Surgical prevention of posterior capsule opacification. Part 3: Intraocular lens optic barrier effect as a second line of defense

Impact of anterior capsule polishing on capsule opacification and capsule bend after age-related cataract surgery

PURPOSE

To investigate the effect of anterior capsule polishing on postoperative capsule opacification and capsular bend in patients with age-related cataract displaying normal axial length.

SETTING

Eye Hospital of Wenzhou Medical University at Hangzhou.

DESIGN

Prospective self-controlled trial.

METHODS

Patients with age-related cataracts aged 56 to 84 years displaying normal axial length were enrolled. Before surgery, a coin-toss method was used to randomly select 1 eye for intraoperative 360 degrees anterior capsule polishing (polishing group); the contralateral eye received no treatment (control group). Capsular bend index (CBI), anterior capsule opacification (ACO), posterior capsule opacification (PCO), and anterior capsule opening area (ACOA) were recorded at 1 week, 1 month, 3 months, 6 months, and 12 months postoperatively using swept-source optical coherence tomography and slitlamp examination.

RESULTS

21 patients (42 eyes) were enrolled. Within-group comparisons showed that both groups had significant differences in CBI between 1 week and 1 month postoperatively, and between 6 months and 12 months postoperatively ( P < .05). Between-group comparisons revealed a significant difference in CBI at 1 week postoperatively ( P < .05); at 12 months postoperatively, there was a significant difference in ACOA ( P < .05). There were no significant between-group differences regarding ACO or PCO at any timepoint ( P > .05).

CONCLUSIONS

For patients with age-related cataracts and normal axial length, 360 degrees anterior capsule polishing can delay early capsular bag deformation without increasing the risks of ACO and PCO. This approach can also limit contraction of the anterior capsule opening.

Comparative histomorphologic study of basement membrane side staining and additional epithelial side staining of the anterior lens capsule with Trypan Blue

PURPOSE

To compare the histomorphologic changes on the anterior lens capsule by both epithelial and basement membrane side staining to those of only basement membrane side staining of the anterior lens capsule with Trypan Blue (TB).

METHODS

A cross-sectional study was done on 72 samples from patients who underwent cataract surgery between April 2021 and September 2022. After capsulorhexis of the TB-stained capsule, it was made into two halves externally and one half labeled as controls (sample A). The other half was immediately stained further with TB on the epithelial side and was taken as cases (sample B). Samples were analyzed for lens epithelial cells and basement membrane changes.

RESULTS

The loss of intactness of lens epithelial cells, partial or complete detachment of lens epithelial cells, degeneration of lens epithelial cells, and basement edema were significantly higher in cases compared to controls, whereas intactness of the basement membrane did not show any statistical significance between the two groups. There was a statistically significant decrease in cell density in cases compared to controls.

CONCLUSION

Staining the epithelial side of the capsular bag with TB is more detrimental to lens epithelial cells and paves the way for a further study of staining the capsular bag before intra-ocular lens implantation to reduce the incidence of posterior capsule opacification.

Polydopamine based photothermal/photodynamic synchronous coating modified intraocular lens for efficient and safer posterior capsule opacification prevention

Posterior capsule opacification (PCO), as one of the most common late complications after intraocular lens (IOL) implantation in cataract surgery, seriously affects patients' postoperative vision and surgical satisfaction, and can only be treated by laser incision of the posterior capsule. Although drug eluting coating modification have been proved to inhibit PCO effectively, the complicated coating methods and the potential toxicity of the antiproliferative drugs hinders its actual application. In this study, an indocyanine green (ICG) loaded polydopamine (PDA) coating modified IOL (IP-IOL) was designed to prevented PCO. In vitro and in vivo studies have shown that IP-IOL can effectively eliminate lens epithelial cells and significantly reduce the degree of PCO. At the same time, it still has good imaging quality and optical properties. Furthermore, both the near-infrared irradiation and ICG loaded PDA coating modified IOLs have proved to possess high biological safety to eyes. Thus, with easy preparation and safer near-infrared irradiated photothermal/photodynamic synchronous properties, such ICG loaded PDA coating provides an effective yet easier and safer PCO prevention after IOL implantation.

Comparison of the Incidence of Nd:YAG Laser Capsulotomy Based on the Type of Intraocular Lens

Background and Objectives: Posterior capsular opacification (PCO) is the most common long-term complication of successful cataract surgery and can cause visual impairment. We aimed to investigate the effects of intraocular lens (IOL) characteristics on PCO by comparing the incidence of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy for different types of intraocular lenses. Materials and Methods: A retrospective analysis was performed on 2866 eyes that underwent cataract surgery between January 2010 and December 2017, with at least 5 years of follow-up. The IOLs used for surgery were the hydrophobic lenses SN60WF (Alcon, Fort Worth, TX, USA), ZCB00 (Johnson & Johnson Vision, Santa Ana, CA, USA), and MX60 (Bausch & Lomb, Rochester, NY, USA), and the hydrophilic lens MI60 (Bausch & Lomb, Rochester, NY, USA). We analyzed the incidence of Nd:YAG laser capsulotomy according to the type of IOL used. Results: The incidence of Nd:YAG laser capsulotomy was significantly higher with MI60 lenses (31.70%, 175/552 eyes) compared to SN60WF (7.90%, 113/1431 eyes), ZCB00 (10.06%, 64/636 eyes), and MX60 (10.57%, 13/123 eyes; p < 0.001) lenses. The incidence of Nd:YAG laser capsulotomy was significantly lower with the hydrophobic IOLs (8.68%, 190/2190 eyes) than with the hydrophilic IOL (31.70%, 175/552 eyes; p < 0.001). Over time, the rate of increase in the cumulative number of Nd:YAG laser capsulotomy cases was the highest with MI60. The cumulative rate of Nd:YAG laser capsulotomy during the first 3 years was 4.90% with SN60WF (70/1431 eyes), 6.76% with ZCB00 (43/636 eyes), 8.94% with MX60 (11/123 eyes), and 26.10% with MI60 (144/552 eyes) lenses. Conclusions: The incidence of PCO is influenced by the material of the IOLs. The hydrophilic IOL was associated with a higher rate of Nd:YAG laser capsulotomy than the hydrophobic IOLs, with a shorter time to Nd:YAG laser capsulotomy.

Development and Validation of a Prediction Model for Nd:YAG Laser Capsulotomy: A Retrospective Cohort Study of 9768 eyes

INTRODUCTION

Posterior capsular opacification (PCO) is the most common complication of cataract surgery. In this study, we develop a model to quantitatively predict the probability of Nd:YAG laser capsulotomy for vision-threatening PCO to improve the life quality of postoperative patients.

METHODS

A registry analysis of cataract procedures performed between the years 2010 and 2021. Following the screening of 16,802 patients (25,883 eyes), 9768 patients (eyes) were enrolled. The cohort was randomly divided into two groups: training (n = 6838) and validation (n = 2930). To identify relevant risk factors, univariate, multivariate, and Least Absolute Shrinkage and Selection Operator (LASSO) algorithm Cox regression analysis were employed, and a nomogram was created to demonstrate the prediction result.

RESULTS

At 5 years, the overall cumulative incidence of Nd:YAG laser capsulotomy was 12.0% (1169/9768). The following variables were included in the prediction model: sex [hazard ratio (HR) = 1.53, 95% CI 1.32-1.76], age (HR = 0.71, 95% CI 0.56-0.88), intraocular lens (IOL) material (HR = 2.65, 95% CI 2.17-3.24), high myopia (HR = 2.28, 95% CI 1.90-2.75), and fibrinogen (HR = 0.79, 95% CI 0.72-0.88). In the validation cohort, the area under the curve (AUC) of 1-, 3-, and 5-year predictions for Nd:YAG laser capsulotomy were 0.702, 0.691, and 0.688, respectively. For a subgroup of patients with high myopia, the protective effect of hydrophobic IOL disappeared (HR = 0.68, 95% CI 0.51-1.12, P = 0.127).

CONCLUSION

This model could predict the probability of Nd:YAG laser capsulotomy for vision-threatening PCO after cataract surgery by taking into account factors such as age, gender, IOL material, high myopia, and fibrinogen. Meanwhile, implantation of a hydrophobic IOL in individuals with high myopia did not demonstrate a protective impact against vision-threatening PCO.

"Comparing outcomes of advanced nurse practitioners to ophthalmologists performing posterior YAG capsulotomy, a six-year study of 6308 eyes"

PURPOSE

To primarily report the baseline characteristics and visual acuity (VA) outcomes of advanced nurse practitioners (ANP) compared to ophthalmologists following YAG posterior capsulotomy (YAGPC). We secondarily looked to characterise the risk factors that lead to a repeated YAGPC.

METHOD

Retrospective consecutive case series of 6,308 eyes attending the Birmingham and Midlands Eye Centre.

RESULTS

ANPs performed 33.1% of YAGPC compared to 66.9% ophthalmologists. Compared to ophthalmologists, ANPs performed YAGPC in lower proportion of patients with ocular co-morbidities (p < 0.001) and had lower proportion of patients requiring further YAGPC compared to ophthalmologists (p < 0.001). Median pre, post-operative and LogMAR gain in VA of 0.48 (IQR 0.30-0.78), 0.18 (IQR 0.10-0.40) and 0.30 (0.08-0.48) LogMAR units, respectively. Multivariate regression showed that ANPs had a significantly lower rate of repeat YAGPC compared to ophthalmologists even when adjusting for age, ethnicity, training grade and ocular co-morbidities. No difference in visual outcomes was found between operator grade and ethnicity on multivariate analysis.

CONCLUSION

YAGPC leads to excellent visual outcomes. ANPs can deliver safe and effective YAGPC.

Evaluation of Nd:YAG Laser Capsulotomy Rates in a Real-Life Population

Objective

The objective of this study was to assess the rate of posterior capsule opacification (PCO), under “real-life” conditions, as measured by rates of Nd:YAG laser intervention, rather than from a controlled study from which patients with conditions predisposing to PCO have been excluded.

Methods and Analysis

This was a retrospective, multicenter study in an unselected consecutive cohort of patients undergoing surgery for senile cataract. Patients aged 18 years and older, previously implanted with the CT LUCIA 611P IOL, were contacted at 12, 18 and 24 months to ascertain if they had received Nd:YAG laser treatment. There was an additional assessment at 36 months at the Austrian centre.

Results

A total of 200 patients were recruited at two centers. Laser capsulotomy rates were 4.5% at 1 year and 10% by year 2 and 12% by year 3. Three Nd:YAG capsulotomies, carried out at other external centers, were performed for reasons other than PCO, including astigmatism, epiretinal membrane and ARMD. If these patients are excluded, the true rate of Nd:YAG carried out for PCO at 1 year was 3.5% and at 2 years was 8.5%.

Conclusion

It is critical to ensure that Nd:YAG capsulotomies are being performed only for the correct clinical reason. Carrying out unnecessary procedures places the patient at risk of adverse events, is a cost to the healthcare system, and is likely to have no direct visual benefit for the patient. In PCO studies, it should be a requirement to document the fibrosis grade to confirm that Nd:YAG capsulotomy was correctly indicated.

Intraocular lens tilt and decentration after Nd:YAG laser posterior capsulotomy: Femtosecond laser capsulorhexis versus manual capsulorhexis

PURPOSE

To compare intraocular lens (IOL) tilt and decentration after Nd:YAG laser posterior capsulotomy in eyes that had femtosecond laser-assisted capsulotomy versus manual capsulorhexis.

SETTING

Ekol Eye Hospital, Izmir, Turkey.

DESIGN

Retrospective case series.

METHODS

Intraocular lens decentration and angle of tilt were measured using a Scheimpflug camera before and 1 month after Nd:YAG capsulotomy.

RESULTS

Eighteen eyes had a femtosecond laser-assisted capsulotomy and 25 eyes a manual capsulorhexis. The mean age was 58.2 years ± 10.2 (SD) (range 44 to 69 years) and 60.6 ± 8.3 years (range 45 to 70 years), respectively. Before capsulotomy, the angle of tilt and decentration at both meridians did not differ significantly between the 2 groups (P > .05). After capsulotomy, the angle of tilt was significantly decreased in both groups (femtosecond: vertical 1.5 degrees and horizontal 1.2 degrees; manual: vertical 1.1 degrees and horizontal) and decentration was significantly increased (femtosecond: vertical 0.085 mm and horizontal 0.096 mm; manual: vertical 0.2 mm and horizontal 0.2 mm) at both meridians (P < .05). After capsulotomy, all tilt and decentration parameters were significantly different between the 2 groups (P < .05) except decentration on the horizontal meridian (P = .669).

CONCLUSIONS

Nd:YAG posterior capsulotomy performed after femtosecond laser-assisted capsulotomy resulted in better mechanical stability of the IOL. This suggests that a femtosecond laser-created capsulotomy better maintains a proper IOL position. Although the differences were statistically significant, the tilt and decentration values were small and might not be clinically significant.

Posterior Capsule Opacification With Two Hydrophobic Acrylic Intraocular Lenses: 3-Year Results of a Randomized Trial

PURPOSE

To compare the incidence and intensity of posterior capsule opacification (PCO) and neodymium-yttrium-aluminum-garnet (Nd:YAG) capsulotomy rates between 2 similar open-loop single-piece hydrophobic acrylic intraocular lenses (IOLs) that differ in the proprietary material characteristics and design features, over a period of 3 years.

DESIGN

Randomized, prospective, patient- and examiner-masked clinical trial with intraindividual comparison.

METHODS

Setting: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria.

PATIENT POPULATION

Eighty patients (160 eyes) had bilateral cataract surgery and received a Vivinex XY1 IOL in 1 eye and an AcrySof SN60WF IOL in the other eye.

OBSERVATION PROCEDURES

Follow-up examinations were performed 3 years after surgery. Digital retroillumination images were taken of each eye. The amount of PCO (score: 0-10) was assessed subjectively at the slit lamp and objectively using automated image analysis software (AQUA).

MAIN OUTCOME MEASURE

PCO score (scale, 0-10).

RESULTS

The mean objective PCO score of the Vivinex XY1 IOLs was 0.9 ± 0.8 compared to the PCO score of 1.4 ± 1.1 for the AcrySof SN60WF IOLs (P < .001). Three years postoperatively, 11.4% of patients had an Nd:YAG capsulotomy in the Vivinex XY1 eye and 18.6% had a capsulotomy in the AcrySof SN60WF eye (P = .23).

CONCLUSION

The new hydrophobic acrylic Vivinex XY1 IOL showed significantly lower PCO rates and lower YAG rates compared to the AcrySof SN60WF IOL. The interaction of various factors such as hydrophobic material, smooth optic surface, and sharp posterior optic edge plays a key role in PCO development.

Comparison of posterior capsule opacification development with 2 single-piece intraocular lens types

PURPOSE

To evaluate the differences in the incidence of posterior capsule opacification (PCO) and visual and optical performance between 2 hydrophobic acrylic single-piece sharp-edged intraocular lenses (IOLs) over 3 years.

SETTING

Department of Ophthalmology, Medical University of Vienna, Vienna, Austria.

DESIGN

Prospective randomized case series.

METHODS

Patients with bilateral cataract were prospectively randomized to receive an Eyecee One IOL (IOL A) or an Acrysof SN60WF IOL (IOL B) and were followed for 36 months. The corrected distance visual acuity (CDVA) and IOL decentration and tilt were measured. The PCO was quantified by analysis of standardized retroillumination images.

RESULTS

The study comprised 160 eyes of 80 patients. The PCO incidence was low for both IOLs at all follow-up visits. Three years postoperatively, the median objective PCO score was 1.4 (range 0 to 5.6) for IOL A and 1.5 (range 0 to 5.0) for IOL B (P = .67). The neodymium:YAG (Nd:YAG) capsulotomy rate 3 years after surgery was 16.4% and 6.0% (P = .06), respectively. Visual acuity and contrast sensitivity outcomes were also comparable at all follow-up visits.

CONCLUSIONS

Both IOLs showed good capsular bag performance and low PCO rates 3 years after surgery. Both IOLs also showed comparable results for visual acuity, contrast sensitivity, decentration and tilt, PCO score, slitlamp examination, and Nd:YAG capsulotomy rates.

5 year incidence of YAG capsulotomy and PCO after cataract surgery with single-piece monofocal intraocular lenses: a real-world evidence study of 20,763 eyes

OBJECTIVES

To evaluate the 3- and 5-year incidence of posterior capsule opacification (PCO) and neodymium-doped yttrium aluminium garnet (Nd:YAG) capsulotomy in patients following cataract surgery, comparing results for different single-piece acrylic hydrophilic and hydrophobic monofocal intraocular lens (IOL) models and other patient factors.

PATIENTS AND METHODS

Electronic medical record data collected from seven United Kingdom (UK) National Health Service (NHS) ophthalmology clinics for routine, age-related (≥65 years) cataract surgeries that implanted single-piece acrylic monofocal IOLs during 2010-2013 were used to calculate 3- and 5-year incidence of Nd:YAG and PCO. IOL models of Alcon Acrysof, AMO Tecnis, Bausch & Lomb (B & L) Akreos, LenStec Softec, and Rayner Flex were analyzed. Pairwise comparisons were conducted between AcrySof IOLs and other IOLs using Bonferroni adjustment for multiplicity. Multivariate analyses were conducted adjusting for known confounders.

RESULTS

The incidence of Nd:YAG capsulotomy ranged between 2.4-12.6% at 3 years and 5.8-19.3% at 5 years post-cataract surgery. Similarly, the incidence of PCO ranged between 4.7-18.6% at 3 years and 7.1-22.6% at 5 years. When comparing all of the single-piece IOLs, AcrySof demonstrated the lowest incidence rates for both PCO and Nd:YAG (P < 0.001 for each comparison). From adjusted logistic regression analysis, AcrySof were associated with lower 3- and 5-year odds of Nd:YAG and PCO incidence.

CONCLUSIONS

Following cataract surgery with single-piece monofocal IOLs different incidence rates of PCO were observed with different IOLs. AcrySof IOLs were associated with significantly lower incidence of PCO requiring Nd:YAG treatment over periods of 3 and 5 years.

Osmotically induced removal of lens epithelial cells to prevent PCO after pediatric cataract surgery: Pilot study to assess feasibility

PURPOSE

Development of an osmotic-shock technique to remove human lens epithelial cells (LECs) as a preventive measure to address posterior capsule opacification (PCO) after pediatric cataract surgery.

SETTING

Department of Genetics, UCL Institute of Ophthalmology, London, England, and Department of Ophthalmology, Ruijin Hospital, Jiao Tong University, Shanghai, China.

DESIGN

Laboratory study.

METHODS

Various tissue preparations of human LECs (cultured on coverslips/collagen-coated membrane inserts, human lens capsule biopsies, and lens organ cultured PCO models) were subjected to a single or incremental hyperosmotic shock (NaCl, 350-4000 mOsm/L) in the presence of inhibitors of the Na+-K+-2Cl- cotransporter (NKCC) (to disable the regulatory volume increase [RVI] process). The integrity of the cell monolayer was determined by phase-contrast microscopy, viability assays, and measurement of transepithelial resistance.

RESULTS

Hyperosmotic shock (400 mOsm/L) caused rapid cell shrinkage (<5 minutes) in all the LEC models studied. In the absence of the NKCC inhibitor, the shrunk cells gradually returned to their original cell volume and architecture over time, while still exposed to the hyperosmotic shock. However, inhibition of the RVI process disabled the ability for restoration of cell volume leading to persistent cell shrinkage, subsequently resulting in cell detachment from the underlying support medium.

CONCLUSION

Hyperosmotic shock in the presence of inhibitors of the RVI process was effective in rapidly detaching LECs from their basement membranes. This technique could potentially facilitate removal of residual LECs left on the lens capsule after cataract surgery, thus decreasing or eliminating the risk for aggressive cell proliferation and the development of PCO.

Misdiagnosed opacification of a hydrophobic acrylic intraocular lens

A 75-year-old woman was referred for decreased visual acuity resulting from "opacification of the IOL" in the immediate period after uneventful bilateral cataract surgery with single-piece AcrySof IQ intraocular lens (IOL) implantation. A neodymium:YAG laser capsulotomy had been performed in both eyes to treat the complication. Anterior segment optical coherence tomography performed at presentation showed an opaque membrane enveloping the IOL. The membrane was peeled from the anterior IOL surface, and all adherences between the IOL and capsular bag were freed. One year later, the eyes remained stable; the uncorrected distance visual acuity was 20/20, the IOL was clear, and there was no evidence of recurrence of the membrane. Appropriate imaging for the diagnosis and surgical peeling with freeing of the adhesions between the IOL and the capsular bag were essential to the success in this case.

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

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.

Edge profile of commercially available square-edged intraocular lenses: Part 2

PURPOSE

To analyze the sharpness of the posterior optic edge and edge thickness of intraocular lenses (IOLs) marketed with a square-edged profile.

SETTING

University of Brighton and Brighton and Sussex University Hospitals NHS Trust, Brighton, England.

DESIGN

Laboratory study.

METHODS

Fourteen square-edged 20.0 diopter IOLs were analyzed, including 9 hydrophobic IOLs (AF-1, AF-1 iSert, Clareon, EyeCee One Crystal, CT Lucia, Envista, EyeCee One, Vivinex iSert, and RayOne Hydrophobic) and 5 hydrophilic IOLs (Asphira, CT Asphina, Incise, Synthesis, and RayOne Hydrophilic). All the IOLs were scanned following a previously published standardized technique using environmental scanning electron microscopy. The posterior optic edges were scanned at a magnification of ×500 and ×200 to measure the radius of curvature of the posterior optic edges and the optic edge thickness.

RESULTS

The radius of curvature of the posterior optic edges ranged from 4.6 to 20.6 μm. Except for the Incise IOL (7.7 μm), all hydrophilic IOLs (Synthesis [10.6 μm], Asphira [13.7 μm], RayOne Hydrophilic [14.0 μm], CT Asphina [13.7 μm]) had a radius of curvature greater than 10.0 μm. For the hydrophobic IOLs, the radius of curvature was less than 10.0 μm for the Clareon (7.9 μm), EyeCee One Crystal (4.7 μm), Vivinex iSert (7.6 μm), and CT Lucia (4.6 μm), and greater than 10.0 μm for the Envista (19.7 μm), EyeCee One (13.7 μm), AF-1 iSert (19.7 μm), AF-1 (19.7 μm) and the RayOne Hydrophobic (20.6 μm). The Vivinex iSert (150.5 μm) and the Incise (218.2 μm) were the thinnest IOLs, and the RayOne Hydrophobic (375.8 μm) and RayOne Hydrophilic IOLs (477.1 μm) were the thickest of the hydrophobic and hydrophilic IOLs, respectively.

CONCLUSIONS

Commercially marketed square-edged IOLs still differed in the sharpness of the posterior optic edge. More hydrophobic IOLs have rounder edges than those studied 10 years ago. Variations in the edge profile of hydrophobic IOLs were greater compared with the hydrophilic IOLs.

Evaluation of intraocular lens position during phacoemulsification using intraoperative spectral-domain optical coherence tomography

PURPOSE

To assess the position of intraocular lenses (IOLs) at the end of standard phacoemulsification with intraoperative spectral-domain optical coherence tomography (SD-OCT).

SETTINGS

Department of Ophthalmology, Rudolf Foundation Hospital, Vienna, Austria.

DESIGN

Prospective case series.

METHODS

Standard phacoemulsification with IOL implantation was performed. The Rescan 700 SD-OCT system was used for intraoperative imaging. The anterior segment of the eye was scanned using SD-OCT at the end of the surgery. The distance from the IOL optic center and the IOL optic edge to the posterior capsule was measured postoperatively using graphic software.

RESULTS

The study comprised 74 patients (101 eyes). The mean axial length was 23.97 mm (range 21.43 to 28.61 mm). The mean IOL power was 20.39 diopters (D) (range 6.5 to 27.5 D). Contact between the IOL and posterior capsule was absent in 88 cases (87.13%), and partial or full contact was present in 13 cases (12.87%). The mean distance between the IOL central optic and posterior capsule was 0.71 pixel (range 0.06 to 1.38 pixels) in 99 cases (98.02%). In 42 cases (57.53%), partial contact between the IOL edges and the posterior capsule was noticed. The mean distance between the IOL edge and posterior capsule was 0.21 pixel (range 0.04 to 0.92 pixel).

CONCLUSIONS

Intraoperative SD-OCT facilitated the imaging of IOL position during standard phacoemulsification. Contact between the IOL central optic and posterior capsule at the end of the surgery occurred rarely. Improved IOL design should be considered.

FINANCIAL DISCLOSURE

Drs. Binder and Glittenberg are consultants to Carl Zeiss Meditech AG. None of the other authors has a financial or proprietary interest in any material or method mentioned.

Advances and challenges of intraocular lens design [Invited]

Phacoemulsification technique with intraocular lens implantation has been a common treatment for cataract patients. With rising demand among the public, new technologies for lens design have emerged to minimize intraocular aberrations, improving visual quality to the largest extent. This paper systematically reviews the development of materials applied in lens manufacturing, the different categories of intraocular lenses, and respective design principles. The advantages and potential drawbacks of intraocular lenses are illustrated in the paper, and prospective research to improve the design are presented in the end.

Biomaterial Influence on Intraocular Lens Performance: An Overview

There is strong evidence that the IOL material is the factor having the greatest impact on posterior capsule opacification (PCO), anterior capsule opacification (ACO) development, and glistening formation after cataract surgery, even though there are other IOL features—such as haptic material and design and edge and optic design—that also have some influence. We reviewed the published literature describing the adverse events that are mainly related to the intraocular lens (IOL) material, such as PCO, ACO, and the subsequent capsule contraction, as well as glistening formation. The adverse events presented in this overview are the most common ones in clinical practice, and therefore, they are generally included in the clinical protocols for IOL evaluation.

Adhesion of the posterior capsule to different intraocular lenses following cataract surgery

PURPOSE

To investigate the prevalence and morphologic and clinical features of posterior capsule-optic inadhesion following cataract surgery.

METHODS

In this prospective cohort study, we examined 518 consecutive patients who had undergone uneventful phacoemulsification and posterior chamber intraocular lens (IOL) implantation. They were assigned into five groups based on the type of IOL used: MC X11 ASP, Rayner 920H A, ZCB00, SN60WF and KS-3Ai. Routine ophthalmic examinations were performed. Patients were followed up at 1 day, 1 week, and 1 and 2 months postsurgery. Anterior segment photography, Scheimpflug imaging and KR-1W aberrometry were conducted after the patients' pupils were dilated.

RESULTS

The overall rate of posterior capsule-optic inadhesion on the first day after surgery was 215/518 (41.5%), and it decreased to 37/518 (7.1%) at 2 months postsurgery. Posterior capsule-optic inadhesion can be morphologically classified into five types with three outcomes, of which gradual absorption of the accumulated fluid predominated for all IOLs. The clinical characteristics of patients with inadhesion varied with IOL type. Notably, visual quality data (Strehl ratios and modulation transfer function) were poorer in patients with posterior capsule-optic inadhesion, especially in those with irregular forms of suspension. Four cases of capsular contraction syndrome were identified among the patients with inadhesion.

CONCLUSIONS

Posterior capsule-optic inadhesion is a prevalent capsule-IOL interaction following cataract surgery. Although the accumulated fluid is absorbed in the majority of patients, its adverse effects on visual outcomes, especially visual quality in the operated eye(s), must not be underestimated in patients with persistent inadhesion.

Comparison of Manual, Femtosecond Laser, and Precision Pulse Capsulotomy Edge Tear Strength in Paired Human Cadaver Eyes

PURPOSE

To compare the anterior lens capsulotomy edge tear strength created by manual continuous curvilinear capsulorhexis (CCC), femtosecond laser capsulotomy (FSLC), and a new automated precision pulse capsulotomy (PPC) device.

DESIGN

A 3-arm study in paired human cadaver eyes.

PARTICIPANTS

A total of 44 eye specimens from 22 donors in the United States.

METHODS

Capsulotomy was performed in all eye specimens using manual CCC, a femtosecond laser (LenSx, Alcon, Fort Worth, TX), or an automated PPC device (Zepto, Mynosys Inc., Fremont, CA). The first study arm consisted of 8 pairs of eyes in which 1 eye received PPC and the fellow eye received FSLC. The second study arm consisted of 8 pairs of eyes, with 1 eye receiving PPC and the fellow eye receiving manual CCC. The third study arm consisted of 6 pairs of eyes, with 1 eye receiving a manual CCC and the fellow eye receiving FSLC. After phacoemulsification, 2 capsulotomy edge retractors attached to force transducers were used to stretch the capsulotomy edge of each eye and to measure the resisting force until the capsulotomy edge was torn.

MAIN OUTCOME MEASURES

Capsulotomy edge tear strength in millinewtons.

RESULTS

The PPC edge tear strength was greater than that of FSLC for all 8 pairs of eyes by an average factor of 3.1-fold (PPC mean 73.3±24.9 mN vs. femtosecond laser mean 26.1±6.8 mN; P = 0.012, Wilcoxon matched-pairs, signed-ranks test). The PPC tear strength was greater than that of manual CCC for all 8 pairs of eyes by an average factor of 4.1-fold (PPC mean 95±35.2 mN vs. manual CCC mean 29.1±23.1 mN; P = 0.012, Wilcoxon matched-pairs signed-ranks test). There was no significant difference in the tear strength of capsulotomies produced by manual CCC (mean 21.3±4.9 mN) and FSLC (mean 24.5±11.4 mN) (P = 0.75, Wilcoxon matched-pairs signed-ranks test).

CONCLUSIONS

The strength of the PPC capsulotomy edge was significantly stronger than that produced by femtosecond laser or manual CCC.

Long-term follow-up of posterior capsule opacification after AquaLase and NeoSoniX phacoemulsification

AIM

To compare the degree of posterior capsule opacification (PCO) after AquaLase and NeoSoniX phacoemulsification methods during an 8-year follow-up period using two types of software.

DESIGN

Prospective, randomized clinical trial.

METHODS

AquaLase was used in the right eye and NeoSoniX in the left eye of each patient with bilateral cataract.

RESULTS

Fifty patients were analyzed 1 year, 46 patients 3 years, and 37 patients 8 years after cataract surgery. Mean EPCO 2000 values were for the AquaLase group 0.324 ± 0.305 and for the NeoSoniX group 0.298 ± 0.341 (P = 0.53) 1 year after surgery, for the AquaLase group 0.582 ± 0.506 and for the NeoSoniX group 0.594 ± 0.515 (P = 0.87) 3 years after surgery, and for the AquaLase group 0.648 ± 0.567 and for the NeoSoniX group 0.673 ± 0.542 (P = 0.30) 8 years after surgery. The OSCA results were for the AquaLase group 0.7097 ± 0.3778 and for the NeoSoniX group 0.8584 ± 0.4323 (P = 0.046) 1 year after surgery, for the AquaLase group 0.9667 ± 0.736 and for the NeoSoniX group 0.9540 ± 0.5250 (P = 0.91) 3 years after surgery, and for the AquaLase group 1,035 ± 0,952 and for the NeoSoniX group 1,103 ± 0,741 (P = 0.44) 8 years after surgery.

CONCLUSION

There was minimal PCO difference between these 2 approaches, AquaLase and NeoSoniX. Neither AquaLase nor NeoSoniX technique was able to prevent a natural progression of PCO.

Defining the ideal femtosecond laser capsulotomy

Purpose

We define the ideal anterior capsulotomy through consideration of capsular histology and biomechanics. Desirable qualities include preventing posterior capsular opacification (PCO), maintaining effective lens position (ELP) and optimising capsular strength.

Methods

Laboratory study of capsular biomechanics and literature review of histology and published clinical results.

Results

Parameters of ideal capsulotomy construction include complete overlap of the intraocular lens to prevent PCO, centration on the clinical approximation of the optical axis of the lens to ensure concentricity with the capsule equator, and maximal capsular thickness at the capsulotomy edge to maintain integrity.

Conclusions

Constructing the capsulotomy centred on the clinical approximation of the optical axis of the lens with diameter 5.25 mm optimises prevention of PCO, consistency of ELP and capsular strength.

Effect of four different intraocular lenses on posterior capsule opacification

AIM

To evaluate the impact of 4 different intraocular lenses (IOLs) on posterior capsule opacification (PCO) by comparing the neodymium: yttrium-aluminum-garnet (Nd:YAG) laser capsulotomy rates.

METHODS

This retrospective study included 4970 eyes of 4013 cataract patients who underwent phacoemulsification and IOL implantation between January 2000 and January 2008 by the same surgeon at one clinic. Four different IOLs were assessed. The outcome parameter was the incidence of Nd:YAG laser posterior capsulotomies.

RESULTS

An Nd:YAG laser posterior capsulotomy was performed in 153 (3.07%) of the 4970 eyes. The mean follow-up time was 84mo for all of the IOL groups. The percentage of eyes developing PCO was significantly greater for the acrylic hydrophilic IOLs than for the hydrophobic IOLs, although eyes with acrylic hydrophilic IOLs did not require Nd:YAG laser capsulotomy as soon as eyes with acrylic hydrophobic IOLs. There was no difference between the long-term PCO rates when 1- and 3-piece acrylic hydrophobic IOLs were compared or when IOLs made of the same material but with different haptic angles were compared.

CONCLUSION

In this study, eyes with acrylic hydrophilic IOLs were more likely to develop PCO than those with acrylic hydrophobic IOLs. The lens design (1-piece versus 3-piece and varying haptic angles) did not affect the PCO rate.

Square-edge intraocular lenses and epithelial lens cell proliferation: implications on posterior capsule opacification in an in vitro model

Background

To evaluate lens epithelial cell (LEC) proliferation with two different designs (one-piece or three-piece) of hydrophobic acrylic IOLs with 360° square optic edge using an in vitro culture model of posterior capsule opacification (PCO).

Methods

This experimental study was conducted at the Department of NEUROFARBA, Section of Pharmacology, University of Florence, Italy. Human LECs were seeded and cultured in transwell cell culture inserts coated with a type-IV collagen membrane on which an IOL (one-piece Tecnis-1 or three-piece AR40E, Abbott Medical Optics Inc.) had been previously placed. As control, cells were plated on the insert membrane without an IOL. At day six (cells confluent in controls) IOLs were removed and cell counting, viability and cell density under and outside the IOLs were evaluated.

Results

No statistically significant difference in the number of cells (p > 0.05) between inserts with the one-piece and three-piece IOLs was found. Cell density in the area under each IOL was significantly lower than in the area outside of it (p < 0.05), or in the control insert. (p < 0.05). Cell density under the single-piece IOL was not significantly different from that under the three-piece IOL (p > 0.05).

Conclusions

A 360° sharp-edge played a crucial role in avoiding LEC migration under the IOL and preventing the formation of PCO after cataract surgery. Long term clinical evaluation is necessary to estimate functional results.

[Cataracts in dogs--overview and guideline for decision making in treatment]

Cataract is the leading cause of impaired vision and vision loss in dogs. Because of the considerable progress in cataract surgery in recent decades, lens opacities can now be operated on with very good short-term success (90-95%), taking into account that proper patient selection is essential to maximize the probability of a successful surgical outcome. Following a description of anatomical and physiological lens characteristics, the etiology and complications of untreated cataracts are discussed. Furthermore, specific criteria for patient selection are addressed while delineating essential steps of the examination. This article aims to aid decision making in cataract therapy on the basis of diagnostic guidance and to facilitate the selection of an appropriate point of time for surgery.

Posterior capsule opacification and neodymium:YAG rates with 2 single-piece hydrophobic acrylic intraocular lenses: three-year results

PURPOSE

To compare the incidence and intensity of posterior capsule opacification (PCO) between 2 similar 1-piece foldable hydrophobic acrylic intraocular lenses (IOLs) over 3 years.

SETTING

Department of Ophthalmology, Medical University Vienna, Vienna, Austria.

DESIGN

Randomized prospective patient- and examiner-masked clinical trial with intraindividual comparison.

METHODS

Patients with bilateral age-related cataract had cataract surgery and implantation of a Tecnis ZCB00 continuous-optic-edge IOL in 1 eye and an Acrysof SA60AT interrupted-optic-edge IOL in the other eye. Postoperative examinations were performed at 6 months and 3 years. Digital retroillumination images were taken of each eye. The amount of PCO (score 0 to 10) was assessed subjectively at the slitlamp and objectively using automated image-analysis software.

RESULTS

The study comprised 54 patients (108 eyes). The mean objective PCO score was 1.3 ± 1.7 (SD) for the continuous-optic-edge IOLs and 0.9 ± 1.3 for the interrupted-optic-edge IOLs (P=.10). Three years postoperatively, a neodymium:YAG (Nd:YAG) capsulotomy was performed in 26.1% of eyes with the continuous-optic-edge IOL and 21.7% with the interrupted-optic-edge IOL (P=.56). There was no significant difference in corrected distance visual acuity, capsulorhexis–IOL overlap, capsule folds, or anterior capsule opacification 3 years after surgery.

CONCLUSIONS

Both IOLs had comparable PCO and Nd:YAG rates 3 years postoperatively. The optimized barrier function of the continuous-optic-edge IOL and the material properties of the interrupted-optic-edge IOL seemingly outbalanced the effect on lens epithelial cell migration and proliferation beneath the optic.

Influence of a variable overall diameter hydrophilic acrylic sharp-edged single-piece intra-ocular lens on capsule opacification one year after surgery

BACKGROUND

To investigate the influence of the overall intraocular lens (IOL) diameter on posterior capsule opacification (PCO) formation.

METHODS

In this prospective randomized clinical trial, 124 eyes of 62 patients with bilateral age-related cataract were included. Each patient received a Corneal A501D IOL in one eye and a Corneal J501D IOL in the fellow eye. Best corrected visual acuity (BCVA) and digital slitlamp photographs were taken a 1 h, 1 week, 1, 3, 6 and 12 months postoperatively. The amount of PCO was assessed subjectively at the slitlamp and objectively using automated image-analysis software.

RESULTS

We found a mean BCVA of 0.81 ± 0.2 for the Corneal A501D group and 0.79 ± 0.21 for the Corneal J501D group. There was no significant difference 12 months after surgery between the two IOLs (p > 0.05). Objective PCO assessment resulted in a mean PCO score (scale 0-10) of 1.65 ± 1.71 was found for the Corneal J501D group and a score of 1.54 ± 1.64 was found for the Corneal A501D group (p > 0.05). The subjective PCO assessment at 1 year resulted in a mean PCO score of 2.0 ± 1.74 in the Corneal J501D group and 2.13 ± 1.64 in the Corneal A501D group (p > 0.05).

CONCLUSION

Both investigated IOLs showed good clinical performance regarding PCO and BCVA. Our study suggests that the use of an IOL with variable total diameter seems not to influence the rate of PCO formation.

Intraocular lens-edge design and material factors contributing to posterior-capsulotomy rates: comparing Hoya FY60aD, PY60aD, and AcrySof SN60WF

PURPOSE

To compare neodymium-doped yttrium aluminum garnet laser posterior capsulotomy (LPC) rates between the Hoya FY60AD, Hoya PY60AD, and Alcon AcrySof SN60WF intraocular lenses (IOLs) after routine cataract surgery.

METHODS

In this retrospective comparative study, patients undergoing uncomplicated cataract surgery over a 3-year period were included, and those subsequently undergoing LPC were identified from laser clinic records. LPC rates at 2 years postoperatively were compared between the round-edged Hoya FY60AD, the newer sharp-edged Hoya PY60AD three-piece IOLs, and the one-piece AcrySof SN60WF IOL.

RESULTS

A total of 1,265 cataract operations were included, and 49 eyes (3.9%) underwent LPC within 2 years of surgery. Twenty-eight of 315 eyes (8.9%) implanted with the FY60AD underwent LPC by 2 years, compared to eleven of 254 (4.3%) with the newer sharp square-edged PY60AD and ten of 696 (1.4%) with the one-piece SN60WF (P < 0.05, Chi-squared analyses).

CONCLUSIONS

The newer, sharper-edged Hoya PY60AD IOL has a lower LPC rate than the Hoya FY60AD IOL at 2 years post-cataract surgery. The one-piece AcrySof SN60WF has a lower LPC rate than both the three-piece Hoya IOLs in the same time period postoperatively. Variations in IOL-edge design and material effect may have contributed to the different rates observed.

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

PURPOSE

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.

SETTING

St. Erik Eye Hospital, Stockholm, Sweden.

DESIGN

Randomized clinical trial.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Capsular adhesion to intraocular lens in highly myopic eyes evaluated in vivo using ultralong-scan-depth optical coherence tomography

PURPOSE

To evaluate the in vivo capsular apposition to the intraocular lens (IOL) in subjects with high myopia by ultralong-scan-depth optical coherence tomography (OCT).

DESIGN

Prospective observational case series.

METHODS

Forty eyes from 40 cataract patients scheduled for phacoemulsification surgery at the Affiliated Eye Hospital, Wenzhou Medical College were studied, of which 20 eyes were highly myopic (axial length >26 mm) and 20 eyes were emmetropic (22 mm < axial length <24.5 mm). All eyes were examined with a custom-built ultralong-scan-depth OCT at 4 hours, 1 day, 7 days, 14 days, and 28 days after surgery.

RESULTS

Anterior capsule contact with the IOL was significantly delayed in highly myopic eyes. Complete apposition of the posterior capsule with the IOL was significantly less common among highly myopic eyes than in emmetropic eyes (4 vs 16 eyes; P = .001). Posterior capsule adhesion to the IOL was inversely correlated with axial length (r = -0.494, P < .001, nonparametric Spearman test). The 3 types of complete adhesive capsular bend configurations observed were classified as anterior adhesion, middle adhesion, and posterior adhesion. Incomplete adhesion patterns were classified as funnel adhesion, parallel adhesion, and furcate adhesion. Five highly myopic eyes had slight posterior capsule opacification (PCO) at the last follow-up, as did 1 emmetropic eye.

CONCLUSIONS

Ultralong-scan-depth OCT revealed weak capsular adhesion and incompletely adhesive types of capsular bend in highly myopic eyes. These features presumably increase the likelihood of PCO during the early postoperative period.

Growth inhibition of human lens epithelial cells by short hairpin RNA in transcription factor forkhead box E3 (FOXE3)

BACKGROUND

Posterior capsule opacification occurs mainly due to the remnant lens epithelial cell proliferation and migration after cataract surgery. The purpose of this study was to investigate whether small hairpin RNA (shRNA)-mediated gene silencing of transcription factor forkhead box E3 (FOXE3) can be employed to inhibit the expression of FOXE3 and suppress the growth in lens epithelial cells.

METHODS

FOXE3-targeted shRNA was transfected into a human lens epithelial cell line (HLEB-3) using Lipofectamine 2000 reagent. Quantitative PCR was used to confirm the downregulation of FOXE3 mRNA expression following infection of lens epithelial cells, and FOXE3 protein expression levels were evaluated by Western blot analysis and immunofluorescence staining. HLEB-3 cell growth after the transduction was analyzed by cell counting and MTT colorimetric assay. Cell cycle of the HLEB-3 cells was examined by flowcytometric analysis.

RESULTS

Compared with the control groups, both mRNA and protein levels of FOXE3 expression were significantly decreased in shRNA-treated groups, and cytostatic effects were obvious within 48 h after transfection. An increased incidence of G1-phase arrest was identified in FOXE3-shRNA transfected HLEB-3 cells.

CONCLUSIONS

shRNA-mediated gene silencing of FOXE3 could significantly inhibit cell growth and induce the G1-phase arrest in HLEB-3 cells. Formation of posterior capsular opacification might be repressed if lens epithelial cell growth ceases after the FOXE3 gene is silenced with molecular biology technology.

Effect of intraocular lens asphericity on posterior capsule opacification between two intraocular lenses with same acrylic material: a fellow-eye study

PURPOSE

To evaluate intra-individual differences in posterior capsule opacification (PCO) and visual performance between spherical AcrySof SN60AT and an aspheric AcrySof SN60WF intraocular lens (IOL) with a posterior aspheric surface, both of which are made of same hydrophobic acrylic material.

SETTING

Ophthalmology Department, St Thomas' Hospital, London, UK.

METHODS

In this prospective randomized, fellow-eye comparison, an aspheric IOL, which is 9% thinner in comparison with the spherical IOL, was randomized to the first eye of 47 patients and fellow-eye surgery was performed within 3 weeks. Follow-up was at 1, 3, 6, 12 and 24 months. Corrected logMAR visual acuity (CDVA) was measured at 100% and 9% contrast. After pupil dilation, digital retroillumination photographs were taken and the mean PCO percentage was calculated using poco software at each follow-up visit.

RESULTS

At 1, 3, 6, 12 and 24 months, 47 (94 eyes), 44 (88 eyes), 42 (84 eyes) and 41 (82 eyes) patients were followed-up respectively. Hundred per cent and 9% of LogMAR CDVA was not significantly different between the two IOLs (p = NS at all time-points). Percentage area PCO scores (mean ± SD) at 1, 3, 6, 12 and 24 months with the spherical IOL was 5.82 ± 9.89, 7.76 ± 16.83, 7.21 ± 12.46, 9.29 ± 18.25 and 14.39 ± 25.42, respectively, and with an aspheric IOL was 8.91 ± 12.79, 5.97 ± 10.32, 5.15 ± 7.92, 7.68 ± 11.18 and 12.18 ± 20.10, respectively (p = NS at all time-points).

CONCLUSIONS

Posterior capsule opacification was not significantly different between the spheric and aspheric IOLs in this fellow-eye, randomized comparison. Additional asphericity on the existing model of IOL does not influence PCO performance.

Modern cataract surgery: unfinished business and unanswered questions

We summarize information, based on clinicopathologic studies over the past decade, on various cataract intraocular lens (IOL) procedures and modern "specialized" IOLs, that will help surgeons continuously improve long-term results for cataract patients. Although most operations do initially provide excellent refractive correction and visual rehabilitation, late complications occur. These sometimes are missed because they are outside of the routine period of follow-up care. We have tried to determine if the various techniques and IOLs truly deliver the long-term results that we desire. Most safety and efficacy information is derived from the manufacturer and is passed through the U.S. Food and Drug Administration (FDA). This is often based on limited, relatively short-term observations made by the manufacturer. After a lens receives FDA approval, there are few means to assess the outcome of each procedure and lens years later. We rarely hear of a 10- or 20-year follow-up study. We have found that one of the best means to assess long-term results is pathologic analyses. We discuss recently studied aspects of pathologic reactions, such as posterior capsule opacification, intracapsular fibrosis, glistenings, intralenticular opacification, and other issues with the various IOL platforms; we then present a clinicopathological overview of tissues and IOLs from our database. These include hydrophobic and hydrophilic acrylic designs, plate lenses, and a dual optic lens.

Comparison of posterior capsule opacification with hydrophobic acrylic and hydrophilic acrylic intraocular lenses

PURPOSE

To compare posterior capsule opacification (PCO) 3 years postoperatively in contralateral eyes with a single-piece hydrophobic acrylic and 1 of 2 single-piece hydrophilic acrylic intraocular lenses (IOLs) with different configurations.

SETTING

Iladevi Cataract and IOL Research Institute, Ahmedabad, India.

DESIGN

Prospective randomized clinical trial.

METHODS

A hydrophobic Acrysof (hydrophobic group) or a hydrophilic C-flex (hydrophilic group C) or Akreos Adapt IOL (hydrophilic group A) was randomized for implantation in the fellow eye or vice versa of each patient. The Evaluation of Posterior Capsule Opacification (EPCO) area, EPCO score, and neodymium:YAG (Nd:YAG) capsulotomy rates were compared using digital photographs.

RESULTS

The study enrolled 68 patients. Although there was no significant difference at 1 month, the median EPCO score was statistically significantly lower in the hydrophobic group than in hydrophilic group C (P = .00) and hydrophilic group A (P = .000) at 3 years. There were no significant differences in the median EPCO area at 1 month; however, the area was statistically significantly less in the hydrophobic group than in hydrophilic group C and hydrophilic group A at 3 years (both P = .000). Four (12.9%) of 31 eyes in hydrophilic group C and 5 (16%) of 31 eyes in hydrophilic group A required an Nd:YAG capsulotomy; no eye in the hydrophobic group required a capsulotomy (P = .04 and P = .02, respectively).

CONCLUSION

Posterior capsule opacification was significantly less with the Acrysof hydrophobic acrylic IOL at 3 years.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Femtosecond laser-assisted cataract surgery with integrated optical coherence tomography

About one-third of people in the developed world will undergo cataract surgery in their lifetime. Although marked improvements in surgical technique have occurred since the development of the current approach to lens replacement in the late 1960s and early 1970s, some critical steps of the procedure can still only be executed with limited precision. Current practice requires manual formation of an opening in the anterior lens capsule, fragmentation and evacuation of the lens tissue with an ultrasound probe, and implantation of a plastic intraocular lens into the remaining capsular bag. The size, shape, and position of the anterior capsular opening (one of the most critical steps in the procedure) are controlled by freehand pulling and tearing of the capsular tissue. Here, we report a technique that improves the precision and reproducibility of cataract surgery by performing anterior capsulotomy, lens segmentation, and corneal incisions with a femtosecond laser. The placement of the cuts was determined by imaging the anterior segment of the eye with integrated optical coherence tomography. Femtosecond laser produced continuous anterior capsular incisions, which were twice as strong and more than five times as precise in size and shape than manual capsulorhexis. Lens segmentation and softening simplified its emulsification and removal, decreasing the perceived cataract hardness by two grades. Three-dimensional cutting of the cornea guided by diagnostic imaging creates multiplanar self-sealing incisions and allows exact placement of the limbal relaxing incisions, potentially increasing the safety and performance of cataract surgery.