What Is PERRLA Eyes and Means in Eye Exam

Perrla Eyes is the kind of test that a medical practitioner often performs on a patient to figure out whether said patient’s nervous system is working properly or not. You might be familiar with the test although you have yet to find out its name: Have you ever seen a doctor or a nurse shedding a bright light to someone’s eyes? Now that procedure is referred to as the PERRLA test. The test is called pupillary response testing medically. The test is meant for measuring the responsiveness of the optic nerve (the cranial nerve II) and the oculomotor nerve (cranial nerve III). The cranial nerve II conveys visual messages the retina receives to the brain. Vision problems can originate from damaged cranial nerve II. The cranial nerve III functions as a controller of the four eye muscles and adjusts pupil constriction and manages focus. Damage to this nerve leads to double vision and blown pupil.

Perrla Eyes is an acronym. It stands for:

  • Pupils
  • Equal
  • Round
  • Reactive to
  • Light and
  • Accommodation
PERRLA Eyes
PERRLA Eyes

Eyes whose pupils meet the above parameters are regarded healthy. Exam results would be considered abnormal if:

  1. The pupils are not of equal size,
  2. The pupils are misshapen (not round),
  3. The pupils are not reactive to exposure to light (healthy pupils react to light by getting smaller in diameter), and
  4. The pupils do not accommodate when a patient is asked to look at an object in close or long distance.

A PERRLA test may reveal a lot of things about a patient, even without said patient realizing the presence of medical condition they actually have. A decrease in direct response to light in one eye could be a sign of RAPD, short for Relative Afferent Pupillary Defect, also known as Marcus Gunn pupil. RAPD itself is oftentimes caused by a variety of conditions such as:

  1. Severe case of glaucoma,
  2. Optic neuritis,
  3. Optic nerve tumor,
  4. Ischemic optic neuropathy, a.k.a. the optic nerve stroke,
  5. Optic nerve damage from head injuries,
  6. Optic nerve damage from surgery (surgical procedures on sinus, orbital, or eye; plastic surgery, or anesthesia-caused damages).
  7. Sever retinal diseases.

When the pupils accommodate abnormally to something moving toward the eye, it could be caused by:

  1. Lesions of the oculomoter nerve (cranial nerve III), or
  2. Lesions of the optic nerve (cranial nerve II).

The eye is an organ so complex that careful observation must be done to find if there is something wrong about it. The eye is governed by billions of nerves that connect it to the brain, which in turn translates signals that the eye receives. PERRLA test is a simple one that offers big benefit for anyone undergoing it. The test serves as a window for medical examiners to peek into your central nervous system as a whole. While the test cannot be relied upon when it comes to getting a firm diagnosis, any abnormalities that the test uncovers could open the doors to more thorough test and medical workup.