September 2026

OPHTHALMOLOGY

CASE REPORT: MONOCULAR BLURRY VISION

A 38-year-old male without significant past medical history presented with 12 hours of sudden-onset then slowly improving blurry vision of the right eye. At the time of evaluation, he reported continued, now mild blurry vision, small central scotomas described as “missing pieces of letters” on the vision card, and no other ocular, visual or systemic symptoms.
 
His visual acuity was 20/25 PHNI on the right and 20/20 on the left with no rAPD. His anterior segment exam was unremarkable. His posterior segment exam had 20 to 25 small, flat, faint scattered cotton-wool-spot-like spots scattered throughout the central macula and trace irregular retinal sheen, with otherwise normal color, no cherry red spot, no hemorrhage, and a normal foveal light reflex. He had mildly attenuated arterioles, equal in both eyes.
 
His near infrared reflectance (NIR) imaging demonstrated a faint reticular pattern in the right eye that was not seen in the left eye, part of which is circled here in the right eye and in the corresponding location in the left eye:
Optical coherence tomography identified focal inner nuclear layer hyperreflectivity in the superior, midline, and inferior macula of the right eye corresponding to the reticular pattern seen on NIR imaging.
These findings confirmed the diagnosis of paracentral acute middle maculopathy (PAMM) of the right eye.
 
Hospital workup included:
  • MRI of the brain and orbits with and without contrast
  • Carotid duplex ultrasound
  • Transthoracic echocardiogram with bubble study
  • Electrocardiogram
  • Telemetry
  • Urine drug screen
  • Lipid panel
  • Hemoglobin A1c
  • Basic metabolic panel
  • Infectious, inflammatory and hypercoagulability studies
 
Hospital workup was negative except for a patent foramen ovale and moderate left ventricular hypertrophy on echocardiogram.
 
Outpatient workup identified mild obstructive sleep apnea, elevated lipoprotein-a and stage 1 hypertension. Closure of the patient’s patent foramen ovale was considered but after consultation between ophthalmology and cardiology was deferred.
 
At three-month follow-up, visual acuity without correction was 20/40 pinhole 20/20 in the right eye. No neovascularization was identified. Thinning of the inner nuclear layer at the areas of prior inner nuclear layer hyperreflectivity was noted.
This is a typical presentation of PAMM, a clinical entity characterized by a subjective paracentral scotoma, relatively good central visual acuity at presentation, ill-defined intraretinal white lesion on fundus exam, corresponding dark lesion(s) on near infrared reflectance imaging, inner nuclear layer hyperreflectivity on OCT imaging and eventual INL thinning.
 
PAMM results from ischemia of the deep capillary plexus from any source. PAMM is often associated with a history of cardiovascular disease; however, in a younger patient (under 40 to 50 years old) PAMM often presents in the absence of known cardiovascular disease. In cases like this one, cardiovascular disease is often found on workup.
 
PAMM often co-occurs with retinal vascular occlusion. However, PAMM can also occur in the absence of vascular occlusion, dubbed “isolated PAMM.”  In patients over age 50, isolated PAMM has been associated with 6.4x increased risk of major adverse cardiovascular events (MACEs) relative to PAMM associated with retinal vascular occlusion, with median time to MACE of one month.
Daniel Balikov, MD, PhD, Clinical Assistant Professor of Ophthalmology at Northwestern
Medicine
Michael Drakopoulos, MD, Ophthalmology Resident at Northwestern Medicine 

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