Mp Holzer

Refractive Surgery Survey 2001.

&NA; To determine the refractive surgery preferences of ophthalmologists worldwide, questionnaires were sent to 8920 members of the American Society of Cataract and Refractive Surgery. A total of 1174 questionnaires was returned by the deadline. The practice distribution included 30.0% cataract surgeons, 47.3% comprehensive ophthalmologists, 14.4% refractive surgery (RS) specialists, 4.5% corneal/external disease specialists, 1.9% glaucoma specialists, and <1% retinal/oculoplastics/pediatrics/neurophthalmologists/researchers/retired. Responses were compared with those in the 2001 and 2002 surveys and demonstrate that RS practice patterns continue to evolve.

Accuracy of a new partial coherence interferometry analyser for biometric measurements

Aims: Precise biometry is an essential preoperative measurement for refractive surgery as well as cataract surgery. A new device based on partial coherence interferometry technology was tested and evaluated for accuracy of measurements. Methods: In a prospective study 200 eyes of 100 healthy phakic volunteers were examined with a functional prototype of the new ALLEGRO BioGraph (Wavelight AG)/LENSTAR LS 900 (Haag Streit AG) biometer and with the IOLMaster V.5 (Carl Zeiss Meditec AG). As recommended by the manufacturers, repeated measurements were performed with both devices and the results compared using Spearman correlation calculations (WinSTAT). Results: Spearman correlation showed high correlations for axial length and keratometry measurements between the two devices tested. Anterior chamber depth, however, had a lower correlation between the two biometry devices. In addition, the mean values of the anterior chamber depth differed (IOLMaster 3.48 (SD 0.42) mm versus BioGraph/LENSTAR 3.64 (SD 0.26) mm); however, this difference was not statistically different (p>0.05, t test). Conclusion: The new biometer provided results that correlated very well with those of the IOLMaster. The ALLEGRO BioGraph/LENSTAR LS 900 is a precise device containing additional features that will be helpful tools for any cataract or refractive surgeon.

Flap thickness accuracy ☆ ☆☆ ★ ★★: Comparison of 6 microkeratome models

Purpose: To determine the flap thickness accuracy of 6 microkeratome models and determine factors that might affect flap thickness. Setting: Magill Research Center for Vision Correction, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. Methods: This multicenter prospective study involved 18 surgeons. Six microkeratomes were evaluated: AMO Amadeus, Bausch & Lomb Hansatome®, Moria Carriazo‐Barraquer, Moria M2, Nidek MK2000, and Alcon Summit Krumeich‐Barraquer. Eyes of 1061 consecutive patients who had laser in situ keratomileusis were included. Age, sex, surgical order (first or second cut), keratometry (flattest, steepest, and mean), white‐to‐white measurement, laser used, plate thickness, head serial number, blade lot number, and occurrence of epithelial defects were recorded. Intraoperative pachymetry was obtained just before the microkeratome was placed on the eye. Residual bed pachymetry was measured after the microkeratome cut had been created and the flap lifted. The estimated flap thickness was determined by subtraction (ie, mean preoperative pachymetry measurement minus mean residual bed pachymetry). Results: A total of 1634 eyes were reviewed. Sex distribution was 54.3% women and 45.7% men, and the mean age was 39.4 years ± 10.6 (SD). In addition, 54.5% of the procedures were in first eyes and 45.5%, in second eyes. The mean preoperative pachymetry measurement was 547 ± 34 &mgr;m. The mean keratometry was 43.6 ± 1.6 diopters (D) in the flattest axis and 44.6 ±1.5 D in the steepest axis. The mean white‐to‐white measurement was 11.7 ± 0.4 mm. The mean flap thickness created by the devices varied between head designs, and microkeratome heads had significant differences (P<.05). Factors that explained 78.4% of the variability included microkeratome model, plate thickness, mean preoperative pachymetry, Kmin, surgery order, head serial number, blade lot number, and surgeon. Factors such as age, sex, Kmax, Kaverage, white to white, and laser had no significant correlation to flap thickness. Conclusions: The results demonstrated variability between the 6 microkeratome models. Device labeling did not necessarily represent the mean flap thickness obtained, nor was it uniform or consistent. Thinner corneas were associated with thinner flaps and thicker corneas with thicker flaps. In addition, first cuts were generally associated with thicker flaps when compared to second cuts in bilateral procedures.

Early Outcomes of INTRACOR Femtosecond Laser Treatment for Presbyopia

PURPOSE To investigate early functional outcomes of the INTRACOR femtosecond laser-based intrastromal procedure to treat presbyopia. METHODS Twenty-five eyes of 25 presbyopic patients were enrolled in this prospective, ethics committee-approved study. Following detailed preoperative examination, the INTRACOR procedure was performed using the TECHNOLAS femtosecond laser (Technolas Perfect Vision GmbH) in the non-dominant eye. Postoperatively, follow-up examinations were performed at 1 day, 1 week, and 1 and 3 months, including near and distance visual acuity, slit-lamp microscopy, and corneal topography. RESULTS All 25 surgeries were uneventful. The mean postoperative uncorrected near visual acuity increased from 0.7+/-0.16 logMAR to 0.26+/-0.21 logMAR and the mean uncorrected distance visual acuity changed slightly from 0.11+/-0.11 logMAR to 0.05+/-0.1 logMAR at 3 months postoperative. Regarding best distance correction, mean sphere changed from +0.75+/-0.23 diopters (D) preoperatively to +0.15+/-0.31 D postoperatively and mean cylinder from -0.33+/-0.17 D to -0.42+/-0.23 D. Postoperative healing was uneventful, and in all eyes, the cornea was clear within a few hours after surgery without any remaining cavitation gas bubbles. CONCLUSIONS The INTRACOR procedure for presbyopia showed good visual acuity outcomes in the early postoperative period. The short treatment time in combination with maintained corneal integrity suggests this new technique has good potential for the treatment of presbyopia.

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. Financial Disclosure Drs. Auffarth, Reddy, and Holzer have received research and travel grants from Technolas Perfect Vision GmbH. Mr. Ritter is an employee of Technolas Perfect Vision GmbH, Munich, Germany.

Two-compartment technique to remove ophthalmic viscosurgical devices

To avoid postoperative intraocular pressure peaks, complete removal of all ophthalmic viscosurgical devices (OVDs) used during cataract surgery is important. Depending on the kind of OVD used, different removal techniques have been applied. We describe a technique that was used in more than 250 eyes for safe removal of OVDs, especially viscoadaptive OVDs such as sodium hyaluronate 2.3% (Healon5). It takes advantage of the viscoadaptive properties of Healon5 and was named the 2-compartment technique.

Effect of hinge location on corneal sensation and dry eye after laser in situ keratomileusis for myopia

PURPOSE: To evaluate the effects of a superior or nasal hinge location on corneal sensation and dry eye after laser in situ keratomileusis (LASIK). SETTING: Magill Research Center for Vision Correction, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS: This prospective randomized masked study included 47 patients having bilateral myopic LASIK surgery. The first eye was randomly assigned to have a nasal or superior hinge flap; the fellow eye had the alternate location. Visual acuity, contrast sensitivity, corneal sensation, basic secretion test, tear film breakup time, conjunctival and corneal staining, and a subjective questionnaire were evaluated preoperatively and postoperatively at 1 week and 1, 3, and 6 months. The Wilcoxon signed rank test and paired t test were used for comparison. RESULTS: Dry eye occurred with the same frequency in both groups. However, eyes with the nasal hinge had significantly better nasal sensation than those with the superior hinge (P<.05) at 1 month. CONCLUSION: Better nasal corneal sensation was found at 1 month in the nasal hinge group but there was no difference in any other parameters measured.

Epithelial downgrowth after clear cornea phacoemulsification: Report of two cases and review of the literature

OBJECTIVE To report two cases of diffuse epithelial downgrowth after clear cornea phacoemulsification and to review the different treatment options for this ominous disease. DESIGN Two interventional case reports. METHODS Retrospective review of two eyes from two different patients in whom epithelial downgrowth developed 7 and 3 months after uneventful clear cornea phacoemulsification. In the first case, the epithelial invasion seemed to be growing from the temporal incision site onto the corneal endothelium toward the visual axis. Cryotherapy was applied to the affected cornea, with control of the growing membrane. A penetrating keratoplasty was performed to restore visual function. In the second patient, the membrane was attached to the iris and posterior cornea and was confirmed by diagnostic argon laser photocoagulation. This case was surgically treated with en bloc excision and a corneoscleral graft. MAIN OUTCOME MEASURES Visual acuity at the final follow-up visit. RESULTS Surgical treatment of the epithelial downgrowth was different for both patients. In the postoperative period, a best-corrected visual acuity of 20/60 and 20/30 was achieved in each case. No regrowth of the membrane was observed. CONCLUSIONS Treatment of epithelial downgrowth is controversial. We present two cases of epithelialization of the anterior chamber with either clinical or histologic confirmation after clear cornea sutureless phacoemulsification. Surgical treatment should be attempted promptly to obtain a good visual prognosis.

Intraocular pressure during corneal flap preparation: comparison among four femtosecond lasers in porcine eyes.

PURPOSE To compare the course of intraocular pressure (IOP) during corneal flap preparation using four different femtosecond lasers in porcine globes. METHODS Forty-eight (12 in each group) enucleated globes were successfully cannulated through the optic nerve. Intraocular pressure was measured continuously through the cannula during a normal lamellar flap creation (regular procedure) using four femtosecond lasers (IntraLase, Abbott Medical Optics; VisuMax, Carl Zeiss Meditec AG; Femtec, Technolas Perfect Vision; and Femto LDV, Ziemer Ophthalmic Systems AG). In an additional measurement (worst-case procedure), the patient interface was pressed against the globe with increasing force until the applanation maneuver was automatically aborted by those devices capable of doing so. RESULTS During the regular procedure, the maximum IOP reached was 135±16 mmHg when using the Intra-Lase, 65±20 mmHg with the VisuMax, 205±32 mmHg with the Femtec, and 184±28 mmHg with the Femto LDV. During the worst-case procedure, a maximum IOP of 260±53 mmHg was reached with the IntraLase, 105±13 mmHg with the VisuMax, and 248±51 mmHg with the Femtec. CONCLUSIONS There is considerable variation in IOP among the tested femtosecond lasers during a regular lamellar flap creation and during the worst-case procedure. The VisuMax femtosecond laser seems to cause the lowest IOP rise in both settings.

Visual outcomes and corneal changes after intrastromal femtosecond laser correction of presbyopia

PURPOSE: To assess the effect of intrastromal femtosecond laser presbyopia treatment on uncorrected near visual acuity (UNVA) and corneal integrity over an 18‐month period. SETTING: Department of Ophthalmology, International Vision Correction Research Centre, University of Heidelberg, Heidelberg, Germany. DESIGN: Clinical trial. METHODS: The UNVA (at 40 cm), corneal pachymetry, and true net power were evaluated preoperatively and 1, 3, 6, 12, and 18 months after femtosecond intrastromal presbyopic treatment (Intracor). Endothelial cell density (ECD) was measured preoperatively and 3, 6, and 12 months postoperatively. Data were analyzed with the Wilcoxon test at a P=.01 level of significance. RESULTS: The median UNVA improved significantly from 0.7 logMAR preoperatively to 0.4 logMAR, 0.2 logMAR, 0.2 logMAR, 0.3 logMAR, and 0.2 logMAR at 1, 3, 6, 12, and 18 months, respectively (all P<.001). The median corneal true net power increased significantly by 1.1 diopters (D) to 0.7 D, 0.8 D, 1.0 D, and 0.9 D, respectively (all P<.001); pachymetry showed no significant thinning postoperatively. There was no significant difference in ECD between preoperatively and postoperatively. CONCLUSIONS: Intrastromal femtosecond presbyopic treatment yielded a significant and stable gain of UNVA and corneal steepening without significant loss of endothelial cells or corneal thinning up to 18 months postoperatively. No significant regression of visual acuity or further corneal steepening occurred during the follow‐up period. Financial Disclosure: Dr. Auffarth and Dr. Holzer received lecture and consulting fees from Technolas Perfect Vision GmbH. No author has a financial or proprietary interest in any material or method mentioned.