Retinal Photography to Diagnose TIAs?

Our diagnostic approach to suspected cerebrovascular disease is quite simple.  Concerning neurologic findings or history?  Magnetic resonance imaging.

However, this approach is grossly inefficient – and, thus, the rise of various clinical scores such as the ABCD2 variants.  And, now, ocular fundus photography.  It generally makes sense – the retinal vessels travel through the optic nerve sheath.  They are, then, a unique window into the cerebrovascular circulation – and, accordingly, the degenerative diseases within.

It sort of works.

Looking at patients presenting to the ED with a report of focal neurologic deficits, the multivariate regression OR for cerebrovascular disease in patients with arterial narrowing in 2 segments is reported as 8.1 for stroke and 5.1 for TIA.  However, this finding was only present in 4 of 22 (18%) stroke patients and 6 of 59 (10%) TIA patients – compared with 5 of 176 (3%) patients who did not receive a diagnosis of cerebrovascular disease.

So, yes – it is probably true, as the authors claim, that finding arterial focal narrowing in the retinal vessels increases the likelihood of cerebrovascular disease (stroke and TIA).  But, clearly, the positive predictive value is still quite low, and the number of patients for whom this ocular photography adds substantially to the diagnosis is quite small.  At ~$25,000 a pop for the camera system, and the need for a specialist to screen the images for abnormalities, I do not share these authors’ enthusiasm for its eventual adoption into clinical practice.

“Ocular fundus photography of patients with focal neurologic deficits in an emergency department”

Foam, Actually

I chastise JAMA on occasion, but, any article that starts like this is the mark of a truly great academic publisher:

“The lights are low and the music volume is high.  As arms and legs sway on a packed dance floor, streams of soapy suds blow down from the ceiling….”

No, it’s not a ‘tween reviewing an illegal high during a rave, it’s a actually CDC surveillance of a spike in eye injuries resulting from “foam parties”.  This write-up details an investigation in Collier County, Florida, in which more than 40 patients sought care for eye irritation and pain in a single night.  These patients all received ocular inoculation with foam during the course of revelry, and over half were ultimately diagnosed with corneal abrasions.  The cause – the highly concentrated chemicals such as sodium lauryl sulfate and other proprietary mixtures similar to those found in soaps and shampoos.

So, beware the foam! (but not the FOAM).

“Party Alert: Here’s Foam in Your Eye”

“Notes from the Field: Eye Injuries Sustained at a Foam Party — Collier County, Florida 2012”

Happy Independence Day!

I ought to have posted this piece regarding firework injuries on Wednesday to get folks in the mood – but, better late than never!

This is an entertaining little experiment published in JAMA investigating the mechanism of ocular trauma from fireworks.  These authors created a setup in which a cadaveric eye was suspended in a network of sensors – and then concussive charges and fireworks were exploded at various distances.

Based on their experiments, these authors conclude most of the ocular injury potential is superficial and results from flying debris, rather from any explosive pressure wave.  Fascinating little study!

“Mechanisms of Eye Injuries From Fireworks”