Performing corneal tunnel incision with keratotomy scars intersection in patients after radial keratotomy during phacoemulsification
Authors:   Eye Research Center of Pirogov Russian National Research Medical University, Takhchidi H.P. , Panteleev E.N. ,   S. Fyodorov Eye Microsurgery Complex–Federal State Institution, Moscow, Russian Federation, Semakina A.S. ,   Eye Research Center of Pirogov Russian National Research Medical University, Afanasova I.V. ,   Eye Research Center of Pirogov Russian National Research Medical University
Published: October 2021

Purpose. A clinical study of safety and changes of refraction during intersection of a keratotomy scar while performing the corneal tunnel incision in phacoemulsification with IOL implantation. Material and methods. The clinical study included 11 patients (19 eyes) suffering from cataract and patients with previously performed anterior radial keratotomy. A tunnel incision 2.2 mm wide was performed with the location of the scar in its center. In case of insufficient area of the corneal tissue between the scars to involve only one keratotomy scar into the tunnel incision, the adjacent scar was transected at the final stage of tunnel formation when entering the anterior chamber. The other stages of phacoemulsification were carried out in a standard way. During the operation, the state of the keratotomy scar was assessed. A day, a week and a month later after the operation, the patients underwent biomicroscopy, autorefractokeratometry, visometry with an assessment of the values of subjective and objective cylindrical correction. In order to assess the postoperative state of the keratotomy scar and the incision zone, OCT of the cornea was performed using an RTVue 100 optical coherence tomograph (Optovue, Inc, USA) in Line, Crossline, 3D cornea modes. Results. In all cases, during the operation and also the next day, biomicroscopically the cornea was transparent, there was no keratotomy scar dehiscence. There is a dynamic of the best corrected visual acuity value by 1 month after surgery and the difference between the value for subjective and objective cylinder correction as well. The next day after the operation, in all cases the keratotomy scar on the OCT scans is uniform, comparable in width, the architectonics of the tunnel incision does not differ from that of standard phacoemulsification. Conclusion. Performing a corneal tunnel incision with the beginning of the formation outside the zone of the keratotomy scar and with further intersection of the scar with the plane of the blade so that most of it is in the projection of the center of the tunnel incision, as well as the intersection of the adjacent keratotomy scar at the end of the formation of the tunnel incision when entering the anterior chamber in case of insufficient the area of the corneal tissue between the incisions is safe at all stages of phacoemulsification and in the postoperative period. Changes in the values of best corrected visual acuity over time and the difference between the values of subjective and objective cylinder correction require further study on a larger sample and using various keratometry methods. Key words: radial keratotomy, phacoemulsification, tunnel incision, intersection of the keratotomy scar, cornea optical coherence tomography.