1. Optic Coherence Tomography Evaluation of Intrastromal Ring Segments Implanted Manually and with a Femtosecond Laser Author: Nicolas Cesário Pereira, M.D Co-Authors: Mayana Freitas Lopes, M.D Camile Tonin, M.D. Leon Grupenmacher, M.D. Luciene Barbosa de Sousa, M.D. Sorocaba Eye Bank Sorocaba-SP - Brazil The authors have no financial interest in the subject matter of this poster Author: Nicolas Cesário Pereira, M.D Co-Authors: Mayana Freitas Lopes, M.D Camile Tonin, M.D. Leon Grupenmacher, M.D. Luciene Barbosa de Sousa, M.D. Sorocaba Eye Bank Sorocaba-SP - Brazil The authors have no financial interest in the subject matter of this poster

2. Introduction  Intrastromal corneal ring segments have been implanted for 14 years with the manual tunnelization technique  Induces central cornea aplanation  Indications: Keratoconus, MPD, Post-LASIK ectasia, post PK, post RK, post trauma  Reversible, adjustable with fast visual reabilitation  Femtosecond Laser can be used for tunnelization  AS-OCT can be used to evaluate ring segments depth

3. Purpose  To evaluate intrastromal corneal ring segment depth with a high-speed corneal optical coherence tomography (OCT) system and to compare two techniques to implant the rings: the manual technique and assisted by the femtosecond laser

4. Setting  Hospital Oftalmologico De Sorocaba, Sorocaba Eye Bank, Sorocaba, Brazil. All the surgeries, exams and this study were carried out at Sorocaba Eye Bank.

5. Methods  Retrospective review of 34 patients submitted to intrastromal corneal ring implantation at Sorocaba Eye Bank between 2006 and 2008. Prospective evaluation with OCT was performed at least 3 months after the procedure.  Statistical analysis: t test, block variable analysis and Pearson correlation analysis  Retrospective review of 34 patients submitted to intrastromal corneal ring implantation at Sorocaba Eye Bank between 2006 and 2008. Prospective evaluation with OCT was performed at least 3 months after the procedure.  Statistical analysis: t test, block variable analysis and Pearson correlation analysis

6. Methods  Measurements with OCT-Visante: Keraring R : Triangular shape with base angle = 0 o Images with High Resolution Corneal Quad Measurements realized with Caliper 3 measurements: M1: Anterior cornea surface to apice of implant M2: Base of implant to posterior cornea surface M3: Full thickness cornea measurement central to the implant  Measurements with OCT-Visante: Keraring R : Triangular shape with base angle = 0 o Images with High Resolution Corneal Quad Measurements realized with Caliper 3 measurements: M1: Anterior cornea surface to apice of implant M2: Base of implant to posterior cornea surface M3: Full thickness cornea measurement central to the implant

7. Results  41 eyes: 39 Keratoconus and 2 MPD  24 implanted manually; 17 with FS  FS: Deeper and more regular  Planed depth was closer achived with FS  No statistical diference in clinical results Complications: 3 extrusions (12,5%) with manual technique; no complications with FS In 2 patients with FS  OCT couldn’t measure residual cornea, but the patients were OK.  41 eyes: 39 Keratoconus and 2 MPD  24 implanted manually; 17 with FS  FS: Deeper and more regular  Planed depth was closer achived with FS  No statistical diference in clinical results Complications: 3 extrusions (12,5%) with manual technique; no complications with FS In 2 patients with FS  OCT couldn’t measure residual cornea, but the patients were OK.

8. MANUALFEMTOSECOND LASER P Value AV pré c/c (Snellen) 0,31790,37790,1656 AV pré c/c (logMAR) 0,59500,72000,2287 AV pós c/c (Snellen) 0,75830,73820,6748 AV pós c/c (logMAR) 0,13330,14120,7830 EE pré-7,7708-8,81250,3975 EE pós-3,8806-3,87500,9954 Astigmatismo topo pré6,14175,75880,6706 Astigmatismo topo pós3,32174,14380,2459 Prof. planejada0,41460,40000,2160 Prof pós ANP ANC AND 0,2794 0,2627 0,2522 0,3507 0,3673 0,001 0,0001 <0,0001 Prof pós ATP ATC ATD 0,2310 0,2371 0,2316 0,3580 0,3607 0,3729 <0,0001 AV= acuidade visual; c/c=com correção; EE= equivalente esférico; Prof.=profundidade; ANP= anel nasal proximal; ANC=anel nasal central; AND= anel nasal distal; ATP= anel temporal proximal; ATC= anel temporal central; ATD= anel temporal distal.

9. MANUAL FS  No relation with VA and depth of implants

10. Results Manual Femtosecond Laser

11. Conclusions  OCT showed to be useful to evaluate the depth and regularity of intracorneal ring segments  No difference in the clinical results  Rings deeper and more regular with the FS  This can lead to less extrusion rate and less complications with FS.  OCT showed to be useful to evaluate the depth and regularity of intracorneal ring segments  No difference in the clinical results  Rings deeper and more regular with the FS  This can lead to less extrusion rate and less complications with FS.

12. THANK YOU!