Intracanalicular Dexamethasone Insert for Post-Corneal Cross-Linking Inflammation and Pain- The LINK Study

Intracanalicular Dexamethasone Insert for Post-Corneal Cross-Linking Inflammation and Pain- The LINK Study

Intracanalicular Dexamethasone Insert for Post-Corneal Cross-Linking Inflammation and Pain- The LINK Study

There is no standard of care medication regimen for the management of pain and inflammation post-corneal crosslinking (CXL), although most cornea specialists agree on use of an antibiotic and steroid eye drop in the immediate postoperative period. However, steroid tapering schedule and use of additional topical non-steroidal anti-inflammatory (NSAID) eyedrops vary amongst practitioners. The goal of this study is to compare postoperative pain scores between patients receiving a tapering dose of topical steroids over 1-month post-CXL, versus those receiving an intracanalicular dexamethasone insert.

Keratoconus is a progressive ectatic disease of the cornea, leading to worsening of astigmatism and vision over time. With FDA approval of corneal collagen cross-linking (CXL), we now have the ability to halt the progression of keratoconus and prevent further vision loss in these patients. Although CXL has now become standard of care, the immediate post-operative period can be quite painful despite use of anti-inflammatory medications/eye drops. The goal of this study is to evaluate the efficacy of an intracanalicular dexamethasone insert in reduction of post-CXL pain as compared to routine steroid eye drop therapy. To date, no studies have been performed evaluating the success of an intracanalicular dexamethasone insert for the treatment of postoperative inflammation and pain in corneal cross-linking patients. Oftentimes, patients experience a great deal of discomfort post-CXL, which may also make it difficult to apply eye drops in the correct fashion. Use of a dexamethasone insert alleviates the need for postoperative steroid eye drops and may provide increased pain relief post-CXL as compared to topical therapy. This will be a head-to-head study where steroid therapy (topical or insert) will begin in a standard fashion on the date of CXL. This will allow for accurate comparison of a 4-week taper of topical steroids, versus a dexamethasone insert designed to release steroid for 30 days.

Two cohorts of patients will be studied (10 patients each group). Cohort A: intracanalicular dexamethasone insert is placed on day of crosslinking (CXL); patients will still receive postoperative fluoroquinolone (or another class if allergy) antibiotic eye drops with instructions for use (i.e. 1 drop in operative eye 4 times daily x 10 days). Cohort B: Patients are placed on standard postoperative regimen of postoperative fluoroquinolone antibiotic eye drops with instructions for use (i.e. 1 drop in operative eye 4 times daily (QID) x 10 days) and Prednisolone acetate 1% ophthalmic solution tapered over 1 month in the following schedule: 4 times daily x1 week, three times daily (TID) x 1 week, twice daily (BID) x 1 week, and once daily (QD) x 1 week).

Intracanalicular dexamethasone insert is placed on day of crosslinking (CXL); patients will still receive postoperative fluoroquinolone (or other class in case of allergy) antibiotic eye drops with instructions for use (i.e. 1 drop in operative eye QID x 10 days).

Patients are placed on standard postoperative regimen of postoperative fluoroquinolone (or other class in case of allergy) antibiotic eye drops with instructions for use (i.e. 1 drop in operative eye QID x 10 days) and Prednisolone acetate 1% ophthalmic solution tapered over 1 month in the following schedule: QID x1 week, TID x 1 week, BID x 1 week, and Qday x 1 week.

Utilizing the standardized Wong-Baker visual analog pain scale, graded from 0 to 10 (no pain to increasingly worse pain (worst at 10/10))

Assessed at 1 day of surgery, postoperative days 1 ,3, 7, postoperative weeks 2 ,3 and 4 (7 visits total)

Degree and improvement of ocular surface inflammation between groups from date of surgery to 1 month post-CXL

Assessment of corneal edema/cells (if any), degree of conjunctival injection (if any) Grading will be standardized according to the Brien Holden Vision Institute grading system

assessed at baseline, 1 day of surgery, postoperative days 1 ,3, 7, postoperative weeks 2 ,3 and 4 (8 visits total)

Assessed at 1 day of surgery, postoperative days 1 ,3, 7, postoperative weeks 2 ,3 and 4 (7 visits total)

Subjective 'ease of postoperative care' for patients receiving standard topical steroid eye drop taper vs. dexamethasone insert

Use of oral non-steroidal antiinflammatory (NSAID), acetaminophen, prescribed pain medication) between groups

Assessement of use of additional/adjunctive pain/antiinflammatory medications will be done for each patient at postoperative days 1 ,3, 7, postoperative weeks 2 ,3 and 4 (7 visits total)

Inclusion Criteria: Progressive keratoconus with planned corneal cross-linking in one or both eyes Age 18 years and older Ability to provide informed consent for procedures Ability to attend scheduled follow up visits Exclusion Criteria: Age less than 18 Pregnancy/currently breast-feeding Inability to provide informed consent Documented adverse reaction to steroid (e.g. "steroid responder", allergy, etc) Punctal stenosis Previous corneal transplant surgery Systemic concomitant use of controlled substance for pain management (i.e. oxycodone) Concurrent use of topical steroid eye drops Systemic, topical or intravitreal steroid use within 1 month of baseline Active history of chronic or recurrent inflammatory eye disease in either eye History of ocular herpetic infection (inclusive of Herpes Simplex 1/2, Varicella Zoster, Epstein Barr, Cytomegalovirus) History of neurotrophic keratitis, uncontrolled diabetes, or other disease entities that may preclude proper healing

We do not plan to share individual participant data (IPD) with other researchers. However, any adverse events will be reported to the governing institutional review board (IRB) and Ocular Therapeutix and FDA if applicable.

Rabinowitz YS. Keratoconus. Surv Ophthalmol. 1998 Jan-Feb;42(4):297-319. doi: 10.1016/s0039-6257(97)00119-7.

Krachmer JH, Feder RS, Belin MW. Keratoconus and related noninflammatory corneal thinning disorders. Surv Ophthalmol. 1984 Jan-Feb;28(4):293-322. doi: 10.1016/0039-6257(84)90094-8.

Wollensak G, Spoerl E, Seiler T. Riboflavin/ultraviolet-a-induced collagen crosslinking for the treatment of keratoconus. Am J Ophthalmol. 2003 May;135(5):620-7. doi: 10.1016/s0002-9394(02)02220-1.

Kohlhaas M, Spoerl E, Schilde T, Unger G, Wittig C, Pillunat LE. Biomechanical evidence of the distribution of cross-links in corneas treated with riboflavin and ultraviolet A light. J Cataract Refract Surg. 2006 Feb;32(2):279-83. doi: 10.1016/j.jcrs.2005.12.092.

Hoyer A, Raiskup-Wolf F, Sporl E, Pillunat LE. [Collagen cross-linking with riboflavin and UVA light in keratoconus. Results from Dresden]. Ophthalmologe. 2009 Feb;106(2):133-40. doi: 10.1007/s00347-008-1783-2. German.

Wollensak G, Sporl E, Seiler T. [Treatment of keratoconus by collagen cross linking]. Ophthalmologe. 2003 Jan;100(1):44-9. doi: 10.1007/s00347-002-0700-3. German.

Snibson GR. Collagen cross-linking: a new treatment paradigm in corneal disease - a review. Clin Exp Ophthalmol. 2010 Mar;38(2):141-53. doi: 10.1111/j.1442-9071.2010.02228.x.

Peyman A, Kamali A, Khushabi M, Nasrollahi K, Kargar N, Taghaodi M, Razmjoo H, Fazel F, Salesi A. Collagen cross-linking effect on progressive keratoconus in patients younger than 18 years of age: A clinical trial. Adv Biomed Res. 2015 Nov 23;4:245. doi: 10.4103/2277-9175.170240. eCollection 2015.

Ghanem VC, Ghanem RC, de Oliveira R. Postoperative pain after corneal collagen cross-linking. Cornea. 2013 Jan;32(1):20-4. doi: 10.1097/ICO.0b013e31824d6fe3.

Zarei-Ghanavati S, Jafarpour S, Radyn-Majd A, Hosseinikhah-Manshadi H. Evaluation of early postoperative ocular pain after photorefractive keratectomy and corneal crosslinking. J Cataract Refract Surg. 2018 May;44(5):566-570. doi: 10.1016/j.jcrs.2018.02.019. Epub 2018 May 9.

Serna-Ojeda JC, Santana-Cruz O, Quiroz-Casian N, Gonzalez-Mendoza E, Mercado-Orozco JL, Navas A, Lichtinger A, Graue-Hernandez EO. Pain Management in Corneal Collagen Crosslinking for Keratoconus: A Comparative Case Series. J Ocul Pharmacol Ther. 2019 Jul/Aug;35(6):325-330. doi: 10.1089/jop.2019.0021. Epub 2019 Jun 19.

Kocluk Y, Cetinkaya S, Sukgen EA, Gunay M, Mete A. Comparing the effects of two different contact lenses on corneal re-epithelialization after corneal collagen cross-linking. Pak J Med Sci. 2017 May-Jun;33(3):680-685. doi: 10.12669/pjms.333.12241.