Clinical Evaluation of an Extended Depth of Focus Intraocular Lens With the Salzburg Reading Desk.

BACKGROUND: Clinical evaluation of an extended depth of focus (EDOF) intraocular lens (IOL) regarding visual performance at various distances, reading performance on an electronic reading desk, and depth of focus on the defocus curve. METHODS: In this prospective study, 30 eyes of 15 patients who received the Tecnis Symfony IOL (Abbott Medical Optics, Inc., Santa Ana, CA) were examined 3.60 ± 1.54 months postoperatively. Uncorrected and corrected distance (UDVA and CDVA), uncorrected and distance-corrected intermediate (UIVA and DCIVA), and uncorrected and distance-corrected near (UNVA and DCNVA) visual acuity were determined. The defocus curve was performed with distance correction. Furthermore, the reading acuity at the preferred near and intermediate distances was measured with consideration of the reading distance, speed, and print size. A subjective questionnaire was also administered. RESULTS: Results showed a median UDVA of 0.03 logMAR or 20/21.43 Snellen (range: 0.44 to -0.18 logMAR or 20/55.08 to 20/13.21 Snellen), UNVA of 0.20 logMAR or 20/31.70 Snellen (range: 0.46 to 0.00 logMAR or 20/57.68 to 20/20 Snellen), and UIVA of -0.03 logMAR or 20/18.67 Snellen (range: 0.14 to -0.18 logMAR or 20/27.61 to 20/13.21 Snellen). The improved performance at intermediate distance was confirmed by an uncorrected reading acuity of 0.09 logMAR or 20/24.61 Snellen (range: 0.36 to 0.00 logMAR or 20/45.82 to 20/20.00 Snellen) at a preferred intermediate distance of 64.10 cm (range: 52.0 to 75.0 cm). The defocus curve showed an extended range of visual acuity of 0.10 logMAR or better between 1.00 and -1.50 diopters. CONCLUSIONS: The EDOF IOL design provided a wide range of improved visual and reading function between far and intermediate distances and also improved near visual acuity. Patients reported a high rate of satisfaction and spectacle independence at the various distances. [J Refract Surg. 2017;33(10):664-669.].

Long-term outcomes of intrastromal femtosecond laser presbyopia correction: 3-year results.

BACKGROUND/AIMS: To analyse visual outcomes and corneal changes 3 years after intrastromal femtosecond laser presbyopia treatment. METHODS: In a prospective, unicentric clinical trial, 25 presbyopic patients received INTRACOR treatment (Technolas femtosecond laser) on their non-dominant eye. Examinations were performed preoperatively as well as 1, 24 and 36 months postoperatively and included refraction, near, intermediate and distance visual acuity tests, reading speed, corneal topography, stray light measurement, endothelial cell count and slit-lamp examination. RESULTS: Comparison of preoperative versus 36 months postoperative values showed in median an improvement of uncorrected near visual acuity (UNVA) from 0.70 logMAR to 0.10 logMAR (p<0.001). Corrected distance visual acuity (CDVA) was reduced from -0.10 logMAR to 0.00 logMAR (p<0.001). The spherical equivalent preoperatively was 0.625 D and after an initial myopic shift after 1 month (0.125 D) and 24 months (0.25 D), the 36 months value (0.50 D) returned to resemble the preoperative value in statistical terms (p=0.123). A significant corneal steepening of 1.50 D in the treated area was measured. Pachymetry (thinnest point) revealed a statistically significant, but clinically insignificant corneal thickening from 535 to 549 µm (p=0.033). Endothelial cell count did not change. 92.86% of patients felt comfortable with the surgery result. CONCLUSION: INTRACOR treatment after 36 months improved UNVA to varying degrees. The effect can be explained by a corneal steepening. An initial myopic shift was reversible. Reductions especially in CDVA have to be taken into account and therefore careful patient selection and information is obligatory. TRIAL REGISTRATION NUMBER: NCT01164358 and NCT01025050, Results.

Intrastromal femtosecond laser surgical compensation of presbyopia with six intrastromal ring cuts: 3-year results.

BACKGROUND/AIMS: To assess over a 36-month period functional results of the modified INTRACOR femtosecond laser-based intrastromal procedure to treat presbyopia. METHODS: 20 eyes of 20 presbyopic patients with mild hyperopia were included. The INTRACOR procedure with a modified pattern (six concentric intrastromal ring cuts) was performed using the FEMTEC femtosecond laser (Bausch+Lomb/Technolas Perfect Vision, Munich, Germany). Patients were also randomly divided into three subgroups to compare the effect of three different small inner ring diameters (1.8/2.0/2.2 mm (Groups A/B/C)). Follow-up examinations were performed at 1, 3, 6, 12, 24 and 36 months, and included near and distance visual acuity tests, slit-lamp examinations and corneal topography. RESULTS: Median uncorrected near visual acuity (UNVA) increased from 0.7/0.7/0.7 logMAR (Groups A/B/C) to -0.1/0.1/0.1 logMAR 36 months after surgery. Uncorrected distance visual acuity changed slightly from 0.1/0.2/0.1 logMAR to 0.2/0.3/0.1 logMAR. Losses of two lines of binocular corrected distance visual acuity (CDVA) were noted in 0/25/0% of eyes. Median spherical equivalent changed from 0.75/0.75/0.75 dioptres to -0.19/0.13/-0.19 dioptres. Overall patient satisfaction with the procedure was 80%. CONCLUSIONS: INTRACOR with a modified pattern improved UNVA in all patients over a 36-month follow-up period. The possibility of reduced CDVA underlines the need for careful patient selection. TRIAL REGISTRATION NUMBER: NCT00928122.

Implantation of three-piece silicone toric additive IOLs in challenging clinical cases with high astigmatism.

PURPOSE: To analyze the refractive outcomes and safety of three-piece silicone toric sulcus-fixated add-on intraocular lenses (IOLs) (HumanOptics/Dr.Schmidt Intraocularlinsen, Erlangen, Germany) in complex clinical cases with high astigmatism such as in cases with previous penetrating keratoplasty. METHODS: Interventional case series of 21 eyes of 20 patients enrolled at two German centers. Functional results including power vector analysis, accuracy of IOL power calculation, rotational stability, and postoperative complications were evaluated from 2 months to 6 years postoperatively. RESULTS: The preoperative subjective cylinder exceeded or was equal to -6.00 diopters (D) in 81% of eyes (range: -2.00 to -17.00 D). The median follow-up period was 7.6 months (range: 57 days to 6 years). The efficacy analysis focused on the 2 to 6 months follow-up visit. Postoperatively, there was a median reduction of astigmatism by 70.59% (subjective cylinder range: 0.00 to -5.00 D), improvement of uncorrected distance visual acuity, and unchanged median corrected distance visual acuity. The attempted spherical equivalent was achieved within ± 0.50 D in 45% and within ± 1.00 D in 65% of cases. Five eyes received secondary surgical alignment of axis. Other complications related to the surgical procedure were mainly transient shortly after implantation, such as intraocular pressure elevation (2 of 21 eyes) or corneal edema (2 of 21 eyes). Persisting changes were seen only in rare cases and included pigment dispersion (1 of 21 eyes) or corneal edema requiring a second keratoplasty within 9 months after surgery (2 of 21 eyes). CONCLUSIONS: Toric add-on IOLs may be useful in reducing high astigmatism and anisometropia and increasing spectacle independence even in complex clinical conditions with high refractive errors.

Influence of +3.00 D and +4.00 D near addition on functional outcomes of a refractive multifocal intraocular lens model.

PURPOSE: To clinically evaluate different near additions (adds) (+3.00 diopters [D] and +4.00 D) of the M-flex 630F refractive multifocal intraocular lens (IOL). SETTING: Departments of Ophthalmology, University of Heidelberg, Germany, and Lithuanian University of Health Sciences, Kaunas, Lithuania. DESIGN: Clinical prospective nonrandomized unmasked study. METHODS: Preoperatively, cataract patients were assigned to receive bilateral +3.00 D IOLs, +4.00 D IOLs, or +3.00 D (dominant eye) and +4.00 D (nondominant eye) IOLs. Follow-up examinations were performed up to 6 months postoperatively and included refraction, visual acuity (near at 40 cm and distance), the defocus curve, contrast sensitivity, and a subjective questionnaire. RESULTS: Fifty-two patients were enrolled. No significant differences were found in the visual acuity results (P>.05). Four to 6 months postoperatively, the following median uncorrected and corrected distance visual acuity, uncorrected and distance-corrected near visual acuity, and corrected near visual acuity (logMAR) were found in all patients: -0.08, -0.12, 0.20, 0.10, and 0.10. Ninety-eight percent of patients reported being satisfied. The highest near peak versus the biggest intermediate decline in the median monocular defocus curves comparing +3.00 D and +4.00 D multifocal IOLs (logMAR) were 0.16 at 40 cm versus 0.22 at 33 cm (P=.24) and 0.38 at 66 cm versus 0.54 at 50 cm (P<.01). CONCLUSION: Compared with the +4.00 D add, the +3.00 D near add gave better intermediate results in the defocus curve without compromising distance or near visual acuity.

Comparison of the maximum applicable stretch force after femtosecond laser-assisted and manual anterior capsulotomy.

PURPOSE: To objectively measure the strength of the capsulotomy performed with a femtosecond laser-assisted technique or performed manually in a pig-eye laboratory study. SETTING: International Vision Correction Research Centre, Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany. DESIGN: Experimental study. METHODS: Ten fresh pig eyes were randomly assigned to femtosecond laser-assisted capsulotomy or manual capsulotomy. The capsule was immersed in hyaluronic acid, and retractors were fixed in the capsule opening with a pull-force measuring device. The force necessary to break the capsulotomy was measured in millinewtons (mN); the maximum stretching ratio was also assessed. RESULTS: The observed mean rupture force (ie, maximum amount of force measured immediately before tissue rupture) was 113 mN ± 12 (SD) in the laser-assisted procedure and 73 ± 22 mN in the manual procedure (P<.05). The stretching ratios were 1.60 ± 0.10 (femtosecond) and 1.35 ± 0.04 (manual) (P<.05). CONCLUSION: In this laboratory pig-eye study, femtosecond laser-assisted capsulotomy resulted in a significantly stronger anterior capsule opening than the standard manually performed capsulotomy.

Implantation of a multifocal toric intraocular lens with a surface-embedded near segment after repeated LASIK treatments.

UNLABELLED: We report a 66-year-old patient who presented with increasing hyperopia, astigmatism, and presbyopia in both eyes 8 years after bilateral laser in situ keratomileusis (LASIK) and LASIK enhancement in the left eye aiming for spectacle independence. Bilateral multifocal toric Lentis Mplus intraocular lenses (IOLs) with an embedded near segment and individually customized cylinder correction were implanted uneventfully following phacoemulsification. The Haigis-L formula after previous hyperopia correction was chosen for IOL power calculation and provided reliable results. Emmetropia was targeted and achieved. Three months postoperatively, the uncorrected distance visual acuity had increased from 0.40 logMAR to 0.10 logMAR in the right eye and from 0.20 logMAR to 0.00 logMAR in the left eye. The patient gained 6 lines of uncorrected near visual acuity: 0.20 logMAR in the right eye and 0.10 logMAR in the left eye. This case shows that customized premium IOL implantation can provide accurate results even in challenging cases. FINANCIAL DISCLOSURE: The International Vision Correction Research Centre, Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany, has received research grants, lecture fees, and travel reimbursement from Oculentis GmbH.

Bilateral implantation of toric multifocal additive intraocular lenses in pseudophakic eyes.

UNLABELLED: A 41-year-old patient presented with hyperopia, astigmatism, and presbyopia for refractive treatment 6 years following cataract surgery. A toric multifocal additive intraocular lens with a near addition of +3.5 diopters (D) for sulcus implantation was chosen and implanted uneventfully. Follow-up examinations were performed from the first day until 9 months after surgery. A predictable refractive correction was seen, with a residual error of +0.125 D (spherical equivalent) in the right eye and emmetropia in the left eye. Monocular uncorrected distance visual acuity (UDVA) and uncorrected near visual acuity (UNVA) (40 cm) improved to 0.1 logMAR. It could not be improved further with near-add spectacles. Binocular UDVA and UNVA were 0.0 logMAR and 0.1 logMAR (80 cm), respectively. Both additive IOLs remained centered and on axis during the follow-up period. Spectacle independence was achieved, as was high patient satisfaction. FINANCIAL DISCLOSURE: The International Vision Correction Research Centre received research grants related to this publication from the following companies: Dr. Schmidt Intraocularlinsen GmbH, Rayner Intraocular Lenses, Ltd., and Carl Zeiss Meditec AG. No author has a financial or proprietary interest in any material or method mentioned.

Cataract surgery after previous femtosecond laser intrastromal presbyopia treatment.

UNLABELLED: We present a 58-year-old man who had cataract surgery in his right eye 8 months after femtosecond laser intrastromal presbyopia treatment (Intracor). The intraocular lens (IOL) power was calculated using the standard optical biometry data and the Holladay I formula without adjusting factors. Routine cataract removal was performed without complications followed by implantation of a monofocal IOL. The achieved spherical equivalent postoperatively was +0.25 diopters (D), which was +0.26 D different than the target refraction of the Holladay 1 formula. In conclusion, the IOL power calculation was predictable and the effect of the femtosecond intrastromal presbyopia treatment remained stable and improved further after cataract surgery: The pre-treatment uncorrected near visual acuity of 20/125 improved to 20/40 after treatment and to 20/25 six months after cataract surgery. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Intraocular lens power calculation after intrastromal femtosecond laser treatment for presbyopia: Theoretic approach.

PURPOSE: To evaluate the accuracy of intraocular lens (IOL) power calculation after an intrastromal femtosecond laser procedure to treat presbyopia using a theoretic approach. SETTING: International Vision Correction Research Centre, Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany. DESIGN: Nonrandomized clinical trial. METHODS: Preoperatively and 12 months after intrastromal femtosecond laser treatment (IntraCor) of presbyopia, biometry was performed by partial coherence interferometry (PCI) (IOLMaster). The postoperative keratometry (K) values and IOL power calculation formulas (Holladay I, Haigis, SRK/T, Hoffer Q) were compared with results derived from the clinical history method, taking the manifest refraction change into account. RESULTS: The study enrolled 25 patients (median age 54 years). Three eyes were excluded for age-related lens changes. The median spherical equivalent change in the other 22 eyes was -0.38 diopter (D). The median difference in K values between the clinical history method and PCI was -0.21 D, resulting in a median IOL power difference between -0.23 D (SRK/T) and -0.29 D (Haigis) (range -1.58 to +1.00 D). The IOL power was underestimated in 59.1% of cases with the Hoffer Q and 63.6% of cases with the Holladay I, Haigis, and SRK/T. There was a difference of ±0.75 D in 72.7% of eyes using the Holladay I, Haigis, and Hoffer Q and in 86.4% of eyes using the SRK/T. Neither K values nor IOL power differences were statistically significant (P > .17). CONCLUSION: Intraocular lens power calculation using modern standard formulas incorporated in a PCI biometry device after intrastromal femtosecond presbyopia treatment was reliable, with minimum underestimation on average.

Intraocular lens power calculation: clinical comparison of 2 optical biometry devices.

PURPOSE: To evaluate intraocular lens (IOL) power calculation using a new optical low-coherence reflectometry (OLCR) biometer and compare the results with those obtained with a partial coherence interferometry (PCI) optical biometer. SETTING: International Vision Correction Research Centre, Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany. METHODS: Biometry measurements in eyes of cataract patients were performed by the same examiner with an OLCR biometer (Lenstar LS 900/Allegro Biograph) and a PCI optical biometer (IOLMaster). After determination of axial length (AL), corneal radii values by keratometry (R1 and R2), and anterior chamber depth (ACD), power calculation for an AcrySof MA60AC IOL was compared between the 2 devices using 4 formulas and the corresponding IOL constants. The target was emmetropia. RESULTS: One hundred eyes of 100 cataract patients (mean age 70.0 years +/- 10.6 [SD]) were measured. Of the biometry parameters, the only statistically significant differences between the 2 devices were in R2 (mean difference 0.02 +/- 0.05 mm), (R1 + R2)/2 (mean difference 0.01 +/- 0.04 mm), and ACD (mean difference 0.05 +/- 0.11 mm) (P<.01, Wilcoxon test). The mean differences in IOL power calculations using the 4 formulas were not statistically significant between the 2 devices (P>.01, Wilcoxon test). CONCLUSION: The OLCR biometry device provided precise and valid measurements and thus can be used for the preoperative examination of cataract patients.

Transscleral fixation of a toric intraocular lens to correct aphakic keratoplasty with high astigmatism.

A 71-year-old man with penetrating keratoplasty (PKP) and aphakia in the right eye and a preoperative refraction of +20.0 -11.0 x 38 and logMAR visual acuity of 20/60 presented to our hospital. The capsular support was absent because of previous complicated intracapsular cataract extraction. The implanted IOL was a custom-made Rayner 570T with +20.5 diopters (D) sphere and +11.0 D cylinder. The IOL's special haptics allowed it to be safely fixated in the sagittal plane. The postoperative refraction was +1.0 -2.0 x 5 with logMAR acuity of 20/60. Follow-up of 2 years revealed no IOL decentration. Transscleral fixation of a toric IOL requires exact outlining. Our case shows that this is possible and can result in improved visual rehabilitation.

Central and peripheral pachymetry measurements according to age using the Pentacam rotating Scheimpflug camera.

PURPOSE: To investigate the mean values and standard deviations as well as the reliability of consecutive examinations of central and peripheral corneal thickness measurements according to age using the Pentacam rotating Scheimpflug camera (Oculus, Inc.). SETTING: Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany. METHODS: Seventy-six healthy volunteers were enrolled in a clinical prospective study. Three consecutive Pentacam measurements of 1 eye per subject were taken. Evaluated were the central corneal thickness (CCT), corneal thickness at 4 peripheral points (3.0 mm superior, inferior, nasal, and temporal), and the thinnest point of the cornea. The volunteers were then assigned to 3 groups to assess the influence of increasing age on the study parameters. RESULTS: The mean age of the subjects was 46.6 years +/- 16.8 (SD). The mean CCT was 539.62 +/- 31.87 microm. Peripherally, the corneal thickness was between 11% and 19% higher than centrally, with the superior cornea being the thickest followed by the nasal, the inferior, and the temporal cornea. The thinnest point was located in the inferotemporal quadrant in 92% of eyes and in the superotemporal quadrant in 8%. There was no correlation between age and corneal thickness. Minor mean standard deviations of consecutive measurements were noted in the corneal center (4.33 microm), increasing significantly toward the periphery (mean 8.31 microm). Increasing age was not associated with decreasing reliability. CONCLUSIONS: Using the Pentacam, it was possible to acquire information about corneal thickness across the entire cornea. No correlation was found between increasing age and change in peripheral or CCT. Good reliability was noted for pachymetry measurements decreasing slightly toward the periphery, which was independent of age.

Penetrating keratoplasty using femtosecond laser.

PURPOSE: To evaluate femtosecond laser technology for penetrating keratoplasty in patients with various corneal diseases. DESIGN: Interventional case series. METHODS: Five patients aged 45 to 81 years underwent penetrating keratoplasty using the 20/10 Perfect Vision Femtec femtosecond laser system in September 2005. Patients had granular corneal dystrophy, Fuchs endothelial dystrophy, keratoconus, and herpetic keratitis with endothelial decompensation. Histopathology was performed to analyze the cut quality of donor and recipient cornea. RESULTS: All procedures were performed without any complications. In all cases, the donor cornea was cut with an 8.0 or 8.1 mm diameter and the recipients' cornea with a 7.8 mm diameter. A complete perforating cut was achieved in all corneas. Histology of donor and recipient specimen showed a straight, smooth cut without any abnormalities. CONCLUSIONS: Penetrating keratoplasty can be performed with the Femtec femtosecond laser safely and accurately. The postoperative outcome was uneventful.

Influence of 360-degree enhanced optic edge design of a hydrophilic acrylic intraocular lens on posterior capsule opacification.

PURPOSE: To compare the rate of posterior capsule opacification (PCO) with the single-piece hydrophilic acrylic foldable Rayner Centerflex 570H intraocular lens (IOL), which has a sharp optic edge design excluding the optic-haptic junction, and the Rayner C-flex 570C IOL, which has an improved 360-degree sharp edge. SETTING: Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany. METHODS: As part of a multicenter U.S. Food and Drug Administration (FDA) study, 42 patients who had implantation of a C-flex IOL in 1 eye after uneventful phacoemulsification were enrolled. Six and 12 months postoperatively, PCO was evaluated by retroillumination photographs using Evaluation of Posterior Capsule Opacification (EPCO) 2000 image-analysis software. The data were then compared with those in a matched group of patients with a Centerflex IOL who participated in a previous FDA study. RESULTS: The mean age of the patients with the C-flex IOL was 71.5 years +/- 8.2 (SD) There was a statistically significant difference in EPCO scores between the C-flex group and Centerflex group. Six months after surgery, the mean EPCO value (total IOL optic) was 0.07 +/- 0.17 in the C-flex group (n = 37) and 0.20 +/- 0.20 in the Centerflex group (n = 36) (P<.01, Wilcoxon test). By 12 months, the mean had increased to 0.16 +/- 0.20 in the C-flex group (n = 37) and 0.35 +/- 0.22 in the Centerflex group (n = 31) (P<.01, Wilcoxon test). CONCLUSIONS: The C-flex IOLs showed good functional results and significantly lower PCO formation than the earlier model Centerflex IOL. The enhanced edge of the C-flex IOL seemed to improve PCO prevention clinically.

Long-term results of sealed capsule irrigation using distilled water to prevent posterior capsule opacification: a prospective clinical randomised trial.

BACKGROUND: We investigated long-term safety and efficacy of sealed capsule irrigation (SCI) during cataract surgery to prevent posterior capsule opacification (PCO). METHODS: One eye of each of 17 patients (mean age: 70.1+/-9.7 years) who presented with bilateral cataracts was randomly chosen for SCI treatment. After phacoemulsification, the capsular bag was vacuum sealed with the PerfectCapsule device (Milvella) followed by SCI using distilled water for two minutes. No vacuum loss occurred during irrigation. Each patient's fellow eye served as a control. One hydrophilic acrylic intraocular lens model was implanted in all eyes. Five patients had to be excluded due to deep anterior chamber, small pupil or unilateral surgery. Follow-up examinations took place one day and one, three, six, 12 and 24 months after surgery. We evaluated safety parameters, anterior capsule (AC) overlapping and PCO. RESULTS: Postoperatively, mean best corrected visual acuity, pachymetry, endothelial cell count, intraocular pressure, AC overlapping and PCO showed no statistically significant difference between SCI and the control group (p>0.05, Wilcoxon test). CONCLUSION: SCI is a safe procedure and enables the specific pharmacological targeting of lens epithelial cells inside the capsular bag. Using distilled water, however, it is not possible to reduce PCO development significantly. Thus, alternative substances should be evaluated.

Femtosecond laser-assisted corneal flap cuts: morphology, accuracy, and histopathology.

PURPOSE: Precision in corneal flap cutting is essential in LASIK surgery. Current mechanical microkeratomes have a very good performance record; however, in a few cases, complications can occur during the microkeratome pass and flap cut. Femtosecond lasers offer an alternative to the mechanical cut and can provide additional features regarding the flap morphology. In this study, we analyzed femtosecond laser flaps regarding their morphology, cut accuracy, and histopathology. METHODS: Forty-five fresh porcine cadaveric eyes were prepared for femtosecond laser flap cutting with the Femtec femtosecond laser system (20/10 Perfect Vision, Heidelberg, Germany). The eyes were assigned to three different thickness groups, with 120-, 140-, or 180-microm cut depth, respectively. In addition, different flap diameters ranging from 8.0 to 9.5 mm and rim edge angulations between 60 degrees and 90 degrees were performed. After the cut, the eyes were examined under a microscope regarding accuracy and potential defects, and flap thickness and diameter were measured. In addition, flaps were prepared for further histopathologic examination. RESULTS: All flap cuts were easily performed without any intraoperative complications. Flap thickness measurements revealed a median (in micrometers) of 110.5 (intended thickness 120), 142.5 (intended 140), and 180.0 (intended 180), respectively. The flap diameter for an intended size between 8.0 and 9.5 mm was within a range of +/-0.4 mm, the median at the maximum was 0.3 mm off. Histopathology revealed very low to almost no changes in the stromal structure of the cornea and correct hinge angulations. CONCLUSIONS: LASIK flap cuts were easily performed without any complications. The accuracy and morphology were very precise and consistent. Histopathology revealed a smooth cut with hinge angulations, as expected.

Anterior chamber measurements using Pentacam rotating Scheimpflug camera.

PURPOSE: To investigate the mean values and standard deviations according to age, reliability, and correlation between different parameters of anterior chamber measurements using the Pentacam rotating Scheimpflug camera. SETTING: Heidelberg IOL and Refractive Surgery Research Group, Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany. METHODS: This prospective clinical study comprised 76 healthy volunteers (mean age 46.6 years +/- 16.8 [SD]). Three consecutive measurements were made of only 1 eye and anterior chamber depth (ACD), mean and minimum anterior chamber angle (ACA), and anterior chamber volume (ACV) were evaluated. RESULTS: Mean ACD was 2.93 +/- 0.36 mm, mean ACA was 34.81 +/- 5.05 degrees, minimum ACA was 29.99 +/- 5.53 degrees, and mean ACV was 160.3 +/- 36.81 mm3. Increasing age was associated with reduced ACD and ACV; however, mean and minimum ACAs were lowest in patients aged 40 to 59 years. Excellent correlation was found between ACD and ACV (R = 0.92). Anterior chamber depth and mean ACA correlated only moderately (R = 0.65). The correlation coefficient between ACD and minimum ACA was smaller (R = 0.58). There was no correlation between ACV and ACA (R = 0.37). Minor standard deviations were noted (ACD 0.02 +/- 0.02 mm, mean ACA 1.12 +/- 0.94 degrees, minimum ACA 2.04 +/- 2.67 degrees, and ACV 2.48 +/- 1.65 mm3). CONCLUSIONS: Using the Pentacam, it was possible to examine different parameters of the anterior chamber within a short period and with good reliability. The evaluation of the ACA in different positions can help to classify the potential risk for angle-closure glaucoma.

Reliability of Orbscan II topography measurements in relation to refractive status.

PURPOSE: To investigate the reliability of corneal topography measurements using the Orbscan II topography system (Bausch & Lomb) not only referring to a normal cohort but also to different refractive conditions. SETTING: Department of Ophthalmology, Ruprecht-Karls-University of Heidelberg, Heidelberg, Germany. METHODS: Eighty patients (mean age 46.4 +/- 19.0 years) were assigned to 4 refractive groups (Group A: emmetropia (n=20); Group B: astigmatism (n=20) (-1.98 +/- 1.77 diopters [D]); Group C: hyperopia (n=20) (+4.84 +/- 1.6 D); Group D: myopia (n=20) (-9.64 +/- 3.79 D). Three measurements were performed in a series. Thirteen defined, standardized points of the entire cornea (apex, 3.0 mm, 5.0 mm, and 7.0 mm zone) were evaluated for 3 different maps (anterior elevation, pachymetry, keratometry). RESULTS: In all 80 patients, the following mean values were found in relation to analyzed zones: with regard to the anterior elevation map, the values decreased from 5.53 microm (center) to -6.52 microm (7.0 mm zone), the corneal thickness increased from 549.41 microm to 638.63 microm peripheral and the keratometry from 43.86 D (apex) to 45.4 D (7.0 mm zone), respectively. Analysis of the 3 different maps in all 4 refraction groups showed a tendency toward an increase in SD from the center to the 7.0 mm zone for anterior elevation and pachymetry maps. For keratometry, however, the lowest SD was found in the 7.0 mm zone. In particular, patients with hyperopia showed significant differences (P<.01), compared with emmetropic patients; the SD was higher with regard to anterior elevation as well as keratometry in peripheral zones. Group B (astigmatism) showed significantly higher SD for anterior elevation in zones 3.0, 5.0, and 7.0 mm when compared with emmetropic patients. CONCLUSIONS: The repeated Orbscan II measurements showed SD in the micrometer range for anterior elevation and pachymetry but values between 0.48 D and 0.97 D for keratometric data. Patients with astigmatism and especially hyperopia showed significantly higher SD values in peripheral zones for anterior elevation and keratometry, indicating a lower reliability, compared with the emmetropic cohort. However, the different ages of the patients could also be a possible explanation for these findings. Therefore, the Orbscan II seems to be a predictable and useful device for measuring corneal topography.