Association between intensity of posterior capsule opacification and contrast sensitivity

Image Contrast and Spectral Transmission in Intraocular Lenses with Nd:YAG Pits

PURPOSE

Neodymium yttrium aluminum garnet (Nd:YAG) laser capsulotomy is considered as safe and effective method in the treatment of posterior capsule opacification. Nevertheless, side effects are described. The incorrectly adjusted focus of the laser beam during the procedure can lead to so-called YAG-pits or YAG-shots. In this experimental study, we measured spectral transmission to evaluate the image contrast and analyze the impact of YAG-pits in intraocular lenses (IOL).

METHODS

Acrylic, foldable, one-piece IOLs with 6.0 mm optic and different material properties were studied. These included: monofocal IOLs and enhanced monofocal IOLs with water content of 0.3%, 26.0%, and 4.0% and a refractive index of 1.49, 1.46, and 1.54, respectively. All measurements were done with new, unaltered IOLs and IOLs with YAG-pits. Damage was intentionally created, performing YAG-pits (n = 7) in the central zone (3.5 mm) using a photodisruption laser (2.0mJ). All laboratory measurements were repeated: These included surface topography characterization, United States Air Force (USAF) resolution test chart analysis, spectral transmittance measurements and through focus contrast measurement.

RESULTS

Significant differences were found between the unaltered lenses and lenses with defects. The YAG-pits within the optic of the IOLs decreased the image contrast and spectral transmission and changed results of USAF test images at the focal position by 62%, 57% and 54%, respectively. In all IOLs a reduction of the relative intensity of total transmitted light was observed between 450 and 700 nm wavelength.

CONCLUSION

This experimental study confirmed that the IOL image performance deteriorates with YAG-pits. The total intensity of transmitted light or transmittance (without scattering) was reduced in the wavelength between 450 and 700 nm. The contrast was significantly reduced and USAF test targets showed much worse results compared to unmodified counterparts. There was no systematic difference between monofocal and enhanced monofocal lenses. Further experiments should investigate the effect of YAG-pits on diffractive IOLs.

Utility of the optical quality analysis system for decision-making in Nd: YAG laser posterior capsulotomy in patients with light posterior capsule opacity

Background

A prospective cohort study was performed to evaluate whether the Optical Quality Analysis System (OQAS) can serve as a valuable additional indicator for appropriate posterior capsulotomy referral.

Methods

One hundred and five eyes from 96 patients undergoing capsulotomy were divided into precapsulotomy logMAR CDVA ≤0.1 group and logMAR CDVA > 0.1 group. CDVA, and the Visual Function 14 index (VF-14) score were estimated before and 1 month after capsulotomy. The objective scattering index (OSI) value was measured by using the OQAS. Posterior capsule opacification (PCO) severity was assessed with Evaluation of PCO 2000 (EPCO 2000) software.

Results

In logMAR CDVA > 0.1 group, the correlations of OSI, logMAR CDVA, EPCO score and VF-14 score were very strong preoperatively. In logMAR CDVA ≤0.1 group, preoperatively, OSI was correlated with logMAR CDVA (r = 0.451), EPCO score (r = 0.789), and VF-14 score (r = 0.852). LogMAR CDVA has weak correlation with VF-14 score (r = − 0.384) and EPCO score (r = 0.566). VF-14 score was correlated with EPCO score (r = − 0.669). In the logMAR CDVA ≤0.1 group, there was no significant difference in logMAR CDVA between precapsulotomy and postcapsulotomy (P > 0.05). In the two groups, all the other optical quality parameters were significantly improved after capsulotomy (P < 0.05). In logMAR CDVA > 0.1 group, the area under the curve of the ROC of the OSI was 0.996 (P = 0.000). In logMAR CDVA ≤0.1 group, the area under the curve of the ROC of the OSI was 0.943 (P = 0.000).

Conclusions

The OSI was useful for evaluating of PCO and prediction of beneficial capsulotomy. Especially for patients with slight PCO and better visual acuity, OSI is more valuable than CDVA and completely objective examination.

Trial registration

The study protocol was registered at the Chinese Clinical Trial Registry. Register: ChiCTR1800018842 (Registered Date: October 13th, 2018).

Impact of posterior vitreous detachment on contrast sensitivity in patients with multifocal intraocular lens

PURPOSE

To investigate posterior vitreous detachment (PVD) and pars plana vitrectomy (PPV) effects on contrast sensitivity function (CSF) in patients with a multifocal intraocular lens (MfIOL).

METHODS

This single-center prospective case-control study analyzed 27 patients with 43 consecutive eyes. Twenty patients with 36 consecutive eyes received MfIOL implantation with either ZLB00 or ZMB00. CSF was measured as the area under the log contrast sensitivity function (AULCSF) in the presence and absence of PVD (PVD+ group and PVD- group, respectively). Seven eyes associated with a symptomatic PVD and severe visual dissatisfaction after MfIOL implantation underwent PPV (symptomatic PVD+ group). CSF was measured prior to and after PPV.

RESULTS

The mean AULCSF was significantly lower in the PVD+ group (1.5 ± 0.1) versus the PVD- group (1.7 ± 0.1, p < 0.0001). Major complaints in the symptomatic PVD+ group included floaters (n = 2) and blurry vision (n = 5). The preoperative AULCSF (1.4 ± 0.1) was significantly lower in the symptomatic PVD+ group versus the PVD- group (p < 0.0001) and PVD+ group (p = 0.02). The preoperative AULCSF in the symptomatic PVD+ group was significantly improved after PPV (1.4 vs. 1.7, respectively, p = 0.002).

CONCLUSIONS

PVD significantly decreased CSF in patients with MfIOL. Patients with symptomatic PVD exhibited the greatest decrease in CSF, which was significantly improved after PPV. Measurement of CSF and careful assessment of PVD may be useful in determining the appropriateness of surgical intervention for improving visual performance and satisfaction in MfIOL patients with symptomatic PVD.

Comparison of the Neodymium-doped Yttrium Aluminum Garnet Capsulotomy Rate with Viscoimplantation and the Hydroimplantation Intraocular Lens Technique

PURPOSE

To investigate the rate of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy in the hydroimplantation intraocular lens (IOL) technique.

METHODS

This retrospective study was comprised of 6,192 eyes in 3,790 patients who underwent surgery from January 2013 to September 2017 and then were followed up for at least 1 year. The eyes of these patients were divided into two groups: either viscoimplantation or hydroimplantation. The follow-up examinations were carried out on the 1st day, 4th day, 1st month, and 3 months to 1 year postoperatively. The Nd:YAG capsulotomy rates were evaluated by the different IOL implantation techniques and IOL materials.

RESULTS

The mean follow-up duration of the patients was in the viscoimplantation group 14.85 ± 2.43 and 15.05 ± 1.93 months in the hydroimplantation group. The Nd:YAG capsulotomy rate was significantly lower in the hydroimplantation group compared with the viscoimplantation group for the entire hydrophilic IOL model (p < 0.001). In addition, the Nd:YAG rate was lower in the hydroimplantation group that used a hydrophilic IOL than it was in the viscoimplantation group, which used a hydrophobic IOL.

CONCLUSIONS

The hydroimplantation technique reduced the Nd:YAG capsulotomy rate.

Comparison of pseudophakic retinal straylight in spherical/aspherical and hydrophobic/hydrophilic intraocular lens

AIM

To study the potential reasons of increased straylight in pseudophakic eyes.

METHODS

Cross-sectional study. Seventy patients diagnosed as bilateral age-related cataract and implanted with Tecnis ZA9003, Sensar AR40e, SA60AT, XLSTABI ZO or Akeros AO intraocular lens (IOL) were enrolled in this research. Straylight was measured by a C-Quant straylight meter three to four weeks postoperatively. Five different modalities of IOL, including spherical/aspherical optics and hydrophobic/hydrophilic material were tested in this study. Normal as well as dilated pupils were used. The main outcome variable for straylight measurement was the logarithmic straylight parameter, log(s).

RESULTS

The straylight parameter increased significantly after pupil dilation (P<0.05). Straylight of aspherical IOL was significantly higher after pupil dilation (P<0.05) compared to spherical IOL. In normal pupil, straylight of hydrophobic IOL was significant higher when compared with hydrophilic IOL (P<0.05).

CONCLUSION

Straylight and visual acuity stand for the different aspects of visual function. Several factors including pupil diameter, optic material, aspherical design of IOL influence intraocular light scattering in pseudophakic eyes. Further investigation was needed to study the impact of optic material and optic surface design on pseudophakic straylight.

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.

The assessment of changes in macular thickness in diabetic and non-diabetic patients: the effect of topical ketorolac on macular thickness change after ND:YAG laser capsulotomy

PURPOSE

The purpose of our study is to assess the changes in macular thickness (MT) in diabetic and non-diabetic patients and to research effects of topical ketorolac (Acular®, Allergan, Irvine, CA) on MT change after neodymium:yttrium aluminum garnet (Nd:YAG) laser capsulotomy.

MATERIAL AND METHODS

This study involved 88 eyes of 88 patients diagnosed as posterior capsule opacification (PCO). Patients were divided into four groups according to presence of diabetes mellitus (DM) and drugs used after capsulotomy. Group 1: Patients with DM using only 0.1% Fluorometholon (FML®, Allergan, Irvine, CA) after capsulotomy (22 patients). Group 2: Patients with DM using 0.5% ketorolac (Acular®) and 0.1 Fluorometholon (FML®, Allergan, Irvine, CA) after capsulotomy (20 patients). Group 3: Patients without DM using only 0.1% Fluorometholon (FML®, Allergan, Irvine, CA) (22 patients). Group 4: Patients without DM using 0.5% ketorolac (Acular®) and 0.1% Fluorometholon (FML®, Allergan, Irvine, CA) (24 patients). A plus-shaped capsulotomy was performed using VISULAS® YAGIII (Carl Zeiss) laser microscope. MT measurement with Cirrus SD-OCT (Carl Zeiss Opthalmic System Inc., Model 400, Dublin, CA, Software 5) were done. Measurements were done before laser, and on the first day, first week, first month, third month and sixth month after laser capsulotomy. We compared the four groups for MT change during 6 months.

RESULTS

Group 1 involving patients with DM using only 0.1% Fluorometholon (FML®, Allergan, Irvine, CA) after capsulotomy had increased MT at the first week, and the first, third, and sixth month after laser (p < 0.001). Group 3 involving patients without DM using only 0.1% Fluorometholon (FML®, Allergan, Irvine, CA) had increased MT at the first week, and at the first and third month, there was no statistically significant difference at the sixth month (p > 0.05). There was no statistically significant increase in MT during the follow-up period in group 2 involving patients with DM using 0.5% ketorolac (Acular®) and 0.1 Fluorometholon (FML®, Allergan, Irvine, CA) after capsulotomy and group 4 involving patients without DM using 0.5% ketorolac (Acular®) and 0.1% Fluorometholon (FML®, Allergan, Irvine, CA) (p > 0.05).

CONCLUSION

An increase in MT can be observed after Nd:YAG laser capsulotomy, especially in diabetic patients. Adding topical ketorolac (Acular®, Allergan, Irvine, CA) to topical Fluorometholon (FML®, Allergan, Irvine, CA) therapy after YAG laser capsulotomy can prevent this increase.

Posterior capsule opacification with 3 intraocular lenses: 12-year prospective study

PURPOSE

To compare posterior capsule opacification (PCO) with 3 intraocular lenses (IOLs) 12 years postoperatively.

SETTING

St. Erik Eye Hospital, Stockholm, Sweden.

DESIGN

Randomized clinical trial.

METHODS

Patients having unilateral standard phacoemulsification were randomized to implantation of a round-edged heparin-surface-modified (HSM) poly(methyl methacrylate) (PMMA) IOL, a round-edged silicone IOL, or a sharp-edged hydrophobic acrylic IOL. The neodymium:YAG (Nd:YAG) capsulotomy rates and timing from surgery were recorded. Survival analysis was used to compare Nd:YAG rates. Retroillumination images were taken to evaluate PCO.

RESULTS

After 12 years, there was no significant difference in the fraction or severity of PCO between the silicone IOL and acrylic IOL. The HSM PMMA IOL had a significantly higher PCO fraction than the silicone IOL (P<.05), but not more than the acrylic IOL. There was no difference in PCO severity between the HSM PMMA IOL and the other 2 IOLs. The silicone IOL had higher median capsulotomy-free survival (>150 months) than the acrylic IOL (108 months) and the HSM PMMA IOL (53 months). Overall survival without Nd:YAG capsulotomy did not differ between the acrylic and silicone IOLs or between the silicone and HSM PMMA IOLs; however, overall survival was significantly better with the acrylic IOL than with the HSM PMMA IOL (P<.001).

CONCLUSIONS

After 12 years, there was no difference in PCO or overall survival without capsulotomy between the acrylic IOL and the silicone IOL. The HSM PMMA IOL had a significantly higher PCO fraction than the silicone IOL and lower overall survival than the acrylic IOL.

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.

Outcome of capsulotomy in patients with low vision and posterior capsule opacification

PURPOSE

To investigate the functional outcome, as defined using the Catquest questionnaire, for patients with posterior capsule opacification (PCO) and low corrected distance visual acuity (CDVA), after capsulotomy.

METHODS

Thirty-one patients with PCO and visual acuity ≥ 0.6 (log MAR, ≤ 0.25 decimal notation) in the PCO eye were examined before and 1 month after capsulotomy. An ophthalmic examination, procuring of a digital image of the posterior lens capsule and completion of Catquest were carried out.

RESULTS

Mean CDVA (p < 0.001), disabilities in daily life (p = 0.004), activity (p = 0.012), symptoms of glare (p = 0.003) and satisfaction with vision (p < 0.001) all improved after capsulotomy. Sixty-five per cent of patients had good or very good benefit and 23% questionable or no benefit. The group with moderate benefit was only 6%. Compared with patients with PCO and better visual acuity, the number of patients with good benefit was greater than the number with moderate benefit.

CONCLUSIONS

Most patients with PCO and low CDVA reported improved visual function in daily life as defined using Catquest, after capsulotomy. The group with moderate benefit was small, indicating that the improvement was either substantial or negligible.

Visual function and quality of life in pseudophakic patients before and after capsulotomy

PURPOSE

To assess the correlation between visual acuity, visual function, and health-related quality of life before and after neodymium:YAG laser posterior capsulotomy.

METHODS

A total of 150 patients with posterior capsule opacification (PCO) were examined before and after capsulotomy. Ocular examination, visual acuity, patient reports of satisfaction with vision, and disease-specific (VF-14 Index of Visual Functions) and generic (EuroQol: EQ-5D) outcomes were measured at baseline and 3 weeks after treatment.

RESULTS

After capsulotomy, patients showed significant improvements in binocular visual acuity, VF-14 index, satisfaction with vision, and EQ-5D measures. The average gains in visual function and quality of life were apparent in groups with good visual outcome and poor visual outcome. The VF-14 score improvement was moderately correlated with the EuroQol Visual Analogue Scale score improvement, showing stronger correlations with changes in self-reported satisfaction with vision than did gains in binocular visual acuity.

CONCLUSIONS

Measuring of the outcomes of capsulotomy by clinical indicators alone may underestimate the overall benefits of treatment. Visual acuity in conjunction with visual function and health-related quality of life questionnaires will likely prove to be better indicators of the need for and outcome of capsulotomy.

Interventions for preventing posterior capsule opacification

BACKGROUND

Posterior capsule opacification (PCO) remains the most common long-term complication after cataract surgery. It can be treated by Nd:YAG laser capsulotomy, however this may lead to other complications and laser treatment is not available in large parts of the developing world. Therefore, many studies try to find factors influencing the development of PCO.

OBJECTIVES

To summarise the effects of different interventions to inhibit PCO. These include modifications of surgical technique and intraocular lens (IOL) design, implantation of additional devices and pharmacological interventions.

SEARCH STRATEGY

We searched CENTRAL, MEDLINE, EMBASE, LILACS in March 2009 and reference lists of identified trial reports.

SELECTION CRITERIA

We included only prospective, randomised and controlled trials with a follow-up time of at least 12 months. Interventions included modifications in surgical technique explicitly to inhibit PCO, modifications in IOL design (material and geometry), implantation of additional devices and pharmacological therapy compared to each other, placebo or standard treatment.

DATA COLLECTION AND ANALYSIS

We extracted data and entered it into RevMan. We compared visual acuity data, PCO scores and YAG capsulotomy rates and performed a meta-analysis when possible.

MAIN RESULTS

Sixty six studies were included in the review. The review was divided into three parts. 1. Influence of IOL optic material on the development of PCO. There was no significant difference in PCO development between the different IOL materials (PMMA, hydrogel, hydrophobic acrylic, silicone) although hydrogel IOLs tend to have higher PCO scores and silicone IOLs lower PCO scores than the other materials. 2. Influence of IOL optic design on the development of PCO. There was a significantly lower PCO score (-8.65 (-10.72 to -6.59), scale 0 to 100) and YAG rate (0.19 (0.11 to 0.35)) in sharp edged than in round edged IOLs, however not between 1-piece and 3-piece IOLs. 3. Influence of surgical technique and drugs on the development of PCO. There was no significant difference between different types of intraoperative/postoperative anti-inflammatory treatment except for treatment with an immunotoxin (MDX-A) which led to a significantly lower PCO rate.

AUTHORS' CONCLUSIONS

Due to the highly significant difference between round and sharp edged IOL optics, IOLs with sharp (posterior) optic edges should be preferred. There is no clear difference between optic materials. The choice of postoperative anti-inflammatory treatment does not seem to influence PCO development.

Comparison of posterior capsule opacification development with 3 intraocular lens types: five-year prospective study

PURPOSE

To compare the effects of hydrophobic acrylic, silicone, and heparin-surface-modified poly(methyl methacrylate) (HSM PMMA) intraocular lenses (IOLs) on posterior capsule opacification (PCO).

METHODS

In this 5-year prospective study, the same surgeon performed standard phacoemulsification in patients who were randomized to implantation of a round-edged HSM PMMA IOL (809C), a round-edged silicone IOL (SI-40NB), or a sharp-edged hydrophobic acrylic IOL (AcrySof MA60BM). The neodymium:YAG capsulotomy rate was recorded. To evaluate PCO and the position of the anterior capsulorhexis, retroillumination digital photographs were taken 5 years postoperatively and analyzed using the POCOman computer-analysis system.

RESULTS

After 5 years, there was no significant difference in the fraction or severity of PCO between the silicone IOLs and acrylic IOLs (both P =1.0). The silicone IOL group had a significantly higher capsulotomy rate (29%) than the acrylic IOL group (8%) (P=.0068). The HSM PMMA IOL group had a significantly higher PCO fraction, severity, and capsulotomy rate (54%) than the silicone and acrylic groups. In all eyes, the fraction (P=.0076) and severity (P=.0081) of PCO were statistically significantly higher when the anterior capsulorhexis was partly decentered than when it was completely on the optic; within each IOL group, there was no significant difference.

CONCLUSION

After 5 years, there was no significant difference in the semiquantitative evaluation of PCO between the sharp-edged acrylic IOL and round-edged silicone IOL. Eyes with the HSM PMMA IOL had more PCO than eyes with the other IOLs.

The effects of posterior continuous curvilinear capsulorhexis on contrast sensitivity

PURPOSE

We aimed at evaluating the effects of posterior continuous curvilinear capsulorhexis (PCCC) on contrast sensitivity.

MATERIALS AND METHODS

In this prospective, randomized, bilateral clinical study, 40 eyes of 20 patients who underwent bilateral cataract surgery were included. The phacoemulsification machine, viscoelastic substances, surgical tools, and intraocular lenses (IOLs) were the same for both eyes. The only difference was that we conducted the PCCC procedure before IOL implantation to one of the eyes of the patients. The selection of the eye that underwent the PCCC procedure was decided randomly.

RESULTS

The mean photopic contrast sensitivity values at spatial frequencies of 1.5, 3, 6, 12, and 18 cpd (cycles per degree) were 41.55, 59.90, 61.25, 32.35, and 9.75, respectively, and for the control group these values were 39.05, 56.60, 57.95, 29.80, and 8.75, respectively. The mean mesopic contrast sensitivity values at special frequencies of 1.5, 3, 6, 12, and 18 cpd were 41.20, 54.75, 55.55, 31.70, and 9.00, respectively, and for the control group these values were 38.35, 51.70, 52.15, 30.05, and 8.00, respectively. The mean contrast sensitivity values of the eyes that underwent the PCCC procedure were slightly better than the fellow eyes at all spatial frequencies, but the difference was statistically insignificant (P>0.05).

CONCLUSIONS

In early post-operative period, the PCCC procedure exerts some positive effects on contrast sensitivity although these effects are statistically insignificant.

Three-year follow-up of posterior capsule opacification after AquaLase and NeoSoniX phacoemulsification

PURPOSE

To prospectively compare the degree of posterior capsule opacification (PCO) after AquaLase and NeoSoniX phacoemulsification methods during the 3-year follow-up period.

DESIGN

Prospective, randomized clinical trial.

METHODS

Setting at the Department of Ophthalmology, University Hospital in Hradec Králové. Patients with bilateral cataract were included. AquaLase was used in the right eye and NeoSoniX in the left eye of each patient. The AcrySof SA60AT intraocular lens (Alcon Laboratories, Fort Worth, Texas, USA) was implanted in all eyes. The Evaluation of Posterior Capsule Opacification (EPCO) 2000 software (Developed by Tetz MR and associates, Berlin, Germany) and the Open-Access Systematic Capsule Assessment (OSCA) system (Devised by Aslam TM, Edinburgh, United Kingdom) were used for PCO assessment 1, 2, and 3 years after cataract surgery.

RESULTS

Fifty patients were analyzed 1 year, 47 patients 2 years, and 46 patients 3 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 = .53) 1 year after surgery, for the AquaLase group 0.429 +/- 0.322 and for the NeoSoniX group 0.478 +/- 0.337 (P = .30) 2 years after surgery, and for the AquaLase group 0.582 +/- 0.506 and for the NeoSoniX group 0.594 +/- 0.515 (P = .87) 3 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 = .046) 1 year after surgery, for the AquaLase group 0.7515 +/- 0.4555 and for the NeoSoniX group 0.8103 +/- 0.4498 (P = .44) 2 years after surgery, and for the AquaLase group 0.9667 +/- 0.736 and for the NeoSoniX group 0.9540 +/- 0.5250 (P = .91) 3 years after surgery. Neodymium-yttrium-aluminun-garnet capsulotomy rate for AquaLase vs NeoSoniX was 0:1 eyes 1 year, 1:3 eyes 2 years, and 1:4 eyes 3 years after surgery. No significant difference between those 2 groups was established, except the OSCA outcomes 1 year postoperatively.

CONCLUSION

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

Effect of intraocular lens design on posterior capsule opacification

Posterior capsule opacification (PCO) remains the most common long-term complication after cataract surgery. Many studies have attempted to identify factors that influence the development of PCO. The aim of this systematic review based on Cochrane methodology was to summarize the effects of intraocular lens (IOL) geometry, including modifications of the IOL optic (especially optic edge design) and haptics, on the development of PCO. Twenty-six prospective randomized controlled trials with a follow-up of at least 12 months were included. In 5 of 7 studies, visual acuity was better in sharp-edged IOLs than in round-edged IOL. The PCO score was significantly lower with sharp-edged IOLs but did not differ significantly between 1-piece and 3-piece open-loop IOLs. Because of the significant difference in the PCO score, sharp-edged IOL optics should be preferred to round-edged IOL optics.

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

PURPOSE

To evaluate posterior capsule opacification (PCO) 2 years after cataract surgery following implantation of a hydrophilic or a hydrophobic single-piece acrylic intraocular lens (IOL) with a sharp edge.

METHODS

Phacoemulsification cataract surgery was performed in one eye of 120 patients with senile cataract in this prospective study. They were randomized to implantation of either a hydrophilic acrylic IOL (BL27; Bausch & Lomb, Rochester, NY, USA) or a hydrophobic acrylic IOL (AcrySof) SA60AT; Alcon Laboratories, Fort Worth, TX, USA). Two years after surgery, retroillumination images were obtained and PCO area and severity were evaluated using pocoman software. Best corrected visual acuity (VA) (both high-contrast [100%] and low-contrast [2.5%]), glare, laser flare and intraocular pressure were measured. Capsulotomy rates were recorded.

RESULTS

Patients implanted with the hydrophilic IOL had a greater percentage area and severity of PCO compared with patients with the hydrophobic IOL (p < 0.001). There was no difference in PCO between men and women in the hydrophilic group. However, in the hydrophobic group, women had significantly more PCO than men (p < 0.05). Patients with the hydrophobic acrylic IOL had better high- and low-contrast visual activity (VA) (p < 0.01) and less glare (p < 0.001) than those with a hydrophilic acrylic IOL. Of the patients with the hydrophilic IOL, 42% underwent capsulotomy, compared with 10% in the hydrophobic group (p < 0.001).

CONCLUSIONS

Two years after surgery, patients with the SA60AT hydrophobic acrylic IOL had less PCO and better high- and low-contrast VA than patients with the BL27 hydrophilic acrylic IOL.

Comparison of posterior capsule opacification after two different surgical methods of cataract extraction

PURPOSE

To compare the extent of posterior capsule opacification (PCO) after AquaLase and NeoSoniX phacoemulsification methods using two types of software for PCO quantification.

DESIGN

Prospective, randomized clinical trial.

METHODS

At the Department of Ophthalmology, University Hospital in Hradec Králové, 50 patients (100 eyes) were analyzed one year after surgery. AquaLase was used in the right eye and NeoSoniX in the left eye of each patient. One year after surgery, digital retroillumination photographs of anterior segments were obtained. The Evaluation of Posterior Capsule Opacification (EPCO) 2000 software (Berlin, Germany) and the Open-Access Systematic Capsule Assessment (OSCA) system (Edinburgh, United Kingdom) were used for PCO assessment. Best-corrected Snellen visual acuity (BCVA) was evaluated before and after surgery. Statistical analysis was performed using parametric tests.

RESULTS

The EPCO 2000 results were as follows: mean value for right eyes, 0.324+/-0.305; mean value for left eyes, 0.298+/-0.341; no difference was proved (P=.532). The OSCA results were as follows: for right eyes, 0.7097+/-0.3777; for left eyes, 0.8584+/-0.4323; significant difference (P=.046), worse for left eyes. No correlation between EPCO 2000 and OSCA results was established (P>.001; correlation coefficient, 0.347). BCVA for the right eyes was 0.837+/-0.262 and for the left eyes was 0.849+/-0.224. Neodymium:yytrium-aluminum-garnet capsulotomy was performed in one eye in the NeoSoniX group, and in no eyes in the AquaLase group.

CONCLUSIONS

There was no significant difference in PCO measured by EPCO 2000, however, PCO after AquaLase as assessed by EPCO 2000 was slightly denser. The OSCA system gave significantly higher scores in the NeoSoniX group. No correlation between EPCO 2000 and OSCA outcomes was proved.

Effect of posterior capsule opacification on macular sensitivity

PURPOSE

To evaluate the effect of posterior capsule opacification (PCO) on macular sensitivity.

SETTING

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

METHODS

Macular sensitivity, best corrected visual acuity (BCVA), and PCO intensity were evaluated before and after neodymium:YAG (Nd:YAG) laser capsulotomy in pseudophakic eyes with clinically significant PCO that had a healthy macula or dry age-related macular degeneration (ARMD). Macular sensitivity was determined using the fundus-related Microperimeter 1 (Nidek) in a central field of 10 degrees. The intensity of the PCO was assessed objectively in the central 3.0 mm area (score 0 to 10) using quantification software.

RESULTS

After Nd:YAG capsulotomy, both groups had a significant improvement in BCVA and mean macular sensitivity; the change in the mean logMAR value was -0.26 in the healthy macula group and -0.23 in the dry ARMD group and the change in mean macular sensitivity, 2.5 dB and 2.0 dB, respectively. Before Nd:YAG capsulotomy, significant correlations were observed between PCO values, BCVA, and macular sensitivity in the healthy macula group only (P<.01).

CONCLUSIONS

Neodymium:YAG laser capsulotomy improved BCVA and macular sensitivity. The PCO scores correlated well with the PCO-induced decrease in BCVA and with PCO-induced loss of macular sensitivity. Functional macular mapping indicated an overall loss of macular sensitivity in patients with dry ARMD. There was no significant association between PCO values and macular sensitivity in eyes with dry ARMD.

Safety of irrigation with 5-fluorouracil in a sealed-capsule irrigation device in the rabbit eye

PURPOSE

To study the safety of irrigation with 5-fluorouracil (5-FU) in the Perfect Capsule sealed-capsule irrigation device (Milvella, Ltd., Epping, Australia).

SETTING

St. Erik's Eye Hospital, Stockholm, Sweden.

METHODS

Thirty 8-week-old rabbits were divided into 4 groups. Clear lens extraction was performed and the Perfect Capsule was applied in 1 eye in Groups 1, 2 and 3. The sealed system was flushed with balanced salt solution (BSS) in Group 1, 5-FU 50 mg/mL in Group 2, and 5-FU followed by BSS in Group 3. In Group 4, the Perfect Capsule was not applied; instead, 0.2 mL of 5-FU was instilled in the capsule and left there for 30 seconds. An endothelial cell count and pachymetry were performed preoperatively and 24 hours postoperatively. At 24 or 48 hours (half of each group at each time point), the rabbits were killed and the retina and trabecular meshwork histopathologically examined. The endothelial cell count and pachymetry were compared between the Perfect Capsule eye and the control eye in Group 1.

RESULTS

There was no difference between the groups in endothelial cell count (P = .96) or pachymetry (P = .32). Histologic evaluation showed no damage from the 5-FU. The comparison between eyes in Group 1 showed that the use of the Perfect Capsule did not cause more endothelial cell loss (P = .86) or increase pachymetry more (P = .28) than in the control eye.

CONCLUSION

Irrigation with 5-FU 50 mg/mL in the sealed-capsule irrigation device was safe and caused no apparent damage to the adjacent intraocular tissues.

Interventions for preventing posterior capsule opacification

BACKGROUND

Posterior capsule opacification (PCO) remains the most common long-term complication after cataract surgery. It can be treated by Nd:YAG laser capsulotomy, however, this may lead to other complications and laser treatment is not available in large parts of the developing world. Therefore, many studies try to find factors influencing the development of PCO.

OBJECTIVES

To summarise the effects of different interventions to inhibit PCO. These include modifications of surgical technique and intraocular lens (IOL) design, implantation of additional devices and pharmacological interventions.

SEARCH STRATEGY

We searched CENTRAL, MEDLINE, EMBASE, LILACS in January 2007 and reference lists of identified trial reports.

SELECTION CRITERIA

We included only prospective, randomised and controlled trials with a follow-up time of at least 12 months. Interventions included modifications in surgical technique explicitly to inhibit PCO, modifications in IOL design (material and geometry), implantation of additional devices, and pharmacological therapy, compared to each other, placebo or standard treatment.

DATA COLLECTION AND ANALYSIS

Data were extracted and entered into Review Manager. Visual acuity data, PCO score and YAG capsulotomy rates were compared and a meta-analysis was performed when possible.

MAIN RESULTS

Fifty three studies were included in the review. The review was divided into three parts. (1) Influence of IOL optic material on the development of PCO. Compared to other materials, the meta-analysis of the included studies showed a significantly higher PCO score (overall effect: 12.39 (95% confidence interval: 9.82 to 14.95), scale 0 to 100) and YAG rate (odds ratio: 8.37 (3.74 to 20.36)) only in hydrogel IOLs. (2) Influence of IOL optic design on the development of PCO. There was a significantly lower PCO score (-8.65 (-10.72 to -6.59), scale 0 to 100) and YAG rate (0.19 (0.11 to 0.35)) in sharp edged than in round edged IOLs, however, not between 1-piece and 3-piece IOLs. (3) Influence of surgical technique and drugs on the development of PCO. There was no significant difference between different types of intra-/postoperative anti-inflammatory treatment except for treatment with an immunotoxin (MDX-A) leading to a significantly lower PCO rate.

AUTHORS' CONCLUSIONS

Due to the highly significant difference between round and sharp edge IOL optics, IOLs with sharp (posterior) optic edges should be preferred. There is no clear difference between optic materials, except for hydrogel IOLs, that showed more PCO than the other materials. The choice of postoperative anti-inflammatory treatment does not seem to influence PCO development.

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

PURPOSE

To observe and document the effect of steroidal and nonsteroidal antiinflammatory treatment on the formation of Elschnig pearls.

DESIGN

A prospective, randomized, double blinded, placebo controlled, two-way-cross-over study.

METHODS

Thirty-nine eyes of 32 patients with pronounced, regeneratory posterior capsule opacification (PCO) were included. The patients were treated topically with prednisolone and diclofenac (verum) or with lubricating eye drops (placebo) four times daily for one week. After a wash-out period of two weeks the patients received the contrary treatment also four times daily for one week. Digital retroillumination images were taken at day one, three, five, eight, and 15 of each medication period. The changes in the size of 4,675 Elschnig pearls were analyzed.

RESULTS

The mean cumulative area of all marked pearls/eye and follow-up was 1.2 mm(2) (range: 0.1 mm(2) to 3.2 mm(2)). The mean pearl size was 12,809 microm(2) (range: 60 microm(2) to 1.08 x 10(6) microm(2)). Between the follow-up examinations, 1,274 pearls disappeared (mean: 33 pearls/eye, range: five to 69 pearls; 27%) and 777 newly formed pearls appeared (mean: 20 pearls/eye, range: three to 53 pearls; 20%). There was no statistically significant difference in pearl size change and in number of disappeared and newly appeared pearls between the verum and the placebo treatments.

CONCLUSIONS

Topical prednisolone and diclofenac do not influence the short-term change of Elschnig pearls. Elschnig pearls disappear and appear within days. The degree of progression and regression varies greatly among eyes.