Optometrists may not perform epi-off corneal collagen crosslinking procedures, but they can still play a crucial role in postoperative management. In this third installment of Optometry Advisor’s 3-part series, Mitch Ibach, OD, discusses the optometrist’s role in providing postoperative care for patients who undergo the corneal crosslinking procedure.
Patients with progressive keratoconus may undergo corneal crosslinking (CXL) to stabilize their biomechanically weak cornea. And optometrists are well-positioned to provide postoperative care for these patients — mainly because they are often the ones who detect corneal ectasias and refer these patients for surgery in the first place. Postoperative care regimens are often provided over the course of 1 year and focus on 3 responsibilities which include avoiding adverse events, providing keratometric stability, and visual rehabilitation.
The CXL follow-up schedule can closely mimic that of common keratectomy procedures where the epithelium is removed. While a 1-day postoperative visit is common, some optometrists choose to skip it considering they will conduct an evaluation 4 to 7 days following surgery. After the 4 to 7 day follow-up evaluation, a 1- and 3-month visit are often followed by 2 visits conducted between 6 and 12 months after the procedure. Clinicians will often prescribe topical antibiotics for infection prophylaxis, and oftentimes, topical corticosteroids with or without topical nonsteroidal anti-inflammatory drugs (NSAIDs) will be used to aid in healing. Although it is rare and occurs in only 0.0017% of CXL cases, infectious keratitis is perhaps the most sight-threatening postoperative adverse event.1
The initial follow-up visit should focus on aiding the patient with pain management and assuring the bandage contact lens is in place. Frequent lubrication, sunglasses for photophobia, keeping the eyes closed as needed, and oral NSAIDs are recommended. In most cases, more aggressive narcotic pain medications are not needed. An open epithelium will often result in decreased visual acuity that will not not return to preoperative levels for a few weeks.
Optometrists should focus on epithelialization and whether or not to remove the bandage contact lens during the 4 to 7 day follow-up visit. If a patient is not epithelialized, ocular surface supportive therapies, including artificial tears, punctal plugs, topical immunomodulators, and doxycycline should be used. Amniotic membrane grafts may be used to accelerate or achieve epithelialization, but are infrequently needed to achieve epithelial closure. This visit may also be an opportune time to assess medication compliance and remind patients that they can anticipate more visual acuity improvements.
Patients have often finished or are close to finishing postoperative medications at 1 month. Since a majority of keratoconus is bilateral, many patients may undergo crosslinking in the contralateral eye 4-6 weeks after the initial crosslinking procedure, when indicated.2 Optometrists are tasked with managing vision in these patients, and this visit serves as a good time for a new refraction and eyeglass prescription update. The optometrist may experience their first encounter with post-CXL anterior corneal haze at this time. This can be seen with the slit lamp and magnified in clarity with anterior segment optical coherence tomography (OCT). It should, however, cause no reason for panic. Research suggests that the condition is self-resolving at 1 year in 98% to 99% of cases, and this haze is not believed to be visually significant.3
The 3-month postoperative visit should focus on maximizing visual potential in the ectatic eye. Specialty contact lenses, soft custom contacts, glasses, or referring the patient for additional corneal surgery should all be considerations. Anterior stromal haze will likely be present and peaking upon slit lamp evaluation. Ancillary diagnostics, including anterior elevation mapping and pachymetry, may be obtained at this time. And sometimes, these test findings may create the perception of keratometric worsening. Anterior elevation mapping (topography, epithelial mapping) may look steep at this visit due to epithelial hyperplasia which lessens over time. While pachymetry will often remain comparable to pre-operative baseline, a corneal thinning or condensing may be noted. However, this does not indicate weakening. When explaining this phenomenon to patients, an analogy of putting a board into a vice grip may help them visualize the outcome of the CXL process. It compresses the thickness, but can add strength.
6-Month Visit and Beyond
Postoperative visits conducted between 6 and 12 months should primarily focus on proving keratometric stability. And 1 year topographic and tomographic scans should confirm that the cornea is becoming more stable. Research shows that many patients achieve keratometric flattening after CXL.3,4 While corneal stability and ectatic regression are big wins, the optometrist’s duties are not over yet. These patients still require stability checks. Age, pre-CXL keratometric severity, and eye rubbing behaviors should determine the frequency of postoperative topography. Younger patients with more advanced keratoconus who rub their eyes more often may benefit from more frequent topographic scans. In many cases, performing topography every 6 months is adequate.
Overall, optometrists may gauge their success in providing postoperative care for patients who underwent CXL by their ability to halt disease progression and maximize visual acuity. Promptly diagnosing keratoconus, referring patients for CXL and providing superior postoperative care will optimize outcomes in these patients. Since so many patients often begin their keratoconus journey in the optometrist’s chair with an initial exam, it is only appropriate they conclude this journey with the optometrist’s postoperative care.
- Shetty R, Kaweri L, Nuijts RMMA, Nagaraja H, Arora V, Kumar RS. Profile of microbial keratitis after corneal collagen cross-linking. Biomed Res Int. 2014;2014:340509. doi:10.1155/2014/340509
- Wagner H, Barr J, Zadnik K. Collaborative longitudinal evaluation of keratoconus (CLEK) study: methods and findings to date. Cont Lens Anterior Eye. 2007;30(4):223-232. doi:10.1016/j.clae.2007.03.001
- Hersh PS, Stulting RD, Muller D, Durrie DS, Rajpal RK. United States multicenter clinical trial of corneal collagen crosslinking for keratoconus treatment. Ophthalmology. 2017;124(9):1259-1270. doi:10.1016/j.ophtha.2017.03.052
- Raiskup F, Theuring A, Pillunat LE, Spoerl E. Corneal collagen crosslinking with riboflavin and ultraviolet-A light in progressive keratoconus: ten-year results. J Cataract Refract Surg. 2015;41(1): 41-46. doi:10.1016/j.jcrs.2014.09.033