A history of known medical conditions, demographics (age/race), and symptoms can give you a working diagnosis on the phone before you ever see the patient. Below is a case that illustrates this fact.

My father, a 74 year-old-Caucasian male, called me last Saturday morning with a two-day history of acute onset visual field loss in his right eye. Now since I live in Houston, Texas and he lives in the countryside of North Carolina, it wasn’t like I could bring him down to the office. I knew, however, that he is mildly hypertensive (on metoprolol) and on a statin cholesterol medication and smoked from age 12 to 40. Other than that, and his hip replacement 5 years ago, he has always been generally healthy. Also, I had dilated my father when he was in Houston about one month ago. No retinal findings at that time OU, mild cataract OU, normal IOP with 0.25 ONH cupping OU, and mild to moderate hyperopia.

I asked him to describe the defect which he said was just inferior nasal to his central vision in his right eye. His central vision in each eye was still good through his glasses, he said. I then asked him to close his right eye and tell me if he noticed any VF defect in his left eye, especially inferior temporal. He reported a clean VF OS. (Doesn’t hurt that he has an engineering mentality and can describe things with accuracy.) No pain, no flashes, no floaters, no trauma.

So what are my differentials given his symptoms, age, and race? RD, CNV from AMD, CVA with VF defect (and he just isn’t noticing the OS defect), NAION or Arteritic ION, or either an artery or vein occlusion. Certainly, more could be added, but these were the most likely.

I didn’t think RD given he had acute-onset central, not peripheral loss, and no flashes or floaters. I also know he is a mild hyperope, never wore glasses as a child (which rules out at least moderate to severe myopia), and no retinal findings of lattice/holes/tears/traction at his last visit one month ago. Macular CNV is possible given his history of smoking but he didn’t have any RPE mottling or drusen at his exam one month ago so I also considered this less likely. He denied other symptoms such as headache, malaise, weight loss, jaw claudication or scalp tenderness. The vision was good as well which is less likely an AION.  He didn’t have a VF defect in his other eye (so unlikely CVA causing homonymous VF defect).

At this point, I am thinking most likely BRVO (is hypertensive), with secondary differentials as BRAO (has high cholesterol) or NAION given his small ONH cupping (disc at risk) and he is vasculopathic. All of these can cause posterior pole VF defects that spare the central vision.

So, now I call the local optometrist (who I have luckily known for years) for help. Chris Holland, OD in Fayetteville, NC graciously agreed to add him on at the end of his Saturday clinic. I asked Chris to send me his VF, his BVA, and a retinal photo for which he was nice enough to text me and the results are included here.

My father did have an inferior nasal defect OD on VF testing, OS VF was essentially WNL, his ONH was WNL without edema or pallor, however, his fundus photo OD (which looks normal at first glance) shows an area of whitening at the superior temporal arcade OD.  These areas can sometimes be missed given the whitening of retinal tissue, unlike a BRVO which is much easier to spot due to the blood.

I then asked Chris to send my father to the ER with a prescription pad dictating the following: Patient with acute BRAO OD. Needs sed rate, CRP, CBC with differential, lipid profile, stroke workup, MRI brain and orbits, ECHO, EKG, and carotid doppler. A BRAO is essentially a stroke to the retina and can be very serious as the next cholesterol plaque could end up in his brain and not his retina. I also had a patient last year who had a BRAO and testing that night showed he had bacterial endocarditis and his aorta was about to perforate necessitating emergency surgery. Finding the underlying source of the plaque, if possible, is of the essence.

My father was admitted through the ER for all the testing. Everything was WNL for his age except for his carotid doppler which showed 80% occlusion in the right internal carotid. He was prepped for endarterectomy and it was performed the next day on the right side. He is currently back at home and doing well with an increase in his cholesterol meds and the addition of Plavix. I will get him an appointment with a retinal specialist next week in NC.

Main take away points…1. Know what is the most likely diagnosis given a person’s age/race/medical history. 2. Get a detailed report of the symptoms with regards to disease states in your differential. 3. Do not send ocular disease patients to the ER without your working diagnosis and your recommendations for testing and imaging. You must guide the ER physician as they are generally not very knowledgeable on ocular pathology and the associated disease states which put the eye at risk.

All of the information and photos were printed with permission.