Surgical prevention of posterior capsule opacification. Part 1: Progress in eliminating this complication of cataract surgery

Safety and efficiency of lens cortex removal assisted by fluid jet

Background

This retrospective study investigated the safety and efficiency of lens cortex removal assisted by a fluid-based capsular polishing technique called a fluid jet.

Methods

This was a retrospective case study. A total of 300 patients were included in this study. All patients underwent phacoemulsification using two different surgical sequences: a fluid jet before irrigation/aspiration (I/A) and an I/A before the fluid jet. They were divided into two groups: the fluid jet before I/A group (group 1, 150 eyes) and the I/A before the fluid jet group (group 2, 150 eyes). The frequencies of posterior capsule rupture (PCR) and posterior capsule being sucked into the I/A tip were recorded. The times of the fluid jet, I/A cortex, and entire procedure were noted.

Results

PCR occurred only in group 2. Compared with group 1, the posterior capsule being sucked into the I/A tip was more frequent in group 2 (P = 0.003). The fluid jet time was longer in group 1 than that in group 2 (P < 0.001). The I/A cortex time was shorter in group 1, and total time for fluid jet and I/A cortex together was shorter in group 2 (P = 0.014 and P = 0.007, respectively). However, the time of the entire procedure was shorter in group 1 (P < 0.001).

Conclusions

Fluid jet-assisted lens cortex removal is safe, time-saving, and simple to perform.

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.

Budget impact analysis of lens material on the posterior capsule opacification (PCO) as a complication after the cataract surgery

Background

Over 300,000 cataract operations are performed in Poland every year, and the most common, late complication of cataract removal surgery is posterior capsule opacification (PCO). The risk of PCO depends on the lens material. Hydrophobic acrylic lenses cause PCO less frequently as lymphatic endothelial cells show lower affinity for the surface of the lens made of silicone. The objective of this study is to assess the economic impact of using hydrophobic acrylic lenses compared to using hydrophilic acrylic lenses for cataract treatment in the Polish inpatient and outpatient settings.

Methods

A budget impact analysis (BIA) compared the economic outcomes associated with using hydrophobic acrylic lenses versus using hydrophilic lenses for patients undergoing cataract surgery. The BIA predicted annual expenses in the following scenarios: performing Nd:YAG to treat PCO within 2 and 3 years after implantation of hydrophobic or hydrophilic acrylic lenses for different lens structure. Data used to assess the frequency of PCO was determined in systematic literature review. Costs of current and predicted interventions were estimated based on average data from 19 Polish hospitals. Prices of health services were taken from official public tariff lists.

Results

The use of a hydrophobic lens significantly limits the number of complications after cataract surgery relative to a hydrophilic lens. As hydrophobic lenses have a higher unit price their use increases the cost of treatment which currently is not reflected by adequate difference in price of the service. Total annual National Health Fund (NHF) expenses for 3-year follow-up model range from 139.1 million EUR to 143.1 million EUR depending on the lens structure, due to the cost of complications.

Conclusions

BIA indicates the possibility of introducing surcharge for the use of hydrophobic lenses, which could increase the frequency of their use and reduce the number of complications after cataract surgery. It was estimated that total NHF expenses reach the minimum value for the surcharge at the level of 9 EUR. The surcharge of 14 EUR is the maximum value that does not increase the initial NHF expenses.

Topical steroid alone vs a combination with a posterior segment NSAID after Nd-YAG capsulotomy: Is the posterior segment NSAID really necessary?

Purpose:

To compare the effect of topical 1% prednisolone acetate and 0.09% bromfenac versus topical 1% prednisolone acetate alone on macular thickness following Nd: YAG laser capsulotomy.

Materials and Methods:

About 150 eyes with posterior capsule opacification following were included. All patients were treated with Nd: YAG laser posterior capsulotomy. Patients were randomly divided into two groups of 75. Group 1-Patients received: Topical 1% prednisolone acetate and Topical 0.09% bromfenac. Group 2-Patients received: Topical 1% prednisolone acetate alone. Outcome measures by an independent observer were BCVA by Snellen chart, IOP by NCT, and Central Macular Thickness (CMT) by Macular OCT. All patients were examined before the procedure, 1 h after the procedure, at 1 week, and at 6 weeks.

Statistics:

1. Quantitative variables: Mann-Whitney Test and Wilcoxon ranked sum test. 2. Qualitative variables: Chi-square test. A P value of < 0.05 was considered statistically significant.

Results:

Mean IOP increase in both groups is statistically significant at 1 h and later decreases back to nonsignificant levels at 1 week and 6 weeks. No significant change in mean CMT was seen in the duration of 6 weeks neither in Group 1 nor Group 2.

Conclusion:

Prophylactic antiglaucoma medications are not recommended in patients undergoing Nd: YAG laser capsulotomy. No evidence of cystoid macular edema was recorded till the end of 6 weeks follow-up.

A comparison of posterior capsular opacification after implantation of three different hydrophobic square edge intraocular lenses

Purpose

To compare the posterior capsular opacification (PCO) after implantation of three types of hydrophobic square edge intraocular lenses (IOLs).

Methods

A single-center, hospital-based, cross-sectional, observational study was conducted wherein patients with senile cataract who had undergone phacoemulsification by a single surgeon, with the implantation of three different types of square edge, hydrophobic IOLs [Group 1: enVista, Bausch and Lomb; Group 2: Tecnis 1 ZCBOO, AMO and Group 3: Acrysof IQ SN60WF, Alcon], and followed up for 12 months were included. The PCO was graded clinically and scored using the EPCO 2000 software.

Results

90 eyes of 90 patients were included. There was no significant difference in the PCO with respect to age, gender, or associated presence of systemic disease. The median PCO score was 0.035, 0.045 and 0.085 in groups 1, 2 and 3, respectively. The PCO grade and score differences between the groups were statistically significant with P < 0.001.

Conclusion

The hydrophobic nature and posterior square edge design in the IOLs probably contributed to the minimal visually-significant PCO in all the groups, in our study. However, PCO scores were lesser in the square edge IOLs having a continuous 360 degrees posterior enhanced barrier, than those without this feature.

Patients' Expectations in Lens Extraction Surgery: a Systematic Review

It is common knowledge that there are patients who have an uncomplicated cataract surgery with an actual improvement of their visual acuity, but they are dissatisfied with their final visual capacity. It is hypothesized that patients' preoperative expectations play a significant role in their postoperative perceptions. A systematic review of the recent literature regarding preoperative expectations of patients before lens extraction surgery and their postoperative perceptions as regards the visual outcome was performed based on the PubMed, Medline, Google Scholar, American Academy of Ophthalmology, Nature and Springer databases in September 2017 and data from 14 descriptive and 7 comparative studies were included in this narrative review. The objective of this review is the determination of the relationship between preoperative expectations and postoperative perception of visual outcome, as well as the investigation of predictors of patient satisfaction by understanding the factors that determine preoperative patient expectations. A considerable number of studies evaluate patient expectations before cataract surgery and compare them with postoperative patient perceptions. In conclusion, the final patient's postoperative perception could be affected both by the actual outcome of the operation and by patient preoperative expectations. Ocular and systemic comorbidity, unrealistic expectations, preoperative spectacle independence, the cost of surgery, and a previous cataract surgery as well as the level of health literacy and age could influence preoperative expectations and predict more accurately patient satisfaction. Taking these factors into consideration could allow surgeons to control the expectations with an extensive preoperative counseling.

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.

Influence of total intraocular lens diameter on efficacy and safety for in the bag cataract surgery

CONTEXT

Intraocular lenses with variable total diameter are supposed to fit better in the capsular bag and lead to fewer complications.

AIMS

This study aims to investigate the efficacy and the safety of an intraocular lens model with variable total diameter.

SETTINGS AND DESIGN

Prospective randomized intraindividual study.

SUBJECTS AND METHODS

Thirty-two eyes of sixteen patients with bilateral age-related cataract received standard cataract surgery with implantation of an intraocular lens with a standard diameter in one eye (Quatrix®, Group A) and with a variable total diameter in the fellow eye (Quatrix Evolutive®, Group B). Primary study endpoints included evaluation of refraction stability and posterior capsule opacification (PCO) over a follow-up period of 6 months.

STATISTICAL ANALYSIS USED

SPSS (Version 19.0) was used for statistical analysis.

RESULTS

Uncorrected and corrected distant visual acuity after 6 months were 0.24 and 0.1 LogMAR in Group A and 0.23 and 0.09 LogMAR in Group B, respectively. The objective and manifest spherical equivalent (OSE, MSE) 6 months postoperatively were + 0.65 D and + 0.62 D in Group A compared to + 0.33 D and + 0.33 D in Group B respectively (P = 0.665 for OSE, P = 0.208 for MSE). PCO-index increased statistically significant in both groups (P = 0.004 in Group A, P = 0.046 in Group B), but the difference of PCO-index between both groups was not statistically significant (P = 0.569).

CONCLUSIONS

An intraocular lens with a variable total diameter shows good visual outcomes and safety performance as well as same outcomes concerning postoperative refractive stability and development of PCO compared to an intraocular lens with standard total diameter.

Investigation of the anti-cataractogenic mechanisms of curcumin through in vivo and in vitro studies

BACKGROUND

Cataract is the leading cause of blindness in elderly people worldwide, especially in developing countries. Studies to identify strategies that can prevent or retard cataract formation are urgently required. This study aimed to investigate the potential mechanism of the cytoprotective effects of curcumin in in vivo and in vitro experiments.

METHODS

Male Wistar rats were randomly divided into three groups: the control group, the model group (administered 20 μmol/kg sodium selenite), and the curcumin group (pretreated with 75 mg/kg body weight curcumin 24 h prior to the administration of sodium selenite). The expression levels of heat shock protein 70 (HSP70), the activities of 8-hydroxy-2-deoxyguanosine (8-OHdG), catalase (CAT), malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) were assessed by using RT-PCR assay and ELISA. In addition, the cell viability, cell apoptosis, and cell cycle were assessed using a CCK-8 assay and flow cytometry in in vitro studies, followed by RT-PCR analysis to identify the mRNA expression levels of caspase 3, Bcl-2 associated X (Bax), B-cell lymphoma 2 (Bcl-2), cyclooxygenase (Cox-2), c-met, and Slug.

RESULTS

Cataract was successfully established in rats of the model group and the curcumin group through intraperitoneal injection of sodium selenite. The expression levels of HSP70 and the activities of 8-OHdG and MDA in the curcumin group were decreased compared with those in the model group, whereas the activities of CAT, SOD, and GSH-Px were significantly higher than those in the model group (P < 0.05). In the in vitro studies, the cell viability and cell apoptosis significantly increased and decreased, respectively, in the curcumin group compared with the model group. Correspondingly, the mRNA expression of caspase-3, Bax, and Cox-2 was lower in the curcumin group than in the model group (P < 0.05).

CONCLUSIONS

This study suggested that curcumin attenuated selenite-induced cataract through the reduction of the intracellular production of reactive oxygen species and the protection of cells from oxidative damage.

Clinical Complications of Combined Phacoemulsification and Vitrectomy for Eyes with Coexisting Cataract and Vitreoretinal Diseases

Purpose

To discuss the intraoperative and postoperative complications of combining phacoemulsification and foldable intraocular lens (IOL) implantation with pars plana vitrectomy in eyes with significant cataract and coexisting vitreoretinal diseases.

Methods

This retrospective study consisted of 186 eyes of 149 patients with various vitreoretinal abnormalities and visually significant cataracts. Vitreoretinal surgery was combined with clear corneal phacoemulsification and foldable IOL implantation. Main outcome measures were the intraoperative and postoperative complications at from 6 to 56 months.

Results

The most common intraoperative complication was iatrogenic retinal hole (5.3%), transient corneal edema (3.2%), and posterior capsule break (2.1%). The most common postoperative complication was posterior capsule opacification (21.5%) and elevated intraocular pressure (9.7%), macular edema (8.1%), fibrinous reaction (6.9%), vitreous hemorrhage (3.7%), posterior synechiae (3.7%), and recurrent retinal detachment (3.2%). Postoperatively, in 162 eyes (87.1%), visual acuity improved by 3 lines or more on the Snellen chart. In 14 eyes (7.5%), vision remained within 3 lines of preoperative levels and in 10 eyes (5.3%), vision had decreased at the last follow-up.

Conclusions

Postoperative complications did not increase significantly in the combined phacoemulsification and vitreoretinal surgery. Combined vitreoretinal surgery and phacoemulsification with foldable IOL implantation is safe and effective in treating vitreoretinal abnormalities coexisting with cataract. Based on extensive experience with the combined procedure, the authors suggest that combined surgery is recommended in select patients having simultaneous vitreoretinal pathologic changes and cataract.

Posterior Capsule Opacification 9 Years after Phacoemulsification with a Hydrophobic and a Hydrophilic Intraocular Lens

Purpose

To compare the development of posterior capsule opacification (PCO) and survival rate without capsulotomy after implantation of a hydrophobic or hydrophilic acrylic intraocular lens (IOL) at the 9-year postoperative follow-up.

Methods

One of 3 experienced cataract surgeons performed standard phacoemulsification in one eye of 120 patients with cataract. The patients were randomized to implantation of either a hydrophobic acrylic IOL or a hydrophilic acrylic IOL. Both IOLs had sharp posterior edges. Retroillumination images of PCO were obtained with a fundus camera 9 years postoperatively and analyzed semiobjectively using POCOman computer software.

Results

Seventy-eight of the 120 patients completed the 9-year follow-up examination. Patients implanted with the hydrophilic IOL had significantly (p<0.001) more and denser PCO. The survival rate without Nd:YAG capsulotomy was significantly higher (p<0.001) in eyes with the hydrophobic IOL.

Conclusions

After 9 years, more and denser PCO developed in eyes with the hydrophilic IOL than the hydrophobic IOL. The survival rate without the need for capsulotomy was higher in eyes with the hydrophobic IOL.

New device for creating a continuous curvilinear capsulorhexis

PURPOSE

To describe the evolution of a new device to facilitate continuous curvilinear capsulorhexis (CCC) creation.

SETTING

Department of Ophthalmology, University of Colorado School of Medicine, Aurora, Colorado, USA.

DESIGN

Experimental study.

METHODS

Bench-side ex vivo testing of unique prototypes for guidance and assistance of CCC in bovine and human eyes was performed. Five designs were sequentially tested as follows: a flexible circular blade of nickel-titanium alloy (nitinol), a flexible nitinol guide wire, a flexible elastomeric suction device, a combination approach of a nitinol guide wire and flexible silicone ring, and a freestanding micropatterned silicone ring.

RESULTS

The first 3 designs were not amenable to insertion through a sub-2.4 mm corneal incision and failed to maintain adequate downward force to cut the capsule and/or prevent radial tears. The fourth design was successfully inserted through a 2.4 mm incision and maintained adequate downward pressure and contact to guide a manual CCC without radial tears. The final design was insertable through a 2.4 mm incision and exhibited self-adhesive characteristics after placement on the anterior capsule of an ophthalmic viscosurgical device-filled anterior chamber.

CONCLUSIONS

Given the steep learning curve of manual capsulorhexis and the high cost of capsulotomy-assistive devices, such as the femtosecond laser, an alternative approach for creating a CCC is desirable. Performance of a highly precise manual CCC through a small incision using a medical-grade silicone device with an adhesive micropatterned design is a viable and cost-effective option for use in cataract surgery across a wide range of user experience.

FINANCIAL DISCLOSURE

All authors are named as the inventors in a patent filed by the University of Colorado covering the details in this report.

Prospective Randomized Intraindividual Comparison of Posterior Capsule Opacification After Implantation of an IOL With and Without Heparin Surface Modification

PURPOSE

To compare posterior capsule opacification (PCO) of a hydrophobic acrylic heparin surface modified intraocular lens (HSM-IOL) and an uncoated IOL (UC-IOL) 1 year after implantation.

METHODS

One hundred two eyes of 51 patients underwent routine phacoemulsification with randomized implantation of a HSM-IOL in one eye (the HSM-IOL group) and a UC-IOL in the fellow eye (the UC-IOL group). Morphologic PCO evaluation was performed comparing digital photographs in retroillumination using the Evaluation of Posterior Capsule Opacification (EPCO) system, grading the density of the opacification from 0 to 4 (0 = none, 1 = minimal, 2 = mild, 3 = moderate, and 4 = severe). Distance visual acuities, subjective manifest refraction, pupil size, straylight measurements, flare in the anterior chamber using a laser flare meter, and contrast sensitivity were also evaluated.

RESULTS

The mean total EPCO score was slightly higher in the HSM-IOL group (0.50 ± 0.45) compared to the UC-IOL group (0.45 ± 0.46), but did not reach statistical significance. No statistically significant differences were found in the other main outcome parameters (straylight measurement, distance visual acuities, flare in the anterior chamber, and mesopic and photopic contrast sensitivity) when comparing both IOLs.

CONCLUSION

Although the HSM-IOL showed decreased flare 1 day postoperatively, no statistically significant differences regarding PCO were found 1 year postoperatively.

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.

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.

Peeling and aspiration of elschnig pearls! An effective alternative to Nd:YAG laser capsulotomy!

To evaluate the efficacy of peeling and aspiration of Elschnig pearls. Retrospective study in a medical college hospital. Records of 217 eyes which underwent surgical peeling and aspiration for membranous PCO between 2006 and 2009, was reviewed. Peeling and aspiration was fashioned with a blunt tipped 20G cannula after stabilizing anterior chamber with anterior chamber maintainer. Post-operative vision and complications were analyzed. Mc Nemar and Chi square tests. The mean age was 56.84 years. 85.71% patients achieved best corrected visual acuity (BCVA) of 20/20 at 3 m. Recurrence of pearls, uveitis and cystoid macular edema were the most common causes of reduced vision. Peeling and aspiration of pearls seem to be a viable alternative to Neodymium yttrium garner aluminium (Nd: YAG) laser capsulotomy for membranous PCO.

Posterior capsule opacification following 20- and 23-gauge phacovitrectomy (posterior capsule opacification following phacovitrectomy)

PURPOSE

To compare the development of posterior capsule opacification (PCO) for idiopathic epi-retinal membrane cases between 20- and 23-gauge phacovitrectomy.

METHODS

Cataract surgery of phacoemulsification with the SA60AT implantation and 20- or 23-gauge vitrectomy was performed for 20 patients in both groups. Cataract surgery alone was performed for 50 patients as the control. The PCO density values were measured using Scheimpflug video photography at 1 week, 1, 3, 6, 12, 18, and 24 months after surgery. The number of eyes that required Nd:YAG laser capsulotomy was also examined.

RESULTS

The mean PCO value in the 20-gauge phacovitrectomy group increased significantly with time (P<0.001), whereas those in the 23-gauge phacovitrectomy group and the cataract surgery group did not show any significant change. Furthermore, the PCO value in the 20-gauge phacovitrectomy group was significantly greater than that in the 23-gauge phacovitrectomy group at 6, 12, 18 (P<0.05), and 24 months (P<0.01) after surgery. The PCO value in the 23-gauge phacovitrectomy group was significantly greater than that in the cataract surgery group 24 months after surgery (P<0.05). The rate of capsulotomy in the 20-gauge phacovitrectomy group was significantly higher than that in the cataract surgery group (P=0.007), whereas there was no significant difference between the 23-gauge phacovitrectomy group and the cataract surgery group.

CONCLUSION

PCO rate in eyes with the 23-gauge phacovitrectomy was lower than in those with the 20-gauge phacovitrectomy, and PCO rate even in the 23-gauge phacovitrectomy was higher than in those with cataract surgery.

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.

Evaluation of Posterior Capsular Opacification following Phacoemulsification, Extracapsular and Small Incision Cataract Surgery

BACKGROUND

Posterior capsular opacification is the most common complication of modern cataract surgery.

METHODS

A prospective study was conducted on 150 patients (150 eyes) out of which 50 eyes each underwent cataract surgery by extracapsular cataract extraction, small incision cataract surgery and phacoemulsification technique. On postoperative follow up posterior capsular opacification and Neodymium: Yttrium Aluminium Garnet laser capsulotomy rate was evaluated.

RESULT

Posterior capsular opacification rate was significantly less (p=0.03) in eyes which had undergone phacoemulsification as compared to extracapsular cataract extraction. However capsulotomy rate was not statistically significant after comparison of the three surgical techniques of cataract surgery.

CONCLUSION

Posterior capsular opacification following cataract surgery can be minimized by the use of small incision cataract surgery and phacoemulsification.

Macular thickness changes after phacoemulsification combined with primary posterior curvilinear capsulorhexis

PURPOSE

To evaluate the changes in central macular thickness measured with optical coherence tomography (OCT) after cataract surgery combined with primary posterior continuous curvilinear capsulorhexis (PCCC).

METHODS

Forty-six eyes of 40 consecutive patients who had uneventful phacoemulsification and in-the-bag intraocular lens implantation surgery with primary PCCC, taking place between August 2005 and January 2006 in Beyoglu Eye Training and Research Hospital, were enrolled. Patients with a history of previous ocular surgery, eye trauma, uveitis, or glaucoma, or any systemic disease such as diabetes mellitus, were excluded from the study. None of the cases had macular pathology before surgery. OCT was performed in all patients preoperatively and postoperatively on the first day, first week, and first, third, and sixth months.

RESULTS

Significant quantitative changes from the preoperative examination were observed in the postoperative first week, first month, and third month (p<0.05). The difference between the mean preoperative and postoperative sixth month central macular thickness was not statistically significant (p=0.20). The greatest change in mean macular thickness was noted in the first month visit. No patient developed cystoid macular edema.

CONCLUSIONS

Because primary PCCC does not have an adverse effect on macular integrity, this procedure may be preferred especially in patients with a high risk of posterior capsular opacification.

Ten-year longitudinal visual function and Nd: YAG laser capsulotomy rates in patients less than 65 years at cataract surgery

PURPOSE

To investigate the longitudinal subjective and objective visual functional results in adult cataract patients younger than 65 years at surgery. To evaluate the 10-year cumulative incidence of neodymium-yttrium-aluminum-garnet (Nd:YAG) laser treatment.

DESIGN

A prospective, longitudinal, population-based cohort study.

METHODS

The study comprised 116 patients younger than 65 years who had cataract surgery during 1 year at Norrlands University Hospital, Umeå, Sweden. Most patients (94%) had received implantation with a hydrophobic acrylic intraocular lens. Evaluated were visual acuity (VA) and visual function questionnaire (VF-14) results before and after surgery. A comparison with patients 65 years or older at surgery was made. Ten years later, 102 survivors were offered eye examinations and again asked to fill out the questionnaire. Past Nd:YAG laser treatment, as well as high- and low-contrast VA results, were analyzed.

RESULTS

Ten years postoperatively, 37% of the patients under 65 at surgery had been treated with Nd:YAG in comparison to 20% of the older patients. The cumulative incidence for not having Nd:YAG over 10 years was 72% for those under 65 and 85% for the patients 65 years or more at surgery. Eighteen percent of the younger patients had lost more than 0.1 logarithm of the minimal angle of resolution (logMAR) units of the operated eye, compared with 37% of the older (P = .00003). A reduction in VF-14 score of 10 points or more was found in 9% of the younger and 28% of the older cataract surgery patients (P = .00004).

CONCLUSION

Ten years after surgery, subjective and objective visual function remained stable in most patients younger than 65 years at surgery. More than one-third had received a posterior capsulotomy. Only a few patients with posterior capsular opacification requiring Nd:YAG were untreated at the 10-year follow-up.

Anterior segment complications after phacoemu-lsification combined vitrectomy and foldable intraocular lens implantation

AIM

To evaluate the anterior segment complications of phacovitrectomy and foldable intraocular lens (IOL) implantation in eyes with significant cataract and co-existing vitreoretinal diseases.

METHODS

This retrospective study was consisted of 285 eyes of 238 patients with various vitreoretinal abnormalities and visually significant cataracts. Vitreoretinal surgery was combined with phacoemulsification and foldable IOL implantation. Main outcome measures were visual acuity, the preoperative data, and the anterior segment complications at postoperative 6 to 72 months.

RESULTS

The most common indications for surgery were non-diabetic vitreous hemorrhage, proliferative diabetic retinopathy. Preoperative vision ranged from 20/30 to light perception and postoperative vision ranged from 20/20 to no light perception. Postoperatively, in 245 eyes (85.9%), visual acuity improved by 3 lines or more on the Snellen chart. In 24 eyes (8.4%), vision remained within 3 lines of preoperative levels and in 16 eyes (5.6%), vision had decreased at the last follow-up. The most common anterior segment pathological change was PCO in 50 eyes (17.5%), the second was corneal edema in 32 eyes (11.2%) and the third was elevated IOP in 31 eyes (10.8%).

CONCLUSION

The combined vitreoretinal surgery and phacoemulsification with foldable IOL implantation is safe and effective.

Longterm results after phacovitrectomy and foldable intraocular lens implantation

PURPOSE

This study aimed to evaluate the longterm results of phacovitrectomy and foldable intraocular lens (IOL) implantation in eyes with significant cataract and co-existing vitreoretinal diseases.

METHODS

We carried out a retrospective study of 186 eyes of 149 patients with various vitreoretinal abnormalities and visually significant cataracts. Vitreoretinal surgery was combined with phacoemulsification and foldable IOL implantation. Main outcome measures were visual acuity (VA), preoperative data, and intraoperative and postoperative complications.

RESULTS

The most common indications for surgery were non-diabetic vitreous haemorrhage and proliferative diabetic retinopathy. Preoperative vision ranged from 0.6 to light perception; postoperative vision ranged from 1.2 to no light perception. Postoperatively, in 162 eyes (87.1%) VA improved by >or= 3 lines on the decimal chart. In 14 eyes (7.5%), vision remained within 3 lines of preoperative levels and in 10 eyes (5.3%), vision had decreased by the last follow-up. Postoperative complications included elevated intraocular pressure and posterior capsule opacification, corneal edema, macular edema, fibrinous reaction, vitreous hemorrhage, corneal epithelial defects, anterior chamber hyphema, choroidal detachment, persistent macular hole, posterior synechiae, recurrent retinal detachment, rubeosis iridis, neovascular glaucoma.

CONCLUSIONS

Combined vitreoretinal surgery and phacoemulsification with foldable IOL implantation is safe and effective in treating vitreoretinal abnormalities co-existing with cataract. Based on extensive experience with the combined procedure, we suggest that combined surgery is recommended in selected patients with simultaneous vitreoretinal pathological changes and cataract.

The Cataract National Dataset electronic multicentre audit of 55,567 operations: when should IOLMaster biometric measurements be rechecked?

PURPOSE

Calculation of intraocular lens (IOL) power for implantation during cataract surgery depends on ocular biometric measurements. The aim of this study was to characterise the normal range of intra- and interindividual variation in axial length (AL) and corneal power (K) when IOLMaster measurements were possible and to derive recommendations as to which outlying measurements merit verification before acceptance.

METHODS

The Medisoft electronic patient database contains prospectively collected data conforming to the United Kingdom (UK) Cataract National Dataset on 55,567 cataract operations. From this AL and K information on the 32,556 eyes (14,016 paired) of patients older than 25 years, without corneal pathology, history of intraocular surgery and who had all biometric measurements taken with the Zeiss IOLMaster (Carl Zeiss Meditec) were extracted. R 2.8.1 (R Foundation for Statistical Computing) was used for statistical analysis.

RESULTS

Mean age was 76.4 years and 62.0% were female. Mean (95% confidence interval) values for AL, mean K and corneal astigmatism were 23.40 (21.27-26.59) mm, 43.90 (40.94-47.01) D and 1.04 (<2.50) D. Nearly all astigmatism was either with or against the rule. Differences between paired eyes were not statistically significant. 95% individuals had asymmetry of AL and mean K<0.70 mm and 0.92 D, respectively.

CONCLUSIONS

On the basis of approximation of the 95% CI above, it is suggested that AL, mean K and keratometric astigmatism measurements outside the ranges 21.30-26.60 mm, 41.00-47.00 D and >2.50 D, respectively, and intraindividual asymmetry of AL >0.70 mm or mean K>0.90 D should be verified before acceptance.

Edge profile of commercially available square-edged intraocular lenses

PURPOSE

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

SETTING

Department of Ophthalmology, St. Thomas' Hospital, London, United Kingdom.

METHODS

Seventeen square-edged 20.0 diopter IOLs of different manufacture, design, and material were selected. After the environmental scanning electron microscopy technique was standardized, repeatability of the technique was tested. Posterior optic edges of all IOLs were scanned at a magnification of x 500. Local radii of curvature of the posterior optic edges were measured by purpose-designed software. Optic edge thickness was also measured from the electron micrographs.

RESULTS

The repeatability of the scanning technique was excellent (+/-0.10 microm). The radius of curvature of posterior optic edges ranged from 7.6 to 23.1 microm. Hydrophilic acrylic IOLs (except the HumanOptics MC Microlens 611 MI-B and 1CU) had radii of curvatures more than 10.0 microm of the posterior optic edge compared with hydrophobic acrylic and silicone IOLs (<10.0 microm) except the Hoya AF-1 (19.9 microm). Alcon AcrySof single-piece (SN60WF), HumanOptics 1CU, and AMO Clariflex CLRFLXC IOLs had the thinnest optic edges in the hydrophobic, hydrophilic, and silicone groups, respectively.

CONCLUSIONS

Commercially marketed square-edged IOLs differed in the sharpness of the posterior optic edge. Hydrophobic acrylic and silicone IOLs have sharper posterior optic square edge than most hydrophilic acrylic IOLs. This probably reflects difference in manufacturing techniques. Differences in posterior optic edge profile may explain variation in posterior capsule opacification performance with different IOLs and materials.

Lithium stabilizes the polarized lens epithelial phenotype and inhibits proliferation, migration, and epithelial mesenchymal transition

Posterior capsule opacification (PCO) is a common complication of cataract surgery caused by epithelial mesenchymal transition (EMT) and aberrant lens cell growth. One path to prevention depends on maintaining the quiescent lens epithelial phenotype. Here we report that lithium chloride (LiCl) is a potent stabilizer of the lens epithelial phenotype. In lens epithelial explants (controls), at low cell density, cells readily depolarized, spread out, and proliferated. By contrast, in the presence of LiCl, cells did not spread out or exhibit migratory behaviour. Using concentrations of 1-30 mM LiCl we also showed that cell proliferation is inhibited in a dose-dependent manner. Confocal microscopy and immunohistochemistry for ZO-1 and E-cadherin showed that LiCl treatment maintained tight junctions at the apical margins of cells. Taken together with measurements of cell heights, this showed that the cells in LiCl-treated explants maintained the apical baso-lateral polarity and cobblestone-like packing that is characteristic of lens epithelial cells in vivo. Significantly, the effects of LiCl also extended to blocking the potent EMT/cataract-promoting effects of transforming growth factor beta (TGFbeta) on lens epithelial cells. In TGFbeta-treated explants, cells progressively dissociated from one another, taking on various elongated spindle shapes and strongly expressing alpha-smooth muscle actin (alpha-SMA). These features are characteristic of PCO. In both rat and human capsulorhexis explants, LiCl treatment effectively blocked the accumulation of alpha-SMA and maintained the cells in a polarized, adherent, cobblestone-packed monolayer. These findings highlight the feasibility of applying molecular strategies to stabilize lens epithelial cells and prevent aberrant differentiation and growth that leads to cataract.

Influence of 360-degree enhanced optic edge design of a hydrophilic acrylic intraocular lens on posterior capsule opacification

PURPOSE

To compare the rate of posterior capsule opacification (PCO) with the single-piece hydrophilic acrylic foldable Rayner Centerflex 570H intraocular lens (IOL), which has a sharp optic edge design excluding the optic-haptic junction, and the Rayner C-flex 570C IOL, which has an improved 360-degree sharp edge.

SETTING

Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany.

METHODS

As part of a multicenter U.S. Food and Drug Administration (FDA) study, 42 patients who had implantation of a C-flex IOL in 1 eye after uneventful phacoemulsification were enrolled. Six and 12 months postoperatively, PCO was evaluated by retroillumination photographs using Evaluation of Posterior Capsule Opacification (EPCO) 2000 image-analysis software. The data were then compared with those in a matched group of patients with a Centerflex IOL who participated in a previous FDA study.

RESULTS

The mean age of the patients with the C-flex IOL was 71.5 years +/- 8.2 (SD) There was a statistically significant difference in EPCO scores between the C-flex group and Centerflex group. Six months after surgery, the mean EPCO value (total IOL optic) was 0.07 +/- 0.17 in the C-flex group (n = 37) and 0.20 +/- 0.20 in the Centerflex group (n = 36) (P<.01, Wilcoxon test). By 12 months, the mean had increased to 0.16 +/- 0.20 in the C-flex group (n = 37) and 0.35 +/- 0.22 in the Centerflex group (n = 31) (P<.01, Wilcoxon test).

CONCLUSIONS

The C-flex IOLs showed good functional results and significantly lower PCO formation than the earlier model Centerflex IOL. The enhanced edge of the C-flex IOL seemed to improve PCO prevention clinically.

Influence of three-piece and single-piece designs of two sharp-edge optic hydrophobic acrylic intraocular lenses on the prevention of posterior capsule opacification: a prospective, randomised, long-term clinical trial

BACKGROUND

Posterior capsule opacification (PCO) is still a major long-term complication of modern cataract surgery. We evaluated the impact of sharp-edged intraocular lenses (IOLs) with different haptic designs made from the same hydrophobic acrylic material on posterior and anterior lens capsule opacification.

SETTING

Eye clinic of Kaunas University of Medicine, Lithuania. Prospective randomised clinical study.

METHODS

Seventy-four eyes of 74 patients scheduled for cataract surgery were included in a prospective randomised clinical study. Thirty-seven eyes of 37 patients received a three-piece acrylic hydrophobic (AcrySof, MA3OBA, Alcon) IOL; and thirty-seven eyes of 37 patients received a one-piece acrylic hydrophobic (AcrySof, SA3OAL, Alcon) IOL. Visual acuity, anterior capsule opacification (ACO), capsular folds, capsulorrhexis/optic overlapping and posterior capsule opacification (PCO) were evaluated. ACO was assessed subjectively. PCO values in the entire IOL optic area and in the central 3 mm optic zone were assessed using a photographic image-analysis system (EPCO2000). Follow-ups were performed postoperatively at 1 day, 6 months, 1 year and 2 years.

RESULTS

There were no significant differences in best corrected visual acuity, grade of ACO and capsulorrhexis/optic overlapping between IOL types during the follow-up period. Patients in the one-piece acrylic hydrophobic IOL group more frequently presented with capsular folds behind the IOL optic area than those in the three-piece IOL group. In the three-piece acrylic hydrophobic IOL group, PCO values (mean (SD)) of the entire IOL optic area were significantly lower six months postoperative (three-piece: 0.002 (0.009); one-piece: 0.007 (0.017); p=0.04), one year postoperative (three-piece: 0.004 (0.016); one-piece: 0.026 (0.041); p=0.001) as well as one year postoperative in the central 3 mm optic zone (three-piece: 0.000 (0.0002); one-piece: 0.019 (0.049); p=0.001). However, two years postoperative, the PCO values of the groups did not show significant differences (entire IOL optic area: three-piece, 0.136 (0.223); one-piece, 0.154 (0.190); p=0.18; central zone: three-piece, 0.023 (0.065); one-piece: 0.020 (0.039); p=0.44).

CONCLUSION

The 2 year follow-up after cataract surgery showed no significant difference in ACO and PCO development between three-piece and one-piece acrylic hydrophobic intraocular lenses.