case_images: PMC11227665_01
case_images: Preoperative ocular alignment photographs revealing left eye esotropia in primary position measuring 90-100 prism diopters prior to modified Nishida surgery. The images show limited abduction of - 6 in the left eye secondary to long-standing left sixth nerve palsy along with adduction deficit in the right eye in levoversion.
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case_images: F1
case_images: AT 900 , Haag-Streit) revealed normal findings in both eyes. A Hirschberg test showed left eye esotropia measuring 90-100 prism diopters (PD) at distance and near on a modified Krimsky test with abduction limitation of -6 in the left eye and adduction deficit in the right eye in levoversion (Figure 1).
case_images: Axial T1-weighted magnetic resonance imaging (SIGNA MR750w, GE Healthcare, Waukesha, WI, USA) of the brain and orbits without fat-suppressed contrast enhancement. The image shows left eye esotropia with contracted medial rectus muscle and fibrotic and atrophied lateral rectus muscle (yellow arrow).
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case_images: F2
case_images: The modified Nishida procedure (A and B), uses (A) Ethibond 6-0 polyester sutures (Ethicon Inc., Somerville, NJ, USA) to attach the temporal one-thirds of the superior rectus (SR) and inferior rectus (IR) muscles to the superotemporal and inferotemporal sclera, respectively, 12 mm behind the limbus, using a scleral bite (A and B). As an adjunct (A), 3 units of botulinum toxin A (BT-A, Botox ; Allergan, Parsippany, NJ, USA) was injected into the left (previously recessed) medial rectus muscle 8 mm posterior to the insertion while firmly grasping the muscle with conjunctival forceps.
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case_images: F3
case_images: Allergan, Parsippany, NJ, USA) (Figure 3A) was administered into the left (previously recessed) MR muscle 8 mm posterior to the insertion while the muscle was firmly grasped using conjunctival forceps. According to the modified Nishida procedure, superior and inferior cul-de-sac conjunctival incisions were created to expose the rectus muscles. Then, the sutures were attached 12 mm posterior to the superotemporal and inferotemporal quadrants of the limbus using a scleral bite (Figure 3A). Subsequently, the temporal margins of the muscles were sutured to the sclera in the superotemporal and inferotemporal quadrants 12 mm from the limbus, midway between the LR and vertical muscle insertions (Figure 3B).
case_images: Ocular alignment photographs at the 9-month postoperative examination. The patient has orthotropia in the primary position (near and distance) with mild improvement of abduction in levoversion. Despite the transportation process, vertical duction was well preserved. These photographs show the mild improvement of abduction in levoversion but continued limited abduction.
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case_images: F4
case_images: The patient's examination findings remained stable after 9 months' follow-up, indicating success of the surgical intervention in correcting ocular malalignment and troublesome diplopia (Figure 4).