Accurate determination of effective lens position and lens-capsule distance with 4 intraocular lenses

Findl, Oliver; Drexler, Wolfgang; Menapace, Rupert; Bobr, Barbara; Bittermann, S.; Vass, Clemens; Rainer, Georg; Hitzenberger, Christoph K.; Fercher, Adolf Friedrich

doi:10.1016/s0886-3350(98)80103-x

Cited by 86 publications

(40 citation statements)

References 13 publications

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“…The principle of this biometry technique has been described in detail previously. [12][13][14] A novel commercially available interferometer, the AC Master (Zeiss Meditec, Jena, Germany), that is based on the same measurement principle was used to measure central corneal thickness (CCT), anterior chamber depth (ACD), and lens thickness (LT). CCT was defined as the distance from the anterior corneal surface to the posterior corneal surface, ACD as the distance from the anterior corneal surface to the anterior lens surface, and LT as the distance from the anterior lens surface to the posterior lens surface.…”

Section: Methodsmentioning

confidence: 99%

Effects of change in intraocular pressure on axial eye length and lens position

Leydolt

Findl

Drexler

2007

Eye

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Purpose To quantify the biometric changes of ocular dimensions with mechanical elevation of intraocular pressure (IOP) in vivo, to get a better understanding of the elastic properties of the human ocular structures that may play a role in the pathogenesis of various diseases such as myopia or glaucoma. Methods Changes in IOP were induced by a suction cup in 18 eyes under cycloplegia. Axial eye length (AEL) and anterior chamber depth (ACD) were measured with non-invasive laser interferometry during elevation of the IOP 10 and 20 mmHg over baseline values and after a 10-min resting period. Results IOP elevation of 10 and 20 mmHg respectively caused a significant increase of AEL of 23 lm (95% confidence interval: 14-34 lm) and 39 lm (confidence interval (CI): 28-51 lm). After mechanical oculopression, which resulted in an IOP reduction of -5.1 mmHg (CI: À6.3 to À4.0 mmHg) vs baseline, a significant shortening of À7 lm (CI: À13 to 0 lm) was observed. The change in AEL correlated with the change in IOP (r ¼ 0.66, P ¼ 0.005). Furthermore, a significant increase in ACD of 30 lm (CI: 24-36 lm) was detected with IOP reduction after oculopression, but no change was seen during IOP elevation. Conclusions Biometric changes of the human eye as a response to IOP changes were assessed in vivo. The correlation between change in AEL and IOP found emphasizes the need of in vivo ocular rigidity measurements in the human eye.

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Section: Methodsmentioning

confidence: 99%

Effects of change in intraocular pressure on axial eye length and lens position

Leydolt

Findl

Drexler

2007

Eye

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“…Although the results might differ owing to measuring principles inherent to the system, ACD was measured with an IOLMaster s in the present study as this is an established method. 11,37,[40][41][42][43][44][45] To avoid significant measurement differences related to imprecisions of the measurement method, we used the same method to measure the ACD in all the groups. We measured the OS at the end of 6 months as anterior capsule fibrosis causes a small backward shift of the IOLs and a slight enlargement in the CCC area with both multi-piece and single-piece IOL designs between 1 and 6 months.…”

Section: Discussionmentioning

confidence: 99%

“…While analyzing this shift in the IOL, some studies have mentioned the anterior capsule cover of the IOL optic edge, 3,4 whereas others have not made any mention of it. [5][6][7][8][9] With the increasing use of multifocal IOLs, in which postoperative emmetropia is the main goal, the size of the capsulorhexis (CCC) would be of immense importance as it could influence its refractive power.…”

Section: Introductionmentioning

confidence: 99%

Anterior capsule cover and axial movement of intraocular lens

Nanavaty

Raj

Vasavada

et al. 2007

Eye

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Purpose To measure optic shift (OS) of a single piece monofocal intraocular lens (IOL) with varying relationships between anterior capsule cover and IOL optic. Methods This is a prospective randomized masked study of 150 eyes undergoing phacoemulsification. Eyes received either option: 360 o total capsule cover (group I); partial cover (group II); or no cover (group III). OS was calculated as difference in anterior chamber depth after administration of cyclopentolate 1% and pilocarpine 2% on IOLMaster s at separate visits at 6 months follow-up. Subsequently, using retro-illumination photographs, percentage area of capsule cover was calculated. OS within and between groups I and II was analyzed. The impact of one quartile change in area of capsule cover on percentage change in OS was measured for both groups. Unpaired t-test, correlation, and regression were applied. Results In groups I, II, and III, mean age of patients was 56.6876.38, 57.0977.34, 59.1576.35 years, respectively; mean OS (mm) was 1.2570.28, 1.2070.24; 0.9570.26 (P ¼ 0.013), respectively; and percentage area of capsule cover (%) was 47.35710.48, 33.83710.11, 0.1670.13 (P ¼ 0.001), respectively. Mean percentage area of capsule cover in group I vs group II was significant (P ¼ 0.001). OS was 1.2270.26 mm in groups I and II (combined) vs 0.9570.26 mm in group III (P ¼ 0.004, (0.06, 0.33)). OS in group I vs group II was not significant (P ¼ 0.46). Correlation coefficient was r ¼ 0.38 (Po0.001). With every increment on quartile (a quartile is any of the three values which divide the sorted data set into four equal parts, so that each part represents one-fourth of the sample or population) class of area of capsule cover the OS increased by 0.12 mm. ConclusionThe OS differed significantly between total and partial cover groups combined vs no cover group.

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“…The ACD can be measured with different ophthalmological techniques, such as ultrasound biometry, high-resolution magnetic resonance imaging, ultrasound biomicroscopy, Scheimpflug imaging, anterior segment optical coherence tomography, and partial coherence interferometry. 31,33,34 We used objective measurements with a newly developed high accuracy interferometric device.…”

Section: Discussionmentioning

confidence: 99%