cone

A 29 year-old-male with a past medical history of left eye enucleation secondary to a gunshot wound several years prior presents to the Emergency Department (ED) for blurry vision, redness, and concern for a deformity to his right eye. The patient states symptoms started 2-3 months ago and he initially thought symptoms were due to allergies and recalls rubbing his eye a lot. Over the past 3-4 days, he noticed an acute decline in his vision with what the patient describes as a “cloudy bump” appearing during that time. The patient normally does not wear contacts or corrective lenses but states his vision is very blurry and he is now having difficulty reading. He also reports photophobia and mild eye pain. Review of systems is negative for any fevers, headache, eye discharge, or any recent falls or trauma.

Vitals: BP 125/83; Pulse 70; Temp 97.6 F (36.4 C); Resp 17; SpO2 100%

Constitutional: No acute distress, lying in stretcher comfortably.

Head: No visible traumatic injuries. No peri-orbital edema or facial swelling.

Eyes:

  • OD: Edematous cone-shaped protrusion with central haziness. V-shaped deformity to lower lid margin noted on downward gaze. The patient reports no pain when performing extraocular movement testing which is intact and pupil is reactive to light. Visual fields intact. There is no fluorescein uptake upon Wood’s Lamp exam and IOP is 18. VisualAcuity OD 20/200.
  • OS: Eye prosthesis in place.

Nose: No foreign bodies.

Mouth/Throat: Oropharynx is clear and moist and mucous membranes are normal.

Neck: Normal range of motion.

Corneal hydrops secondary to keratoconus.

Keratoconus is a degenerative, multifactorial, non-inflammatory disorder of the cornea that causes bilateral thinning of the cornea and distorted vision. The corneal thinning leads to a structural weakness in the collagen fibers that causes the characteristic bulging, “cone-shaped” cornea. If the thinning is significant enough, a break in collagen fibers and Descemet’s membrane lead to sudden edema which appears as a corneal opacification. This complication is known as corneal hydrops and causes sudden eye pain and decreased visual acuity. Patients with keratoconus present in young adulthood with progressive blurry or distorted vision. Risk factors include connective tissue disorders and Down syndrome as well as a familial history of keratoconus. There is also a risk in patients with a history of eye rubbing as was the case with this patient. The initial treatment for keratoconus is corrective eyewear for refractive correction.

The clinical hallmark of keratoconus is the cone-like protrusion of the cornea. The bulging may eventually lead to “Munson’s sign”, a v-shaped indentation of the lower eyelid on downward gaze as the cornea bulges outward that is seen in advanced keratoconus.

Take-Home Points

  • Suspect keratoconus in patients with a history of constant eye rubbing, developmental delay (i.e. Down Syndrome), and in patients with connective tissue disorders.
  • Munson’s Sign is a v-shaped indentation of the lower eyelid on downward gaze as the cornea bulges outward.
  • Initial treatment of keratoconus is conservative management with prompt ophthalmology follow-up.

  • V. Mas Tur, C. MacGregor, R. Jayaswal, D. O’Brart, N. MaycockA review of keratoconus: Diagnosis, pathophysiology, and genetics Surv Ophthalmol, 62 (6) (2017), pp. 770-783
  • Gold J, Chauhan V, Rojanasthien S, Fitzgerald J. Munson’s Sign: An Obvious Finding to Explain Acute Vision Loss. Clin Pract Cases Emerg Med. 2019 Jul 8;3(3):312-313. doi: 10.5811/cpcem.2019.5.42793. PMID: 31403106; PMCID: PMC6682229.
  • Gialousakis, John P. “Management of Acute Corneal Hydrops in a Patient with Keratoconus: a Teaching Case Report.” The Journal of the Association of Schools and Colleges of Optometry, vol. 45, 2020.
  • Greenwald MF, Vislisel JM, Goins KM. Acute Corneal Hydrops. EyeRounds.org. August 3, 2016; Available from: http://EyeRounds.org/cases/241-acute-corneal-hydrops.htm
  • Stack L, Sheedy C, Bales B. Corneeal Hydrops: A Complication of Keratoconus. Visual Diagnosis Ophthalmology. Published 2015 Dec 11. Available from: https://www.emra.org/emresident/article/corneal-hydrops-a-complication-of-keratoconus/

Jonathon Brewer, MD

Jonathon Brewer, MD

Resident Physician
UT Southwestern Medical Center
Jonathon Brewer, MD

Latest posts by Jonathon Brewer, MD (see all)

Melissa Smith, MD

Melissa Smith, MD

Assistant Professor
APD
UT Southwestern Medical Center