Haigis and SRKT formulae accuracy for intentional myopic overcorrection.
Int Ophthalmol
; 38(4): 1459-1463, 2018 Aug.
Article
em En
| MEDLINE
| ID: mdl-28639087
ABSTRACT
PURPOSE:
To investigate the influence of preoperative biometric parameters on the accuracy of Haigis and SRKT formulae in predicting postoperative target refraction.METHODS:
Retrospective analysis of 108 eyes (70 patients) underwent uneventful phacoemulsification surgery with implant of Alcon-SN60WF intraocular lens (IOL). Forty-five eyes were intentionally targeted to myopia (-0.75 to -1.25 dpt), while the others targeted between 0 and -0.75 dpt. Preoperative axial length and keratometry (K) were measured with optical biometry (LENSTAR-Haag-Streit). Postoperative spherical equivalent was assessed 3 ± 2 months after surgery.RESULTS:
There is a significant correlation between the mean keratometry (K) and the Haigis-SRKT prediction differences (P < 0.001; r = 0.749). Linear regression indicates that a decrease of 1 diopter (D) on K implies an increase of 0.23 D on the difference between formulae prediction. K alone does not influence the prediction error for both formulas. The difference between the two formulae is dependent on K (r = -0.75; P < 0.01). Moreover, eyes with K <43.75 targeted at myopia (n = 23) showed a significant myopic shift of -0.26 ± 0.09 dpt (P < 0.05) with Haigis, but a hyperopic shift of 0.24 ± 0.09 dpt (P < 0.05) with SRKT.CONCLUSION:
Divergences between Haigis and SRKT formulae cause uncertainty in choosing the IOL. Our results indicate that, in eyes with lower preoperative K, an IOL targeted at myopia might result in a small, but significant myopic shift with the Haigis formula, while a hyperopic shift with the SRKT formula.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Refração Ocular
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Catarata
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Biometria
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Facoemulsificação
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Óptica e Fotônica
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Lentes Intraoculares
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Miopia
Tipo de estudo:
Observational_studies
/
Risk_factors_studies
Limite:
Aged
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Aged80
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article