A 44 year old female with HTN, DM, and psychiatric disease presents with non-traumatic pain and vision loss in her right eye for 12 hours.  She has a right sided throbbing headache. On exam she has a 5mm R pupil which is sluggish to react, 3mm L pupil that is fully reactive. Her R eye appears cloudy with injected conjunctiva. EOMI are intact, and her corrected visual acuity is significantly reduced on the R compared to left.  What diagnosis do you suspect?  How would you confirm your diagnosis?

Acute angle closure glaucoma.

After performing your visual acuity, visual field, and pen-light eye examinations, measure intraocular pressure.

Here is how with the Tono-Pen XL used in our ED:

1) Cover pen with fresh Ocu-Film tip

2) Calibrate: Push button 2 times rapidly, a beep will follow.  Point pen directly down toward the floor. LCD will read “CAL” for a number of seconds and then “up.”  Point directly upward.  Pen will beep. LCD should read “good.”  If LCD reads “bad” repeat.

3) Measure pressure: Anesthetize eye with single drop of topical ophthalmic anesthetic such as tetracaine.  Hold Tono-Pen with tip 1/2in from the patient’s cornea bracing with heel of hand on pts cheek for stability. Press button once.  LCD should cycle to a display showing two rows of dashes [=====], indicating you are ready to take a measurement. (All other displays indicate need for recalibration or service.)  Place Ocu-film covered tip directly onto cornea using only very gentile pressure. The Pen will beep after a successful reading.  Repeat until 4 successful measurements are taken from the eye.  The Pen will display a calculated average pressure. 

-Normal Pressure range is 10-20mmhg.

-Elevated pressure with the associated vision loss necessitates prompt treatment for acute angle closure glaucoma and ophthalmologist consultation. 

-Repeat IOP measurement q1h until evaluated by ophthalmology.


Pokhrel PK, Loftus SA. Ocular emergencies. Am Fam Physician 2007; 76:829.

Walker RA, Adhikari S. Chapter 236. Eye Emergencies. In: Tintinalli JE, Stapczynski JS, Cline DM, Ma OJ, Cydulka RK, Meckler GD, eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 7th ed. New York: McGraw-Hill; 2011.

Tono-Pen® XL Instruction Manual Copyright© 2000 Medtronic Solan