Advances in the management of the surgical complications for congenital cataract

Prevalence of Glaucoma Following Paediatric Cataract Surgery in an Australian Tertiary Referral Centre

Purpose

Secondary glaucoma following childhood cataract surgery remains the most common complication in the paediatric population. This study aimed to determine the incidence, time to progression and risk factors associated with the development of secondary glaucoma following childhood cataract surgery in a paediatric population. Outcome measures were the detection of secondary glaucoma, postoperative time frame to development of glaucoma and risk factors in its development.

Patients and Methods

A retrospective case series was conducted between 2003 and 2017 at a tertiary children's hospital in Sydney. The patient population included those 16 years or less of age who underwent congenital cataract extraction, with or without an intraocular lens implantation and who had been followed up for a minimum of six months following surgery. Patients were excluded if they had cataract aetiology other than congenital idiopathic cataract. Multivariate Cox Regression analysis was used to determine relevant risk factors.

Results

A total of 320 eyes in 216 patients were included in the study. Secondary glaucoma developed in 11.9% of eyes. In those that developed secondary glaucoma, the average time to onset from surgery was 3.2 years (median 2.75 years). The mean age of diagnosis of secondary glaucoma was 4.58 years (median 3.5 years, range 2.5 months to 13.23 years). Microcornea was the only adverse characteristic significantly associated with an increased risk of secondary glaucoma (HR 6.30, p 0.003).

Conclusion

Despite modern surgical techniques, glaucoma remains a significant long-term sequela in children following cataract surgery.

Effect of pterygopalatine blockade on perioperative stress and inflammatory outcomes following paediatric cataract surgery

BACKGROUND

General anesthesia is required to perform pediatric cataract surgery. To reduce severity of surgical intervention and postoperative complications, regional techniques have been concomitantly used. The traditional regional ophthalmic techniques are retrobulbar, peribulbar and sub-Tenon blocks, which present some technical difficulties and associated complication risks. The pterygopalatine blockade has been exempt of many of these concerns as it is performed out of the orbit. The purpose of this study was to compare the analgesic and anti-inflammatory effects of the pterygopalatine blockade with retrobulbar block in children undergoing elective congenital cataract surgery.

METHODS

After approval of ethics committee and informed consents, patients were enrolled to the study to have either ultrasound-guided pterygopalatine block (group P) or retrobulbar block (group R), with 2 mL lidocaine 2% and 1 mL ropivacaine 0.5%. Hemodynamic monitoring was recorded throughout the perioperative period. Cortisol level and oxidation-reduction status were assessed before and after surgery. Pain and inflammatory response (Tyndall effect, corneal syndrome and edema) were assessed on the first postoperative day.

RESULTS

Comparative analysis demonstrated a decrease in cortisol of 123.24% (p˂0.05) and an increase in the redox coefficient of 37.7% (p˂0.05) in group P. Pain intensity was significantly higher in group R until the 16th postoperative hour. The corneal syndrome in patients in group P and group R was noted by 7.6% and in 32.1%, respectively (p˂0.05).

CONCLUSION

The use of the pterygopalatine blockade as a component of anesthesia in pediatric cataract surgery allows reduction of the severity of surgical stress during surgical intervention, providing intraoperative hemodynamic stability and prolonged analgesia.

Effect of Exogenous Alpha-B Crystallin on the Structures and Functions of Trabecular Meshwork Cells

Purpose

Secondary open-angle glaucoma may develop as a postoperative complication of early childhood cataract surgery. Its mechanism is poorly understood. Surgical removal of cataracts is typically incomplete, and we estimate that this disease is associated with alpha-B crystallin (CRYAB) secreted from the retained lens material. This study, for the first time, focused on the role of CRYAB in undesired changes of the structures and functions in trabecular meshwork (TM) cells.

Methods

Cell proliferation and migration were assessed using a cell counting kit-8 (CCK8) and transwell assay analysis, respectively. Immunofluorescence (IF), quantitative real-time PCR (Rt-qPCR), and Western blot were performed to determine the effect of CRYAB on F-actin, tight junctions, and the expression of epithelial to mesenchymal transition- (EMT-) associated proteins in TM cells.

Results

CRYAB promoted proliferation (p < 0.0001), migration (p < 0.001), and F-actin reorganization in TM cells. There were statistically significant increases in the mRNA and protein levels of zo-1, cadherin-N, and vimentin (all p < 0.0001) and cadherin-E decreased (p < 0.0001) and the mRNA level of claudin-1 increased (p < 0.0001) compared to those of the control group.

Conclusion

All of the changes in structures and functions first observed in the TM cells after exposure to CRYAB resembled alterations seen in primary open-angle glaucoma, suggesting that CRYAB might be related to the pathogenesis of secondary open-angle glaucoma after congenital cataract surgery.

Visual outcomes of dense pediatric cataract surgery in eastern China

Purpose

To evaluate the visual outcomes of dense pediatric cataract surgery in eastern China.

Methods

Medical records of children who underwent surgery for dense unilateral or bilateral pediatric cataract in Shandong Provincial Hospital between January 2007 and December 2012 were collected. Patients who cooperated with optical correction and aggressive patching of the sound eye and who had a minimum postoperative follow-up of more than 2 years were included. Risk factors for poor visual outcomes were analyzed.

Results

Of the 105 eligible patients (181 eyes), 76 had bilateral cataract, and 29 unilateral. With a mean follow up of 46.77 mo (range 24.0~96.0 mo), the final best corrected visual acuity (BCVA) of 158 eyes were recorded, and 4.43% (7/158) achieved 0.1 logarithm of the minimum angle of resolution (logMAR) or better; 15.19% (24/158) obtained a BCVA between 0.1 logMAR and 0.3 logMAR; 18.99%, (30/158) between 0.3 logMAR and 0.5 logMAR; 46.84% (74/158), between 0.5 logMAR and 1 logMAR; 14.55%, worse than 1 logMAR. The mean BCVA of the patients who underwent lensectomy before 3 months of age was significantly better than that of patients who underwent lensectomy between 3 and 12 months (p = 0.001). In the same lensectomy age groups, the final BCVA of the children in the bilateral and unilateral groups did not differ significantly (P>0.05). Lensectomy after 3 months of age, postoperative complications, strabismus and nystagmus were shown to be risk factors for poor visual outcomes.

Conclusions

Lensectomy before 3 months of age, IOL implantation, proper managing of postoperative complications, early optical correction and aggressive postoperative patching of the sound eye would increase the final BCVA for patients with dense pediatric cataract.

Screening, genetics, risk factors, and treatment of neonatal cataracts

Neonatal cataracts remain the most common cause of visual loss in children worldwide and have diverse, often unknown, etiologies. This review summarizes current knowledge about the detection, treatment, genetics, risk factors, and molecular mechanisms of congenital cataracts. We emphasize significant progress and topics requiring further study in both clinical cataract therapy and basic lens research. Advances in genetic screening and surgical technologies have improved the diagnosis, management, and visual outcomes of affected children. For example, mutations in lens crystallins and membrane/cytoskeletal components that commonly underlie genetically inherited cataracts are now known. However, many questions still remain regarding the causes, progression, and pathology of neonatal cataracts. Further investigations are also required to improve diagnostic criteria for determining the timing of appropriate interventions, such as the implantation of intraocular lenses and postoperative management strategies, to ensure safety and predictable visual outcomes for children. Birth Defects Research 109:734-743, 2017. © 2017 Wiley Periodicals, Inc.

Systematic Review of the Manifestations of Congenital Rubella Syndrome in Infants and Characterization of Disability-Adjusted Life Years (DALYs)

Congenital rubella syndrome (CRS) continues to cause disability among unvaccinated populations in countries with no or insufficient rubella vaccine coverage to prevent transmission. We systematically reviewed the literature on birth outcomes associated with CRS to estimate the duration, severity, and frequency of combinations of morbidities. We searched PubMed, the Science Citation Index, and references from relevant articles for studies in English with primary data on the frequency of CRS manifestations for ≥20 cases and identified 65 studies representing 66 study populations that met our inclusion criteria. We abstracted available data on CRS cases with one or more hearing, heart, and/or eye defect following maternal rubella infection during the period of 0-20 weeks since the last menstrual period. We assessed the quality and weight of the available evidence using a modified Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Most of the evidence originates from studies in developed countries of cohorts of infants identified with CRS in the 1960s and 1970s, prior to the development of standardized definitions for CRS and widespread use of vaccine. We developed estimates of undiscounted disability-adjusted life years (DALYs) lost per CRS case for countries of different income levels. The estimates ranged from approximately 19 to 39 for high-income countries assuming optimal treatment and from approximately 29 to 39 DALYs lost per CRS case in low- and lower- middle-income countries assuming minimal treatment, with the lower bound based on 2010 general global burden of disease disability weights and the upper bound based on 1990 age-specific and treatment-specific global burden of disease disability weights. Policymakers and analysts should appreciate the significant burden of disability caused by CRS as they evaluate opportunities to manage rubella.

Comparison between Limbal and Pars Plana Approaches Using Microincision Vitrectomy for Removal of Congenital Cataracts with Primary Intraocular Lens Implantation

Purpose. To compare the surgical outcomes of limbal versus pars plana vitrectomy using the 23-gauge microincision system for removal of congenital cataracts with primary intraocular lens implantation. Methods. We retrospectively reviewed all eyes that underwent cataract removal through limbal or pars plana incision. Main outcome measures included visual outcomes and complications. Results. We included 40 eyes (26 patients) in the limbal group and 41 eyes (30 patients) in the pars plana group. The mean age was 46 months. There was no significant difference in best-corrected visual acuity between the two groups (P = 0.64). Significantly, more eyes had at least one intraoperative complication in the limbal group than in the pars plana group (P = 0.03) that were mainly distributed at 1.5-3 years of age (P = 0.01). The most common intraoperative complications were iris aspiration, iris prolapse, and iris injury. More eyes in the limbal group had postoperative complications and required additional intraocular surgery, but the difference was not significant (P = 0.19). Conclusions. The visual results were encouraging in both approaches. We recommend the pars plana approach for lower incidence of complications. The limbal approach should be reserved for children older than 3 years of age and caution should be exercised to minimize iris disturbance.