Heparin-surface-modified intraocular lenses in pediatric cataract surgery: prospective randomized study

Surgical interventions for bilateral congenital cataract in children aged two years and under

BACKGROUND

Congenital cataracts are lens opacities in one or both eyes of babies or children present at birth. These may cause a reduction in vision severe enough to require surgery. Cataracts are proportionally the most treatable cause of visual loss in childhood, and are a particular problem in low-income countries, where early intervention may not be possible. Paediatric cataracts provide different challenges to those in adults. Intense inflammation, amblyopia (vision is obstructed by cataract from birth which prevents normal development of the visual system), posterior capsule opacification and uncertainty about the final trajectory of ocular growth parameters can affect results of treatment. Two options currently considered for children under 2 years of age with bilateral congenital cataracts are: (i) intraocular lens (IOL) implantation; or (ii) leaving a child with primary aphakia (no lens in the eye), necessitating the need for contact lenses or aphakic glasses. Other important considerations regarding surgery include the prevention of visual axis opacification (VAO), glaucoma and the route used to perform lensectomy.

OBJECTIVES

To assess the effectiveness of infant cataract surgery or lensectomy to no surgery for bilateral congenital cataracts in children aged 2 years and under.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; which contains the Cochrane Eyes and Vision Trials Register; 2022, Issue 1); Ovid MEDLINE; Ovid Embase; the ISRCTN registry; ClinicalTrials.gov and the WHO ICTRP. The date of the search was 25 January 2022.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) that compared infant cataract surgery or lensectomy to no surgery, in children with bilateral congenital cataracts aged 2 years and younger. This update (of a review published in 2001 and updated in 2006) does not include children over 2 years of age because they have a wider variety of aetiologies, and are therefore managed differently, and have contrasting outcomes.

DATA COLLECTION AND ANALYSIS

We used standard methods expected by Cochrane. Two review authors extracted data independently. We assessed the risk of bias of included studies using RoB 1 and assessed the certainty of the evidence using GRADE.

MAIN RESULTS

We identified three RCTs that met our inclusion criteria with each trial comparing a different aspect of surgical intervention for this condition. The trials included a total of 79 participants under 2 years of age, were conducted in India and follow-up ranged from 1 to 5 years. Study participants and outcome assessors were not masked in these trials. One study (60 children) compared primary IOL implantation with primary aphakia. The results from this study suggest that there may be little or no difference in visual acuity at 5 years comparing children with pseudophakia (mean logMAR 0.50) and aphakia (mean logMAR 0.59) (mean difference (MD) -0.09 logMAR, 95% confidence intervals (CIs) -0.24 to 0.06; 54 participants; very low-certainty evidence), but the evidence is very uncertain. The evidence is very uncertain as to the effect of IOL implantation compared with aphakia on visual axis opacification (VAO) (risk ratio (RR) 1.29, 95% CI 0.23 to 7.13; 54 participants; very low-certainty evidence). The trial investigators did not report on the cases of amblyopia. There was little evidence of a difference betwen the two groups in cases of glaucoma at 5 years follow-up (RR 0.86, 95% CI 0.24 to 3.10; 54 participants; very low-certainty evidence). Cases of retinal detachment and reoperation rates were not reported. The impact of IOL implantation on adverse effects is very uncertain because of the sparse data available: of the children who were pseudophakic, 1/29  needed a trabeculectomy and 8/29 developed posterior synechiae. In comparison, no trabeculectomies were needed in the aphakic group and 2/25 children had posterior synechiae (54 participants; very low-certainty evidence).  The second study (14 eyes of 7 children under 2 years of age) compared posterior optic capture of IOL without vitrectomy versus endocapsular implantations with anterior vitrectomy (commonly called 'in-the-bag surgery'). The authors did not report on visual acuity, amblyopia, glaucoma and reoperation rate. They had no cases of VAO in either group. The evidence is very uncertain as to the effect of in-the-bag implantation in children aged under 1 year. There was a higher incidence of inflammatory sequelae: 4/7 in-the-bag implantation eyes and 1/7 in optic capture eyes (P = 0.04, 7 participants; very low-certainty evidence). We graded the certainty of evidence as low or very low for imprecision in all outcomes because their statistical analysis reported that a sample size of 13 was needed in each group to achieve a power of 80%, whereas their subset of children under the age of 1 year had only 7 eyes in each group. The third study (24 eyes of 12 children) compared a transcorneal versus pars plana route using a 25-gauge transconjunctival sutureless vitrectomy system. The evidence is very uncertain as to the effect of the route chosen on the incidence of VAO, with no cases reported at 1 year follow-up in either group. The investigators did not report on visual acuity, amblyopia, glaucoma, retinal detachment and reoperation rate. The pars plana route had the adverse effects of posterior capsule rupture in 2/12 eyes, and 1/12 eyes needing sutures. Conversely, 1/12 eyes operated on by the transcorneal route needed sutures. We graded the outcomes with very low-certainty because of the small sample size and the absence of a priori sample size calculation.

AUTHORS' CONCLUSIONS

There is no high level evidence for the effectiveness of one type of surgery for bilateral congenital cataracts over another, or whether surgery itself is better than primary aphakia. Further RCTs are required to inform modern practice about concerns, including the timing of surgery, age at which surgery should be undertaken, age for implantation of an IOL and development of complications, such as reoperations, glaucoma and retinal detachment. Standardising the methods used to measure visual function, along with objective monitoring of compliance with the use of aphakic glasses/contact lenses would greatly improve the quality of study data and enable more reliable interpretation of outcomes.

Efficacy and safety of vitrectomy for congenital cataract surgery: a systematic review and meta-analysis based on randomized and controlled trials

PURPOSE

To explore the effectiveness and safety of vitrectomy for congenital cataract surgery.

METHODS

We searched PubMed, Science Direct, The Cochrane Library, China National Knowledge Infrastructure and the Wanfang Database. Two researchers extracted data and assessed paper quality independently. Posterior capsule opacification (PCO) or visual axis opacification (VAO), reoperation rate, visual acuity, intraocular lenses (IOL) deposit, synechias, uveitis, secondary glaucoma, low-contrast sensitivity and IOL decentration were compared.

RESULTS

We included 11 randomized controlled trials (RCTs) with 634 congenital cataract eyes. Cases of posterior capsule opacification in vitrectomy group were significantly less than that of control group, with risk ratio (RR) of 0.15 [95% confidence interval (CI): 0.09, 0.26], and there was no heterogeneity (I²  = 0%, p = 0.94). Reoperation rate in vitrectomy group was lower than that of control group either (RR = 0.40, 95%CI: 0.17, 0.94), and there was no heterogeneity (I²  = 0%, p = 0.85). Best-corrected visual acuity (BCVA) measured in LogMAR unit of vitrectomy group was smaller, with a mean difference (MD) of -0.17 (95%CI: -0.28, -0.05), and I² was only 22%, indicating of a small heterogeneity. No statistical difference was found between two groups on IOL deposit (RR = 1.23, 95%CI: 0.70, 2.17), and the heterogeneity was small (I²  = 16%, p = 0.31). No statistical difference was found between two groups on synechias (RR = 1.08, 95%CI: 0.60, 1.94), with a quite small heterogeneity (I²  = 3%, p = 0.38). No statistical difference was found between two groups on uveitis (RR = 0.55, 95%CI: 0.15, 2.01), and there was no heterogeneity (I²  = 0%, p = 0.94). There was no statistical difference on IOP either, with a MD of 0.25 (95%CI: -1.56, 2.07), and there was no heterogeneity (I²  = 0%). Egger's test showed that there was no publication bias for all assessed outcomes. Low-contrast sensitivity was better in the vitrectomy group. And no evidence indicated vitrectomy could lead to a higher risk on secondary glaucoma or IOL decentration.

CONCLUSION

Vitrectomy helps lower the PCO risk and reoperation risk after congenital cataract surgery, and also, vitrectomy helps patients gain a better BCVA and achieve a better low-contrast sensitivity, with no trade-off on IOP control, IOL deposit, synechias, uveitis and secondary glaucoma. We recommend performing vitrectomy during congenital cataract surgery.

Use of a Juvenile Rabbit Animal Model to Evaluate Therapeutic Interventions for Postoperative Inflammation and Fibrin Formation After Lensectomy

Purpose

We used the juvenile rabbit as a model for investigating therapeutic interventions for postoperative inflammation and fibrin formation following intraocular lens (IOL) insertion for management of pediatric cataracts.

Methods

Twelve 6- to 7-week-old, 600 to 900 g rabbits underwent bilateral clear-cornea lensectomy via irrigation and aspiration with IOL insertion. Following wound closure, enoxaparin 8 mg (n = 6 eyes), preservative-free triamcinolone 0.5 mg (n = 6), 8 mg enoxaparin plus 0.5 mg triamcinolone (n = 6), or balanced salt solution (n = 6) was injected into the anterior chamber. Slit-lamp examinations and optical coherence tomography (OCT) scans were performed postoperatively on days 3 through 7, and 14 to characterize levels of inflammation and fibrin. Using 17 additional rabbits, enzyme-linked immunosorbent assays (ELISAs) with 100 μL of aqueous humor were performed to quantify the amount of fibrinogen and fibrin preoperatively and on postoperative day 3. Immunohistochemistry was performed to confirm the presence of fibrin.

Results

Enoxaparin alone and combined with triamcinolone reduced the amount of fibrin present in the anterior chamber compared to untreated eyes, which corresponded to an increase in OCT signal strength. Despite the clear visual axis shown in clinical images, the combination treatment group had the highest levels of soluble fibrin when assessed by ELISA. Immunohistochemistry confirmed the presence of insoluble fibrin seen clinically.

Conclusions

A combination of enoxaparin and triamcinolone appears to provide the most therapeutic benefit by reducing fibrin formation and postoperative inflammation.

Translational Relevance

The juvenile rabbit is an excellent model to investigate inflammation and fibrin formation following lensectomy with IOL insertion and possibly any intraocular surgery in children.

Intraocular lens optic capture in pediatric cataract surgery

Posterior capsule opacification (PCO) remains the most common complication of pediatric cataract surgery despite continuous efforts to reduce its incidence. For this reason, pediatric cataract surgeons have expended considerable effort into preventing and mitigating PCO. The intraocular lens (IOL) optic capture technique has been used for the prevention of PCO after pediatric cataract surgery for more than 20y, but there is still no professional consensus. However, recent research has shown encouraging results. The IOL optic capture technique can be performed without anterior vitrectomy to prevent PCO, even in younger children. The type and characteristics of IOLs used for optic capture technique, the location of IOL and the complications of IOL optic capture in children are here reviewed.

Pediatric cataract

Pediatric cataract is a leading cause of childhood blindness. Untreated cataracts in children lead to tremendous social, economical, and emotional burden to the child, family, and society. Blindness related to pediatric cataract can be treated with early identification and appropriate management. Most cases are diagnosed on routine screening whereas some may be diagnosed after the parents have noticed leukocoria or strabismus. Etiology of pediatric cataract is varied and diagnosis of specific etiology aids in prognostication and effective management. Pediatric cataract surgery has evolved over years, and with improving knowledge of myopic shift and axial length growth, outcomes of these patients have become more predictable. Favorable outcomes depend not only on effective surgery, but also on meticulous postoperative care and visual rehabilitation. Hence, it is the combined effort of parents, surgeons, anesthesiologists, pediatricians, and optometrists that can make all the difference.

Pediatric cataract: challenges and future directions

Cataract is a significant cause of visual disability in the pediatric population worldwide and can significantly impact the neurobiological development of a child. Early diagnosis and prompt surgical intervention is critical to prevent irreversible amblyopia. Thorough ocular evaluation, including the onset, duration, and morphology of a cataract, is essential to determine the timing for surgical intervention. Detailed assessment of the general health of the child, preferably in conjunction with a pediatrician, is helpful to rule out any associated systemic condition. Although pediatric cataracts have a diverse etiology, with the majority being idiopathic, genetic counseling and molecular testing should be undertaken with the help of a genetic counselor and/or geneticist in cases of hereditary cataracts. Advancement in surgical techniques and methods of optical rehabilitation has substantially improved the functional and anatomic outcomes of pediatric cataract surgeries in recent years. However, the phenomenon of refractive growth and the process of emmetropization have continued to puzzle pediatric ophthalmologists and highlight the need for future prospective studies. Posterior capsule opacification and secondary glaucoma are still the major postoperative complications necessitating long-term surveillance in children undergoing cataract surgery early in life. Successful management of pediatric cataracts depends on individualized care and experienced teamwork. We reviewed the etiology, preoperative evaluation including biometry, choice of intraocular lens, surgical techniques, and recent developments in the field of childhood cataract.

The effect of enoxaparin-containing irrigation fluid used during cataract surgery on postoperative inflammation in patients with diabetes

PURPOSE

To investigate effects of enoxaparin on postoperative inflammation in patients with moderate nonproliferative diabetic retinopathy (NPDR) and nuclear cataract.

DESIGN

Prospective masked controlled trial.

METHODS

setting: Institutional practice. study population: The study included 51 eyes of 51 diabetes mellitus (DM) patients with moderate NPDR and grade 2-3 nuclear cataracts. Group 1 included randomly selected patients who received enoxaparin in balanced salt solution (BSS) during cataract surgery, while standard BSS was used in Group 2. observation procedure: Patients were followed up 1 day, 1 week, and 1 and 2 months after the surgery. main outcome measures: Anterior chamber cell and flare.

RESULTS

Postoperatively, 20 patients from Group 1 and 4 patients in Group 2 had less than a mean of 10 cells at day 1 (P = .012). At the first week, 20 patients from Group 1 and 10 patients from Group 2 had less than a mean of 10 cells (P = .004). When compared for flare, 20 patients from Group 1 and 8 patients from Group 2 had a flare between 0 and +1 at postoperative day 1 (P < .001). By the end of postoperative first week, 24 patients from Group 1and 18 patients from Group 2 had a flare between 0 and +1 (P = .012). There was no difference between groups in terms of postoperative inflammation at the first and second months after the surgery.

CONCLUSION

The results of the study suggest that enoxaparin added into the infusion fluid may reduce postoperative inflammation in patients with DM, and this result supports the anti-inflammatory effect of enoxaparin.

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.

Technological advances in pediatric cataract surgery

PURPOSE

Managing pediatric cataracts is often challenging. It is technically difficult to perform surgery in these small complaint eyes and there is higher prevalence of postoperative complications. The outcomes of surgery depend on technique and technology. The purpose of this study is to review the current literature on technological advances in pediatric cataract surgery.

METHODS

Review of literature on management of pediatric cataract surgery.

RESULTS

The advent of vitrectomy machines and intraocular lenses (IOLs) has revolutionized pediatric cataract surgery. "Vitrectorhexis" has become a good alternative to manual capsulorhexis. Primary management of posterior capsule and limited anterior vitrectomy has reduced the incidence of visual axis opacification. Primary IOL implantation is becoming a standard of care in the youngest children. Single piece Acrysof® is preferred for in-the-bag implantation and 3-piece Acrysof® for sulcus implantation. Newer IOLs are being evaluated in pediatric eyes. Precise measurement of intraocular lens power and predicting refractive change are major challenges in long term care of children after surgery.

CONCLUSION

New technology and surgical techniques have refined pediatric cataract surgery. It is critical to focus our efforts on precise biometry measurements, IOL power calculation, and designing IOLs that may address refractive changes in the growing pediatric eye.

Effect of intracameral cefuroxime on fibrinous uveitis after pediatric cataract surgery

PURPOSE

To determine whether intracameral cefuroxime reduces postoperative fibrin formation after pediatric cataract surgery.

METHODS

Children aged 3 months to 10 years with bilateral congenital or developmental cataracts who underwent surgery between February and July 2008 were eligible for inclusion in this prospective double-masked study. The same surgical technique was used in each eye. The intraocular lens was placed in either the bag or sulcus in both eyes. The same intraocular lens type was used in both eyes (polymethylmethacrylate). One eye was randomized to receive intracameral cefuroxime at the end of surgery and the fellow eye received saline. The surgeon was masked to the treatment assignment. The amount of fibrin formation in the anterior chamber of each eye was assessed by a masked grader on the fourth postoperative day.

RESULTS

Seventy eyes of 35 children were included in the study. Fibrin formation was noted on the fourth postoperative day in 14 of 70 eyes (20%), 7 in the cefuroxime group and 7 in the saline group. The mean fibrin score was 0.57 ± 1.31 in the cefuroxime group and 0.49 ± 1.07 in the saline group. There was no statistically significant difference in the amount of fibrin formation between groups (P = .857, Wilcoxon ranked signs test).

CONCLUSION

Intracameral cefuroxime did not significantly reduce postoperative fibrin formation in this study. Fibrin formation does not appear to be due to bacterial contamination in most cases of pediatric cataract surgery.

Effect of heparin in the intraocular irrigating solution on postoperative inflammation in the pediatric cataract surgery

Purpose:

To evaluate the influence of irrigation of the anterior chamber with heparin sodium on postoperative inflammation after pediatric cataract surgery.

Setting:

Kartal Training and Research Hospital, First Eye Clinic, Istanbul, Turkey.

Design:

Randomized prospective double-blind study.

Methods:

Fourteen consecutive eyes from 14 patients aged 8.9 ± 5.9 years, (range 3–18 years) (group 1) and 19 eyes from 19 patients aged 9.1 ± 5.2 (range 1.5–18 years) (group 2) underwent pediatric cataract surgery. Five patients in group 1 were between three and five years old. One patient was 1.5 years old and six patients in group 2 were between three and five years old. During the procedure, group 1 received anterior chamber irrigation with heparin sodium (5 IU/cc) and 1 ml of heparin sodium (concentration 10 IU/ml) added to the irrigating balanced salt solution (BSS Plus; Alcon Laboratories, Inc., Fort Worth, TX, USA) while group 2 received BSS without heparin sodium only. Cases aged under three years received anterior vitrectomy in addition to posterior capsulorrhexis. One eye received anterior vitrectomy in group 1 and two eyes received anterior vitrectomy in group 2. Cases with preoperative complications were not included in the study. Early and late postoperative inflammatory complications, including fibrin formation, anterior and posterior synechia, cyclitic and pupillary membrane formation were recorded and compared.

Results:

Mild anterior chamber reaction was observed in three patients in Group 1, while nine cases in group 2 experienced marked anterior chamber reaction. In four of nine patients from group 2, anterior chamber reaction was severe and resulted in pupillary membrane and synechia despite treatment in the postoperative 7th day, while in all three cases in group 1, reaction disappeared by the 7th day.

Conclusion:

Anterior chamber irrigation with heparin during pediatric cataract surgery may minimize early inflammatory reaction and decrease the number of postoperative inflammatory related complications.

Surgical interventions for bilateral congenital cataract

BACKGROUND

Congenital cataracts are opacities of the lens in one or both eyes of children that cause a reduction in vision severe enough to require surgery. Cataract is the largest treatable cause of visual loss in childhood. Paediatric cataracts provide different challenges to those in adults. Intense inflammation, amblyopia and posterior capsule opacification can affect results of treatment. Two treatments commonly considered for congenital cataract are lensectomy and lens aspiration.

OBJECTIVES

The objective of this review was to assess the effects of surgical treatments for bilateral symmetrical congenital cataracts. Success was measured according to the vision attained and occurrence of adverse events.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library, which contains the Cochrane Eyes and Vision Group Trials Register (2005, Issue 2), MEDLINE (1966 to June 2005), EMBASE (1980 to June 2005, week 27), LILACS (6 July 2005), the Science Citation Index and the reference list of the included studies. We also contacted trial investigators and experts in the field for details of further studies.

SELECTION CRITERIA

We included all prospective, randomised controlled trials that compared one type of cataract surgery to another, or to no surgery, in children with bilateral congenital cataracts aged 15 years or younger.

DATA COLLECTION AND ANALYSIS

Two authors extracted data. No meta-analysis was performed.

MAIN RESULTS

Four trials met the inclusion criteria. All trials were concerned with reducing the development of visual axis opacification (VAO). This was achieved with techniques that included an anterior vitrectomy or optic capture. Posterior capsulotomy alone was inadequate except in older children.

AUTHORS' CONCLUSIONS

Evidence exists for the care of children with congenital or developmental bilateral cataracts to reduce the occurrence of visual axis opacification. Further randomised trials are required to inform modern practice about other concerns including the timing of surgery, age for implantation of an intraocular lens and development of long-term complications such as glaucoma and retinal detachment.

Effect of surface coating an acrylic intraocular lens with poly(2-methacryloyloxyethyl phosphorylcholine) polymer on lens epithelial cell line behavior

PURPOSE

To evaluate the effect of surface coating of an acrylic intraocular lens (IOL) with poly(2-methacryloyloxyethyl phosphorylcholine) (MPC) on the behavior of the lens epithelial cell (LEC) line, alpha-TN4.

SETTING

Department of Ophthalmology, Nihon University School of Medicine, Tokyo, Japan.

METHODS

A hydrophobic soft acrylic IOL (AF-1, Hoya) was coated with MPC polymer. A noncoated IOL served as control. An IOL from each group was placed on the membrane of collagen I or IV of the cell culture dish. The alpha-TN4 cells were seeded in the insert. Cell behaviors (ie, cell proliferation and spreading) on IOLs and membranes were observed. Cell migration beneath the IOL optic portion was assayed using a computer software program (POCOman system) for posterior capsule opacification (PCO). Type I or IV collagen is the major matrix component of PCO or native lens capsule.

RESULTS

Cell proliferation was more marked on the noncoated IOL than on the coated IOL. Type IV collagen accelerated proliferation more than type I collagen. Cell migration to the area beneath the IOL optic was more prominent in the group with the type I collagen membrane and noncoated IOL than in other groups.

CONCLUSION

Coating an acrylic IOL surface with MPC polymer suppressed adhesion and proliferation of LECs, suggesting it improves IOL biocompatibility.

Influence of a new surface modification of intraocular lenses with fluoroalkylsilan on the adherence of endophthalmitis-causing bacteria in vitro

INTRODUCTION

Dynasilan is a fluoroalkylsilan that is able to interact with surface active centres on intraocular lenses (IOL), offering a new way for surface modification of different IOL materials. The purpose of this in vitro study was to investigate the influence of this new surface modification on the adherence of two typical endophthalmitis causing bacteria (Staphylococcus epidermidis, Propionibacterium acnes).

MATERIALS AND METHODS

In a pilot experiment, the effect of Dynasilan coating on the adherence of S. epidermidis was tested on glass slides. Forty-two Dynasilan-modified and 42 unmodified IOL (14 PMMA, 14 silicone and 14 hydrogel) were incubated at 37 degrees C in brain heart infusion broth (10(8) CFU/ml) with either S. epidermidis for 24 h or with P. acnes for 1 h. Subsequently, the adherent bacteria were resuspended using ultrasonification at 35 kHz for 3x45 s. After dilution series and incubation at 37 degrees C on Petri dishes for 24 h and 3 days, respectively, the colonies were counted.

RESULTS

In the pilot experiment, a markedly lower number of adherent S. epidermidis was observed on Dynasilan-modified glass slides. Of all IOL materials incubated with S. epidermidis, those modified with Dynasilan showed a lower mean number of adherent bacteria (mean 1.37x10(7); SD 2.37x10(7)) than those untreated (2.43x10(7); SD 3.04x10(7)). IOLs incubated with P. acnes showed a significantly lower mean number of adherent bacteria of 2.51x10(4) (SD 2.71x10(4)) on Dynasilan-modified IOLs versus 6.27x10(4) (SD 7.70x10(4)) on untreated IOLs.

CONCLUSION

The presented in vitro results indicate that Dynasilan surface modification is able to reduce the adherence of S. epidermidis and P. acnes on all IOL materials tested. Further studies regarding the stability of this modification and its biocompatibility must be performed.

Cataracts in children

Bilateral congenital cataract is the most common cause of treatable childhood blindness. Nuclear cataract is usually present at birth and is nonprogressive, whereas lamellar cataract usually develops later and is progressive. Surgery must be performed promptly in cases with dense congenital cataract; if nystagmus has developed, the amblyopia is irreversible. A treatment regimen based on surgery within 2 months of birth combined with prompt optical correction of the aphakia and aggressive occlusion therapy with frequent follow-up has been successful in unilateral and bilateral cases. Both anterior and posterior capsulorhexes are performed in most children. Intraocular lens implantation can be performed safely in children older than 1 year. Anterior dry vitrectomy is recommended in preschool children to avoid after-cataract. Opacification of the visual axis is the most common complication of cataract surgery in children. Secondary glaucoma is the most sight-threatening complication and is common if surgery is performed early. Life-long follow-up is essential in these cases.

Visual axis opacification after AcrySof intraocular lens implantation in children

PURPOSE

To evaluate visual axis opacification after AcrySof intraocular lens (IOL) (Alcon) implantation in pediatric eyes.

SETTING

Iladevi Cataract and IOL Research Centre, Ahmedabad, India.

METHODS

This prospective study evaluated 103 consecutive eyes of 72 children with congenital cataract. Two groups were formed based on age at surgery: Group 1, younger than 2 years, and Group 2, older than 2 years. All eyes in Group 1 (n = 37) had primary posterior continuous curvilinear capsulorhexis (PCCC) with anterior vitrectomy. In Group 2 (n = 66), management of the posterior capsule was assigned randomly to no PCCC (Group 2A, n = 37) or PCCC (Group 2B, n = 29). The PCCC group was further randomized into 2 subgroups: no vitrectomy (Group 2BN, n = 14) or vitrectomy (Group 2BV, n = 15). The primary outcome measures were visual axis opacification and the resulting need for a secondary procedure. Statistical analysis was performed using SPSS for Windows (version 11.0.1).

RESULTS

The mean age of the patients was 5.2 years +/- 5.0 (SD) (range 0.2 to 16.0 years) and the mean follow-up, 2.3 +/- 0.9 years (range 1.0 to 4.0 years). Overall, 41 eyes (39.8%) developed visual axis opacification and 14 (13.6%) required secondary intervention. In Group 1, 4 eyes (10.8%) developed visual axis opacification and 3 (8.1%) had a secondary pars plana vitrectomy. In Group 2A, 31 eyes (83.8%) developed posterior capsule opacification (PCO) and 10 eyes (27.7%) had secondary intervention. Children 8 years or younger at the time of surgery developed significantly greater PCO than older children (P =.01). Five eyes (37.5%) in Group 2BN had opacification of the anterior vitreous face, 1 of which required a secondary procedure. One eye (6.7%) in Group 2BV had visual axis opacification that did not require a secondary procedure.

CONCLUSIONS

AcrySof IOL implantation with appropriate management of the posterior capsule maintained a clear visual axis in 60.2% of eyes. Of the 39.8% of eyes with visual axis opacification, 13.6% had visually significant opacification and required a secondary procedure.

Cataract treatment in the beginning of the 21st century

PURPOSE

To describe the principles upon which present day cataract treatment success resides.

DESIGN

Literature review and collective experience of the authors.

RESULTS

Surgical removal remains the standard treatment for cataract now and in the foreseeable future. Ultrasound cataract removal with a foldable "in-the-bag" intraocular lens with a truncated edge treated for dysphotopsia best correlates with core treatment principles, as we now understand them. Improving refractive results is an important trend. The worldwide burden of this problem is immense.

CONCLUSIONS

While results for treatment of cataracts are excellent today, improvements in safety and refraction precision are needed. Other approaches are desperately needed to stem the worldwide tide of cataract related ocular dysfunction.

Morphological and functional results of AcrySof intraocular lens implantation in children: prospective randomized study of age-related surgical management

PURPOSE

To evaluate the prevalence and severity of posterior capsule opacification (PCO) in pediatric eyes with a foldable acrylic AcrySof (Alcon) intraocular lens (IOL) and age-related surgical methods.

SETTING

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

METHODS

This prospective randomized study comprised 50 eyes of 34 children aged between 2 and 16 years. Eyes of children between 2 and 5.9 years were consecutively randomized to Group 1a (primary posterior capsulotomy and anterior vitrectomy) or Group 1b (optic capture in addition). Eyes of children between 6 and 16 years were consecutively randomized to Group 2a (primary posterior capsulotomy without anterior vitrectomy), Group 2b (optic capture in addition), or Group 2c (in-the-bag IOL implantation without opening the posterior capsule). Main outcome parameters were the incidence and severity of PCO formation, early postoperative complications, pigmented cell deposits on the IOL surface, and cataract morphology.

RESULTS

The visual axis was clear at the last follow-up in all eyes in Groups 1a, 1b, 2a, and 2b except in 1 eye in Group 1a. Sixty-percent of eyes in Group 2c had PCO. The incidence of early postoperative complications was significantly higher in eyes that developed PCO than in those that maintained a clear visual axis. There was no evidence that cataract morphology influenced PCO rates.

CONCLUSIONS

The AcrySof IOL was well tolerated in pediatric eyes. Optic capture was not necessary to ensure a clear visual axis. Primary posterior capsulotomy should be performed in preschool and uncooperative children and in eyes expected to have relatively high postoperative inflammation. Implanting the AcrySof in the bag and leaving the posterior capsule intact is acceptable for school children and juveniles with isolated developmental cataract.

AcrySof acrylic intraocular lens implantation in children: clinical indications of biocompatibility

PURPOSE

To assess the clinical biocompatibility of AcrySof (Alcon, Ft Worth, Tex) acrylic intraocular lenses (IOLs) in the highly reactive eyes of infants and children.

METHODS

A database of 230 pediatric IOL implantations was queried to allow retrospective review of all eyes implanted with an AcrySof IOL. Eyes implanted with polymethyl methacrylate (PMMA) IOLs were also reviewed and were used as a historical comparison group. Follow-up examinations were conducted by the surgeon on postoperative day 1, day 7, week 4, and week 8 and every 3 months during the first year and every 6 months thereafter. The presence of synechiae, lens deposits, and posterior capsule opacification were noted in the record at each visit. Examination notes were photocopied, and data were extracted from each visit note and entered into a computerized database.

RESULTS

One hundred and ten eyes had an AcrySof IOL at an average age of 60.4 months and had an average postoperative follow-up of 64.6 weeks. In comparison, 120 eyes had PMMA IOLs inserted at an average age of 71.9 months with an average postoperative follow-up of 136.9 weeks. IOL cell deposits were seen at the slit lamp in 7 of 110 (6.4%) AcrySof lenses as compared with 26 of 120 (21.75%) PMMA lenses (P =.002). Posterior synechiae were seen in 5 of 110 (4.5%) AcrySof lenses as compared with 23 of 120 (19.2%) PMMA lenses (P =.001). Twenty-two AcrySof-implanted eyes had an intact posterior capsule. Twenty-eight PMMA-implanted eyes had an intact posterior capsule. The YAG laser capsulotomy rate was similar in the 2 groups at 45.4% for AcrySof and 50% for PMMA (P =.973). The average time from surgery to YAG posterior capsulotomy was 18.6 months with an AcrySof lens and 18.3 months with a PMMA lens (P =.951; t test). A total of 60 patients (68%) implanted with AcrySof IOLs were able to cooperate for Snellen visual acuities. Of their 67 eyes, 48 (72%) had a 20/40 or better visual acuity at the last follow-up examination, and 63 eyes (94%) had a 20/100 or better visual acuity. Thirty-five eyes (52%) required amblyopia therapy, and patching continues as needed.

CONCLUSIONS

The AcrySof IOL is representative of a new group of foldable IOLs made from flexible hydrophobic acrylic material. The AcrySof IOL appears clinically to be biocompatible when placed in the eyes of children despite the increased tissue reactivity known to occur in young patients.

Surgical interventions for bilateral congenital cataract

BACKGROUND

Congenital cataracts are opacities of the lens in one or both eyes of children, causing a reduction in vision bad enough to require surgery. Cataract is the largest preventable cause of visual loss in childhood. Paediatric cataracts provide different challenges to those in adults. Intense inflammation, amblyopia and posterior capsule opacification can affect results of treatment. Two treatments commonly considered for congenital cataract are lensectomy and lens aspiration.

OBJECTIVES

The objective of this review is to assess the effects of surgical treatments for bilateral symmetrical congenital cataracts. Success is measured according to the vision attained and occurrence of adverse events.

SEARCH STRATEGY

We searched the Cochrane Controlled Trials Register - CENTRAL (which includes the Cochrane Eyes and Vision Group specialised register), MEDLINE, EMBASE, the Science Citation Index and the reference list of the included study. We also contacted trial investigators and experts in the field for details of further studies.

SELECTION CRITERIA

We included all prospective, randomised controlled trials that compared one type of cataract surgery to another or to no surgery, in children aged 15 years or younger with bilateral congenital cataracts.

DATA COLLECTION AND ANALYSIS

Two reviewers extracted data. No meta-analysis was performed.

MAIN RESULTS

One trial met the inclusion criteria. This trial randomised 130 eyes of 65 children. Follow up of 56 children at three years found no difference in visual acuity between lensectomy and lens aspiration with primary capsulotomy. Secondary opacification developed at a higher rate in the lens aspiration group (66%) compared to the lensectomy group (2%).

REVIEWER'S CONCLUSIONS

The two methods of surgery for bilateral congenital cataracts in this review have good visual results but the incidences of side effects differ. Further randomised trials are required to inform modern practice.