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Purpose: To assess the accuracy of intraocular lens (IOL) power formulas, namely, SRK/T, Haigis, Barrett Universal II, Barrett True-K for keratoconus, Kane formula, and Kane formula for keratoconus, for cataract with keratoconus in Japanese eyes. Setting: Five surgical sites in Japan. Design: A retrospective case series. Methods: Eyes with keratoconus undergoing cataract surgery were included. Postoperative refraction was compared with the prediction by the formulas. Visual acuity, manifest spherical equivalent, prediction error (PE), and mean absolute errors (MAEs) were determined 1 month postoperatively. The PE within 0.50 diopter (D), 1.00 D, and 2.00 D were compared between IOL formulas. Subgroup analysis based on the steepest keratometry (stage 1, ≤ 48 D; stage 2, > 48 D and ≤ 53 D; and stage 3, > 53 D) was performed. The relationship between PE and preoperative biometric data were assessed. Results: Fifty eyes were included. The MAE of the Barrett True-K for keratoconus, Kane keratoconus, and Kane formulas were significantly lower than that of Haigis. A statistically significant difference in the prediction accuracy within ± 0.50 D was found between Kane keratoconus and Haigis. The prediction accuracy of the Barrett True-K for keratoconus, SRK/T, and Kane within ± 1.00 D was statistically significant compared with that of Haigis. In stage 3, the Barrett True-K for keratoconus had a significantly lower MAE than SRK/T and Haigis. Conclusion: Keratoconus-specific formulas were more accurate than existing formulas in Japanese eyes. The Barrett True-K formula for keratoconus had higher prediction accuracy in severe keratoconus. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the repeatability of the optical coherence tomography (OCT) retinal shape measurement with and without alignment correction in children and adults. Methods: 62 eyes of the 31 subjects were examined on the OCT with auto-alignment and alignment correction functions. We performed three measurements on each eye, created 2D retinal height maps, and extracted horizontal and vertical profiles for repeatability analysis and Legendre polynomial representation. Repeatability was determined from the average standard deviation. We estimated the refractive errors produced by the observed alignment errors. We also examined the repeatability improvement of the slopes, curvatures, and higher-order coefficients for the subjects using the Student t test. Results: Repeatability was higher in the data with alignment. We observed the average repeatability in the child group with standard deviation (SD) equal 38.20 µm in raw data, and SD = 6.11 µm in the corrected data, in adults SD = 17.04 µm in raw data, and SD = 5.22 µm in the corrected data. The slope repeatability improved in both child [horizontal t (18) = 4.62, p < 0.001 and vertical t (17) = 4.43, p < 0.001] and adult groups [t (18) = 2.73, p = 0.007 and vertical t (26) = 2.14, p = 0.02], while higher-order coefficients were not affected. Conclusions: Alignment correction improved repeatability of the OCT retinal shape measurements, especially for child subjects. Curvature and higher-order distortions were not affected by the alignment error. The refractive errors produced by alignment errors are low, and the model can be used to estimate the peripheral refraction. [ABSTRACT FROM AUTHOR]

It is difficult to assess the pure impact of the type of residual astigmatism (with-the-rule; WTR, against-the-rule; ATR, and oblique astigmatism) on uncorrected distance visual acuity (UDVA) in pseudophakic eyes due to different age distribution of patients between those subgroups. We conducted the current study to investigate the association between astigmatism type and UDVA in eyes after cataract surgery with consideration for various confounding factors such as age. Data were retrospectively collected from 1535 pseudophakic eyes with corrected distance visual acuity (CDVA) of 20/20 or better, and spherical equivalent between − 0.125 D and 0.0 D. They were classified based on the pattern of residual refractive astigmatism into four groups; minimum astigmatism (< 0.5 D), WTR, ATR, and oblique astigmatism groups. The stepwise multivariate regression analysis showed that the magnitude of residual refractive astigmatism (standardized partial regression coefficient β = 0.559, p < 0.001), CDVA (β = 0.381, p < 0.001), minimum astigmatism group (β = − 0.188, p < 0.001), and WTR astigmatism group (β = − 0.058, p < 0.001) were significantly associated with UDVA (r2 = 0.795). Variables excluded from the multivariate regression model include age, preoperative corneal astigmatism, axial length, anterior chamber depth, intraocular lens power, and postoperative spherical equivalent. These results indicate that UDVA is significantly better in eyes with minimum and WTR astigmatism than in those with ATR and oblique astigmatism, after adjustment for confounding parameters. In pseudophakic eyes, oblique and ATR astigmatism exerts a greater impact on UDVA than WTR astigmatism does, even after controlling for age. [ABSTRACT FROM AUTHOR]

Purpose: To assess whether the outcomes of toric intraocular lens (IOL) implantation in eyes with oblique astigmatism can be improved by direct measurements of posterior corneal astigmatism using anterior segment optical coherence tomography (AS-OCT) instead of by using anterior corneal measurements alone. Study design: Retrospective case series. Methods: Two toric IOL power calculation methods were compared: anterior corneal astigmatism was used in the keratometry group, whilst total corneal astigmatism determined by ray tracing through the measured anterior and posterior corneal surfaces was used in the AS-OCT group. In a total of 279 eyes of 232 patients, subgroup analysis was conducted for with-the-rule (WTR) (85 eyes in the keratometry group and 34 eyes in the AS-OCT group), against-the-rule (ATR) (73/29 eyes), and oblique (26/32 eyes) astigmatism. Results: In the WTR and ATR astigmatism groups, the uncorrected distance visual acuity (UDVA) was significantly better in the AS-OCT group than in the keratometry group (P = 0.012 and P < 0.001, Mann–Whitney test), and the residual astigmatism was significantly smaller in the AS-OCT group than in the keratometry group (P = 0.037 and P < 0.001). In eyes with oblique astigmatism, the UDVA (P = 0.299) and residual astigmatism (P = 0.373) of the keratometry and AS-OCT groups did not differ. Conclusion: Incorporation of posterior corneal astigmatism measured with AS-OCT can significantly improve the outcomes of toric IOL implantation in eyes with WTR and ATR astigmatism, but not in eyes with oblique astigmatism. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to determine the incidence of and risk factors for intraocular pressure (IOP) elevation within 24 h following vitrectomy for rhegmatogenous retinal detachment (RD). Methods: We assessed 34 eyes of 34 consecutive patients with RD undergoing vitrectomy and 12 eyes of 12 patients with macular hole as controls. IOP was measured using Tonopen XL before surgery, at the end of surgery, and at 5 h and 1 day postoperatively. IOP at the end of surgery was adjusted to 15.0 ± 2.0 mmHg. Results: IOP elevation was found in five RD eyes at 5 h and in 13 1 day postoperatively. IOP in patients with RD at both 5 h and 1 day postoperatively was significantly higher than that of controls. Circumferential dimension of retinal tears and disease duration were significantly associated with IOP elevation at both 5 h and 1 day postoperatively. Conclusions: IOP elevation in the early postoperative period following vitrectomy for RD is common. The risk factors for IOP elevation include the extent of retinal tears and duration of detachment. Prophylactic treatment may be useful in eyes with higher risks of IOP elevation. [ABSTRACT FROM AUTHOR]