Comparison of the Refractive Outcomes According to the Differences of Biometry and Keratometry Reading

PURPOSE: The purpose of this study was to investigate the error tendency between preoperative expected refraction and postoperative manifest refraction based on axial length, anterior chamber depth, and keratometric data obtained by an automated keratometer and Pentacam(R) in cataract surgery cases and to report how their differences affect determination of intraocular lens (IOL) power. METHODS: The authors retrospectively reviewed the medical records of 110 eyes of 84 patients who underwent cataract surgery. Axial length and anterior chamber depth were measured by A scan ultrasound biometry, while keratometric values were obtained by an automated keratometer and Pentacam(R). IOL power was calculated using the SRK/T formula. Patients were divided into 3 groups based on the axial length, anterior chamber depth, and the difference of keratometric values between the 2 devices. Refractive error was analyzed 2 months after surgery. RESULTS: There were no statistically significant differences between axial length and anterior chamber depth among the groups; however, the K reading differences were statistically significant. Although the mean absolute error (MAE) of each group showed no statistical significance among the groups, the MAE was more pronounced in the group in which the keratometeric value measured by Pentacam(R) differed more than 1.00 diopter from the automated keratometer measurements. CONCLUSIONS: There was no statistically significant difference between axial length and anterior chamber depth among the groups. A difference of 1.00 diopter or more between the keratometric values obtained by an automated keratometer and Pentacam(R) significantly affects the postoperative refractive error; therefore, these factors should be considered when determining IOL power.

Current progress in the application of Pentacam scheimpflug system in anterior eye segment photography / 中华实验眼科杂志

Pentacam scheimpflug system utilize the principle of Scheimpflug to image the anterior eye segment.It equips with an automatically rotating Scheimpflug camera to perform a complete measurement of the anterior segment.A precise analysis of the corneal thickness,corneal topography,anterior chamber and crystalline lens are carried out during the operation.These data then provide the basis for a three-dimensional model of the complete anterior segment.The Pentacam scheimpflug system offers a wide range of functions in refractive surgery,keratoconus analysis,glaucoma screening and phacoemulsification.The newest progression in the application of the Pentacam in anterior ocular segment photography were reviewed.

Angle imaging: Advances and challenges.

Primary angle closure glaucoma (PACG) is a major form of glaucoma in large populous countries in East and South Asia. The high visual morbidity from PACG is related to the destructive nature of the asymptomatic form of the disease. Early detection of anatomically narrow angles is important and the subsequent prevention of visual loss from PACG depends on an accurate assessment of the anterior chamber angle (ACA). This review paper discusses the advantages and limitations of newer ACA imaging technologies, namely ultrasound biomicroscopy, Scheimpflug photography, anterior segment optical coherence tomography and EyeCam, highlighting the current clinical evidence comparing these devices with each other and with clinical dynamic indentation gonioscopy, the current reference standard.

Periodic Biometry in Three Types of Posteriorly Implanted IOLs: PMMA, Silicone, and Acrylic Soft, by EAS-1000 Scheimpflug Photography

To compare any differences in the periodic biometric values (decentration, tilt and anterior chamber depth)and corrected visual acuity among PMMA, silicone, and acrylic IOLs, a total of 137 cataractous eyes of 108 patients undergoing IOL implant surgery were divided into 3 groups based on the type of IOL :group A -65 eyes of PMMA IOL (MZ60BD), group B -47 eyes of silicone IOL (SI30NB), and group C -25 eyes of Acrysof IOL (MA60BM). The biometric analyses of all study groups were quantified using EAS-1000 Scheimpflug camera.All eyes underwent EAS-1000 examination at 1, 3, and 6 months after surgery.Also best corrected visual acuity was examined at 1, 3, and 6 months.The anterior chamber increased at 1 month after surgery and no statistical differences were found among the three groups. Furthermore, the differences regarding both the position of the IOLs (decentration and tilting)and the final corrected visual acuity of three groups throughout the observation period were not statistically significant. In conclusion, as long as proper capsulorhexis was performed and the IOLs were placed accurately in the healthy capsular bags, changes of anterior chamber depth, decentration, tilt and corrected visual acuity were all found to be almost similar among any of the three IOL types.

Long-term Periodic Analysis of Senile Cataract with Computerized Anterior Segment Analyser

To evaluate the progression of the cataract, we examined the retroillumination and the slit image of the lens by using EAS-1000 Scheimpflug photography in 50 individuals(91 eyes) with senile cataract from September 1990 to January 1996. We analyzed the cataract progression periodically by retroillumination for opacity area(%) change and Scheimpflug photography for density change of at each eyes at the same time. And we examined cataract type progression by aging and medication effect. In the retroillumination image, the monthly increment of opacity areas were 1.24%. In the Scheimpflug photography(slit image), the monthly incerement was 4.23 CCT. Both the opacity area(%) changes and the density changes at each cataract type were faster in the young age group than other age group. Both the opacity area changes and the density changes were slower in the anticataract medication group than non-medication group, but it was statistically insignificant.

The Measurement of Therapeutic Effect of Bendaline(R) in Early Cataract using with Scheimpflug Camera

The Scheimpflug photography was used to evauate objectively changes in lens opacity at a month interval in 143 eyes of 78 patients affected by early cataract. from Dec. 1993 to Dec. 1994. A total of 48 patients were treated daily with 1.5g bendazac-lysine, and 30 patients constituted the control group. We checked visual acuity and analyzed change of lens opacity by using axial densitometry and retroillumination of Scheimpflug photography after Bendaline(R) medication up to 9 months After treatment, improvement or no change of subjective visual acuity was observed in 65 eyes(78.3%) of treated group, whereas decrement in 35 eyes (58.3%) of control group. In the axial densitometry, the nuclear opacity began to improve after 3 months of medication and opacities of lens between anterior supranucleus and posterior capsule were statistically significant improved after 5 months of medication (p0.05). The result show that bendazac lysine may be effective in improvement of visual acuity and delay the formation of lens opacity in early cataract.

Periodic Analysis of Senile Cataract with EAS-1000 Scheimpflug Photography

To evaluate the progression of senile cataract, we examined slit retroillumination and the slit image of the lens by using Scheimpflug photography in 56 individuals (96 eyes) with senile cataract from October. 1990 to July, 1992. We analyzed the cataract progression peridically by using retroillumination for opacity area (%) change and Scheimpflug photography for density change of at each eyes at the same time. And we examed cataract type progression by aging and medication effect. In the retroillumination image, the monthly changes of opacity areas were 2.67% in the first follow-up group. and 1.58% (p<0.01) in the second follow up group. In the Scheimpflug photography (slit image), the monthly changes of density at each cataract type were 7.67 CCT (p<0.01) in the first follow-up group, and 4.07 CCT (p<0.01) in the second follow-up group. Both the opacity area (%) changes and the deugity changes at each cataract type were faster in the young age group than other age group (p<0.01, p<0.05). Both the opacity area changes and the density changes were slower in the anticataract medication group than non-medication group, but it was insinificant statistically.