Evaluation of anterior and posterior surfaces of the cornea using a dual Scheimpflug analyzer in keratoconus patients implanted with intrastromal corneal ring segments.
OBJECTIVE
To evaluate corneal parameters measured with a dual Scheimpflug analyzer in keratoconus patients implanted with intrastromal corneal ring segments (ICRS).


METHODS
Fifty eyes of 40 keratoconus patients had Ferrara ICRS implantation from November 2010 to April 2014. Uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), refraction, keratometry, asphericity, elevation, pachymetry, root mean square (RMS), spherical aberration and coma were studied. All patients were evaluated using a dual Scheimpflug system.


RESULTS
The mean follow-up time after the procedure was 12.7mo. The mean UCVA improved from 0.82 to 0.31 (P<0.001); the mean BCVA improved from 0.42 to 0.05 (P<0.0001), the mean spherical refraction changed from -3.06±3.80 D to -0.80±2.5 D (P<0.0001) and the mean refraction astigmatism reduced from -4.51±2.08 D to -2.26±1.18 D (P<0.0001). The changes from preoperative to postoperative, in parameters of the anterior and posterior surface of the cornea, were statistically significant except the elevation posterior at the apex of the cornea and posterior asphericity.


CONCLUSIONS
The implantation of Ferrara ICRS induces changes in both anterior and posterior surfaces of the cornea.
Center for Excellence in Ophthalmology, Pará de Minas 35660-051, Brazil; Arce Clinic, Campinas 13106-028, Brazil.
Leonardo
L
Torquetti
Arce Clinic, Campinas 13106-028, Brazil.
Carlos
C
Arce
Fernandez-Vega Eye Institute, Oviedo 33012, Spain.
Jesús
J
Merayo-Lloves
Paulo Ferrara Eye Clinic, Belo Horizonte 30110-921, Brazil.
Guilherme
G
Ferrara
Paulo Ferrara Eye Clinic, Belo Horizonte 30110-921, Brazil.
Paulo
P
Ferrara
Campineiro Microsurgery Eye Center, Campinas 13013-161, Brazil.
Brenno
B
Signorelli
Campineiro Microsurgery Eye Center, Campinas 13013-161, Brazil.
Armando
A
Signorelli
dual Scheimpflug; intrastromal corneal ring segments; keratoconus
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