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Review
. 2020 Jan-Feb;83(1):76-81.
doi: 10.5935/0004-2749.20200014.

Centration in refractive surgery

Lívia Cristina Rios  1 , Patrícia Gomes da Silva  1 , Aristófanes Mendonça Canamary Junior  2 , Pablo Rodrigues  2 , Caio Vinícius Saito Regatieri  1   2 , Mauro Campos  2 , Bernardo Kaplan Moscovici  1   2
Affiliations
Review

Centration in refractive surgery

Lívia Cristina Rios et al. Arq Bras Oftalmol. 2020 Jan-Feb.

Abstract
in English, Portuguese

The point of centration for refractive surgery is a theme of great importance that generates considerable discussion among specialists and surgeons in the field. Notably, any changes in light can alter the size of the pupil, and the visual axis of the fixation line to the fovea is unique in each patient. A variety of options have been described in the literature with respect to centration in refractive surgery, and the results differ among these methods. No consensus has been established regarding the ideal refractive surgery technique for evaluation of centration in each patient that will yield a satisfactory surgical result.

O ponto de centralização da cirurgia refrativa é tema de grande importância e gera muita discussão entre especialistas e cirurgiões da área. Afinal, qualquer alteração na luz pode alterar o tamanho da pupila, além disso, o eixo visual da linha de fixação para a fóvea é particular em cada paciente. Existem opções para centralização em cirurgia refrativa com resultados diferentes na literatura. Ainda não há consenso sobre a melhor técnica em cirurgia refrativa que avalie cada caso específico visando um resultado cirúrgico final satisfatório.

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Conflict of interest statement

Disclosure of potential conflicts of interest: None of the authors have any potential conflicts of interest to disclose.

Figures

Figure 1
Figure 1
Corneal Vertex and Pupil Center using AcuTarget (SensoMotoric Instruments, Teltow, Germany).
Figure 2
Figure 2
Geometric center of the cornea (GCC), entrance pupil center (EPC), and coaxially sighted corneal light reflex (CSCLR) as identified by Pande and Hillman,[] (b) Surgeon’s view of a large angle kappa, (c) Surgeon’s view of a normal but small positive angle kappa. Reference: Moshirfar M, Hoggan RN, Muthappan V. Angle Kappa and its importance in refractive surgery. Oman J Ophthalmol. 2013;6(3):151-8. (15)
Figure 3
Figure 3
Schematic drawing of reference points: corneal vertex; pupil center; pupillary axis; visual axis; and line of sight.
Figure 4
Figure 4
Chord mu (m) as measured under (top panel) photopic and (bottom panel) scotopic light conditions. While the position of subject-fixated coaxially sighted corneal light reflex does not change under different lighting conditions, the center of the entrance pupil is altered with dilation, resulting in an increased chord m under scotopic conditions.
See this image and copyright information in PMC

References

    1. Schor P. Óptica-fisiológica e cirurgia refrativa [Livre docência] São Paulo: Universidade de São Paulo, Escola Paulista de Medicina, Departamento de Oftalmologia; 2003.
    1. De Ortueta D, Schreyger FD. Centration on the cornea vertex normal during hyperopic refractive photoablation using videokeratoscopy. J Refract. 2007;23(2):198–200. - PubMed
    1. Reinstein DZ, Gobbe M, Archer TJ. Coaxially sighted corneal light reflex versus entrance pupil center centration of moderate to high hyperopic corneal ablations in eyes with small and large angle kappa. J Refract Surg. 2013;29(8):518–525. - PubMed
    1. Chang JS, Law AK, Ng JC, Chan VK. Comparison of refractive and visual outcomes with centration points 80% and 100% from pupil center toward the coaxially sighted corneal light reflex. J Cataract Refract Surg. 2016;42(3):412–419. - PubMed
    1. Fahd DC, Jabbour E, Fahed CD. Static cyclotorsion measurements using the Schwind Amaris laser. Arq Bras Oftalmol. 2014;77(3):159–163. - PubMed

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