ANN WAS FITTED with scleral lenses five years ago, after a bilateral corneal graft. Until now, her story has been one of dreams: easy adaptation in a short period of time, perfect vision and comfort, and the ability to carry out daily activities. But for the last few months, nothing has been going right for her, which is why she is looking for help.

Whenever something like this happens, one wonders what could have happened to explain the sudden change. First, try to identify the symptoms: onset, description, and evolution. Next is the identification of possible causes. Some may be obvious: lenses too old, covered with debris, a lens worn on the wrong eye, changes in the patient’s systemic condition, and/or medications, etc.

The ocular condition may also evolve such as a flare-up in dry eye, graft failure or decompensation, or cataracts, etc. Compliance may also be called into question: overnight wear or changes in the care of their lenses. Less frequently, practitioners may consider modified work or home environment. Lastly, take into account problems with new lenses, like manufacturing process leading to discomfort even if the new lenses are a perfect duplicate of the old ones.

For three months, Ann has noticed that her eyes are watery when she wears lenses, and her vision is slightly reduced as a consequence. She is a not sensitive to light but she does complain of burning one to two hours post-application.

On examination, her visual acuity is normal at 20/25 OD and 20/30 OS, due to an incipient cataract that has not progressed since her last examination. The lenses are less than 12 months old and clean. Fitting is still optimal. When the lenses are removed, there is no evidence of lens compression, dry eye, or blepharitis, but a moderate amount of diffuse corneal staining is noted, which is new.

Subjective reduced visual acuity (Diec et al, 2012), diffuse corneal staining, and burning are characteristic of solution-induced corneal staining (SICS) (Woods, 2013; Woods et al, 2012; Fonn et al, 2010).

Patients should be asked to re-explain their lens care during the case history. Sometimes, as in this case, it was assumed that the recommendations made at the outset were being followed.

When specifically asked about this aspect of things, Ann shared that the hydrogen peroxide was no longer available and that the pharmacist had advised her to replace it with an older generation multipurpose care solution. A green bottle, she remembers, under a private label. She admits to using some of this cheaper solution to fill her scleral lens, mixing it with the preservative-free artificial tears (AT) originally suggested. Upon reflection, Ann confirms that her problems began shortly after this change in lens care system.

The cause of Ann’s problems is now clear—soft lens solutions to clean and soak scleral lenses is considered off-label but does not contribute to SICS. The real problem is that the preserved solution remains in the scleral reservoir for all hours of wear. The corneal reaction and associated symptoms are a result of this prolonged contact.

Treatment of this condition is essential because SICS is associated with corneal infiltrates (Carnt et all, 2007). A few days of washout with frequent lubrication (non-preserved AT) is recommended. A return to good lens care habits will keep the eye healthy afterward. CLS

References

1. Diec J, Evans VE, Tilia D, Naduvilath T, Holden BA, Lazon de la Jara P. Comparison of ocular comfort, vision, and SICS during silicone hydrogel contact lens daily wear. Eye Contact Lens. 2012 Jan;38:2-6.
2. Woods J. What do we know about solution-induced corneal staining? Contact Lens Update. 2013 Aug 14. Available at contactlensupdate.com/2013/08/14/what-do-we-know-about-solution-induced-corneal-staining . Accessed Oct. 8, 2023.
3. Woods J, Keir N, Jones JW. Solution Induced Corneal Staining (SICS): Symptoms and Staining Patterns. Contact Lens Update. 2013 Aug 14. Available at contactlensupdate.com/2013/08/14/solution-induced-corneal-staining-sics-symptoms-and-staining-patterns . Accessed oct. 6, 2023.
4. Fonn D, Peterson R, Woods C. Corneal staining as a response to contact lens wear. Eye Contact Lens. 2010 Sep;36:318-321.
5. Carnt N, Jalbert I, Stretton S, Naduvilath T, Papas E. Solution toxicity in soft contact lens daily wear is associated with corneal inflammation. Optom Vis Sci. 2007 Apr;84:309-315.