What is characterized by conjugate lateral gaze palsy and horizontal diplopia?

The condition characterized by conjugate lateral gaze palsy and horizontal diplopia is indeed internuclear ophthalmoplegia (INO). This neurological disorder results from a lesion in the medial longitudinal fasciculus (MLF), which is a critical pathway for coordinating eye movements.

In internuclear ophthalmoplegia, when a person attempts to look to the side, the eye on the side to which they are looking moves laterally (abducts), while the contralateral eye does not adduct properly due to the disrupted signals through the MLF. This imbalance leads to the classic presentation of conjugate lateral gaze palsy. Additionally, the misalignment of the eyes during lateral gaze results in horizontal diplopia, as the person perceives two images of one object instead of one.

In contrast, oculomotor nerve palsy typically presents with ptosis, a "down and out" position of the affected eye, and does not primarily involve lateral gaze issues in the same manner as INO does. Trochlear nerve palsy is characterized by vertical diplopia, particularly noticeable when looking down, and affects the superior oblique muscle, which alters the vertical alignment of the eye. Lastly, optic nerve damage primarily affects visual acuity and visual field but