National Board of Chiropractic Examiners (NBCE) Practice Test

Which condition is most likely if a patient's pupils do NOT constrict with light but react with accommodation?

1. Horner's Syndrome

2. Tabes Dorsalis

3. Glaucoma

4. Diabetic Retinopathy

The correct answer is: Tabes Dorsalis

In the scenario presented, the condition characterized by pupils that do not constrict to light but react to accommodation is indicative of a specific neuro-ophthalmic response. This pattern of pupillary reaction aligns with conditions affecting the afferent pathway, particularly in cases related to lesions in structures involved with the light reflex. The most relevant condition among the choices is Tabes Dorsalis, which is a late manifestation of untreated syphilis. In this condition, there are disruptions to sensory pathways, and patients often experience Argyll Robertson pupils—where the pupils do not constrict in response to light but will constrict with accommodation. The presence of this type of pupillary reaction makes Tabes Dorsalis the most likely diagnosis. Other conditions, while related to eye health or neurological pathways, do not typically present with this specific combination of pupil responses. For instance, Horner's Syndrome usually results in miosis (constricted pupils) in one eye due to sympathetic nerve damage. Glaucoma is characterized by increased intraocular pressure and may present differently in terms of pupil reactions, while diabetic retinopathy leads primarily to retinal changes and does not directly affect the pupillary light reflex in this manner.