Biomedical subjects

Wolf Buehl

Publications and source records attributed to Wolf Buehl.

At least 19 recordsLinked to original sources

PubMed2006

Effect of the hydrophilicity of acrylic intraocular lens material and haptic angulation on anterior capsule opacification.

AIM: To evaluate the influence of hydrophilic and hydrophobic acrylic material and haptic angulation on anterior capsule opacification (ACO). METHODS: Prospective study on 53 patients with bilateral age-related cataract. Patients underwent standard cataract surgery by the same surgeon and randomly received a hydrophilic acrylic intraocular lens (IOL) in one eye and a hydrophobic acrylic IOL in the other eye. Forty five of these patients completed the one-year follow-up. The following parameters were assessed: decentration, buttonholing, anterolenticular gap (ALG), ACO, outgrowth and refractive outcome. RESULTS: At the one-year follow-up, ACO was seen in 80% of the hydrophilic and 100% of the hydrophobic IOLs. ACO was more intense in the hydrophobic IOLs (p<0.001). Outgrowth was seen in 42% of the hydrophilic and 2% of the hydrophobic IOLs (p = 0.0003). No case of persisting ALG was seen in the hydrophobic IOLs, but in 42% of the hydrophilic IOLs. The refractive outcome was -0.29 (SD 0.56) dioptres for the hydrophilic and 0.003 (SD 0.44) dioptres for the hydrophobic IOLs (p<0.001). CONCLUSION: These results suggest that there is less ACO in hydrophilic acrylic than in hydrophobic acrylic IOLs. Although material properties might play a role, the angulated haptics of the hydrophilic IOLs exert an additional effect by the persisting ALG and a lack of contact between the IOL and the anterior capsule.

Acrylates↗

PubMed2006

Comparison of three methods of measuring corneal thickness and anterior chamber depth.

PURPOSE: To compare three different methods of measuring corneal thickness (CT) and anterior chamber depth (ACD). DESIGN: Prospective clinical trial (Medical University of Vienna, Austria). METHODS: Central CT (CCT), CT at four peripheral points, and central ACD were measured in 88 eyes of 44 healthy subjects with the Pentacam (rotating Scheimpflug camera; Oculus, Wetzlar, Germany), Orbscan I (scanning-slit topography system; Orbtek Inc, Salt Lake City, Utah, USA), and AC-Master (partial coherence interferometry; Zeiss Meditec, Jena, Germany), and the results were compared. RESULTS: The upper (lower) limits of agreement for CCT measurements were 7.9 (-22.2) microm between AC-Master and Pentacam, 17.6 (-32.5) microm between AC-Master and Orbscan, and 25.2 (-25.9) microm between Pentacam and Orbscan. Correlation was high between all three methods (r = 0.94 to 0.97). The upper and lower limits of agreement for ACD were 0.174 (-0.251) mm between AC-Master and Pentacam, 0.406 (-0.004) mm between AC-Master and Orbscan, and 0.384 (0.095) mm between Pentacam and Orbscan. Correlation was high between the three methods (r = 0.96 between Orbscan and Pentacam; others 0.92). Correlation was lower for the CT measurements at the four peripheral points. CONCLUSIONS: The CCT and ACD values obtained by Pentacam, Orbscan, and AC-Master measurements correlated well and showed few outliers. The two new systems (Pentacam, AC-Master) provide a reliable, easy-to-use, noncontact method of measuring CCT and ACD. Larger differences occurred only when measuring peripheral CT values, especially between AC-Master and the other two methods.

Adult↗

PubMed2006

Daily changes in the morphology of Elschnig pearls.

PURPOSE: To observe and document the daily changes in the morphology of Elschnig pearls. DESIGN: A prospective cohort study. METHODS: Twenty-nine pseudophakic eyes with pronounced, regeneratory posterior capsule opacification (PCO) were included in this prospective study. Retroillumination images were taken at days 0, 1, 2, and 14. A square grid was laid over the images. Increase, decrease, appearance, and disappearance of pearls between the follow-up images were quantified. RESULTS: A total of 1371 areas (mean: 53/eye) of 26 eyes were analyzed between days 0 and 1 and 1 and 2, and 896 areas (50/eye) of 18 eyes between days 0 and 14. Between days 0 and 1, days 1 and 2, and days 0 and 14, we observed "no change" in pearl size in 72%, 77%, and 32%, a "minor increase" in 16%, 14%, and 10%, a "major increase" in 4%, 3%, and 42%, a "minor decrease" in 14%, 11%, and 11%, and a "major decrease" in 4%, 3%, and 37%, respectively. Appearance of newly formed pearls was found in 1%, 1%, and 9% and disappearance of pearls in 1%, 1%, and 5%, respectively. CONCLUSIONS: Significant changes in the morphology of Elschnig pearls were observed within time intervals of only 24 hours. Appearance and disappearance of pearls, as well as progression and regression of pearls within these short intervals illustrate the dynamic behavior of regeneratory PCO. These findings may contribute to a better understanding of PCO and have implications on pharmaceutical interventions for PCO.

Adult↗

PubMed2006

Effect of topical prednisolone and diclofenac on the short-term change in morphology of posterior capsular opacification.

PURPOSE: To observe and document the effect of steroidal and nonsteroidal antiinflammatory treatment on the formation of Elschnig pearls. DESIGN: A prospective, randomized, double blinded, placebo controlled, two-way-cross-over study. METHODS: Thirty-nine eyes of 32 patients with pronounced, regeneratory posterior capsule opacification (PCO) were included. The patients were treated topically with prednisolone and diclofenac (verum) or with lubricating eye drops (placebo) four times daily for one week. After a wash-out period of two weeks the patients received the contrary treatment also four times daily for one week. Digital retroillumination images were taken at day one, three, five, eight, and 15 of each medication period. The changes in the size of 4,675 Elschnig pearls were analyzed. RESULTS: The mean cumulative area of all marked pearls/eye and follow-up was 1.2 mm(2) (range: 0.1 mm(2) to 3.2 mm(2)). The mean pearl size was 12,809 microm(2) (range: 60 microm(2) to 1.08 x 10(6) microm(2)). Between the follow-up examinations, 1,274 pearls disappeared (mean: 33 pearls/eye, range: five to 69 pearls; 27%) and 777 newly formed pearls appeared (mean: 20 pearls/eye, range: three to 53 pearls; 20%). There was no statistically significant difference in pearl size change and in number of disappeared and newly appeared pearls between the verum and the placebo treatments. CONCLUSIONS: Topical prednisolone and diclofenac do not influence the short-term change of Elschnig pearls. Elschnig pearls disappear and appear within days. The degree of progression and regression varies greatly among eyes.

Administration, Topical↗

PubMed2006

Influence of severity of nuclear cataract on optical biometry.

PURPOSE: To compare preoperative and postoperative measurements of the axial length (AL) performed with the IOLMaster (Carl Zeiss Meditec) to evaluate the effect of nuclear cataract on the optical biometry. SETTING: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. METHODS: In 245 consecutive eyes of 162 patients scheduled for cataract surgery, type and severity of cataract was evaluated using the Lens Opacities Classification System III. Preoperative and postoperative axial length measurements were performed with the IOLMaster. The postoperative readings of AL were corrected for the IOL optic material implanted. RESULTS: The preoperative AL measurements were 0.07 mm +/- 0.05 (SD) (range -0.18 to 0.11 mm) longer than the postoperative measurements (P<.001). These differences in AL were only weakly correlated (r = -0.28, P = .01) with the nuclear cataract grade, mean 3.5 +/- 0.9. CONCLUSION: In this study, AL measurements with optical biometry using the IOLMaster were not influenced by the severity of nuclear cataract to a clinically relevant degree. Furthermore, it was found that AL in the phakic eye was overestimated by about 0.07 mm because of a slightly too low value of the group refractive index used for the crystalline lens.

Adult↗

PubMed2006

Effect of anterior capsule polishing on the posterior capsule opacification-inhibiting properties of a sharp-edged, 3-piece, silicone intraocular lens: three- and 5-year results of a randomized trial.

PURPOSE: To evaluate the long-term effects of anterior capsule polishing on regeneratory posterior capsule opacification (PCO), anterior capsule opacification (ACO), and fibrotic PCO with a silicone intraocular lens (IOL) with sharp optic edges. SETTING: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. METHODS: This prospective bilateral randomized patient- and examiner-masked clinical trial comprised 130 eyes of 65 patients with bilateral age-related cataract. All eyes had implantation of a 3-piece silicone IOL with a truncated, sharp-edged optic (CeeOn Edge 911A, Advanced Medical Optics). In 1 eye, the anterior capsule was extensively polished using an aspiration curette after phacoemulsification and cortex aspiration. Regenerative PCO was quantified objectively, while ACO and fibrotic PCO were graded subjectively 1, 2, 3, and 5 years postoperatively. RESULTS: The mean ACO score was significantly lower in the eyes in which the anterior capsule had been polished (1 year, P<.02; 2 years, P<.03; 3 years, P<.01; 5 years, P<.01). The mean difference in regeneratory PCO and fibrotic PCO scores between the 2 groups was not statistically significant. CONCLUSIONS: Three years after cataract surgery, eyes in which the anterior capsule had been polished had significantly less ACO. However, polishing did not lower PCO intensity when a sharp-edged CeeOn 911A IOL was implanted in the bag. Although results indicate that anterior capsule polishing may enhance the development of regeneratory PCO, this trend did not reach statistical significance.

Cataract↗

PubMed2005

Long-term effect of sharp optic edges of a polymethyl methacrylate intraocular lens on posterior capsule opacification: a randomized trial.

PURPOSE: To compare the posterior capsule opacification (PCO) inhibiting effect of a 3-piece polymethyl methacrylate (PMMA) intraocular lens (IOL) with a sharp optic edge design with that of the round-edged version of the same IOL during a 5-year period. DESIGN: Randomized patient- and examiner-masked clinical trial with intraindividual comparison. PARTICIPANTS: Thirty-two patients with bilateral age-related cataract (64 eyes). METHODS: Each study patient had phacoemulsification cataract surgery in both eyes and received a sharp optic edge PMMA IOL in one eye and a round optic edge PMMA IOL in the fellow eye (both by Dr Schmidt in Germany). Follow-up examinations were at 1 week, 1 month, 1 year, 3 years, and 5 years. Digital retroillumination images were taken from each eye. The amount of posterior capsule opacification was assessed objectively by means of automated image analysis software (Automated Quantification of After-Cataract) at 1 year, 3 years, and 5 years after surgery. MAIN OUTCOME MEASURE: Posterior capsule opacification score: 0-10. RESULTS: The sharp optic edge IOL showed significantly less regeneratory and fibrotic PCO at 1 year, 3 years, and 5 years after surgery. The mean AQUA PCO score was 5.12 for the round-edge and 2.49 for the sharp-edge IOL (scale, 0-10; P<0.001) at 5 years. The mean difference among patients for the PCO score in the eye implanted with the sharp optic edge versus the score in the eye with the round optic edge was 2.83 at 5 years (95% confidence interval, 1.66-4.00). Due to the large number of neodymium:yttrium-aluminum-garnet laser capsulotomies that were performed (12 in the round-edge group and 4 in the sharp-edge group), there was no significant difference in visual acuity between both groups at any time point. CONCLUSIONS: Compared with the round-edge version, the sharp optic edge design of a 3-piece PMMA IOL led to significantly less PCO at 1 year, 3 years, and 5 years after surgery. However, the sharp optic edge did not lead to complete PCO prevention during this follow-up period. This finding has implications for the design of PMMA IOLs used for cataract surgery, especially in the developing world.

Aged↗

PubMed2005

Long-term efficacy of adding a sharp posterior optic edge to a three-piece silicone intraocular lens on capsule opacification: five-year results of a randomized study.

PURPOSE: To compare the intensity of capsule opacification with the sharp and the round optic edge variant of an open-loop hydrophobic silicone intraocular lens (IOL). DESIGN: Randomized, controlled, double-blind clinical trial with intraindividual comparison. METHODS: Fifty-one patients with bilateral age-related cataract were included (102 eyes). Each patient had had cataract surgery in both eyes and received a Microsil IOL with a sharp optic edge design (model S) in one eye and a Microsil IOL with a round optic edge design (model R) in the fellow eye. Both IOLs had an identical haptic design (nonangulated polymethylmethacrylate) and silicone optic material. The patients were examined at the slit lamp, best-corrected visual acuity was assessed, and standardized high-resolution digital retroillumination images of the posterior capsule were taken 5 years after surgery. The intensity of regeneratory posterior capsule opacification (rPCO), fibrotic PCO (fPCO), and anterior capsule opacification (ACO) was assessed subjectively at the slit lamp, and of rPCO, objectively using automated image analysis software (AQUA). The need for an Nd:YAG laser capsulotomy (Nd:YAG-LCT) was noted. RESULTS: The mean AQUA PCO score was 1.2 for the model S and 2.4 for the model R lens (P = .001). The model S lens also led to less peripheral fPCO (P = .003). Concerning ACO, there was no significant difference between both IOL groups (P = .72). Whereas no capsulotomy was required with the model S, four cases (16%) had been performed in the model R group. CONCLUSION: Five years postoperatively, the sharp-edged silicone IOL showed less rPCO and fPCO than the round-edged IOL. However, regarding ACO, there was no significant difference between both IOL styles.

Aged↗

PubMed2005

Association between intensity of posterior capsule opacification and contrast sensitivity.

PURPOSE: To investigate the correlation between change in contrast sensitivity (CS) and difference in objective posterior capsule opacification (PCO) score before and after Nd:YAG laser capsulotomy. DESIGN: Prospective interventional case series. METHODS: CS (Functional Acuity Contrast Test, or FACT, chart), distance visual acuity (Early Treatment Diabetic Retinopathy Study [ETDRS] chart), and pupil size of 30 pseudophakic eyes with PCO of varying intensity were measured before and after capsulotomy. Digital retroillumination images were taken, and the area corresponding to the pupil size was evaluated with an automated PCO analysis program known as AQUA. RESULTS: The correlation between change in PCO score and change in CS was highest (r = 0.85) for row B on the FACT chart and lowest (r = 0.09) for row E. The correlation with change in ETDRS visual acuity was 0.57. CONCLUSIONS: Objective PCO assessment by an automated image analysis system correlates well with PCO-induced loss of CS and is therefore an appropriate method for clinical studies on the development and prevention of PCO.

Cataract↗

PubMed2005

Association between intensity of posterior capsule opacification and visual acuity.

PURPOSE: To investigate the correlation between the change in visual acuity and the difference in objective posterior capsule opacification (PCO) scores before and after neodymium:YAG (Nd:YAG) laser capsulotomy. SETTING: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. METHODS: Forty pseudophakic eyes of 35 patients with PCO of varying intensity were examined before and after Nd:YAG laser capsulotomy. Visual acuity was determined using the Early Treatment Diabetic Retinopathy Study (ETDRS) chart at 4 m and the Holladay reading chart at 40 cm. The pupil diameter under reading conditions was measured each time. Digital retroillumination images of the posterior capsule were taken, and the corresponding area inside the pupil was evaluated using the Automated Quantification of After-Cataract (AQUA) automated PCO analysis program. The change in visual acuity and difference between PCO scores before and after Nd:YAG laser capsulotomy were calculated for all eyes. RESULTS: The mean AQUA score (scale 0 to 10) was 3.56 before and 0.13 after Nd:YAG laser capsulotomy. The mean ETDRS visual acuity score (logMAR scale) was 0.28 and -0.07, respectively. The correlation coefficient between the differences in PCO score and distance visual acuity was 0.61 and near visual acuity, 0.62. CONCLUSIONS: The objective PCO score obtained by an automated image-analysis program correlates well with the PCO-induced decrease in visual acuity when the central area (inside the pupillary aperture) of the posterior lens capsule was evaluated. Objective PCO assessment by automated image-analysis systems is, therefore, a valuable and clinically relevant method for clinical studies of the development and prevention of PCO.

Cataract↗

PubMed2005

Short-term changes in the morphology of posterior capsule opacification.

PURPOSE: To observe and document posterior capsule opacification (PCO) growth in vivo over a short period of time (4 weeks). SETTING: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. METHODS: Fifteen eyes of pseudophakic patients with PCO of varying degrees were included in this prospective study. Digital retroillumination images were taken in a standardized fashion at 3 time points: 1 baseline image, a second image after 2 weeks, and a third image after 4 weeks. Thus, a 3-image series could be created for each eye. Additionally, sections of the posterior capsule with interesting structures were photographed with higher magnification and compared in supplementary image series. Morphologic changes in the PCO structure (eg, number and size of Elschnig pearls, total PCO area) were analyzed in the image series. RESULTS: In all cases, significant changes could be observed between the 3 time points. In 71% of cases, some Elschnig pearls increased in size during the first 2 weeks and during weeks 3 and 4. In 73% of cases, however, there was a reduction a pearl size or even disappearance of some Elschnig pearls. The total PCO area did not change significantly during the 4-week period. CONCLUSIONS: Development of (regeneratory) PCO is a very dynamic process that includes not only growth of preexisting structures and occurrence of new Elschnig pearls, but also reorganization and even disappearance of pearls within a short time period (2-4 weeks). The latter in particular is not well known but could be observed in the majority of cases in this study.

Cataract↗

PubMed2005

Long-term effect of optic edge design in an acrylic intraocular lens on posterior capsule opacification.

PURPOSE: To compare the posterior capsule opacification (PCO) inhibiting effect of the sharp posterior optic edge design of the Sensar OptiEdge AR40e intraocular lens (IOL) with that of the double-round edge design of the Sensar AR40 IOL over a period of 3 years. SETTING: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. METHODS: Fifty-three patients with bilateral age-related cataract (106 eyes) were included in this randomized prospective bilateral patient- and examiner-masked clinical trial with intraindividual comparison. Each study patient had cataract surgery in both eyes and received a Sensar AR40 IOL (anterior and posterior round optic edges) in 1 eye and a Sensar OptiEdge AR40e IOL (round anterior and sharp posterior optic edge) in the other eye. Follow-up examinations were at 1 week, 1 and 6 months, and 1, 2, and 3 years. Digital retroillumination images were taken of each eye. The amount of PCO was assessed subjectively at the slitlamp and objectively using automated image-analysis software (AQUA) 1, 2, and 3 years after surgery. RESULTS: The sharp-edged AR40e lens showed significantly less regeneratory and fibrotic PCO 1, 2, and 3 years after surgery. The mean AQUA PCO score was 2.18 for the AR40 and 1.00 for the AR40e lens after 1 year; 2.94 and 1.56 after 2 years, and estimated at 3.13 and 1.77, respectively, after 3 years (scale 0 to 10; P<.001). The neodymium:YAG laser capsulotomy rate was significantly higher in the AR40 group. The AR40e lens also led to less peripheral fibrotic PCO. There was no significant difference in complaints concerning edge glare between the groups. CONCLUSION: Compared with the AR40 IOL, the sharp posterior optic edge design of the Sensar OptiEdge AR40e IOL led to significantly less PCO 1, 2, and 3 years postoperatively. In contrast with most past studies on PCO-preventative factors, this study varied only 1 parameter, namely the optic edge design, and the main outcome measure (PCO) was assessed with an objective image-analysis system.

Acrylic Resins↗

PubMed2005

Pilocarpine-induced shift of an accommodating intraocular lens: AT-45 Crystalens.

PURPOSE: To measure the shift of an accommodating plate-haptic intraocular lens (IOL) along the visual axis induced by ciliary muscle contraction after application of pilocarpine. SETTING: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. METHODS: Fifty-four eyes of 28 patients with age-related cataract comprised this prospective study. Each patient received an AT-45 silicone accommodating IOL (Crystalens, Eyeonics Corp.) after standardized cataract surgery. In a subgroup of 24 eyes, capsular bag fibrosis was reduced by extensive polishing of the anterior capsule with a slit cannula. Assessment included measurements of anterior chamber depth, assessed with partial coherence interferometry, before and after application of pilocarpine 2% and evaluation of near visual acuity 1 month and 3 months postoperatively. RESULTS: A slight backward shift of the IOL of 151 mum in the nonpolished group (P < .001) and 122 mum in the polished group (P < .005) could be detected after application of pilocarpine. Polishing the capsule did not influence IOL shift. The median near visual acuity with distance correction 1 month and 3 months postoperatively was J5 and J4, respectively, in the nonpolished group and J6 at both times in the polished group. CONCLUSIONS: Pilocarpine induced a counterproductive active backward shift of the AT-45 IOL. Polishing of the capsular bag had no impact on accommodative ability. The reading performance of patients with the AT-45 IOL patients at 1 and 3 months was not significantly different from that of with a standard IOL under similar testing methods.

Accommodation, Ocular↗

PubMed2005

Influence of optic edge design, optic material, and haptic design on capsular bend configuration.

PURPOSE: To assess and classify capsular bend configuration at the optic rim and its association with posterior capsule (PCO) and anterior capsule opacification (ACO) and capsulorhexis contraction with various intraocular lenses (IOLs). SETTING: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. METHODS: A total of 659 post-cataract surgery eyes of 370 patients from different prospective randomized studies were evaluated. All eyes had standardized phacoemulsification surgery with implantation of an IOL in the capsular bag. The IOLs had a sharp or round optic edge design and were made of silicone, acrylic, or poly(methyl methacrylate) optic materials. One year postoperatively, the configuration of the capsular bend at the optic rim was assessed at the slitlamp, and standardized slitlamp images of ACO and fibrotic PCO were taken. One week, 1 year, and 3 years postoperatively, digital retroillumination images were taken for objective quantification of regeneratory PCO and the capsulorhexis area. The outcome measures were the type of capsular bend configuration, ACO score (0% to 100%), regeneratory PCO score (0 to 10), fibrotic PCO score (0 to 3), and amount of capsulorhexis contraction (mm(2)). RESULTS: Four main types of capsular bend configuration were classified: parallel, "Y," right angle, and wrapping. The right-angle type was observed in the most cases (52%). Eyes with a wrapping capsular bend configuration had significantly less PCO, more capsulorhexis contraction, and more ACO than eyes with the other configurations. Wrapping capsule configuration was seen most often (55%) in round-edged silicone IOLs that had a thin optic rim. CONCLUSION: The design and material of IOLs influenced the long-term capsular bend configuration at the optic rim. The right-angle type was the most common capsular bend configuration. Intraocular lenses with silicone optic material and a thin optic rim caused a wrapping capsule configuration and resulted in more capsulorhexis contraction and ACO, but less PCO.

Biocompatible Materials↗

PubMed2005

Optical biometry of the anterior eye segment: interexaminer and intraexaminer reliability of ACMaster.

PURPOSE: To evaluate the interexaminer and intraexaminer reliability of corneal thickness, anterior chamber depth (ACD), and crystalline lens thickness measurements using a commercially available anterior segment optical biometry instrument (ACMaster, Carl Zeiss Meditec) based on partial coherence interferometry (PCI). SETTING: Medical University of Vienna, Vienna, Austria. METHODS: Interexaminer reliability and intraexaminer reliability were evaluated in 10 eyes of 10 young volunteers and 11 eyes of 11 cataract patients. The measurements of the interexaminer reliability were taken by 3 examiners. Corneal thickness, ACD, and lens thickness of the intraexaminer reliability were measured twice in all eyes by 1 examiner. To evaluate the effect of cycloplegia on the variability, the measurements were performed on 5 volunteers under cyclopentolate 1%. Measurements were performed using the prototype of the ACMaster based on PCI. RESULTS: The interexaminer/intraexaminer reliabilities were 99.9% for corneal thickness and ACD. The reliability of lens thickness could not be estimated because of a large number of missing values in the cataract patient group. The median interexaminer variability (SD) was 1.9 microm for corneal thickness, 7.5 microm for ACD, and 10.6 microm for lens thickness. The median intraexaminer variability (SD) was 1.6 microm for corneal thickness, 10.8 microm for ACD, and 8.7 microm for lens thickness. With cycloplegia, both the interexaminer variability and intraexaminer variability were smaller than without cycloplegia. CONCLUSIONS: Partial coherence interferometry measurements of anterior chamber distances (corneal thickness, ACD, lens thickness) using the prototype of ACMaster were highly reliable, allowing examiner-independent measurements. However, lens thickness measurements in cataract eyes were often difficult.

Adult↗

PubMed2005

Long-term changes in the morphology of posterior capsule opacification.

PURPOSE: To classify the morphologic appearance of posterior capsule opacification (PCO) and to observe and document the changes over longer periods of time. SETTING: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. METHODS: Eighty-one pseudophakic eyes of 53 patients with PCO of varying degrees were included in this prospective study. Digital retroillumination images of the posterior capsule were taken in a standardized fashion 1, 2, and 3 years after cataract surgery. The PCO morphology was classified, and changes among the 3 follow-up images were analyzed. RESULTS: At 1, 2, and 3 years, pearls occurred in 16 (20%), 41 (51%), and 57 (63%) eyes. Pearls increased in size and number. Cases with thin layers of PCO decreased from 53 to 33 to 16 eyes. Conversely, cases with thick layers increased from 18 to 45 and 64 eyes. "Cheese holes" appeared most frequently as the predominant structure (range 47% to 51%), followed by plates (range 28% to 31%), islands (range 15% to 20%), and traces of PCO (range 1% to 5%). Changes in expansion of the PCO area were observed in 61 eyes (75%) during period 1 (1 to 2 years) and period 2 (2 to 3 years). Regions of expansion and regression in the same eye occurred in periods 1 and 2 in 11 eyes (14%) and 9 eyes (11%), respectively. The phenomenon of thinning bridges, a regression of syncytial extensions of PCO, occurred in 22 eyes (27%) and 32 eyes (40%), respectively. An overlapping growth of 2 layers was observed in 18 eyes (22%). CONCLUSIONS: The morphology of PCO is multifaceted. Apart from the Elschnig pearls, categories such as cheese holes, plates, islands, and traces of PCO were distinguished. Over the years, pearls increased in frequency, size, and number. Expansion and regression occurred simultaneously in some cases. Two or more layers grew on top of each other in some eyes.

Cataract↗

PubMed2005

Effect of anterior capsule polishing on posterior capsule opacification and neodymium:YAG capsulotomy rates: three-year randomized trial.

PURPOSE: To compare the long-term effect of extensive polishing and nonpolishing of the anterior lens capsule on posterior capsule opacification (PCO) and neodymium:YAG (Nd:YAG) capsulotomy rates. SETTING: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. METHODS: This prospective randomized bilateral double-masked study included 108 eyes of 54 consecutive patients with age-related cataract. Following phacoemulsification, 3-piece intraocular lenses (IOLs) with round-edged silicone optics were implanted. Patients received an Allergan SI-40 IOL with a truncated, round optic edge or a Domilens Silens6 IOL with a fully round optic edge. Patients were randomly assigned to have extensive anterior capsule polishing with the Menapace aspiration curette or no treatment in the first eye; the second eye received the opposite treatment. Digital retroillumination images were taken at 1 week, 1 year, and 3 years, and Nd:YAG capsulotomy rates were evaluated. Posterior capsule opacification was objectively scored using automated image analysis software (AQUA) or estimated based on clearly defined assumptions if a capsulotomy had been performed. RESULTS: Thirty-nine patients (78 eyes) concluded the study. Three-year PCO scores after polishing did not differ significantly (P>.05). However, 21 polished eyes (53.8%) required Nd:YAG laser capsulotomy compared with 14 nonpolished eyes (35.9%). The mismatch between PCO scores and Nd:YAG rates resulted from a change in PCO morphology that is not detected by scoring methods based on retroillumination photography but is visually disturbing to patients. CONCLUSIONS: Polishing the anterior capsule was effective in reducing fibrotic opacification but ineffective in reducing regeneratory opacification. Changes in regeneratory PCO morphology not picked up by retroillumination photography increased the need for Nd:YAG laser capsulotomy.

Cataract↗

PubMed2005

Effect of optic material on posterior capsule opacification in intraocular lenses with sharp-edge optics: randomized clinical trial.

PURPOSE: Comparison of the intensity of posterior capsule opacification (PCO) between a silicone intraocular lens (IOL) and a hydrophobic acrylic IOL, both of them 3-piece and open-loop and having truncated optics with sharp edges. DESIGN: Randomized, controlled, patient- and examiner-masked trial with intrapatient comparison. PARTICIPANTS AND CONTROLS: One hundred six eyes of 53 patients with age-related bilateral cataract. METHODS: Each patient had cataract surgery in both eyes and received a silicone IOL in one eye and a hydrophobic acrylic IOL in the fellow eye. Follow-up examinations were at 1 and 3 years after surgery. The patients were examined at the slit lamp, visual acuity (VA) was assessed, and standardized high-resolution digital retroillumination images of the posterior capsule were taken. The amount of PCO was assessed subjectively at the slit lamp and objectively using automated image analysis software. Data of 56 eyes of 28 patients, who were examined at each follow-up, were analyzed. MAIN OUTCOME MEASURE: Posterior capsule opacification intensity at 3 years as measured with automated image analysis. RESULTS: At 1 and 3 years after surgery, PCO did not differ between the silicone (1.6 and 1.9 [image analysis scores, 0-10 scale], respectively) and acrylic IOLs (1.7 and 2.2) (P > 0.24). Furthermore, there was no significant difference in best-corrected VA, rhexis/IOL overlap, capsular folds, and amount of anterior capsule opacification during the follow-up period. In each group, one neodymium:yttrium-aluminum-garnet (YAG) laser capsulotomy was performed during the entire study duration. CONCLUSION: Silicone and hydrophobic acrylic are similarly effective in inducing the PCO-inhibiting effect of a rectangular, sharp optic edge. Three years after surgery, the PCO intensity and the YAG rate were low with both IOL models.

Acrylic Resins↗