Esotropia with hypertropia with severe restriction treated with reverse Yokoyama procedure

1. Takashi Negishi^1,3
2. Nobuo Kyu²
3. Miho Sato¹

¹Hamamatsu University School of Medicine, Hamamatsu, Japan
²Kyu Eye Clinic, Shizuoka Japan
³Juntendo University School of Medicine, Tokyo, Japan

Purpose: Myopic strabismus fixus is known as esotropia and hypotropia with severe restriction. Prolapse of posterior globe between a superior rectus muscle (SR) and a lateral rectus muscle (LR) is recognized to cause this abnormality. Yokoyama advocated uniting both muscles to regain good eye movement. We experienced a case of esotropia and hypertropia with a severe restriction treated with reverse Yokoyama procedure.

Methods: A 77-year-old man was referred to us showing residual esotropia and hypertropia with a severe restriction after multiple strabismus surgeries. He had poor visual acuities and esotropia from childhood. He underwent a right medial rectus muscle (MR) tenotomy and a left LR resection 2 years before the referral, followed by a right SR tenotomy and a right inferior rectus muscle (IR) resection. Upon initial examination, his visual acuities were 0.03 (OD) and no light sense (OS). He had microcorneas and iris colobomas, but lenses and fundi were unable to evaluate. Orbital MRIs disclosed prolapse of the posterior globe between the LR and the IR, staphylomas, and dislocation of the lenses into the vitreous cavities on both eyes. Dislocations of the LRs and the SRs were suspected to cause his strabismus. We united the LR and the IR and repeated the MR tenotomy of the right eye.

Results: His right eye position normalized.

Conclusions: A superior dislocation of a LR and a nasal dislocation of an IR caused esotropia and hypertropia with restriction. The etiology seems to be same as myopic strabismus fixus but on different muscles.