BLOG: Corneal white spot an acute dilemma for keratoconus patients
A white spot on the cornea is usually never a good thing. It could be a corneal scar or ulcer or, in keratoconus patients, something entirely different.
If you haven’t already, you will receive a call one day from a panicked keratoconus (KC) patient stating that they have noticed a new “white spot” on their cornea, with associated blurry vision. This will most likely be acute corneal hydrops (CH), a rare condition that develops from a tear in Descemet’s membrane leading to stromal edema from aqueous fluid seeping into the cornea. Although CH is most often associated with KC, it has also been reported in other corneal ectasias (Maharana et al).
Individuals with a higher risk for CH include those with earlier age of ectasia onset, vernal keratoconjunctivitis, asthma, atopic dermatitis, keratometry values of 48 D or less, Down syndrome and especially those who rub their eyes. Studies have reported that CH is also more common in males (Barsam et al). A patient with CH may complain of markedly decreased vision, light sensitivity and pain. Upon presentation, you may see conjunctival hyperemia, corneal epithelial microcystic edema and large fluid-filled stromal pockets that have formed between the collagen lamellae.
Management of CH may involve frequent lubrication, topical antibiotics to prevent infection, cycloplegics to reduce pain, hypertonic saline drops to reduce swelling, anti-glaucoma medications to lower the hydrodynamic force on the cornea and topical steroids or nonsteroidal anti-inflammatory drugs. Most importantly, the patient will need patience and time. CH may stimulate corneal neovascularization, especially if the affected area reaches the limbus; topical corticosteroids have been recommended to reduce this risk (Rowson et al). Although uncommon, intracameral air/gas injections or compressive sutures may be considered to expedite resolution of the corneal edema.
Additionally, it has been reported that a mini-Descemet’s membrane endothelial keratoplasty could be helpful in patients with larger Descemet’s membrane tears and those with very ectatic corneas in the acute phase of CH (Bachmann et al).
Depending on the area of involvement, resolution of CH generally takes about 2 to 4 months. Upon healing, the cornea typically has a residual scar and may become flatter. If the residual scar is central and visually significant, corneal transplantation may be required. However, improvements in specialty contact lenses and fitting techniques have allowed for successful nonsurgical visual correction for many keratoconus patients, even after CH.
Ultimately, it would be awesome if we could detect KC in its earliest stages to educate our patients against eye rubbing, which could potentially trigger and worsen the condition in genetically predisposed individuals and to also quickly intervene with corneal cross-linking to slow progression. These actions could possibly help prevent the development of CH altogether. Nevertheless, you are now equipped to respond to those urgent calls from your frightened KC patients reporting a new white spot on their eye.
- Bachmann B, et al. Cornea. 2019;doi:10.1097/ICO.0000000000002001.Cornea.
- Barsam A, et al. Br J Ophthalmol. 2017;doi:10.1136/bjophthalmol-2015-308251.
- Barsam A, et al. Eye (Lond). 2015;doi:10.1038/eye.2014.333.
- Bawazeer AM, et al. Br J Ophthalmol. 2000;doi:10.1136/bjo.84.8.834.
- Gordon-Shaag A, et al. Biomed Res Int. 2015;doi:10.1155/2015/795738.
- Kreps EO, et al. Cornea. 2019;doi:10.1097/ICO.0000000000001946.
- Maharana PK, et al. Indian J Ophthalmol. 2013;doi:10.4103/0301-4738.116062.
- Raiskup F, et al. J Cataract Refract Surg. 2015;doi:10.1016/j.jcrs.2014.09.033.
- Rowson NJ, et al. Eye (Lond). 1992;doi:10.1038/eye.1992.83.
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Gloria Chiu, OD, FAAO, FSLS, is an associate professor of clinical ophthalmology at the University of Southern California Roski Eye Institute and department of ophthalmology at the University of Southern California Keck School of Medicine. Her clinical interests include contact lens fittings and treatment for patients with ocular surface disease and irregular corneas. Additionally, she is conducting microbiology studies to evaluate saline solutions commonly used with scleral lens wear and potential risks for microbial infections.