Haigis and SRKT formulae accuracy for intentional myopic overcorrection.

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.

Vitamin A and the eye: an old tale for modern times.

Clinical presentations associated with vitamin A deficiency persist in poor regions globally with the same clinical features as those described centuries ago. However, new forms of vitamin A deficiency affecting the eyes, which have become widespread, as a result of modern societal habits are of increasing concern. Ophthalmic conditions related to vitamin A deficiency require the combined attention of ophthalmologists, pediatricians, internists, dermatologists, and nutritionists due to their potential severity and the diversity of causes. As the eyes and their adnexa are particularly sensitive to vitamin A deficiency and excess, ocular disturbances are often early indicators of vitamin A imbalance. The present review describes the clinical manifestations of hypovitaminosis A with an emphasis on so-called modern dietary disorders and multidisciplinary treatment approaches. The present review also discusses the relationship between retinoic acid therapy and dry eye disease.

Vitamin A and the eye: an old tale for modern times / A vitamina A e o olho: uma velha história em tempos modernos

ABSTRACT Clinical presentations associated with vitamin A deficiency persist in poor regions globally with the same clinical features as those described centuries ago. However, new forms of vitamin A deficiency affecting the eyes, which have become widespread, as a result of modern societal habits are of increasing concern. Ophthalmic conditions related to vitamin A deficiency require the combined attention of ophthalmologists, pediatricians, internists, dermatologists, and nutritionists due to their potential severity and the diversity of causes. As the eyes and their adnexa are particularly sensitive to vitamin A deficiency and excess, ocular disturbances are often early indicators of vitamin A imbalance. The present review describes the clinical manifestations of hypovitaminosis A with an emphasis on so-called modern dietary disorders and multidisciplinary treatment approaches. The present review also discusses the relationship between retinoic acid therapy and dry eye disease.

RESUMO As apresentações clínicas associadas à deficiência de vitamina A persistem em regiões pobres ao redor do mundo com os mesmos achados clínicos descritos há séculos. No entanto, novas formas de problemas causados pela vitamina A afetam os olhos, estão associados com os hábitos da sociedade moderna e tem causado preocupação. Eles exigem a atenção dos oftalmologistas, pediatras, internistas, dermatologistas e nutricionistas, devido à sua gravidade e diversidade de causas. Uma vez que os olhos e seus anexos são órgãos muito sensíveis à deficiência e excesso de vitamina A, manifestações oculares podem ser indicadores precoces do desequilíbrio de vitamina A. Essa revisão traz as manifestações clínicas de hipovitaminose A enfatizando os chamados distúrbios dietéticos modernos e formas de abordagem multidisciplinar. E também traz evidências sobre a relação entre a terapia com ácido retinóico e doença do olho seco.