Date: February 15th, 2019

Reference: Gottileb, Holladay and Peksa. Point-of-Care Ocular Ultrasound for the Diagnosis of Retinal Detachment: A Systematic Review and Meta-Analysis. AEM January 2019.

Guest Skeptic: Dr. Daniel Theodoro is an Assistant Professor of Emergency Medicine at Washington University School of Medicine in St. Louis and the Emergency Medicine Point of Care Ultrasound Section Chief.

Case: A 54-year-old diabetic female presents to your emergency department (ED) complaining of floaters of flashing lights and blurry vision. She has no pain and no history of trauma. She noticed that she couldn’t read her newspaper, like there was a wall of light between her left eye and the words on paper. She presents to the ED looking for answers.

The vision in her right eye is 20/40 and vision in the left eye is 20/50. The left eye field of vision is significant for floaters and decreased capacity to see medially. She has no afferent pupillary deficit and she has no obvious cranial nerve deficits. Her eye is not red, and her cornea is not hazy. The rest of her examination is unremarkable.

Background: Ocular complaints account for 3-4% of all ED visits but the cause for the vast majority of these are benign. One in five of patients with eye complaints, however, will require an ED work up and referral for vision preservation. This group of pathology includes diagnoses such as uveitis, macular degeneration, occipital lobe disorders (amaurosis fugax), and posterior chamber pathology such as vitreous hemorrhage, vitreous detachment and retinal detachment.

Retinal detachment is important because, in some cases, there is an intervention that will prevent and possibly restore vision. Since the preservation of vision and quality of life are closely related, cases with retinal detachment deserve proper follow up and referral to a retina specialist.

Traditionally posterior chamber pathologies are diagnosed with direct and indirect ophthalmoscopy. However, few doctors other than ophthalmologists are sufficiently expert enough to do this examination. So, in the majority of ocular cases in the ED the examination is skipped entirely.

In the FOTO-ED study, ED physicians only did fundoscopy in 14% of appropriate cases. In the study trained nurse practitioners took photos of patient’s funduscopic examination and the photos were reviewed by retina specialists in 24 hours. They enrolled 350 patients, but ED physicians only examined 33 patients whose findings were unknown and in whom fundoscopy may have had a role. In all 33 the diagnosis was missed. Granted that in two-thirds the findings were not in the posterior chamber (e.g. retinopathy and optic nerve pallor) but still, this observational study showed ED physicians haven’t developed or maintained fundoscopic skills.

Further complicating matters is that one study in California demonstrated that fewer than 50% of rural EDs and only 75% of urban EDs have ophthalmology coverage. There are currently some tele-ophthalmology services going up online. They require a photograph taken of the fundus by the practitioner that is remotely reviewed. These are known as 45-degree non-mydriatic ocular fundus photographs and one such company is known as Topcon.

To make matters worse direct ophthalmoscopy has poor test characteristics and even indirect ophthalmoscopy has limits until it’s in the hands of experienced and skilled ophthalmologists. In the hands of experienced operators, indirect ophthalmoscopy has an LR+ 44 and LR- of 0.23. Remember, you need a LR- of less than 0.01 to rule out a condition.

If you are repeatedly performing a skill or procedure, receiving feedback, and working to improve you are engaged in Ericsson’s “deliberate practice,”  the key to becoming an expert.