[Results of implantation of a Worst Iris Claw Lens for correction of high myopia]. / Ergebnisse nach Implantation einer Worst Iris Claw Lens zur Korrektur der hohen Myopie.

BACKGROUND: The purpose of this clinical study was to evaluate refraction, best visual acuity and anterior chamber flare after implantation of a Worst Iris Claw Lens to correct high myopia. PATIENTS AND METHODS: From September 1996 to February 1999 the implantation of a Worst Iris Claw lens was performed on 44 highly myopic phakic eyes of 28 patients. Data after 6 weeks and 6 months follow-up were assessed. RESULTS: The mean preoperative spherical equivalent was--17.35 +/- 3.57 dpt and 6 months after implantation 79% of the eyes were within +/- 1.0 dpt of target refraction. The mean best corrected visual acuity increased from 0.43 preoperatively to 0.65 postoperatively and 6 months after the treatment there was no flare (< 10 photons/ms) in 21% and a mild anterior chamber flare (10-80 photons/ms) in 76% of the treated eyes. The median laser flare was 20 p/ms. CONCLUSIONS: In conclusion, implantation of a Worst Iris Claw lens has proved to be a precise method to correct high myopia. No or mild anterior chamber flare and a good visual acuity were measured in most eyes 6 weeks and 6 months after surgery. Longer follow-up periods are needed to assess the long-term safety and efficiency.

Expression of fibroblast growth factors 1 and 2 in a human retinal pigment epithelium cell line (K1034).

The primary source of fibroblast growth factors (FGFs) is the retinal pigment epithelium (RPE). Investigations on FGF secretion in RPE primary cultures are hampered by the rapid run-down of cell vitality after a few passages. Therefore, long-term experiments require an alternative to primary cultures. We detected FGF-1 and FGF-2 in the established human K1034 cell line by immunohistochemistry. In addition, mRNA for both FGFs was found by RT-PCR. By immunohistochemistry, the signal was more pronounced with FGF-2 than with FGF-1. K1034 is capable of expressing both FGF-1 and FGF-2. With respect to these features, this cell line can be used as an alternative to primary cultured human RPE cells.

[Computer program for retinopathy of prematurity screening]. / Computerprogramm für das Screening auf Retinopathia praematurorum.

BACKGROUND: The goal of retinopathy of prematurity (ROP) screening is complete detection of all preterm infants with threshold ROP. AIM: We wanted to develop software to facilitate registration of ROP findings, checking due dates of re-examination, and evaluation of screening data. By means of complete and faultless registration and evaluation of the data of preterm infants, the effectiveness and safety of the screening should increase. METHODS: We developed software that runs under Microsoft Windows 3.1 or Windows 95 and is programmed in Microsoft Access Basic and Microsoft Visual Basic. The software allows all screening data to be registered and evaluated. Intuitive handling, third level of normalization in database architecture, and automatic plausibility checks guarantee the utmost integrity of data and efficacy of database. RESULTS AND CONCLUSION: To date, the software has been used routinely in 2000 examinations in 1000 preterm infants. Our software facilitates clinical management and evaluation of ROP screening, which therefore becomes more safe.

[LASIK for myopia correction. 2-year follow-up]. / LASIK zur Myopiekorrektur. 2-Jahres-Ergebnisse.

BACKGROUND: Long-term results on LASIK are not available to date. We therefore evaluated the predictability, stability and complication rate after LASIK in moderate--to-high myopia. PATIENTS AND METHODS: We treated 70 eyes (41 patients) using the Automatic Corneal Shaper and the Keracor 116 excimer laser. Patients were followed for 1, 6, 12 and 24 months. Spectacle refraction, visual acuity, rate of retreatment, and patient satisfaction were evaluated. RESULTS: At 24 months the results were as follows: Myopia -5 to -9.9 D (n = 18): 94% within 1 D; regression between 1 and 12 (12 and 24) months > 1 D in 6% (6%); uncorrected acuity 20/40 or better in 83%; no loss of 2 ore more lines of visual acuity; 89% highly satisfied. Myopia -10 to -14.9 D (n = 12): 88% within 1 D; regression between 1 and 12 (12 and 24) months > 1 D in 20% (0%); uncorrected acuity 20/40 or better in 72%; 4% lost 2 or more lines of visual acuity; 96% highly satisfied. Myopia -15 to -29 D (n = 22): 33% within 1 D; regression between 1 and 12 (12 and 24) months > 1 D in 41% (18%); uncorrected acuity 20/40 or better in 7%; no loss of 2 or more lines of visual acuity; 67% highly satisfied. CONCLUSION: LASIK is an accurate, effective and stable procedure for correcting myopia of -5 to -10 D. Results are less precise in myopia up to -15 D, and some visual loss occurs in a number of patients. In myopia > -15 D, results are not satisfactory because of poor accuracy and low stability.

Laser in situ keratomileusis for moderate and high myopia and myopic astigmatism.

OBJECTIVE: This study evaluated the predictability, stability, and safety of laser in situ keratomileusis (LASIK) in myopia and myopic astigmatism. DESIGN: The study design was a prospective, unmasked, nonrandomized clinical trial. PARTICIPANTS: Participating were 25 patients with myopia (37 eyes) with astigmatism of less than 1.00 diopter (D), divided into 3 subgroups (-5.00 to -9.90 D, 8 eyes; -10.00 to -14.90 D, 10 eyes; -15.00 to -29.00 D, 19 eyes), and 37 patients with myopia (56 eyes) with corneal astigmatism of 1.00 to 4.50 D, divided into 3 subgroups (-5.00 to -9.90 D, 12 eyes; -10.00 to -14.90 D, 24 eyes; -15.00 to -29.00 D, 20 eyes). INTERVENTION: LASIK was performed using the Automatic Corneal Shaper and the Keracor 116 excimer laser. MAIN OUTCOME MEASURES: Visual acuity, manifest refraction, central corneal islands, ablation decentration, and patient satisfaction were measured. RESULTS: At 12 months, predictability, regression between 1 and 12 months, uncorrected visual acuity (UCVA), loss of two or more lines of corrected visual acuity, and patient satisfaction of the spherical (toric) groups are reported. Subgroups -5.00 to -9.90 D: 100% (75%) +1.00 D; regression less than or equal to 1.00 D in 100% (91.7%); UCVA greater than or equal to 20/40 in 87.5% (70%); none lost two or more lines; 100% (84%) highly satisfied. Subgroups -10.00 to -14.90 D: 60% (78.3%) +/-1.00 D; regression less than or equal to 1.00 D in 100% (87%); UCVA greater than or equal to 20/40 in 77.8% (86.4%); 10% (4.3%) lost two lines; 90% (91%) highly satisfied. Subgroups -15.00 to -29.00 D: 38.9% (21.4%) +/-1.00 D; regression less than or equal to 1.00 D in 72.2% (64.3%); UCVA greater than or equal to 20/40 in 33.3% (40%); 5.6% (7.1%) lost two lines; 78% (50%) highly satisfied. Differences of predictability and change of manifest refraction between subgroups of -5.00 to -9.90 D and -15.00 to -29.00 D were statistically significant. Central islands (decentrations) were observed in 17% (5.6%) of eyes of the spherical and in 16% (4.1%) of the toric group. Overall, the corneal interface was visible in 8.2%. CONCLUSIONS: The LASIK method used in this study showed stability of manifest refraction and adequate uncorrected central visual acuity in a large percentage of patients with myopia up to -15.00 D. Corneal stability was not as uniform. Central corneal islands were observed in a sizable minority of patients despite pretreatment. For myopia greater than 15.00 D, accuracy and patient satisfaction were sufficiently poor to advise against using the authors' treatment technique in these groups. Visually significant microkeratome and laser-related problems were noted in a smaller percentage of patients. Patients with astigmatism correction were less pleased with results than were patients who received spherical corrections.

Basic, not acidic fibroblast growth factor stimulates proliferation of cultured human retinal pigment epithelial cells.

PURPOSE: In this study, we evaluated a possible effect of acidic and basic fibroblast growth factor (aFGF, bFGF) on the proliferation of human retinal pigment epithelial (RPE) cells in culture. As the RPE is the primary source for bFGF in the retina, such an effect would suggest autocrinic actions of FGFs. METHODS: Primary cultures of human and porcine RPE and an established human RPE cell line (D407) were subjected to aFGF and bFGF at different culture conditions. Cell proliferation was determined using the BrdU non-radioactive nucleotide analogue assay, and total protein was measured colorimetrically. The cells were subjected to aFGF and bFGF from 0.1 to 100 ng/ml for 1 to 14 days. RESULTS: In the presence of 100 ng/ml bFGF, cell proliferation doubled from day 2 (143+/-12 units) to day 6 (227+/-17). This effect was neither seen without bFGF nor with aFGF at the same concentration. The stimulating effect of bFGF on cell proliferation was dose-dependent, the ED50 being around 1-10 ng/ml. The bFGF effect was markedly greater at high fetal calf serum concentration (10% vs. 1%). No bFGF effect was seen on cells of the established human RPE cell line D407 nor on primary cultures from porcine RPE. CONCLUSIONS: bFGF, in contrast to its analogue aFGF, stimulates cell proliferation in cultured human RPE cells. It may act as an autocrinic agent (secretion by and action on the same cell) and thus be a specific regulator for cell proliferation in repair and replacement of the RPE cell monolayer.

[Laser in situ keratomileusis (LASIK) for correction of myopia]. / Laser-in-situ-Keratomileusis (LASIK) zur Myopiekorrektur.

BACKGROUND: Laser in situ keratomileusis (LASIK) preserves the corneal epithelium and Bowman's layer, which theoretically minimizes corneal scarring. We, therefore, evaluated the accuracy, stability and safety of LASIK in moderate to high myopia. PATIENTS AND METHODS: Eighty-five eyes (50 patients) treated using the Automatic Corneal Shaper and the Keracor 116 excimer laser were followed up for 1, 6, and 12 months. Spectacle refraction, visual acuity and rate of retreatments were evaluated. RESULTS: At 12 months, results were as follows: Myopia -5 to -9.9 D (n = 20); 85% within 1 D; regression between one and 12 months < or = 1 D in 90%; uncorrected acuity 20/40 or better in 75%; no loss of two or more lines of visual acuity. Myopia -10 to -14.9 D (n = 33): 73% within 1 D; regression between 1 and 12 months < or = 1 D in 91%; uncorrected acuity 20/40 or better in 79%; 6.1% lost two lines of visual acuity. Myopia -15 to -29 D (n = 32): 31% within 1 D; regression between one and 12 months < or = 1 D in 63%; 6.3% lost two or more lines of visual acuity. Reoperations were performed in two eyes (2.4%) due to epithelial ingrowth or folds of the flap, and in four eyes (4.7%) because of undercorrections or "central islands". CONCLUSIONS: LASIK is an accurate and stable procedure for correcting myopia of -5 to -15 D. In higher myopia, however, results are not satisfactory.

[Correction of myopia using laser in situ keratomileusis (LASIK)]. / Myopiekorrektur mittels Laser in situ Keratomileusis (LASIK).

BACKGROUND: In contrast to photorefractive keratectomy (PRK), the corneal epithelium and Bowman's layer are preserved in LASIK. Thus, there should be less scarring and regression after LASIK than after PRK. PATIENTS: Between December 1993 and October 1995, we treated 113 eyes (66 patients). The Automated Corneal Shaper and the Keracor 116 excimer laser were used. We evaluated refraction, visual acuity and corneal topography. RESULTS: To date, 61 eyes reached six months follow up. Mean preoperative refraction was -14.3 D (-3.3 to -29 D; SD = 7). Mean deviation from target refraction was -1.4 D (-9.5 to +2.5 D; SD = 2.7) at six months. 34% were within +/-0.5 D of target refraction, 46% within +/-1 D, 67% within +/-2 D, and 82% within +/-3 D. Mean change of refraction ("regression") from one to six months postoperatively was +0.13 D (-7.5 to +8 D; SD = 2.1). Refractive change was < 0.5 D in 51%, < 1 D in 66%, < 2 D in 84%, and < 3 D in 89%. In 88% of eyes, the corneal interface was not or just barely visible, while it was clearly visible in 12%. No scars were observed. CONCLUSIONS: Our results indicate that LASIK is an effective procedure in the correction of high myopia. The incidence of scar formation and regression is considerably lower than after PRK.

[Diode laser coagulation of stage 3+ retinopathy of prematurity]. / Diodenlaserkoagulation der Retinopathia praematurorum Stadium 3+.

BACKGROUND: Laser photocoagulation in retinopathy of prematurity (ROP) appears to have fewer adverse effects and to be at least as effective as cryotherapy. METHODS: To evaluate the efficacy and safety of diode laser photocoagulation we examined 50 eyes affected by stage 3+ ROP in 30 very low birth weight infants (gestational age 24-29 weeks, mean +/- SD 26.5 +/- 1.4 weeks; birth weight 480-1400 g, 898 +/- 208 g) in a prospective (uncontrolled) clinical study. Photocoagulation treatment was performed using a diode laser (810 nm) with a laser indirect ophthalmoscope delivery system. Follow-up ranged from 3 to 23 months (10.5 +/- 6.4 months). RESULTS: In 46 (92%) of the 50 eyes ROP regressed after a single laser treatment and the outcome was a flat, attached retina. Two eyes (4%) had a second laser session and one other eye (2%) had additional retinal detachment surgery, resulting in the regression of ROP and a flat, attached retina. Thus, the success rate was 98% (49 out of 50 eyes). In 1 (2%) of the 50 eyes treatment failed and ROP progressed to stage 5, although additional retinal detachment surgery was performed. No adverse side effects of diode laser treatment were noted, except for a small amount of retinal/preretinal bleeding in the ridge in 8 eyes (16%) and slight postoperative anterior chamber bleeding in 1 eye (2%) with dense tunica vasculosa lentis. There were neither lenticular opacities nor cataract formation. CONCLUSION: Diode laser photo coagulation using the laser indirect ophthalmoscope for stage 3+ ROP was easy to administer. Laser treatment had only minor side effects and was at least as effective as cryotherapy.

[Vector analysis of surgically-induced astigmatism in cataract operation with 4 tunnel incision techniques]. / Vektoranalyse des chirurgisch induzierten Astigmatismus bei Kataraktoperation mit 4 Tunnel-Schnitt-Techniken.

UNLABELLED: Evaluation of astigmatism induced by cataract surgery requires the calculation of surgically induced astigmatism using vector analysis. This method was performed for four tunnel-incision techniques and compared with the results of computer-assisted videokeratoscopy. METHODS: Phacoemulsification with IOL implantation was performed in 59 eyes using four different incisions (4- or 5- to 6-mm scleral tunnel and 4- or 5.5-mm clear cornea). Surgically induced astigmatism was calculated by vector subtraction using the formulas of Retzlaff. In addition, corneal topography was performed and astigmatism was calculated within three concentric corneal zones (3 mm, 3-5 mm, 5-7 mm). RESULTS: Surgically induced astigmatism after a 4-mm scleral tunnel incision was 0.55 D (pre-op 0.58 D, post-op 0.72 D), the 5-6-mm incision induced 0.89 D (pre-op 0.97 D and post-op 1.02 D). The 4-mm clear cornea incision induced 2.00 D (from 0.89 D to 1.56 D), the 5.5-mm corneal incision, performed in the steepest meridian to reduce preexisting astigmatism, induced 3.57 D; pre-op 3.38 D, post-op 2.09 D. Corneal topography revealed a slight increase in astigmatism within all corneal zones (4-mm scleral tunnel: 0.26 D, 5-6-mm scleral tunnel: 0.36 D and 4-mm clear cornea incision: 0.22 D). After a 5.5-mm clear cornea incision, however, astigmatism of the central 3-mm zone was reduced by 1 D, while astigmatism of the 5-7 mm zone increased by 0.22 D. CONCLUSION: The 4- and 5- to 6-mm scleral tunnel as well as the 4-mm clear cornea incision were shown to be nearly astigmatism-neutral. The 5.5-mm clear cornea incision reduced astigmatism of the central cornea by about 35%, but induced irregular astigmatism in the periphery.

Contrast sensitivity with monofocal and bifocal intraocular lenses.

Bifocal intraocular lenses (BIOLs) reduce image contrast. We measured contrast sensitivity (CS) to evaluate the clinical significance of the loss in image contrast. Four groups were compared: 15 patients with a monofocal IOL, 13 with the True Vista BIOL, 13 with the AcuraSee BIOL, 11 with the diffractive BIOL. CS was measured using the Mentor B-VAT II-SG. Distance CS was slightly better in monofocal eyes than in all bifocal eyes, and distance CS was considerably better than near CS in eyes with the True Vista or the AcuraSee BIOL. With the diffractive BIOL, values were about the same at distance and near focus. Our results demonstrate that BIOLs reduce CS. thereby performing differently: both True Vista and AcuraSee favor distance vision, while the diffractive BIOL provides about the same contrast at distance and near focus.

Diode laser photocoagulation for stage 3+ retinopathy of prematurity.

BACKGROUND: Laser photocoagulation in retinopathy of prematurity (ROP) appears to have fewer adverse effects than cryotherapy and seems to be at least as effective. METHODS: To evaluate the efficacy and safety of diode laser photocoagulation, we included 42 eyes with stage 3+ ROP of 24 preterm infants (gestational age 24-29 weeks, mean +/- SD 26.6 +/- 1.3 weeks; birth weight 480-1400 g, 896 +/- 196 g) in a prospective clinical study. Photocoagulation treatment was performed using a diode laser (810 nm) with a laser indirect ophthalmoscope delivery system. Follow-up ranged from 3 to 16 months (8.8 +/- 4.0 months). RESULTS: In 39 (93%) of 42 eyes ROP regressed after a single laser treatment and the outcome was a flat, attached retina. One eye (2%) had a second laser session and another eye (2%) had additional retinal detachment surgery, resulting in the regression of ROP and a flat, attached retina. Thus, the success rate was 41 (98%) out of 42 eyes. In one (2%) of the 42 eyes treatment failed and ROP progressed to stage 5, although additional retinal detachment surgery was performed. No adverse side effects of diode laser treatment were noticed except for a small amount of retinal/preretinal bleeding in the ridge in five eyes (12%) and a small postoperative anterior chamber hemorrhage in one eye (2%) with dense tunica vasculosa lentis. Neither lenticular opacities nor cataract formation were encountered. CONCLUSION: Diode laser photocoagulation for stage 3+ ROP showed only minor side effects and was at least as effective as cryotherapy treatment.

Diode laser photocoagulation for threshold retinopathy of prematurity in eyes with tunica vasculosa lentis.

PURPOSE: To determine possible side effects of diode laser photocoagulation for threshold retinopathy of prematurity in eyes with tunica vasculosa lentis. METHODS: In a prospective clinical study, threshold retinopathy of prematurity was treated in 14 eyes of seven consecutive preterm infants with tunica vasculosa lentis (birth weight, 480 to 980 g; mean +/- S.D., 777 +/- 175 g; gestational age, 24 to 27 weeks; mean +/- S.D., 25.7 +/- 0.9 weeks) by using the diode laser indirect ophthalmoscope. Main outcome measure was the incidence of adverse treatment effects. Follow-up included anterior segment examination with a hand-held slit lamp and ranged from seven to 17 months (12.6 +/- 3.5 months). RESULTS: The tunica vasculosa lentis did not interfere with photocoagulation in any of the 14 eyes. Laser power ranged from 200 to 400 mW (260 +/- 52 mW). Duration of a single spot was 200 msec. Number of burns ranged from 1,060 to 2,132 (1,556 +/- 315). Retinopathy of prematurity regressed in all eyes, and the outcome was a flat, attached retina. A small amount of postoperative anterior chamber bleeding was noticed in one eye (7% of the eyes, 14% of the patients). There were neither lenticular opacities nor cataract formation. CONCLUSION: Diode laser photocoagulation with the laser indirect ophthalmoscope can be used safely in eyes with tunica vasculosa lentis. At the laser energy levels used in our study, no transient lens opacities or cataract formation occurred. However, the results of this study are limited by a relatively small number of patients and a relatively short follow-up.

A controlled clinical trial of light and retinopathy of prematurity.

Bright continuous light has been implicated in the pathogenesis of retinopathy of prematurity. To investigate the influence of light on the incidence and severity of retinopathy of prematurity, we enrolled 127 preterm infants (birth weight < or = 1,500 g; gestational age < or = 32 weeks) in a controlled clinical study. Randomization was done separately for three birth-weight groups (< 1,000 g; 1,000 to 1,249 g; 1,250 to 1,500 g). The babies' eyes were patched all day and night from birth to a gestational age of 35 weeks. The infants in the control group were exposed to cycled lighting conditions (that is, reduced light level during the night). Of 62 infants with patched eyes, 26 (42%) developed retinopathy of prematurity. In the control group, 25 of 65 infants (39%) showed retinopathy of prematurity (P = .596). There were also no statistically significant differences in the incidences of retinopathy of prematurity in the birth-weight subgroups or in the severity of retinopathy of prematurity. Thus, patching of the eyes from birth to 35 weeks of postconceptional age does not decrease the risk of retinopathy of prematurity in preterm infants when compared to a control group exposed to cycled lighting conditions.

[Ocular findings in former premature infants at the age of 11 to 14 years]. / Augenbefunde ehemaliger Frühgeborener im Alter von 11 bis 14 Jahren.

BACKGROUND: Functional disturbances as well as morphologic changes can be various in regressed retinopathy of prematurity (ROP). PATIENTS AND METHODS: To investigate the incidence and the degree of such changes, we examined prematurely born infants in the age of 11 to 14 years. Of the 142 prematures (birthweight < or = 2000 g), who were cared for in their first weeks of life in the University Children's Hospital at the Klinikum Mannheim in 1977 to 1979, 48 could be reexamined. RESULTS: Of 48 infants (mean birth weight 1808 +/- 211 g, gestational age 34.6 +/- 3.1 weeks) six (12.5%; birth weight 1742 +/- 218 g, gestational age 32.2 +/- 2.5) had had acute ROP (stage 2 or 3). When reexamined in school age 10 (21%) of the children had physical deficits. Eight (17%) visited a school for handicapped children. Eight (17%) children had a squint. In 13 out of 96 (14%) eyes visual acuity was reduced to 0.8 or less. Thirteen eyes (14%) were emmetropic, 67 (70%) hyperopic, 16 (17%) myopic and 15 (16%) astigmatic. The intraocular pressure was normal in all eyes (15 +/- 4 mm Hg). The anterior segments did not show findings caused by ROP. The fundus findings in the 12 eyes, in which the diagnosis of acute ROP was established in the first weeks of life, showed in 5 (42%) eyes a slightly reduced angle kappa between the vascular arcades and avascular retina in the temporal fundus periphery in all of the 12 (100%) eyes. In 1 (8%) eye the retinal periphery showed extensive scarring after cryotherapy because of acute ROP. None of the eyes which had had acute ROP showed macular ectopia or retinal folds (amotio falciformis). In 16 of the 84 (19%) eyes, which did not have a history of acute ROP, minor changes of the retinal periphery, the peripheral retinal vessels and the pigment epithelium were present, which were caused by prematurity. CONCLUSION: Prematurely born infants examined in school age, who were comparatively mature preterms at birth (mean birth weight 1800 g; mean gestational age 34.6 weeks), did not show a higher risk of refractive errors, i.e. myopia. However, they were at higher risk having squint. The functional disturbances found in the prematurely born infants in this study were not caused by morphologic changes due to ROP.

Comparison of the optical and visual quality of poly(methyl methacrylate) and silicone intraocular lenses.

We evaluated experimentally the optical quality of poly(methyl methacrylate) (PMMA) (Storz 68UV, AMO PC58) and silicone (AMO SI19, Adatomed 90D) intraocular lenses (IOLs) and compared the results with our clinical data. We measured surface and image quality using the Zygo laser interferometer and modulation transfer function (MTF) using the Ealing EROS MTF analyzer. Contrast acuity was tested clinically with glare and without glare (Regan charts); AMO PC58, n = 18; AMO SI19, n = 7; Adatomed 90D, n = 18). Modulation transfer function and image quality were slightly better with PMMA IOLs but the reduction of MTF with silicone lenses was within the 1/8 diopter defocus range. Surface quality of silicone IOLs was superior to that of PMMA IOLs. Contrast acuity measured clinically was also slightly better with PMMA IOLs at low contrast and with glare but differences were not significant. Our results suggest that optical and visual quality of silicone IOLs is slightly lower than with PMMA IOLs. Experimental and clinical results correlated closely. However, the small differences observed are unlikely to be significant clinically.

[Contrast sensitivity and defocus curve with various bifocal-IOL]. / Kontrastsehschärfe und Defokussierkurve mit verschiedenen Bifokal-IOLs.

Simultaneous vision, the basic principle of all bifocal intraocular lenses (IOLs), provides increased depth of focus but also causes a loss in contrast. We therefore measured contrast acuity (CA) (Regan Charts) and the defocus curve at different pupil sizes in 14 patients with a TRUE VISTA bifocal IOL (TV) (Storz Co.), 10 patients with a 3M diffractive bifocal IOL (3M) (3M Co.) and 9 patients with a Nordan Aspheric Varifocal Silicone IOL (VF) (Wright Medical Inc.). CA at distance focus was best with VF; next was TV, and 3M showed the lowest values. At near focus, CA was best with 3M; next was TV, and VF showed the lowest values. Differences between VF and 3M were significant (P = 0.05; t-test). CA at near focus was significantly lower than at distance focus with TV and VF (TV: P = 0.0001; VF: P = 0.005). Pseudoaccommodation was 4.5 D with TV and 3M and 3D with VF. In conclusion, distance CA was best with VF but pseudoaccommodation was not sufficient for reading. Near CA was best with 3M while distance CA was somewhat reduced. TV showed good distance CA while near CA was still sufficient. TV therefore seems to provide a good compromise.

Evaluation of contrast acuity and defocus curve in bifocal and monofocal intraocular lenses.

We compared visual quality of the following intraocular lenses in a prospective study: monofocal, True Vista bifocal, 3M diffractive bifocal, and Nordan aspheric VariFocal silicone. Four to six months postoperatively we measured distance acuity, Snellen near acuity (Lighthouse chart), reading acuity (Nieden chart), and contrast acuity at far and near focus (Regan charts: 96%, 50%, 25%, 11% contrast) with different pupil sizes. A defocus curve was obtained by spectacle defocus (+1 diopter [D] to -5 D). Eleven patients had True Vista in one eye and monofocal in the fellow. Contrast acuity at far focus decreased with decreasing contrast and increasing pupil size. This decrease was more pronounced with the True Vista than with the monofocal lenses. These differences were significant, with a 4.5 mm pupil at lower contrast (25%, P = .02; 11%, P = .01). Depth of focus was 4.5 D (+1.0 D to -2.0 D) with True Vista lenses and 2.5 D (+1.0 D to -1.5 D) with monofocal lenses. Corrected distance acuity was 20/22 with True Vista, 20/25 with 3M, and 20/20 with VariFocal. Distance corrected Snellen near acuity was 20/39 with True Vista, 20/34 with 3M, and 20/57 with VariFocal. Distance corrected reading acuity was 20/29 with True Vista, 20/23 with 3M, and 20/44 with VariFocal (P = .005). Contrast acuity at far focus was best with the VariFocal IOL, followed by True Vista and 3M. At near focus it was best with 3M, followed by True Vista and VariFocal. Contrast acuity at near focus was lower than at far focus. Average acuity differences were as follows: VariFocal 0.43, P = .01; True Vista 0.19, P = .05; 3M 0.04, P = .3. Depth of focus was 4.5 D (+1.0 D to -3.5 D) with True Vista and 3M and was 3 D (+1.0 D to -2.0 D) with VariFocal. Each design offers unique features. VariFocal is best at distance, but near vision is not sufficient. The 3M lens is best at near vision but distance contrast acuity is somewhat reduced. The True Vista lens provides a good compromise as distance contrast acuity is good and near vision is sufficient.

[Indications and contraindications for implantation of bifocal intraocular lenses]. / Indikationen und Kontraindikationen für die Implantation bifokaler Intraokularlinsen.

BACKGROUND: Bifocal intraocular lenses (BIOLs) performed satisfactorily in a certain number of patients only. This paper therefore provides an overview of the indications and contraindications of BIOLs. INDICATIONS: BIOLs are indicated in younger and active patients without ocular pathologies. BIOLs should be implanted bilaterally, corneal astigmatism should be less than 1 dpt, emmetropia should be the target refraction, pupil size and responsiveness must be normal, and IOL decentration should be avoided. CONTRAINDICATIONS: Corneal astigmatism in excess of 1 dpt, very small or atonic pupils, ocular pathologies, and a monofocal fellow eye are definite contraindications. In addition, BIOLs are contraindicated in patients who require maximum resolution at low contrast. Relative contraindications include very old patients, eyes with an axial length of more than 24.5 mm or less than 22 mm, and patients who may not tolerate the visual side effects (halos, glare).