Heparin in the intraocular irrigating solution in pediatric cataract surgery

Pharmacology of Heparin and Related Drugs: An Update

Heparin has been used extensively as an antithrombotic and anticoagulant for close to 100 years. This anticoagulant activity is attributed mainly to the pentasaccharide sequence, which potentiates the inhibitory action of antithrombin, a major inhibitor of the coagulation cascade. More recently it has been elucidated that heparin exhibits anti-inflammatory effect via interference of the formation of neutrophil extracellular traps and this may also contribute to heparin's antithrombotic activity. This illustrates that heparin interacts with a broad range of biomolecules, exerting both anticoagulant and nonanticoagulant actions. Since our previous review, there has been an increased interest in these nonanticoagulant effects of heparin, with the beneficial role in patients infected with SARS2-coronavirus a highly topical example. This article provides an update on our previous review with more recent developments and observations made for these novel uses of heparin and an overview of the development status of heparin-based drugs. SIGNIFICANCE STATEMENT: This state-of-the-art review covers recent developments in the use of heparin and heparin-like materials as anticoagulant, now including immunothrombosis observations, and as nonanticoagulant including a role in the treatment of SARS-coronavirus and inflammatory conditions.

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.

Successful pediatric DMEK facilitated by intracameral tissue plasminogen activator to mitigate anterior chamber fibrin reaction

Purpose

To report a case of a successful Descemet's membrane endothelial keratoplasty (DMEK) facilitated by the use of intracameral tissue plasminogen activator (tPA) in a 4-year old with posterior polymorphous corneal dystrophy (PPCD).

Observations

A 4-year old male was referred for bilateral corneal haze and blurry vision. Patient's exam and genetic testing were consistent with a diagnosis of PPCD. Patient was successfully treated with DMEK augmented by the use of intracameral tPA intraoperatively to combat the anterior chamber fibrin formation that can occur in DMEK.

Conclusions

To our knowledge, this case represents the youngest reported successful DMEK procedure and the first case describing the use of intracameral tPA intraoperatively to attenuate the anterior chamber fibrin formation that can occur in DMEK.

Second intraocular surgery after primary pediatric cataract surgery: indications and outcomes during long-term follow-up at a tertiary eye care center

PurposeAlthough pediatric cataract surgery has become standardized and safe, further surgical interventions are not uncommon. The purpose of this study was to analyze the incidence of complications in children who required an intraocular intervention.MethodsA retrospective review of medical records of children (<7 years) with cataract who underwent cataract surgery with or without primary posterior chamber intraocular lens (IOL) placement between January 2006 and December 2014 was carried out. Data were collected regarding visual axis opacification (VAO), glaucoma, IOL decentration, intraocular infections, and other indications that required a second intraocular surgery.ResultsOut of 814 (570 pseudophakic and 244 aphakic) eyes of 620 operated children, 45 eyes of 40 children (5.5%, 45/814) needed a second surgery. The most common indication being VAO (2.9%, 24/814), followed by glaucoma (0.73%, 6/814). Incidence of complications was higher in children <1 year (VAO 6.1%, 19/308 and glaucoma 6%, 6/308). Among all children, repeat interventions and VAO were slightly less frequent in pseudophakics (4.91%, 28/570) vs aphakics (6.91%, 17/244) (P=0.31). As VAO was more common in pseudophakic eyes in infants, glaucoma was equally common in both groups. Best-corrected visual acuity improved from 1.6±0.56 LogMAR preoperatively to 0.80±0.50 LogMAR postoperatively.ConclusionsOur study suggests that overall incidence of second intraocular surgery is low after primary pediatric cataract surgery. VAO remains the most common indication followed by secondary glaucoma. Incidence of complications is higher in children <1 year of age at initial surgery.

Intraindividual aqueous flare comparison after implantation of hydrophobic intraocular lenses with or without a heparin-coated surface

PURPOSE

To assess the efficacy of a heparin-surface-modified (HSM) hydrophobic acrylic intraocular lens (IOL) (EC-1YH PAL) and the same IOL without heparin coating (EC-1Y-PAL) by the flare and cell intensity in the anterior chamber after uneventful cataract surgery.

SETTING

Department of Ophthalmology, Paracelsus Medical University Salzburg, Austria.

DESIGN

Comparative case series.

METHODS

Routine phacoemulsification with randomized implantation of an HSM IOL in 1 eye (HSM IOL group) and an uncoated IOL (uncoated IOL group) in the fellow eye was performed. Postoperative inflammation was assessed objectively using a laser flare-cell meter (FM-600) preoperatively as well as 1 day and 1 and 3 months postoperatively. Aqueous cells in the anterior chamber, distance visual acuities, and subjective manifest refraction were also evaluated at each visit.

RESULTS

One hundred eyes (50 patients) were enrolled. In both groups, the mean flare values increased significantly from preoperatively to 1 day postoperatively (P<.001) and nearly reached preoperative values by 3 months postoperatively. One day postoperatively, the mean flare value was statistically significantly lower in the HSM IOL group (14.92 photons per millisecond [ph/ms] ± 7.47 [SD]) than in the uncoated IOL group (mean 16.73 ± 7.81 ph/ms) (P=.04); there was no statistically significant difference between groups 1 and 3 months postoperatively (both P>.58). The HSM IOL group had a greater and quicker decrease in aqueous cells, reaching statistical significance 1 month postoperatively (P=.01).

CONCLUSION

The HSM IOL showed a significant lower inflammatory reaction in the early postoperative stage with a faster disappearance of inflammatory signs.

FINANCIAL DISCLOSURE

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

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.

Effect of heparin coating of a foldable intraocular lens on inflammation and capsular bag performance after cataract surgery

PURPOSE

To evaluate the effect of a heparin-coated foldable intraocular lens (IOL) on postoperative flare in high-risk patients.

SETTING

Vienna Institute for Research in Ocular Surgery, Department of Ophthalmology, Hanusch Hospital, Vienna, Austria.

DESIGN

Randomized clinical trial.

METHODS

This study included patients with diabetes mellitus (DM), pseudoexfoliation syndrome (PXF), or both scheduled for cataract surgery in both eyes. One eye received a coated IOL (Polylens EC-1YH PAL) and the other eye, an uncoated control IOL (Polylens EC-1Y PAL). Aqueous flare measurements were taken using a laser flare meter (FM-600, Kowa) preoperatively and 1 hour, 1 day, 3 weeks, and 3 months postoperatively. Visual acuity and anterior (ACO) and posterior (PCO) capsule opacification were assessed, and IOL centration and tilt were measured with a Purkinje meter.

RESULTS

Eighty eyes of 40 patients were included in the study; 64 eyes of 32 patients completed the study. The mean flare values (photons/ms) preoperatively and 1 hour, 1 day, 3 weeks, and 3 months postoperatively were 6.98 ± 3.71 (SD), 19.14 ± 18.90, 16.62 ± 25.33, 10.33 ± 9.70, 8.74 ± 4.64, respectively, with the coated IOL and 8.65 ± 5.73, 22.08 ± 16.23, 13.44 ± 13.71, 7.50 ± 4.11, and 7.03 ± 3.70, respectively, with the control IOL. No significant differences were found in flare, visual acuity, ACO, PCO, tilt, or centration between the coated IOL and the control IOL at any timepoint.

CONCLUSION

No significant differences in flare or capsule performance were found between the coated IOL and control IOL.

[Treatment of pediatric cataracts. Part 2: IOL implantation, postoperative complications, aphakia management and postoperative development]

There is a lot of uncertainty concerning intraocular lens (IOL) implantation for pediatric cataracts. The appropriate age which ocular abnormalities are contraindications and according to which formula IOL should be calculated are controversial. In addition to the imperative of identifying postoperative complications, such as secondary cataract formation and secondary glaucoma in a sufficiently timely manner, a modern management of aphakia with refractive compensation and occlusion is necessary. Some easy rules can help prevent pitfalls.

Effect of low molecular weight heparin (enoxaparin) on congenital cataract surgery

AIM

To assess the efficacy of intracameral enoxaparin (a low-molecular-weight heparin) infusion, in variable doses on postoperative inflammatory response in congenital cataract surgery.

METHODS

It is a prospective, randomized controlled trial. Eighty eyes of 53 children with congenital cataract were enrolled in this study. Every eye had primary posterior capsulorrhexis and intraocular lens (IOL) implantation after lens aspiration. The eyes were divided into 4 equal groups. In group 1 balanced salt solution (BSS) without enoxaparin was used as an irrigation solution. Whereas in group 2, 3 and 4, 40mg, 20mg and 10mg enoxaparin in 500mL BSS was used respectively. The inflammatory response in the anterior chamber was compared among the groups with slit-lamp biomicroscopy.

RESULTS

The mean follow-up period was (17.75±3.95) months in group 1, (18.00±5.15) months in group 2, (19.20±5.47) months in group 3 and (18.65±5.16) months in group 4. Mean number of inflammatory cells in the anterior chamber in group 1 was significantly higher than that of group 2, 3, 4 (P<0.001). There was fibrin formation in the anterior chambers of 3 eyes in group 1 and one eye in group 4. There was synechiae formation in 3 eyes of group 1 and one eye of group 4. There was no significant difference among the groups by means of fibrin or synechiae formation (P>0.05). There were IOL precipitates in 4 eyes of group 1 and 2 eyes of group 4. IOL precipitate formation was significantly higher in group 1 than that of group 2 and 3 in which there was no IOL precipitate (P=0.048). There was IOL subluxation in only one eye of group 1, 3 and 4 while no subluxation was observed in group 2 (P>0.05). There was no statistically significant difference detected about IOL subluxation occurance in all 4 groups (P>0.05).

CONCLUSION

Complications of cataract surgery in congenital cataract patients associated with postoperative inflammatory response found to be decreased with the use of enoxaparin in intraocular infusion solutions. Furthermore according to our results the anti-inflammatory effect of enoxaparin was dose dependant.

Anti-inflammatory effect of low-molecular-weight heparin in pediatric cataract surgery: a randomized clinical trial

PURPOSE

To determine if intraocular infusion of low-molecular-weight heparin (enoxaparin) reduces postoperative inflammation in pediatric eyes undergoing cataract surgery with IOL implantation.

DESIGN

Prospective masked randomized controlled trial.

METHODS

setting: Private, institutional practice. study population: Twenty children (40 eyes) undergoing bilateral cataract surgery with IOL implantation were randomized to receive enoxaparin in the intraocular infusion fluid (BSS) (Group I) or not to receive enoxaparin (Group II). The first eye was randomly assigned to 1 of the 2 groups and the second eye received alternate treatment. observation procedure: Patients were followed up in the first week and 1 and 3 months after surgery. main outcome measures: Anterior chamber flare and cells (Hogan's criteria), cell deposits on IOL, posterior synechiae.

RESULTS

One week postoperatively, no eyes had >grade 2 flare/cells. Proportion of eyes with grade 2 cells was higher in eyes that did not receive enoxaparin (Group II: 80% vs Group I: 40%, P = .009). In the first week >10 small cell deposits were noted in the eyes that received enoxaparin (Group I: 20%, Group II: none, P = .005). Large cell deposits first appeared at 1 month in 40% of eyes in Group I and 55% of eyes in Group II (P = .34) and increased at 3 months (60% in both groups, P > .999). Posterior synechiae were seen in 10% of eyes in Group I at 1 month, which persisted at 3 months; no eyes in Group II showed posterior synechiae (P = .14).

CONCLUSION

The results of our study suggest that there does not seem to be a benefit of using enoxaparin in the infusion fluid with respect to early postoperative inflammation.

Intracameral triamcinolone acetonide after pediatric cataract surgery

PURPOSE

To assess the use of preservative-free intracameral triamcinolone as an adjunct to topical steroidal agents after pediatric cataract surgery.

SETTING

Children's University Hospital, Dublin, Ireland.

DESIGN

Retrospective case series.

METHODS

From the 2008 to 2009, intracameral preservative-free triamcinolone 4 mg/0.1 mL (Triesence) was used immediately after cataract surgery. Clinical indices of anterior segment inflammation were assessed at 1, 7, 14, 21 days and at 6 weeks postoperatively.

RESULTS

There were no complications secondary to triamcinolone use in 36 eyes of 26 children. In all but 1 case, intracameral triamcinolone was highly effective in controlling postoperative inflammation after pediatric cataract surgery, resulting in quiet eyes with few inflammatory signs (grade 0 to 1).

CONCLUSION

Intracameral triamcinolone provided a safe and useful adjunct to topical steroid drops after 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.

Cataract surgery in pediatric uveitis

Uveitis in children is associated with several sight-threatening ocular complications, including the formation of cataracts. The surgical management of uveitic cataracts in children is both challenging and controversial and, unlike in adult uveitic cataracts, surgery has historically been associated with poor visual outcomes. Juvenile idiopathic arthritis-associated uveitis in particular poses unique therapeutic challenges and the issue of correction of aphakia in these patients remains a contentious one. The growing use of immunotherapies and, where needed, targeted biologic agents in childhood uveitis increases our potential to implant lenses and predict outcomes. The authors review the available evidence base for the treatment of these children.

Bilateral paediatric cataract surgery in the same session

PURPOSE

To evaluate the results of bilateral paediatric cataract surgery in the same session with a focus on patient selection criteria, operative guidelines, and controversial issues.

SETTING

Departments of Ophthalmology, Inönü University Turgut Ozal Medical Center (Malatya) and Fatih University Hospital (Ankara, Turkey).

METHODS

This retrospective noncomparative case series comprised 39 children (78 eyes), who underwent bilateral cataract surgery and/or primary or secondary IOL implantation in one sitting. Ten patients had bilateral lensectomy-primary posterior capsulotomy-anterior vitrectomy, and the remaining 29 patients had bilateral IOL implantation either primarily (20 cases) at the time of cataract extraction or secondarily for aphakic correction (9 cases). Both eyes were treated as two separate but consecutive surgeries in the same session. Maximum possible care was taken to ensure surgical asepsis.

RESULTS

Age at surgery ranged from 2 months to 17 years. Average follow-up was 12 months. No serious intraoperative or postoperative complications occurred leading to permanent vision loss. During the last follow-up, 91% of eyes tested had a visual acuity of 20/40 or better.

CONCLUSION

Bilateral paediatric cataract surgery in one session may be a safe and useful approach alternative to sequential surgery in selected patients, if operative guidelines and surgical asepsis are strictly followed.

Advances in the management of congenital and infantile cataract

Congenital and infantile cataracts produce deprivation amblyopia and can thus cause lifelong visual impairment. Successful management is dependent on early diagnosis and referral for surgery when indicated. Accurate optical rehabilitation and postoperative supervision are essential.The timing of surgery and its relationship to the duration of deprivation is important. Unilateral congenital cataract surgery within 6 weeks of birth produces the best outcomes. The equivalent 'latent' period for bilateral visual deprivation may be longer at around 10 weeks. Visual deprivation has a significant impact on the development of fixation stability. Major form deprivation, even after early surgery, leads to nystagmus. This is mostly manifest latent nystagmus (MLN). The latent period for fixation stability may be as short as 3 weeks. Preoperative congenital nystagmus (CN) can convert to more benign MLN after surgery. Infantile IOL implantation is becoming increasingly accepted. A satisfactory long-term refractive result requires that allowance be made for childhood axial growth and myopic shift. In a series of 25 infants (33 eyes) implanted before 12 months of age, the mean myopic shift at 12 months was 4.83 D. This increased to 5.3 D in infants implanted before 10 weeks. The initial desired refractive outcome following IOL implantation is thus hypermetropia, with the degree dependent on the age of the child. Glaucoma or ocular hypertension is a common complication following paediatric cataract surgery. Microphthalmia and surgery in early infancy are risk factors. Tonometry results may be influenced by the increased corneal thickness seen in aphakic and pseudophakic children. The long-term prognosis of eyes with aphakic glaucoma is not necessarily poor but intraocular pressure control may require three or more medications. Surgical intervention appears to be necessary in over a quarter of eyes. Posterior capsule opacification (PCO) is common in infants undergoing primary lens implantation. Primary capsulotomy and anterior vitrectomy reduce the risk of PCO. In the absence of anterior vitrectomy, primary posterior capsulotomy does not prevent visual axis opacification. Further developments will continue to be driven by clinical research. The prevention of capsule opacification and cellular proliferation may in future be achieved by the use of devices to specifically target epithelial cells at surgery.

Chirurgische Therapie der kongenitalen Katarakt

Due to the anatomical dimensions being smaller and the tissue structures being softer and more elastic in the young patient, surgery of paediatric cataracts represents a special challenge for the ophthalmic surgeon. Surgery is performed via a limbal or pars plana approach. The extreme high rate of secondary cataract formation in the paediatric or adolescent eye with closed posterior capsules is countered by means of complicated capsular surgery, special intraocular lens (IOL) implantation techniques, and vitreoretinal surgical procedures. It is customary not to implant IOLs before the children are 1-2 years old as increased axial length growth must be expected during the first 18 months after birth. IOL power is selected so that postoperative refraction is within the hyperopic range and with time, undercorrection will be balanced by bulbus growth. Preoperative and postoperative therapy is highly dependant on the extent of trauma sustained during surgery and should contain anti-inflammatory medication with and without steroids as well as antibiotics. Orthoptic follow-up examinations are also decisive for the long-term result.

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.

Intraoperative enoxaparin minimizes inflammatory reaction after pediatric cataract surgery

PURPOSE

To evaluate the effect of intraocular infusion of enoxaparin, a low-molecular-weight heparin, on postoperative inflammatory response in pediatric cataract surgery.

DESIGN

Prospective, comparative, consecutive interventional case series.

METHODS

Seventeen consecutive eyes (11 patients) underwent pediatric cataract surgery in two tertiary medical centers. During the procedure, balanced salt solution with enoxaparin (40 mg in 500 ml) was infused into the anterior chamber. Eleven consecutive eyes (eight patients) received balanced salt solution without enoxaparin in the infusion bottle. The inflammatory response in the anterior chamber was compared between the two groups by semiquantification with slit-lamp biomicroscopy. Postoperative inflammatory complications, including fibrin formation, intraocular lens precipitates, anterior and posterior synechiae, cyclitic and pupillary membrane formation, and anterior subluxation of the intraocular lens, were also compared. The follow-up period after surgery was between 3 and 36 months (average 12.3 months).

RESULTS

The number of cells and the degree of flare were minimal in the group with enoxaparin in the infusion bottle (P < .001). The total number of postoperative inflammation-related complications was also lower in the enoxaparin-treated group (P = .007). All corneas remained clear, and the endothelial cell count, which was performed in two patients, did not show substantial decrease in their density or changes in shape and size. No other enoxaparin-related complications were observed.

CONCLUSIONS

Infusion of enoxaparin during pediatric cataract surgery may minimize the postoperative inflammatory response and decrease the number of postoperative inflammatory related complications. Enoxaparin should also be evaluated for cataract surgery in other conditions where postoperative inflammation may be exacerbated.

New techniques and technologies for pediatric cataract surgery

PURPOSE OF REVIEW

This paper surveys the literature from April 2004 to April 2005 and addresses trends in pediatric cataract surgery techniques.

RECENT FINDINGS

The evolution of pediatric cataract surgery continues, with many adult cataract surgical techniques being applied to children with minor technical adjustments. More and more, surgeons are implanting intraocular lenses in younger children. One of the most widely reported technologic advances in 2004-2005 was the use of hydrophobic acrylic intraocular lenses in children. Predicting axial growth, and refractive change that accompanies it, is one of the major remaining challenges for the long-term care of children who have had cataract surgery.

SUMMARY

Automation and intraocular lenses have helped to provide better anatomic and functional outcome for cataract surgery in children. Two major challenges in the coming years will be to find a way to obviate invasive procedures like posterior capsulotomy and vitrectomy and to study the growth of eyes in a well designed prospective study that will help to design new intraocular lens power calculation formulas specifically suited for children's eyes.

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.