Ophthalmic Case Study 3: Infantile esotropia and amblyopia

  Patient History

HPI: A 6-month-old child presents with occasional cross-eyes. The parents believe that the left eye deviates more nasally than the right. The baby responds to light, tracks faces, and plays with toys without any issues.

Past Ocular History: None

Ocular Medications: None

Past Medical History: Term birth without complications.

Past Surgical History: None

Past Ocular Family History: Mother with refractive error and maternal uncle with "lazy eye." Paternal history not noteworthy.

Social History: Lives in a smoke-free home with mother and father.

Medications: None

Allergies: None

ROS: Otherwise negative eye examination

Visual Acuity (cc): OD: Fixates and follows OS: Fixates and follows

Intraocular Pressure (tonometry): OD: Soft on palpation OS: Soft on palpation

Pupils: Equal, round, and reactive to light, no APD. No leukocoria.

Extraocular Movements: Full. No nystagmus.

Confrontation Visual Fields: Responds to directed light in all four quadrants with each eye.

External: Left eye is inwardly crossed (esotropic). Face is symmetrical.

Slit Lamp:

Eyelids and Lashes: Normal OU

Conjunctiva/Sclera: Normal OU

Cornea: Clear OU

Anterior Chamber: Grossly normal

Iris: Normal OU

Lens: Clear OU

Anterior Vitreous: Clear OU

Dilated Fundus Exam: OD: Clear vision, CDR 0.2 with sharp margins of the optic disc, no optic nerve hypoplasia, flat macula with normal foveal light reflex, normal vessels. OS: Clear vision, CDR 0.2 with sharp margins of the optic disc, no optic nerve hypoplasia, flat macula with normal foveal light reflex, normal vessels. Other: Corneal reflex test (Hirschberg test): The reflection of a flashlight directed at the infant is located at the center of the right pupil and temporally to the center of the left pupil.

Cover-Uncover Test: When the right eye is covered, the left eye deviates outward and intermittently fixates on a toy in front. When the right eye is uncovered, the left eye returns inward. When the left eye is covered, the right eye remains straight and looks at the target.

Alternate Cover Test: When alternating covering from one eye to the other, there is an outward shift of the opposite eye upon uncovering. Deviation measured at approximately 25 prism diopters.

Stereopsis: Unable to determine in the patient's age.

Retinoscopy: Mild hyperopia OD (+1.00) without astigmatism.

Diagnosis and Discussion Diagnosis: Infantile esotropia and amblyopia of the left eye

Discussion: Differential Diagnosis: This patient presents with infantile esotropia. Other diagnoses to consider are pseudostrabismus (where prominent epicanthal folds give the appearance of cross-eyes) and accommodative esotropia (convergence movement of the eyes is stronger than necessary for accommodation—this results in esotropia with near focus). Paralyses of the nerves that innervate the extraocular muscles (e.g., cranial nerve 6) can result in esotropia. In adults, entrapment of the extraocular muscles due to trauma or enlargement of the extraocular muscles due to severe orbitopathy can lead to strabismus. Systemic conditions such as brain tumor or meningitis can cause sudden eye deviations.