BLOG: Perioperative optimization of cross-linking patients
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Key takeaways:
- It is important to treat underlying conditions that could affect epithelial healing after cross-linking.
- Keratoconus patients need to be educated about eye rubbing.
For patients with progressive keratoconus, corneal cross-linking is indicated to slow or stop the progression of the disease.
Given that the only form of cross-linking that is FDA approved for use in the U.S. is epi-off cross-linking with the iLink system (Glaukos), it is also important to treat other underlying conditions that could affect epithelial healing and increase the risk for haze or infection after the procedure.
For example, many keratoconus (KC) patients (and especially younger ones) have allergic conjunctivitis and/or a history of other forms of atopic disease. Treating ocular allergy prior to cross-linking with antihistamine drops such as Pataday (olopatadine 0.1%, 0.2% or 0.7%, Alcon), Zaditor (ketotifen 0.025%, Alcon) or Zerviate (cetirizine 0.24%, Eyevance Pharmaceuticals) will not only help the epithelium heal but also prevent itchiness that leads to eye rubbing. Patients can also be referred to an allergist or other practitioner to address rhinitis, asthma and other conditions.
Patients should be evaluated preoperatively for underlying ocular surface and lid disease, whether they are symptomatic or not, and treated aggressively accordingly. Corneal nerve density is reduced in patients with KC compared with those with healthy corneas, so it is possible that corneal sensitivity may be impaired. If there is already some dry eye, any surgical or corneal procedure can worsen the condition, as we have learned with cataract surgery, so it is important to treat with topical steroids and immunomodulators such as cyclosporine or lifitegrast or other measures, as appropriate. Treating the ocular surface proactively can avoid exposing the patient to prolonged dryness, diffuse persistent epithelial defects and nonhealing epithelial defects, all of which can temporarily compromise vision and cause further discomfort as the patient is recovering from cross-linking.
After cross-linking, the most important thing we can do for our patients with KC is to educate them about eye rubbing. In the Collaborative Longitudinal Evaluation of Keratoconus study, fully half of KC patients reported rubbing their eyes vigorously. KC patients already have elevated levels of inflammatory cytokines in their tears. Cytokine overexpression may be part of the inflammatory KC disease process, but it may also be exacerbated by the kind of abnormal, protracted, circular eye rubbing that we see in KC. Researchers have found that even in normal subjects, eye rubbing for 60 seconds increased the level of tear MMP-13, IL-6 and TNF-alpha. This increase in inflammatory mediators in tears after eye rubbing may be exacerbated even further during the forceful eye rubbing seen in people with KC, and this in turn may contribute to the progression of the disease.
Finally, we can also encourage first-degree relatives of our keratoconic patients to be evaluated by a cornea specialist. Family members have a higher risk for KC. In one study of healthy subjects whose siblings had KC, 30% had KC or suspicious topographies themselves, despite having good vision and no other known signs or symptoms.
Cross-linking is the most important thing we can do for patients with progressive KC because it is the only intervention that slows or halts disease progression. But making sure their corneas are optimized preoperatively and taking additional steps to educate patients and families about risks for KC and KC progression after cross-linking should be part of the perioperative process.
References:
- Acar Eser N, et al. Ocul Immunol Inflamm. 2023;doi:10.1080/09273948.2023.2165950.
- Balasubramanian SA, et al. Clin Exp Optom. 2013;doi:10.1111/cxo.12038.
- Christy JS, et al. Corneal topographic changes in healthy siblings of patients with keratoconus. Presented at: American Society of Cataract and Refractive Surgeons meeting; April 22-26, 2022; Washington.
- Claessens JLJ, et al. The effect of violet light filtration and manufacturing improvements on the clinical performance of an extended depth of focus IOL. Presented at: American Society of Cataract and Refractive Surgeons meeting; April 22-26, 2022; Washington.
- Ionescu IC, et al. Mediators Inflamm. 2018;doi:10.1155/2018/4285268.
- Parissi M, et al. JAMA Ophthalmol. 2016;doi:10.1001/jamaophthalmol.2015.4518.
- Wagner H, et al. Cont Lens Anterior Eye. 2007;doi:10.1016/j.clae.2007.03.001.
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