Biomedical subjects

M P Holzer

Publications and source records attributed to M P Holzer.

10 recordsLinked to original sources

PubMed2006

Intraocular lens power calculation using ray tracing following excimer laser surgery.

PURPOSE: To evaluate intraocular lens (IOL) power calculation using ray tracing in patients presenting with cataract after excimer laser surgery. METHODS: Ten eyes of seven consecutive patients who presented for cataract surgery following excimer laser treatment without any pre-refractive biometry data were enrolled in this prospective clinical study. Preoperatively, IOL power calculation was performed using a ray tracing software called OKULIX. Keratometry data (C-Scan) were imported and axial length (IOLMaster) was entered manually. Accuracy of IOL power calculation was investigated by subtracting attempted and achieved spherical equivalent. RESULTS: Mean spherical equivalent was -3.51+/-2.77 D (range -10.38 to -0.5 D) preoperatively and -1.01+/-1.08 D (range -2.5 to +0.75 D) postoperatively. Mean error was 0.31+/-0.84 D, mean absolute error was 0.74+/-0.46 D, and IOL calculation errors ranged from -1.39 to +1.47 D. A total of 40% of eyes were within +/-0.5 D, 70% within +/-1.0 D, and 100% within +/-1.5 D. Three eyes with corneal radii over 10 mm showed calculation errors exceeding +/-1.0 D. Mean best-corrected visual acuity increased from 20/60 to 20/30 postoperatively. CONCLUSIONS: IOL power calculation after excimer laser surgery can be difficult, especially when pre-refractive keratometry values are not available. In these cases, ray tracing combined with corneal topography measurements provides reliable and satisfactory postoperative results. However, it is advisable to be careful when calculating IOL power for eyes with corneal radii exceeding 10 mm because of slightly higher prediction errors.

Aged↗

PubMed2006

[Quantitative evaluation of acrylic and silicone intraocular lenses with a sharp optic edge design].

BACKGROUND: At the Department of Ophthalmology, Heidelberg, Germany, posterior capsule opacification (PCO) of a silicone and an acrylic intraocular lens (IOL) with a sharp optic edge design was evaluated. PATIENTS AND METHODS: In a prospective study either the AMO ClariFlex silicone IOL or the Sensar AR40e hydrophobic acrylic IOL were implanted in 47 patients following uneventful phacoemulsification. Mean patient age was 76.2+/-7.8 (ClariFlex) and 73.4+/-12.9 years (AR40e), respectively. The mean follow-up time was 19.7+/-5.34 in the ClariFlex and 21.9+/-1.89 months in the AR40e group. PCO development was evaluated postoperatively using the EPCO 2000 analysis software (scale 0-4). Areas of interest were the total IOL optic, the central 3-mm zone as well as the capsulorhexis. RESULTS: In both groups, all patients achieved a BCVA of 20/32 (AR40e) and 20/25 (ClariFlex), respectively. There was a very low incidence of PCO development with a mean EPCO score of 0.07+/-0.2 (ClariFlex and 0.15+/-0.2 (AR40e). Within the 3-mm zone and the capsulorhexis, there was a tendency for even lower EPCO scores in both groups. We calculated a statistically significant difference for the two lens materials for all investigated IOL areas (Wilcoxon's test, p<0.05). CONCLUSION: Both IOLs with a sharp edge design showed good functional results, a stable position in the capsular bag as well as a low incidence of PCO development. However, the silicone IOL showed statistically significantly lower PCO scores.

Acrylic Resins↗

PubMed2006

[Presbyopia correction using intraocular lenses].

Modern cataract surgery has advanced tremendously over the past 20 years. Improved surgical techniques, as well as improved implant materials and designs, have enlarged patient profiles and indications not only for cataract surgery, but also for refractive lens exchange surgery. This has also created much higher patient expectations. The loss of accommodation is a loss of quality of life for presbyopic and especially young pseudophakic patients. Multifocal intraocular lenses (MIOL) have been implanted since 1986, starting with 2-3 zone refractive and diffractive designs. Due to the surgical techniques available at that time, MIOL decentration and surgically induced astigmatism were possible complications. In addition, reduced contrast perception and increased glare were common problems of MIOL because of their optical principles. New developments in this field in recent years such as the folding, multizonal, progressive refractive MIOL and aspheric diffractive MIOL in combination with improved surgical techniques have overcome those initial problems. Therefore, modern MIOL (and in the future also accommodative IOL) can be considered not only for the correction of aphakia but also for refractive purposes.

Humans↗

PubMed2006

[Accuracy of lens power calculation and centration of an aspheric intraocular lens].

BACKGROUND: Aspherical intraocular lenses (IOLs) are presumed to optimize the optical characteristics of IOLs. In order to profit from these characteristics, exact calculation of the IOL power and good centration of the lens are essential. METHODS: In all, 43 eyes of 43 patients with an average age of 70.9+/-8.3 years underwent implantation of a Tecnis IOL (AMO, Ettlingen) after uneventful cataract surgery with topical anesthesia. IOL power calculation was performed using the Holladay, Haigis, and SRK II formulas. Spherical equivalent refraction and centration and position of the implanted IOLs were measured 6 months postoperatively. Centration of the IOL was analyzed using digital slit lamp photographs and an image analysis program. RESULTS: Best corrected visual acuity (BCVA) increased from 0.47+/-0.25 (LogMAR) preoperatively to 0.1+/-0.11 6 months postoperatively (spherical equivalent +0.3+/-0.6 D). The intraindividual difference between target refraction and achieved postoperative refraction was 0.64+/-0.11 D for the Holladay formula, -0.21+/-0.11 D for the Haigis formula, and 0.97+/-0.15 D for the SRK II formula. The mean decentration of the IOL from the center of the corneal limbus was 0.4+/-0.1 mm. CONCLUSIONS: For the aspherical Tecnis IOL very good postoperative functional results are reported, which are supported by an accurate calculation of the IOL power and a good centration of the IOL inside the capsular bag. In this study the Haigis formula showed the lowest difference between target refraction and achieved postoperative refraction.

Aged↗

PubMed2003

[Diagnosis and treatment of mycobacterial keratitis following LASIK. Case report and review of the literature].

BACKGROUND: Mycobacterial keratitis is a rare complication following LASIK but can lead to an extremely unfavourable outcome. The diagnosis and treatment is often delayed due to confusion with other entities including diffuse lamellar keratitis and poor clinical outcomes with flap amputation and/or keratoplasty are often the case. PATIENT AND METHODS: We report the results of LASIK in a 51-year-old woman with subsequent early-diagnosed mycobacterial keratitis and compared this case to treatments and outcomes reported in the literature. RESULTS: The patient presented 10 days following LASIK with a white focal infiltrate in the stromal interface. The flap was lifted and cultures from the stromal bed and the reverse of the flap were obtained and the interface irrigated. The patient was treated with topical antibiotics (ciprofloxacin 0.3%, amikacin 2.5%, clarithromycin 40 mg/ml and tobramycin 15 mg/ml) for 8 weeks and at the most recent follow-up she had a visual acuity of 1.25. CONCLUSION: In a large number of published cases in the literature the flap had to be amputated and/or corneal transplants were necessary. Early diagnosis and treatment however, are essential to successfully treat post-LASIK keratitis. Therefore the patients should be followed up carefully in the early postoperative period.

Anti-Bacterial Agents↗

PubMed2002

[Diffuse lamellar keratitis. Postoperative prophylactic treatment with corticosteroids in an experimental animal study].

PURPOSE: The aim of this experimental ani-mal study was to induce diffuse lamellar keratitis (DLK), and investigate a prophylactic treatment with corticosteroids. MATERIALS AND METHODS: A corneal flap was cut in 40 eyes from 20 Dutch-belted rabbits and the interface inoculated with either Pseudomonas aeruginosa lipopolysaccharide (LPS) endotoxin ( n=21) or Palmolive Ultra soap ( n=19). Half of the eyes were treated with topical corticosteroids and the other half remained untreated. Slitlamp examinations were performed 1, 3, 5 and 7 days postoperatively and DLK was graded from I-IV. RESULTS: At the end of the study 33 eyes were available for evaluation and 94% of the non-treated eyes developed DLK. Out of those eyes treated with steroids 19% developed DLK during the 1 week follow-up period. This was statistically significantly lower ( P=0.018) when compared to the untreated group. CONCLUSION: Pseudomonas aeruginosa LPS endotoxin as well as Palmolive((R)) Ultra caused a very high rate of DLK in rabbit eyes. The postoperative prophylactic treatment with corticosteroids showed a statistically significant lower DLK rate in this rabbit eye model.

Adrenal Cortex Hormones↗

PubMed2002

[Diffuse lamellar keratitis: prophylactic treatment with ketorolac tromethamine 0.5% in an animal model].

PURPOSE: The objective of this study is to evaluate the use of a topical non-steroidal anti-inflammatory drug in the treatment of induced diffuse lamellar keratitis (DLK) in an animal model. MATERIALS AND METHODS: A corneal flap was created in 40 eyes of 20 Dutch-belted rabbits using the ASC microkeratome. The interface was inoculated with either Pseudomonas Aeruginosa Lipopolysaccharide (LPS) endotoxin or Ultra Palmolive liquid dish washer. The rabbits were divided in two groups: Group I (n=20) treated with ketorolac tromethamine ophthalmic solution 0.5% 4 times a day and the group II (n=20) used as control. The rabbits were examined at the slit lamp at day 1, 3, 5 and 7 postoperatively. DLK was graded from I-IV. RESULTS: At the end of the study 31 eyes were available for evaluation. 28 eyes (90%) developed DLK: 86% of the treated group and 94% of the control group during the follow-up. The treated group showed a lower rate of DLK as well as a lower severity. However, no statistically significant difference was found when comparing both groups (P>0.05). CONCLUSION: Pseudomonas aeruginosa LPS endotoxin and Palmolive Ultra can induce DLK in rabbit eyes. The postoperative prophylactic treatment with a topical non-steroidal anti-inflammatory drug showed a tendency towards a lower DLK rate as well as the severity of the disease.

Animals↗

PubMed2001

Effect of Healon5 and 4 other viscoelastic substances on intraocular pressure and endothelium after cataract surgery.

PURPOSE: To compare the ophthalmic viscoelastic device (OVD) Healon5 (sodium hyaluronate 2.3%) with 4 other commonly used OVDs during phacoemulsification and intraocular lens implantation in terms of influence on intraocular pressure (IOP) postoperatively and endothelial cells preoperatively and postoperatively. SETTING: Department of Ophthalmology, Ruprecht-Karls-University Heidelberg, Germany. METHODS: This clinical randomized prospective study, in which patients and observer were masked, comprised 81 eyes. Seventy-four eyes (mean patient age 71.2 years +/- 7.8 [SD]) completed all preoperative and 5 postoperative examinations. The OVDs used were OcuCoat and Celoftal (hydroxypropyl methylcellulose 2.0%), Viscoat (sodium hyaluronate 3.0%-chondroitin sulfate 4.0%), Healon GV (sodium hyaluronate 1.4%), and Healon5 (sodium hyaluronate 2.3%). Intraocular pressure was measured by standard Goldmann applanation tonometry preoperatively and 4 to 6 and 24 hours and 7, 30, and 90 days postoperatively. Endothelial cell counts were done preoperatively and 90 days postoperatively using a Pro/Koester WFSCM contact endothelial microscope. Exclusion criteria were IOP greater than 21 mm Hg at the preoperative examination, age younger than 40 years, significant corneal pathology, and a history or presence of uveitis or pseudoexfoliation syndrome. RESULTS: All groups had increased IOP 4 hours postoperatively. The Healon5 group had the highest mean pressure (24.9 mm Hg) followed by the Viscoat group (23.6 mm Hg). The mean IOP in the other OVD groups was less than 22.1 mm Hg. These differences were not significant. Twenty-four hours postoperatively and at all subsequent examinations, mean IOP was below 20 mm Hg. The Healon5 group had the lowest mean endothelial cell loss (6.2%), significantly lower than in the other groups (P < .02). CONCLUSION: With all 5 OVDs, endothelial cell loss was found, with the lowest in the Healon5 group, and IOP was increased 4 to 6 hours postoperatively. After 24 hours, no significant increases in IOP were noted.

Aged↗

PubMed2001

Clinical results of phacoemulsification with the use of Healon5 or Viscoat.

PURPOSE: To compare the ophthalmic viscosurgical devices Healon5 (viscoadaptive) and Viscoat (dispersive) regarding their overall clinical performance during phacoemulsification and posterior chamber intraocular lens (IOL) implantation as well as their influence on intraocular pressure (IOP). SETTING: Department of Ophthalmology, Ruprecht-Karls-University Heidelberg, Heidelberg, Germany. METHODS: In this prospective randomized patient- and observer-masked clinical study, the performance of Healon5 (sodium hyaluronate 2.3%) and Viscoat (sodium hyaluronate 3.0%-chondroitin sulfate 4.0%) was assessed by 3 surgeons during cataract surgery in 90 patients. Surgeons used a 5-point scale for the subjective assessment of the ease of injection, maintenance capacity during continuous curvilinear capsulorhexis, remaining capacity during phacoemulsification, facilitation of IOL implantation, removal from the eye, transparency, and overall performance throughout surgery. Intraocular pressure was measured preoperatively and 24 hours and 7 days postoperatively. Best corrected visual acuity was assessed preoperatively and 7 days postoperatively. RESULTS: Overall intraoperative product performance was assessed as good or very good in 34 of 44 patients (77%) in the Healon5 group and in 16 of 46 patients (35%) in the Viscoat group (P <.001). Retention in the anterior chamber was graded good or very good in 36 patients (82%) in the Healon5 group and in 23 (50%) in the Viscoat group (P =.001). There were no statistically significant between-group differences in mean IOP preoperatively and 24 hours postoperatively. CONCLUSIONS: Surgeons graded Healon5 better than Viscoat in overall surgical performance and retention in the anterior chamber during phacoemulsification. These data support that Healon5 adapts to each step during surgery.

Aged↗

PubMed2000

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.

Cataract Extraction↗