.

RESULTS

Symptoms of asthenopia were significantly decreased at 1 week after ICL surgeries than those before surgeries, but increased gradually as time went by, eventually recovered at 3 months postoperatively. AA, AF, AC/A decreased 1 week postoperatively, returned to the baseline at 1 month and were improved at 3 months after surgeries. NBUT at 1 week, 1 month and 3 months after surgeries were significantly decreased and was the lowest at 1 week postoperatively. PRA, NRA, Schiermer values and HOA had no significant change. Correlation analysis showed that the lower AF and NBUT after ICL surgeries, the more severe the asthenopia symptoms.

CONCLUSION

The symptoms of asthenopia aggravated transiently after ICL implantation surgeries, but improved gradually with time. AF and NBUT were important factors affecting the changes of asthenopia.

Resection of both medial rectus muscles in organic convergence insufficiency

Six patients with a prolonged history of severe muscular asthenopia caused by persistent convergence insufficiency underwent resection of both medial rectus muscles. A temporary consecutive esotrapia occurred in each instance and was controlled with prisms. Five weeks after surgery the consecutive esotropia had disappeared in all but one patient who still required prismatic correction for distance fixation. All patients experienced relief from their symptoms. Whereas orthoptic training is useful in most cases of convergence insufficiency a resection of both medial rectus muscles should be considered in persistent cases especially with an associated weakness of accommodation.