Purpose
To compare the accuracy of SRK/T and Haigis formulae used for intraocular lens (IOL) power calculation by a partial coherence interferometer in patients undergoing phacoemulsification surgery.
Patients and methods
A prospective interventional clinical study included 70 eyes of 60 patients, who underwent uncomplicated phacoemulsification with IOL implantation from October 2015 to December 2017. Preoperative axial length (AL), corneal curvature (keratometry), and preoperative anterior chamber depth (preoperative ACD) were measured using Nidek AL-scan optical biometer and the IOL power was determined using both SRK/T and Haigis formulae. The difference between the predicted value and the postoperative spherical equivalent was calculated for both the formulae by the end of the follow-up (3 months postoperatively).
Results
The mean errors of the two formulae were SRK/T: −0.225±0.61 D and Haigis: 0.171±0.68 D; the mean absolute errors of the two formulae were 0.534±0.36 and 0.533±0.44 D, respectively. There was no statistically significant difference between the mean error of the two formulas used in the overall performance, but was significant in eyes with an AL of more than 25 mm. The proportion of patients having a prediction error within ±0.50 D of SRK/T formula (54.29%) was comparable to those of Haigis (55.71%) and the prediction errors within ±1.0 D were 87.14 and 85.71%, respectively. There is a weak correlation between the mean AL, keratometry and the Haigis–SRK/T prediction differences (r
2=0.273).
Conclusion
The calculation of IOL power using SRK/T and Haigis formulae resulted in an accurate postoperative refraction. In long AL subcategory, the mean absolute error of Haigis was less compared with the SRK/T formula.
Article informationBackground: Impression cytology is a noninvasive technique for assessing the ocular surface cells and can be used for recognition of changes that occur in the conjunctiva especially among patients who had thyroid diseases.
Aim of the work:To assess the efficacy of impression cytology in the diagnosis of ocular surface changes in patients with thyroid diseases in relation to other noninvasive diagnostic methods.
Patients and Methods: The study included 30 patients [60 eyes] with thyroid disease [both hypo-and hyper-thyroidism] aged 20-40 years, in which an ocular tear film was evaluated. In addition, 30 subjects [60 eyes] in age from 20-40 years were also examined as control group. All patients finished the routine ophthalmological assessment, fluorescein tear breakup time [TBUT], Schirmer test and conjunctival impression cytology [CIC]. Results: The eyes in the thyroid disorder patients showed grade 1, 2 and 3 in CIC with decreasing Schirmer test and tear breakup time test values less than 10 seconds, while the control group showed grade 0 in the CIC with increasing Schirmer test and tear breakup time test values more than 10 seconds [P-value < 0.01].
Conclusion:Impression cytology is a non-invasive method for evaluating ocular surface cell morphology and can be used to recognize, and assess the severity of the changes occurring in the conjunctiva in patients with thyroid disease.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.