PURPOSE: To study the long-term results of implantation of the 3M diffractive multifocal intraocular lens (IOL). SETTING: Eye Department, ASA, Arendal, Norway. METHODS: The study comprised 97 eyes in 72 patients. Follow-up was 8 years. Distance and near visual acuities, refractive results, contrast sensitivity, IOL centration, and neodymium:YAG (Nd:YAG) capsulotomies to treat posterior capsule opacification were evaluated. RESULTS: All patients without ocular pathology achieved a best corrected visual acuity (BCVA) of 0.5 or better (i.e., 98.7% had a BCVA of 1.0 or better). Without correction, 73.8% of eyes had a Jaeger acuity of J3 or better and with distance correction, 92.1%. Emmetropia or within +/-0.25 diopter (D) of it was achieved in 58.8% of eyes. An astigmatic shift of 0.827 D cylinder correction was induced. This shift was mainly against the rule (0.717 D). Contrast sensitivity was reduced with spatial frequencies of 6 to 18 cycles per degree. No need for spectacles was reported by 54.2% of patients and by 68.0% of those with bilateral implantation. For near tasks, 63.9% of patients never used spectacles. The IOLs were well centered or minimally decentered in 99.0% of eyes. Posterior capsule opacification was treated by Nd:YAG laser capsulotomy in 55.7% of eyes, with a mean time between surgery and treatment of 34.0 months +/- 23.2 (SD). CONCLUSION: This long-term study proved the 3M diffractive IOL to be safe and effective despite some reduction in contrast sensitivity at higher spatial frequencies. More than half the patients never wore spectacles; 2 of 3 patients with IOLs in both eyes never wore spectacles. Proper patient selection is crucial.
PURPOSE: To evaluate whether cataract surgery in children should be performed with anterior vitrectomy and to examine the properties of the AcrySof SA30AL intraocular lens (IOL) in the pediatric eye. SETTING: Filatov Institute, Odessa, Ukraine. METHODS: Cataract surgery was performed in 66 children aged 3 to 15 years. They were randomized to surgery with or without anterior vitrectomy. All eyes were implanted with the single-piece AcrySof SA30AL IOL (Alcon). During the study, the patients who needed surgery for after-cataract had a second surgical procedure. Two years after surgery, the surgical method was evaluated using exact logistic regression. Also, the Evaluation of Posterior Capsule Opacification (EPCO) score was compared between the patients who had surgery for after-cataract and the patients who did not need this. The presence of posterior synechias and centration of the IOL were assessed. RESULTS: Children in the younger age group (
To determine the extent and magnitude of unexpected refractive errors following cataract surgery with intraocular lens (IOL) implantation and to determine what characteristics were associated with the errors.
In this nonconcurrent prospective study, preoperative, intraoperative and postoperative information was collected from the charts of the 523 consecutive patients who underwent cataract extraction and polymethylmethacrylate IOL implantation performed by one of nine participating surgeons between Jan. 1 and Apr. 30, 1995, or the same dates in 1996.
University-affiliated eye care centre in Vancouver.
Postoperative excess correction, calculated for each patient by subtracting the actual postoperative spherical equivalent from the expected spherical equivalent. Eyes with an excess correction of more than 1.00 dioptre were considered "overcorrected."
Univariate analysis showed that the formula used to calculate the lens power, axial length, year of surgery, A-constant/surgeon factor used and lens manufacturer were associated with overcorrection. In a logistic regression model, lens manufacturer was the only variable independently associated with overcorrection.
Routine reporting and follow-up is necessary to identify this kind of "outbreak" and the associated factors. The current guidelines of the Health Protection Branch, Health Canada, for evaluation of IOLs that have changed manufacturers are not adequate to identify the kind of error that we detected.
Comment In: Can J Ophthalmol. 1998 Jun;33(4):197-89660000
Comment In: Can J Ophthalmol. 1998 Aug;33(5):2909740961
To assess postoperative intraocular lens (IOL) position in relation to the cornea and iris, compare 2 devices for anterior chamber depth (ACD) measurement, and assess the impact of these factors on postoperative refraction in phacoemulsification.
Department of Clinical Sciences/Ophthalmology, Umeå University Hospital, Umeå, Sweden.
Evaluation of diagnostic test or technology.
Biometry and measurement of the anterior segment were performed preoperatively and postoperatively with the partial coherence interferometry (PCI)-based IOLMaster and the Pentacam HR Scheimpflug device. Predicted refraction was calculated with ACD estimations according to the Haigis formula and was compared with the actual postoperative refraction. Changes in ACD and the distance between the cornea-iris and the iris-lens/IOL were assessed from Scheimpflug images. The theoretical refractive impact of differences in ACD was calculated.
The mean preoperative ACD and refractive prediction error, respectively, was 3.22 mm ± 0.37 (SD) and 0.41 ± 0.43 diopters (D) for the PCI device and 3.21 ± 0.35 mm and 0.41 ± 0.41 D for the Scheimpflug device; the difference was not statistically significant. The mean ACD, cornea-iris distance, and iris-lens/IOL distance changes were 1.62 ± 0.38 mm, 0.78 ± 0.29 mm, and 0.85 ± 0.27 mm, respectively. The mean predicted refractive outcome from a 1.0 mm difference in ACD was 0.32 D.
No difference was found between the measurement devices. Although the exact postoperative IOL position is difficult to predict, its impact on postoperative refraction was comparatively small compared with the impact of minor corneal curvature or axial length measurement errors.
PURPOSE: To evaluate methods of measuring anterior chamber depth (ACD) before and after cataract surgery. SETTING: St. Erik's Eye Hospital, Stockholm, Sweden. METHODS: A-scan (BVI Axis) and Scheimpflug imaging (Nidek EAS-1000) were used to measure ACD preoperatively and 6 and 18 weeks after phacoemulsification with implantation of a poly(methyl methacrylate) (PMMA) intraocular lens (IOL) in 23 patients. Because of a large systematic difference between the 2 methods, measurement with Orbscan (Orbtek) and optical pachymetry (Haag-Streit) were included when measurements were repeated 36 weeks postoperatively. A t test for paired observations was used for statistical analysis. RESULTS: Preoperatively, the mean A-scan measurements were significantly shorter than the Scheimpflug values: 3.05 mm +/- 0.36 (SD) and 3.37 +/- 0.35 mm, respectively (P
PURPOSE: To evaluate changes in astigmatism in the first 6 months after 5.2 mm superior scleral incision phacoemulsification using three different closures. SETTING: Department of Ophthalmology, Vejle Hospital, Denmark. METHODS: This study comprised 75 consecutive patients who had 5.2 mm superior scleral incision phacoemulsification. Patients were randomly assigned to one of three groups based on type of incision closure: Group 1, one intraoperatively adjusted cross suture; Group 2, one unadjusted cross suture; Group 3, no suture. Inclusion criteria were preoperative astigmatism of 2.00 diopters (D) or less (range of median 0.74 to 0.81 D) and no eye disease except cataract. Postoperative astigmatism was evaluated by keratometric cylinder, induced astigmatism (Naeser), and induced cylinder (Jaffe) on the first day and after 1 week and 1, 3, and 6 months. Time before stability was estimated. RESULTS: All groups had the same level of postoperative keratometric cylinder with no significant change between 1 week and 6 months (range of median 0.81 to 1.06 D). The groups reached the same level of induced astigmatism (Naeser) 3 to 6 months after surgery (range of median -0.44 to -0.64 D). Group 3 (sutureless) reached that value after 1 week, and induced astigmatism was stable thereafter. Both sutured groups (Groups 1 and 2) had a highly significant change between the first week and third month (P
PURPOSE: To study the conditions for consistent axial length measurements with partial coherence interferometry (PCI) performed with the Zeiss IOLMaster. SETTING: University Eye Clinic, Aarhus, Denmark. METHODS: A consecutive, unselected series of 1289 cataractous eyes were measured with the optical technique of PCI according to the IOLMaster as well as with conventional (contact) A-scan ultrasound (US) for the measurement of axial length. For each PCI reading, the signal-to-noise ratio (SNR) was recorded and used for comparison with the US measurement. All patients had routine phacoemulsification with implantation of an intraocular lens (IOL). In 284 cases, the patients were reexamined 2 to 3 months after surgery and the axial length was again measured using PCI. The readings of the IOLMaster, which had been calibrated against immersion US from the manufacturer, were recalculated to represent the true optical length and used in the analysis of the consistency of the measurements. RESULTS: Not all readings obtainable with the IOLMaster were of good quality, and large differences with conventional US were found. The error between US and PCI decreased significantly with increasing SNR, showing a minimum error at an SNR value above 2.1. The SNR correlated significantly with the visual acuity with considerable scatter, however. Excluding readings with a poor quality (SNR
Extracapsular cataract extraction with implantation of an intraocular lens (IOL) is a routine operation in Norway today. With the conventional monofocal IOL, most people require spectacles post-operatively to attain optimal vision. A new principle is the bifocal IOL, which is designed to minimize the patient's need for additional post-operative near vision correction. In this article we present the first results using this bifocal lens. Ten out of 17 patients (18 eyes) had no need of post-operative spectacles. We believe that this lens represents a promising new optical principle, and is an advance in IOL implant technology.
With the Cataract Analysis System (CAS) we have analyzed 5878 consecutive cataract patients operated from 1986 through 1990. The material is complete enough to be regarded as representative of the cataract surgery performed in the entire referral region of the Lund Health Care District during this period. There has been a striking increase in the number of operations, in 1990 reaching 3.6 per 1000 inhabitants in the referral region. Simultaneously, surgery has changed from being mainly an in-patient to an out-patient procedure. Females predominate in the material, also after adjustment for the female preponderance in the population. Most likely, this is due to a higher incidence of cataract in women than in men.