Posterior Capsule Opacification Area Research Articles

Anterior segment OCT application in quantifying posterior capsule opacification severity with varied intraocular lens designs.

To evaluate the application of anterior segment-optical coherence tomography (AS-OCT) in posterior capsule opacification (PCO) severity assessment and analyse the relationship between PCO severity and intraocular lens (IOL) characters. PCO patients were prospectively recruited. Cross-sectional images of the anterior segment at horizontal and vertical meridians were acquired with AS-OCT. The area of the IOL-PC (posterior capsular) space and PCO severity (area, thickness, and density at 3 mm and 5 mm IOL optic regions) were measured. The relationship between PCO severity and visual acuity, comparisons of PCO severity and IOL-PC space using varied IOL designs were analysed. One hundred PCO eyes were enrolled. IOL-PC space, PCO thickness and area were positively correlated with axial length. In addition, PCO area and thickness were positively correlated with visual acuity when it was ≤0.52 logMAR. The cut-off level of visual acuity should be 0.52 logMAR. With varied IOL designs, 3-piece C haptic IOL showed a smaller PCO area and thickness than the 1-piece 3 haptic IOL and 1-piece 4 haptic IOL. PCO area and thickness values for an IOL with a diameter ≤11.0 mm was greater than for an IOL with a diameter of 12.5 mm, and the differences were statistically significant. PCO area and thickness increased when IOL haptic angulation increased (from 0 to 12 degrees). In PCO eyes, cut-off level of visual acuity is 0.52 logMAR. With more severe PCO, visual acuity maybe not enough to describe the visual function impairment. PCO severity and IOL-PC space are significantly correlated with axial length and IOL design and material.

Fluid-jet technique to polish the posterior capsule for phacoemulsification surgeries: efficacy and safety evaluation.

To compare the efficacy and safety of a fluid-jet technique with capsular polish in reducing residual lens fibers (RLFs) in phacoemulsification surgery. Single center. Prospective nonrandomized comparative study. Patients receiving phacoemulsification were included. Consecutive eligible patients alternately underwent either removal of RLFs on the posterior capsule using capsular polish after irrigation and aspiration, and before intraocular lens (IOL) implantation, or RLF removal using a fluid-jet technique after IOL implantation. Posterior capsular images were used to quantify RLFs. Visual parameters were evaluated at 1 day, 1 week, and 1 year postoperatively. The proportion of capsule occupied by posterior capsule opacification (PCO) (area %) and incidence of protocol-driven laser posterior capsulotomy were recorded at 1 year in masked fashion. Seven hundred forty eyes were allocated to polishing (n = 370) or fluid-jet technique (n = 370). Polishing required 70.4 ± 17.5 seconds and fluid-jet 32.2 ± 9.9 seconds (P ≤ 0.001). Compared with the polishing group, capsular area occupied by RLFs in the fluid-jet group was significantly smaller (3.5% vs 0.5%, P = .031) at the end of surgery. One day postoperatively, the fluid-jet group had more desirable corrected distance visual acuity, objective scattering index, and Strehl ratio (all P < .05). PCO area percentage did not differ between groups (6.5% vs 4.5%, P = .252) 1 year postoperatively, but incidence of posterior capsulotomy was lower in the fluid-jet group (3.2% vs 0.8%, P = .019). Fluid-jet removed RLFs effectively and had lower incidence of postoperative capsulotomy than capsular polishing.

Relationship of Posterior Capsular Opacification and Capsular Bend Type Investigation Based on Swept-source Optical Coherence Tomography

ABSTRACT Purpose To investigate the relationship between capsular bend type and posterior capsule opacification (PCO) at a three-dimensional (3D) level using high-speed swept-source optical coherence tomography (SS-OCT). Methods This was a retrospective study. A total of 99 eyes that underwent standard cataract surgery with phacoemulsification 2 years ago were analyzed. Standard SS-OCT radial scanning was performed in all eyes and the obtained photos were used for morphological observations of the capsular bend-IOL complex, the adhesion of posterior capsule to the IOL optic, and the position of the anterior capsulorhexis. Digital retroillumination photographs were taken of the posterior capsule of each eye to evaluate PCO (scoring and area). Results In terms of the PCO score and area, there was no statistical difference between eyes with complete and incomplete adhesion of posterior capsule to IOL (both P > .05), whereas the partial overlap group showed a statistical difference greater than the total overlap group (P < .05). There were two types of capsular bends, completed adhesion (CA) and incomplete adhesion (IA). IA was divided into funnel adhesion (IA-F), parallel adhesion (IA-P), and detached adhesion (IA-D). The incomplete adhesion index (IAI) varied between eyes and ranged from 0 to 1. The PCO score and area in the high IAI group (higher than 0.50) were significantly greater than the low IAI group (< 0.50) (P < .05). In addition, the PCO score and area were significantly higher in the cohort with at least one IA-D capsular bend in six districts to the group that did not have IA-D capsular bend (P < .05). Conclusions Complete or incomplete adhesion of the posterior capsule to the IOL optic may not be necessary for the development of PCO. Our study suggests that capsular bend type may be used as an index to predict PCO.

Posterior capsular opacification comparison between morphology and objective visual function

BackgroundTo compare the influence of posterior capsule opacification (PCO) morphology and severity on intraocular stray light and visual function with different levels of contrast.MethodsForty-five patients diagnosed with PCO were included in this prospective consecutive case series. The Optical Quality Analysis System II (OQAS II) was adopted to assess the objective visual function including objective scatter index (OSI) and optical quality analysis system values (OVs) with 100, 20, and 9% contrast. RTVue-100 OCT was used to evaluate the PCO morphology and severity. Comparisons among visual function, morphology, and severity between pear type and fibrosis PCO were performed. The correlations among the PCO morphology, severity, OSI, and OVs were also determined.ResultsThere was a significant correlation between increased OSI and decreased visual acuity in PCO patients before laser capsulotomy. The changes of OSI were also correlated with the PCO area for the 3 mm IOL optic region (r = 0.43, p = 0.02). The OSI was significantly higher in pear type PCO when compared with fibrosis PCO (Z = − 4.06, p ≤ 0.001). In addition, the increased OSI in pear type PCO was significantly correlated with the 100% OVs and the 20% OVs but not with the 9% OVs. In fibrosis PCO, OSI was only correlated with the 100% OVs and the 20% OVs pre-YAG.ConclusionsOSI and OVs could objectively indicate the visual function impairment in PCO patients. Effects of PCO on light scattering and on objective visual function might be explained by the variations of morphology and severity.

Anterior and posterior capsule densitometry levels after femtosecond laser-assisted cataract surgery.

To analyze and compare five different variables over one year follow-up (1wk, 1, 3, 6 and 12mo): anterior capsule (AC), and posterior capsule (PC) area densitometry values, AC and PC linear densitometry values, and AC opening area reduction ratio after femtosecond laser-assisted cataract surgery. This was a prospective comparative study. Seventy-one patients underwent femtosecond laser-assisted cataract surgery on single eye between June 2014 and December 2015. A 5.0 mm diameter laser assisted anterior capsulotomy was performed on all eyes. In every post-surgery evaluation, AC opacificaction (ACO) and PC opacification (PCO) density levels were provided by Oculus Pentacam®HR using area and linear densitometry methods. Digital images were captured with a slit-lamp Topcon photographic camera and IMAGEnet® 5 software. The AC opening area on the digital images was measured using the Sketchandcalc area calculator and converted to reduction ratio levels. Using Pearson correlation coefficient (PCC), we found no correlation (r=-0.091, P=0.46) in the twelfth month assessment between the evolution of ACO area densitometry values and PCO area densitometry values considered as independent variables. We found no correlation, using PCC (r=-0.096, P=0.43) between the evolution of ACO linear densitometry values and PCO linear densitometry values, in the twelfth month visit, working both as independent variables. AC linear densitometry levels and AC area densitometry levels continued to grow strongly from sixth to twelfth months. Analysis of the values of AC opening area reduction ratio (1wk, 1, 3, 6, 12mo) revealed statistically significant differences between the values of successive examinations but the magnitude of the change decreased. In the final period of monitoring between six and twelve months the magnitude of change was low. Our results show strong increases of Scheimpflug ACO densitometry values from the sixth to the twelfth month while capsulorhexis area reduction ratio levels displayed a considerable decrease. We found no correlation between ACO area and linear densitometry values and PCO area and linear densitometry values, in the twelfth month examination, working as independent variables.

Comparison of posterior capsule opacification and glistenings with 2 hydrophobic acrylic intraocular lenses: 5- to 7-year follow-up

To compare posterior capsule opacification (PCO) and glistenings 5 to 7 years after cataract surgery with implantation of 2 hydrophobic acrylic intraocular lenses (IOLs) and evaluate the effects on corrected distance visual acuity (CDVA) and contrast sensitivity. St. Erik Eye Hospital, Stockholm, Sweden. Randomized clinical trial. Cataract surgery with standard phacoemulsification was performed in 1 eye of patients. The patients were randomized to an Acrysof SA60AT (1-piece IOL group) or a Sensar AR40e (3-piece IOL group), both hydrophobic acrylic IOLs with a sharp-edged design. Five to 7 years postoperatively, retroillumination images were obtained and the PCO area and severity (area affected within the capsulorhexis and severity) were evaluated using computer software. High-contrast (100%) and low-contrast (2.5%) CDVAs were measured. The neodymium:YAG laser capsulotomy rates were recorded. Scheimpflug images were obtained to evaluate glistenings, which were graded subjectively at the slitlamp and quantified objectively by digital image analysis using computer software. The study enrolled 80 patients. There were no significant differences in PCO between the 2 groups. The 3-piece IOL group had significantly fewer glistenings (P<.001). There was good correlation between the subjective grading of glistenings and objective computer-processed image grading. The glistenings were not correlated with IOL power, CDVA, or contrast sensitivity. There were no significant differences in PCO between the 2 acrylic hydrophobic IOLs 5 to 7 years postoperatively. The 1-piece IOL group developed more glistenings than the 3-piece IOL group.

Prospective evaluation of posterior capsule opacification in myopic eyes 4 years after implantation of a single-piece acrylic IOL

To determine whether axial myopia affects posterior capsule opacification (PCO) in eyes with high myopia (axial length [AL] > or = 26.00 mm) 4 years after implantation of an AcrySof single-piece intraocular lens (IOL). Clinical practice, Ahmedabad, India. In a prospective masked trial, consecutive eyes with high axial myopia (myopia group) and age-matched eyes with a normal AL (21.00 to 23.99 mm) (control group) had phacoemulsification and in-the-bag IOL implantation. Postoperatively, PCO was documented by standardized digital retroillumination images. The PCO area behind the IOL optic was scored (scale 0% to 100%) using the POCO software system. The presence of PCO within the central 3.0 mm of the optic was assessed with the Evaluation of Posterior Capsule Opacification software system. The incidence of neodymium:YAG (Nd:YAG) capsulotomy was determined. The median PCO in the myopia group and control group, respectively, was 3.2% and 5.6% at 1 month (P = .2), 2.2% and 1.6% at 12 months (P = .079), 7.0% and 2.3% at 24 months (P = .079), 3.7% and 3.6% at 36 months (P = .78), and 10.0% and 2.3% at 48 months (P = .61). By 4 years, PCO had encroached onto the central 3.0 mm of the optic in 38% in the myopia group and 20% in the control group (P = .04). One eye (2%) in each group had an Nd:YAG capsulotomy, at 3.2 years and 3.9 years, respectively. Axial myopia did not significantly increase the area or incidence of PCO at 4 years.

Two‐year follow‐up of posterior capsule opacification after implantation of a hydrophilic or hydrophobic acrylic intraocular lens

To evaluate posterior capsule opacification (PCO) 2 years after cataract surgery following implantation of a hydrophilic or a hydrophobic single-piece acrylic intraocular lens (IOL) with a sharp edge. Phacoemulsification cataract surgery was performed in one eye of 120 patients with senile cataract in this prospective study. They were randomized to implantation of either a hydrophilic acrylic IOL (BL27; Bausch & Lomb, Rochester, NY, USA) or a hydrophobic acrylic IOL (AcrySof) SA60AT; Alcon Laboratories, Fort Worth, TX, USA). Two years after surgery, retroillumination images were obtained and PCO area and severity were evaluated using pocoman software. Best corrected visual acuity (VA) (both high-contrast [100%] and low-contrast [2.5%]), glare, laser flare and intraocular pressure were measured. Capsulotomy rates were recorded. Patients implanted with the hydrophilic IOL had a greater percentage area and severity of PCO compared with patients with the hydrophobic IOL (p < 0.001). There was no difference in PCO between men and women in the hydrophilic group. However, in the hydrophobic group, women had significantly more PCO than men (p < 0.05). Patients with the hydrophobic acrylic IOL had better high- and low-contrast visual activity (VA) (p < 0.01) and less glare (p < 0.001) than those with a hydrophilic acrylic IOL. Of the patients with the hydrophilic IOL, 42% underwent capsulotomy, compared with 10% in the hydrophobic group (p < 0.001). Two years after surgery, patients with the SA60AT hydrophobic acrylic IOL had less PCO and better high- and low-contrast VA than patients with the BL27 hydrophilic acrylic IOL.

Effect of intraocular lens edge profile on posterior capsule opacification after extracapsular cataract surgery in a developing country

To determine whether square-edged polymethyl methacrylate (PMMA) intraocular lenses (IOLs) reduce posterior capsule opacification (PCO) in the context of extracapsular cataract surgery in a developing country. A rural hospital in India. This was a prospective randomized double-masked fellow-eye controlled study. Over a 4-month period, 118 patients with normal eyes apart from age-related cataract were randomized to receive a square-edged or round-edged PMMA IOL in the first eye. The IOLs were identical apart from the edge profile. The fellow-eye had implantation of the alternative IOL within 1 month. Retroillumination images of the posterior capsule were taken using a dedicated camera system and analyzed to quantify the PCO area using POCO software 1 and 2 years postoperatively and the PCO area and severity using POCOman semiqualitative software at 2 years. Visual acuity was measured using a Gujarati logMAR chart. One hundred fifteen patients were available for examination at 1 year and 107 at 2 years. With POCO software, the PCO area was reduced in the square-edged IOL group at 1 year (median 30% versus 20%, P=.001) and at 2 years (median 45% versus 35%, P=.006). With POCOman, the PCO area and severity were reduced in the square-edged group at 2 years (median 41.5% versus 33.2%, P=.019 and 0.59 versus 0.46, P=.037, respectively). There was no significant difference in visual acuity between the 2 groups at 1 or 2 years. Sophisticated image analysis techniques can be used in developing countries to quantify PCO. Using extracapsular surgery, square-edged PMMA IOLs reduced the PCO area and severity compared with an identical round-edged IOL; however, the differences were not as marked as those reported with phacoemulsification. This may be due to the difficulty of performing a capsulorhexis that lies on the IOL surface in this situation. Nevertheless, square-edged IOLs offer a potential benefit for extracapsular surgery in the developing world.

The Relationship between the Adhesion Characteristics of Acrylic Intraocular Lens Materials and Posterior Capsule Opacification

Purpose: To investigate the relationship between the adhesion characteristics of similarly designed hydrophobic acrylic intraocular lenses (IOLs) and posterior capsule opacification (PCO). Methods: Three similarly shaped hydrophobic acrylic IOLs with a sharp-edged optic were used. Adhesive force of IOLs was measured with a tackiness tester. Human lens epithelial cells (LECs) were grown on each IOL for 48 h. LECs were then stained with crystal violet, which served as an index of the amount of cells attached to IOLs. Cellular migration and proliferation assays were performed using chamber inserts containing a collagen membrane. After 96 h of incubation, the collagen membranes were stained with hematoxylin and eosin for analysis. Three similarly shaped IOLs were implanted in rabbits. The eyes were enucleated 3 weeks later and analyzed for PCO area. Results: Hydrophobic acrylic IOLs were classified into three groups: A (less adhesive), B (moderately) and C (highly). The migration area of LECs on the collagen membrane was 5.65 ± 4.5% in group A, 2.83 ± 2.1% in group B, and 1.41 ± 1.5% in group C, with a significant difference between groups A and C (p < 0.05). The mean percentage area of PCO in the rabbit eye was 19.4 ± 16.7% in group A, 17.5 ± 8.5% in group B, and 5.5 ± 3.8% in group C, with a significant difference between groups A and C (p < 0.05). Conclusion: Adhesive force of hydrophobic acrylic IOLs may play an important role in preventing PCO. Among the similarly shaped hydrophobic acrylic IOLs, IOLs of highly adhesive material inhibited LEC migration and PCO more than IOLs of less adhesive material.

Long-term changes in the morphology of posterior capsule opacification

To classify the morphologic appearance of posterior capsule opacification (PCO) and to observe and document the changes over longer periods of time. Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. 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. 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%). 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.

Short-term changes in the morphology of posterior capsule opacification

To observe and document posterior capsule opacification (PCO) growth in vivo over a short period of time (4 weeks). Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. 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. 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. 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.

Comparison of 4 methods for quantifying posterior capsule opacification

Purpose To compare the results of posterior capsule opacification (PCO) quantification and the repeatability of a fully automated analysis system (Automated Quantification of After-Cataract [AQUA]) with that of 2 other quantification methods and subjective grading of PCO. A test set of digital retroillumination images of 100 eyes with PCO of varying degrees was used. Setting Department of Ophthalmology, University of Vienna, Vienna, Austria. Methods One hundred digital retroillumination images of eyes (100 patients) with PCO were selected to attain an even distribution from mild to severe cases. The images were evaluated by 4 methods: subjective grading by 4 experienced and 4 inexperienced examiners, the subjective Evaluation of Posterior Capsular Opacification (EPCO) system, posterior capsule opacification (POCO) software, and the AQUA system. Ten images were presented twice to assess the reproducibility of the analysis systems. Results Subjective grading correlated best with the subjective EPCO system and the objective AQUA system ( r = 0.94 and r = 0.93, respectively). The POCO system showed very early saturation and therefore a much weaker correlation ( r = 0.73). The POCO scores reached the maximum of 100% in several minimal to mild PCO cases. The reproducibility of the AQUA software was perfect and that of the other analysis systems, comparably satisfactory. Conclusion The objective AQUA score correlated well with subjective methods including the EPCO system. The POCO system, which assesses PCO area, did not adequately describe PCO intensity and includes a subjective step in the analysis process. The AQUA system could become an important tool for randomized masked trials of PCO inhibition.

The Effect of Polymethylmethacrylate and AcrySof Intraocular Lenses on the Posterior Capsule in Patients with a Large Capsulorrhexis

Purpose: We have previously shown that patients who have a capsulorrhexis larger than the diameter of a polymethylmethacrylate (PMMA) intraocular lens (IOL) rapidly develop increased posterior capsule opacification (PCO), in effect, producing an example of enhanced PCO. This study focuses on the influence of AcrySof IOLs on this process. Methods: Phacoemulsification was performed on two groups of patients. The first consisted of 38 patients with a large capsulorrhexis of 6–7 mm who received a 5.5-mm PMMA IOL. The second group of 32 patients had identical surgery and a 5.5-mm MA30 AcrySof IOL was implanted. On days 1,14, 28, 90, 180, and 360, high resolution digitized retroillumination images were taken of the posterior capsule. The PCO area was measured by image analysis at 90, 180, and 360 days. Wrinkling of the posterior capsule was determined at 90 days, and the progression or regression of lens epithelial cell (LEC) proliferation was established by examination of serial images at 28 and 180 days. Results: At 90 days, 79% of the patients with PMMA IOLs had moderate to severe wrinkling of the posterior capsule, whereas the patients with AcrySof IOLs had none ( P < .001). The percentage of PCO area was 69% for the PMMA IOLs and 24% for the AcrySof IOL group at 360 days ( P < .0001). In the PMMA group, LEC progression occurred in 77%, LEC growth was stable in 15%, and LEC regression occurred in only 8%, compared to 69% of patients with AcrySof IOLs ( P < .0001). Conclusions: In patients with a rhexis larger than the IOL, AcrySof IOLs potentially can prevent capsular wrinkling and cause less PCO than a PMMA IOL with a similar rhexis size. The LEC regression occurs with AcrySof between 28 and 180 days. The reasons for this are discussed.