Eyeworld

114 | EYEWORLD | APRIL 2019 C ORNEA Contact information Jacob: dr_soosanj@hotmail.com by Vanessa Caceres EyeWorld Contributing Writer Contact lens-assisted crosslinking approach refined, expanded UV barrier-free soft contact lens soaked in riboflavin The contact lens is then placed on the cornea, and this increases the functional corneal thickness by a mean of 107+–9.4 µ (90–124 µ). UV-A irradiation is continued. Source (all): Soosan Jacob, MS, FRCS A s corneal crosslinking (CXL) continues to expand around the globe, one sur- geon's approach to treat thin corneas also continues to grow in popularity. The method is contact lens-assist- ed corneal crosslinking (CACXL), and it was created by Soosan Jacob, MS, FRCS. The technique was originally published in 2014, and Dr. Jacob began to perform it in 2012. 1 Dr. Jacob developed the idea behind CACXL after seeing patients who would be suitable for CXL but who did not have the minimum corneal thickness (400 microns after removing epitheli- um) considered safe for treatment. One potential treatment option is corneal transplantation, but that seemed extreme to perform just because the cornea was thin, Dr. Jacob said. She also saw some patients treated with hypotonic CXL, but noticed the results were not always ideal and that sometimes the patient would not get the required thickness. CACXL technique With CACXL, Dr. Jacob works with corneas that are less than 400 microns. Iso-osmolar riboflavin 0.1% in dextran or riboflavin in HPMC (VibeX Rapid, Avedro) is applied every 3 minutes for 30 minutes after epithelial removal. Patients then use an ultraviolet (UV) barrier-free soft contact lens About the doctor Soosan Jacob, MS, FRCS Director and chief Dr. Agarwal's Refractive and Cornea Foundation Senior consultant, cataract and glaucoma services Dr. Agarwal's Eye Hospital Chennai, India that has also been simultaneously soaked in ribo- flavin for 30 minutes. The contact lens adds ap- proximately 100 microns of functional thickness. Ultraviolet-A treatment can begin, along with iso-osmolar riboflavin 0.1% applied intermittently as in the standard CXL technique. Dr. Jacob per- forms CACXL with an epithelium-off accelerated CXL protocol (10 mW/cm 2 for 9 minutes). The accelerated protocol is more patient-friendly and decreases intraoperative dehydration, she said. In an initial report of CACXL results pub- lished in 2014 in 14 eyes, the mean preop mini- mum corneal thickness was 377.2 microns com- pared to 485.1 microns after the contact lens and riboflavin use. 1 Patients had an average absolute increase in minimum corneal thickness of 107.9 ± 9.4 microns; the mean stromal demarcation line depth was 252.9 ± 40.8 microns. None of the eyes had significant endothelial loss, and all had stable corneal topography at follow-up. Use of anterior segment OCT (AS-OCT) and intraop pachymetry are important measure- ments before and during CACXL, Dr. Jacob said. "We've seen on average that the contact lens gives 110 microns of additional thickness, but to make calculations easier, it is simple to remember it as 100 microns," Dr. Jacob advised. This technique generally works well for corneas up to 350 microns. In very thin corneas

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