Pupillary assessment (i.e., bilateral evaluation of pupils size, shape, symmetry, and reactivity) is a cornerstone of the neurologic physical examination in the critically ill, particularly the neurocritically ill. Systematic pupillary assessments are routinely performed in the critically ill because they can render early signs of neurologic deterioration, which, in some cases, may be the only clinically obtainable sign.
The Brain Trauma Foundation’s guidelines for the management of severe traumatic brain injury acknowledge the evaluation of pupils’ size and reactivity to light as source for early prognostic signs of neurologic pathology. The writer assigned to write my essay request related to medical content is qualified to the same academic level or higher than your writing requirements.
There are reports of pupillary assessment as far back as 1929, when Otto Lowestein first developed a technique based on the analysis of simple, direct, visual evaluations. Nonetheless, despite remarkable technologic advances and substantial improvements on the understanding of the central nervous system, the pupillary examination has not much changed during the last century.
Regarding the conventional, visual pupillary assessment, there is considerable intra- and inter-observer variability due to inconsistency on several factors, such as illumination of patient’s room, examiner’s visual acuity and experience, and intensity and technique of light stimuli. Therefore, alternative techniques have been proposed.
The most accepted alternative technique is the infrared pupillary assessment (IPA), first described in 1958 by Lowestein himself, and then, as from 1993, extensively studied by Merlin Larson; by these means, both of Lowestein and Larson ended up elucidating the association between pupillary abnormalities and brainstem injuries or pharmacologic effects. In 2003, Taylor et al., using an infrared pupillometer, established an association between intracranial pressure and pupillary abnormalities in patients with acute brain injury. In 2011, Chen et al. using the infrared pupillometer, described a significant inverse relationship between decreasing pupil reactivity and increasing intracranial pressure; the first evidence of pupil abnormalities occurred, on average, 15.9 h prior to the time of the peak of intracranial pressure.
Today, the IPA is being increasingly adopted as a routine part of the neurologic examination, supported by a growing body of literature demonstrating its reliability, accuracy, and ease of use. Automated pupillometry allows rapid, non-invasive, reliable, and quantifiable assessment of pupillary function which may allow rapid diagnosis of intracranial pathology that affects clinical decision-making. Hire a reliable free essay writer who will create an original mediical cure information and deliver it on time.
On the other hand, the first report of ocular ultrasound was made in 1956. Technologic advances in ultrasound devices have since allowed implementing ocular ultrasound in the evaluation of several ophthalmologic pathologies such as ocular trauma and intraocular foreign body identification. However, the ultrasonographic evaluation of the pupillary diameter and pupillary light reflex has not been well studied, let alone implemented.
In cases when direct visualization of the pupil is not possible due to soft tissue injury that precludes eye opening, alternative techniques such as IPA and LED-based perimetric pupillometry have been proposed; unfortunately, most of these techniques do not overcome the physical barrier placed by the soft tissue, rely on advanced devices that are not generally available in emergency situations, and require of specialized technical support. In this context, UPA is particularly useful because it offers a simple yet accurate alternative that can be performed with small, portable devices at the point of care.