Ocular biometric changes after double arc ICRS implantation in keratoconus treatment

Session Details

Session Title: Photoablation, Cross-Linking and Intracorneal Ring Segment

Session Date/Time: Monday 07/09/2015 | 08:00-10:30

Paper Time: 09:06

Venue: Room 16

First Author: : P.Caddah BRAZIL

Co Author(s): :    C. Oliveira   H. Melo   M. Machado   J. Filho   C. Costa   E. Nakano     

Abstract Details

Purpose:

To evaluate intra-ocular structures biometric relationship changes in conic eyes after implantation of a double arc ICRS in keratoconus.

Setting:

This multicenter, prospective, randomized study is being conducted at Federal University of São Paulo, UNIFESP and at Hospital Oftalmológico de Brasília, HOB.

Methods:

Forty eyes of 40 patients were divided into group A (K max up to 60D) and B (K max from 61 to 75D). Eyes were also divided into two sub-groups according to the corneal astigmatism. Corneas with topographic astigmatism up to 5D received a 330 degrees segment; and those with higher amounts of astigmatism received two 160 degrees segments. Interferometry was used to assess ocular biometric data. Corneal paqhymetry and Q-value data were obtained with scheimpflug imaging system.

Results:

To date, 28 eyes completed 3 months of follow-up. Mean preoperative K max was 59.55D; axial length (AL) was 24.15mm; corneal thickness 468 micra; anterior chamber depth (ACD) 3.78mm; vitreous chamber (VC) 20.35mm.The ratio ACD/AL varied from 0.156, to 0.154 and 0.157; ACD/VC from 0.185 to 0.183 and 0.187; and VC/AL from 0.842 to 0.845 and 0.842, respectively from the preop to 30 days and 3 months after the surgery.Corneal Q-value and Kmax evouluted from -0.271 (59.55D) preoperatively, to -0.675 (57.58D) and -1.784 (58.88D) after 30 days and 3 months of the implant.

Conclusions:

The expected effects of the double arc ICRS are central flattening, corneal asphericity modulation and centration, and corneal astigmatism management. An increase of Q-value within 5mm central zone was observed overtime due to the centralization of the corneal asphericity after the implant. Nevertheless, nor change of Kmax neither in ratio between AL, ACD and VC may lead us believe that the used 45D proflie double arc ICRS played a role on remodelling the corneal asphericity with its better centration, without altering the relashionshipe between ocular structures. These findings may also be important in a future cataract surgery for these patients.

Financial Interest:

NONE