[Postoperative complication after cataract operation. Early postoperative capsular block syndrome, caused by viscoelastic Healon 5].
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Aged↗
Biomedical subjects
H B Dick
Publications and source records attributed to H B Dick.
[Striae in the flap after laser in situ keratomileusis. Etiology, diagnosis and treatment].
OBJECTIVE: Laser in situ keratomileusis (LASIK) has become the leading refractive option to correct myopia, hyperopia and astigmatism. In addition to the relative rapid visual recovery and the lack of postoperative pain, new flap-related complications are being added. The formation of striae can lead to a significant loss of corrected visual acuity if the central pupil zone is affected. Awareness of possible complications is important not only for the surgeon, but also for the ophthalmologist in practice for a rapid diagnosis and prompt management. CLINICAL COURSE AND THERAPY: Striae have a variety of appearances and are caused by misalignment/displacement of the corneal flap after replacement or are results of a slippage effect of the flap over the stromal bed after LASIK. Symptomatic striae ideally are treated on the first or second day after surgery by refloating the flap, irrigation with balanced salt solution or hypotonic saline solution, stroking and stretching the surface with moist and dry sponges. In more severe cases scraping away the epithelium and antitorque or interrupted sutures can be performed to treat persistent striae. CONCLUSION: Symptomatic deep striae should be diagnosed early and managed promptly within the first days. Any later intervention decreases the chance of successful elimination and visual outcome. Hints to prevent the development of striae formation are provided.
Corneal Diseases↗
Incidence of endophthalmitis in ophthalmic surgery.
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Denmark↗
[Prevention of early postoperative increase in intraocular pressure after phacoemulsification. Comparison of different antiglaucoma drugs].
PURPOSE: To compare the ocular hypotensive effect of different antiglaucomatous eye drops. PATIENTS AND METHODS: This double-blind, randomized study included 119 eyes of 119 patients without other ocular pathology undergoing standardized (one surgeon, Healon) small incision cataract surgery with foldable intraocular lens implantation. The patients were assigned to one of five groups: group 1: 0.25% timolol in Gelrite (extended efficacy, n = 23); group 2: 2% dorzolamide (n = 24); group 3: combination of 0.5% timolol plus 2% dorzolamide (n = 22); group 4: brimonidine (n = 26); group 5: gentamicin (control, n = 24). Intraocular pressure (IOP) was measured preoperatively and at 3 +/- 1, 6 +/- 1, 9 +/- 1, 24 +/- 3, and 48 +/- 3 h postoperatively. Statistical interference was determined by nonparametric group comparisons using Wilcoxon's tests. Absolute values (static comparison) and intraindividual differences from preoperative measurements (dynamic comparisons) were evaluated. All p values should be regarded as descriptive values since they were not formally adjusted for multiplicity. A p value lower than 0.05 therefore indicates local statistical significance. RESULTS: There were no differences between the groups with regard to age, phacoemulsification time, axial length, and preoperative IOP. A statistically significant IOP decrease was measured in group 1 at 24 (p = 0.028) and 48 h (p = 0.007) and in group 3 at 3 (p = 0.001), 6 (p = 0.001), 24 (p = 0.001), and 48 h (p = 0.001) after surgery. A statistically significant IOP increase occurred in group 4 at 3 (p = 0.001), 6 (p = 0.001), and 9 h (p = 0.001) and in group 5 at 3 (p = 0.001), 6 (p = 0.001), 9 (p = 0.001), and 24 h (p = 0.002) postoperatively. Groups 1, 2, and 3 demonstrated lower IOPs at different time points in comparison to groups 4 and 5. Furthermore, group 3 had lower IOPs at 3 h (compared to group 1) and at 6 h (compared to group 2) postoperatively. No statistical differences in IOP were found after 48 h. CONCLUSION: The results favor a combination of 0.5% timolol plus 2% dorzolamide to control postoperative IOP elevation.
Adrenergic alpha-Agonists↗
[Internet-based teaching and learning in ophthalmology].
The transmission of clinical knowledge occurs traditionally through lectures, theoretical and practical courses, bed-side teaching as well as case-oriented teaching in small groups. The realisation is, however often very laborious and problematical because of low resources. For these reasons the development of computer-based, and in particular internet-based tutorials have increased dramatically in recent years. Furthermore, the transmission of knowledge by means of internet-based tutorials offers several advantages. The content can be quickly updated and multimedia presentations are possible. The use of these sources is normally independent of time and location. The possibilities of internet-based teaching and learning are on-line lectures, case simulations and online quizes. At present, the number of ophthalmological applications on the internet is still restricted. Internet-based multimedial tutorials represent a meaningful supplement to traditional forms of teaching. Especially in ophthalmology, a visual presentation of details can be performed in an easier way via multimedial tools and the training is followed without causing stress for the patients.
Computer Graphics↗
[Phacoemulsification and vitrectomy with the erbium:YAG laser and phacoemulsification with the neodymium:YAG laser].
There are an increasing number of possible applications for the use of Erbium:YAG and Neodymium:YAG lasers in ophthalmology. Laser-phacoemulsification as well as Erbium-laser vitrectomy is of major interest. We report on the underlying technology and more than 1-year-experience using the PHACOLASE (Asclepion-Meditec, Jena, Germany, 10-100 Hz frequency, 5-50 mJ single pulse energy) for phacoemulsification and pars plana vitrectomy and the Lyla-Dodick laser photolysis (A.R.C. Laser, Eckental-Forth, Germany, 1-20 Hz, up to 8 mJ single pulse energy). The Erbium:YAG-laser as well as the Neodymium:YAG-laser enabled us to extract lenses with up to medium hard nuclei. Moreover, the Erbium laser enabled fast vitrectomy with little mechanical traction. In many of our initial surgical operations we had to change to mechanical vitrectomy due to initial technical problems. No new complications occurred intra- or postoperatively. The handpiece worked well in removing vitreous bodies, but was not feasible for cutting membranes. Modified handpieces for this purpose are under development.
Equipment Design↗
[Cause and prevention of oxidative damage to the eye. Current knowledge].
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Adult↗
[Refraction, anterior chamber depth, decentration and tilt after implantation of monofocal and multifocal silicone lenses].
BACKGROUND: We prospectively investigated changes in refraction, anterior chamber depth, decentration and tilt after implantation of multifocal (MIOL) and monofocal (MONO) intraocular lenses (IOL). PATIENTS AND METHODS: We examined 103 cataractous eyes from 103 patients receiving either a three-piece monofocal or multifocal silicone IOL. Anterior chamber depth (ACD), amount of IOL decentration, and degree of IOL tilt were quantified using retroillumination and Scheimpflug photographs. Examinations, including subjective refraction, were performed preoperatively, one week and 6 months postoperatively. RESULTS: All eyes were within 2 dpt (spherical equivalent) from the target refraction, and 93% of eyes with a MIOL were within 1 dpt. No significant refractive shift or ACD change occurred during the postoperative course. Median tilt in the MIOL group at 6 months was 1.1 degrees (0-2.6) and that in the MONO group 1.0 degree (0-2.5). There was no statistically significant change in intraindividual IOL decentration or tilt. CONCLUSION: Three-piece silicone MIOLs and MONOs with polymethylmethacrylate haptics implanted in the capsular bag after circular capsulorhexis provide good centration and very little tilt without statistically significant change up to 6 months after surgery. Postoperative refractive shift is of minor concern for 6 months after surgery.
Adult↗
[Multifocal intraocular lenses. A review].
Modern cataract surgery has developed tremendously during the past 10-15 years. Improved surgical techniques, as well as improved implant materials and designs, have enlarged patient profiles and indications for cataract surgery. This also created much higher expectations from the patients' site. The loss of accommodation is loss of quality of life for presbyopic and especially young pseudophakic patients. Therefore cataract surgery with multifocal IOL implantation is not only of academic interest, but reflects demands and expectations of our patients. Multifocal IOLs have been implanted since 1986, starting with 2-3 zone refractive and diffractive designs. Due to surgical techniques of that time MIOL decentration and surgically induced astigmatism were possible complications. In addition reduced contrast sensitivity and increased glare were common problems of MIOL because of their optical principles. New developments in this field in recent years such as the multizonal, progressive refractive MIOL in combination with improved surgical techniques have overcome those initial problems. Therefore, modern multifocal IOLs can be considered not only for correction of aphakia but also for refractive purposes.
Age Factors↗
Late opacification of the foldable hydrophilic acrylic lens SC60B-OUV.
OBJECTIVE: To investigate the cause of severe central opacification in 41 foldable acrylic intraocular lenses (IOLs) requiring explantation. Another IOL was opacified in the original sealed vial. DESIGN: Case series and laboratory analysis. TESTING: Light microscopy, high performance liquid chromatography, sodium dodecyl sulfate polyacoylamide gel electrophoresis, spectrometric analysis, and autoclaving. RESULTS: Neither fatty acids nor proteins could be identified within the IOLs. Spectrometric analysis yielded absorption peaks in the ultraviolet spectral range. CONCLUSIONS: The spectroscopic findings indicate premature aging of the ultraviolet blocking agent. The source of the opacification is a change in the IOL material itself.
Acrylic Resins↗
Healon5 viscoadaptive formulation: Comparison to Healon and Healon GV.
PURPOSE: To compare the rheological characteristics of a viscoadaptive viscoelastic formulation with those of 2 standard ophthalmic viscosurgical devices (OVDs). SETTING: Department of Ophthalmology, Johannes Gutenberg-University, and Max Planck-Institute for Polymer Research, Mainz, Germany. METHODS: An independent comparative study of 3 OVDs of sodium hyaluronate (Healon(R), Healon GV(R), and Healon(R)5) was performed using the Advanced Rheometric Expansion System to analyze rheologic behavior (eg, dynamic frequency dependence of the complex viscosity) as well as rheological parameters (eg, viscosity at zero shear rate, pseudoplasticity, relaxation time, elastic and viscous modulus). RESULTS: Mean viscosity at zero shear rate was 243 Pas +/- 5 (SD) for Healon, 2451 +/- 12 Pas for Healon GV, and 5525 +/- 14 Pas for Healon5. Mean pseudoplasticity was 173 +/- 7, 754 +/- 10, and 591 +/- 6, respectively. Mean relaxation time was 21 +/- 3 sec, 83 +/- 4 sec, and 88 +/- 6 sec. At low shear rates, viscosity and elasticity (elastic and viscous modulus) increased from Healon through Healon5. Healon5 exhibited a dynamic behavior of the complex viscosity dependent on the duration of the shear rate exposure: At low shear rates, it slowly built up a high viscosity. At higher shear rates, it demonstrated a lower viscosity that decreased further during constant exposure to a specific shear rate. CONCLUSIONS: Healon5 had the highest viscosity and elasticity when exposed to low and high shear rates. These characteristics maintain anterior chamber depth. Also, the high viscosity of Healon5 exhibited a dynamic frequency dependence. In the presence of turbulence and phaco power (continuous high shear rates), it became dispersive by fragmentation and formed a cavity with an outer retentive shell. The cohesive and dispersive properties of Healon5 make it the best of the 3 OVDs evaluated for use at all stages of phacoemulsification.
Chemistry, Pharmaceutical↗
Subjective photic phenomena with refractive multifocal and monofocal intraocular lenses. results of a multicenter questionnaire.
PURPOSE: To compare the incidence and severity of photic phenomena after the implantation of the Array(R) (Allergan) refractive multifocal intraocular lens (MIOL) and a monofocal IOL. SETTING: Multicenter study at Kiel, Mainz, Karlsruhe, and Bremerhaven, Germany. METHODS: The study comprised 231 randomly selected patients from 4 study centers. The patients had had uneventful phacoemulsification with implantation of a refractive MIOL (n = 138) or a monofocal IOL (n = 93). By questionnaire, patients were asked whether they experienced light sensations postoperatively (light streaks, halos, flare, flashes, or glare) that had not been noticed preoperatively. Additional questions evaluated whether these phenomena had changed over time and how much they affected the patients' quality of life. RESULTS: Overall, 9% of patients with a monofocal IOL and 41% of those with an MIOL reported photic phenomena that had not been noticed before cataract surgery. Halos and flare were mentioned significantly more often by patients with MIOLs than by those with monofocal IOLs. There was no significant between-group difference in the mention of flashes. Eighteen percent of patients with MIOLs and 4% with monofocal IOLs were slightly or moderately bothered by the photic phenomena, whereas 5% of patients with MIOLs and none in the monofocal group were severely disturbed by the light sensations. CONCLUSION: Subjective photic phenomena were experienced significantly more often by patients who had refractive MIOLs than by those who had monofocal IOLs. The differences in the results of the 4 study centers were probably influenced by different patient selection criteria for the implantation of MIOLs.
Glare↗
Intraocular pressure after small incision cataract surgery: temporal sclerocorneal versus clear corneal incision.
PURPOSE: To compare intraocular pressure (IOP) after phacoemulsification and foldable intraocular lens (IOL) implantation using a temporal sclerocorneal or clear corneal incision. SETTING: Department of Ophthalmology, Johannes Gutenberg-University, Mainz, Germany. METHODS: One hundred patients (100 eyes) with cataract having phacoemulsification with posterior chamber IOL implantation were randomly assigned to receive a temporal sclerocorneal or clear corneal tunnel incision. Intraocular pressure was measured preoperatively and 6 hours, 1, 2, and 3 days, and 5 months postoperatively. Statistical significance was determined by nonparametric group comparisons using 2-sample random Wilcoxon tests. RESULTS: Six hours postoperatively, the median IOP increase was significantly higher in the sclerocorneal tunnel group (57%) than in the clear corneal incision group (18%) (P <.001). No significant between-group difference in IOP was found at 1, 2, or 3 days or 5 months. At 5 months, IOP was 0.6 mm Hg lower than preoperatively in the sclerocorneal tunnel group and 1.5 mm Hg lower in the clear corneal group. CONCLUSIONS: After phacoemulsification and foldable IOL implantation, the immediate postoperative IOP increase was higher in eyes having a sclerocorneal incision than in those having a clear corneal tunnel incision. These results could be important in eyes with decreased outflow facility or preexisting optic nerve damage.
Adult↗
Beam-deflection method of diagnosing impaired vision.
We describe a simple method to assign a diagnosis of cataract to patients with obscurely impaired vision as well as to those with mild lens opacities. When the narrowest slit is used in a slitlamp examination, a small beam of light appears on the macula. Routine fundoscopy with the 78.0 diopter lens or a 3-mirror glass is appropriate. If a cataract is present, the beam of light is scattered into several straight lines, distorted lines, or both. This has proved a useful diagnostic tool when the lens appears clear but the patient's vision is impaired, and extensive examinations such as computer tomography or nuclear magnetic resonance tomography for impaired vision may be avoided. The beam-deflection method uses devices that are generally available and can detect cataract in the early stages of development.
Adolescent↗
Evaluation of viscoelastic substances.
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Chondroitin Sulfates↗
Reproducibility of optical biometry using partial coherence interferometry : intraobserver and interobserver reliability.
PURPOSE: To evaluate the intraobserver and interobserver variability in axial length (AL), anterior chamber depth (ACD), and corneal radius measurements using an optical biometry instrument based on partial coherence interferometry (PCI). SETTING: Johannes Gutenberg University, Mainz, Germany. METHODS: In this observational case series and interobserver reliability trial, 30 healthy, emmetropic to moderately myopic eyes of 15 volunteers were evaluated. The AL, ACD, and corneal radius were measured 20 times in 10 eyes by 1 observer to evaluate the intraobserver variability. To evaluate the interobserver variability, the measurements were taken in 20 eyes by 5 different observers. Measurements were performed using the IOLMaster (Carl Zeiss) based on PCI. The data description is based on coefficients of variation and the statistical inference on reliability estimation based on analysis of variance. The main outcome measures were intraobserver and interobserver variability and reliability in AL, ACD, and corneal radii. RESULTS: The intraobserver variability (SD) was +/-25.6 microm for AL, +/-33.4 microm for ACD, and +/-12.9 microm for corneal radius. The coefficients of variation were 0.1%, 0.9%, and 0.17%, respectively. The interobserver variability (SD) was +/-21.5 microm for AL, +/-29.8 microm for ACD, and +/-15.9 microm for corneal radius. The coefficients of variation were 0.09%, 0.82%, and 0.21%, respectively. The reliability was 99.9% for AL, 97.8% for ACD, and 99.8%/99.5% for corneal radius (r1/r2). The slightly reduced reliability in ACD measurement was caused by a reduced intraobserver reliability of 1 of the 5 observers (R = 0.87). CONCLUSION: Partial coherence biometry using the IOLMaster for AL measurement was highly reliable, offering observer-independent measurement results.
Adult↗
[Near vision after implantation of monofocal versus multifocal intraocular lenses].
AIM: Object of this study was to compare the near visual acuity between eyes with monofocal intraocular lens (MONO) and myopic target refraction in comparison with eyes after refractive multifocal intraocular lens (MIOL) implantation and emmetropic to slight hyperopic target refraction. PATIENTS AND METHOD: 89 eyes of 83 patients underwent cataract surgery, in 49 eyes a MONO (SI-40NB, Allergan) was implanted, in 40 eyes a refractive MIOL (SA-40N, Allergan). At day 2 after surgery and after 5 months the uncorrected near visual acuity, the near visual aculty with distance correction and with an addition of +3 diopters (D) were determined. The refractive outcome targeted in case of MIOL implantation was emmetropia to slight hyperopia and myopia for the MONO subjects. The eyes with MONO were classified in 4 categories depending on their postoperative refractive error (spherical equivalent, SE): category 1 with SE +1 to > 0 D, category 2 with SE 0 to > -1 D, category 3 with SE -1 to > -2 D and category 4 with a SE -2 to > -3 D. RESULTS: We found a statistically significant better uncorrected near visual acuity in eyes with MIOL than in MONO subjects for category 1-3. In category 4 there was no statistically significant difference between MONO and MIOL. With best distance correction near visual acuity in MIOL was statistically significant better than in all 4 MONO categories. After adding 3 D, there was no statistically significant difference between the groups. CONCLUSION: Even in case of a myopic target refraction near visual acuity in eyes of the MONO group was statistically significant worse than in the eyes of the MIOL group. Only in case of postoperative SE of < or = -2 D eyes of the MONO group had a near visual acuity similar to the eyes of the MIOL group. This advantage is accomplished with a decrease in the uncorrected distance visual acuity.
Aged↗
[Comparison of intraocular lenses--a review].
The wide array of intraocular lenses (IOLs) commercially available today makes it a formidable challenge to choose the most appropriate lens for the patient. Many wonder whether there truly are clinical differences among various IOLs. This update traces the evolution of IOLs in response to the widespread acceptance of phacoemulsification, and discusses the respective advantages and disadvantages of the IOLs available today based on clinical investigations.
Biocompatible Materials↗