Glaucoma and increased central corneal thickness in aphakic and pseudophakic patients after congenital cataract surgery

Changes and Influencing Factors of Corneal Endothelial Cells and Central Corneal Thickness after Pediatric Cataract Surgery

INTRODUCTION

This study aimed to examine the impact of cataract surgery on the corneal endothelium and central corneal thickness (CCT) in pediatric patients, and to identify the factors associated with corneal alterations.

METHODS

This retrospective study included consecutive children undergoing bilateral or unilateral cataract surgery and intraocular lens implantation at the Eye Hospital of Wenzhou Medical University, with or without posterior capsulorhexis and anterior vitrectomy, and an age-matched normal control group. This study aimed to assess whether changes in corneal parameters, including CCT, corneal endothelial cell density (CD), average cell area (AVE), standard deviation of size (SD), coefficient of variation (CV), percentage of hexagonal cells (6A) before and after surgery, and endothelial cell loss (ECL) differed among the bilateral cataract, unilateral cataract, and control groups. Furthermore, the potential effects of anterior vitrectomy, axial length, preoperative anterior chamber depth, surgical duration, horizontal corneal diameter, intraoperative pupil diameter (PD), and the number of corneal sutures on corneal endothelial parameters and CCT were investigated.

RESULTS

A total of 107 eyes from 107 children were included in the study. In the bilateral cataract group, CD significantly decreased, AVE and CCT significantly increased, and ECL was significantly higher than in the control group. The unilateral cataract group also exhibited a significant increase in CCT. Additionally, the number of corneal sutures was negatively correlated with CD, and PD was negatively correlated with CV in the unilateral cataract group.

CONCLUSION

Cataract surgery in pediatric patients results in increased CCT, reduced CD, and morphological changes in corneal cells. A greater number of corneal sutures and a smaller PD increased the risk of CD reduction and elevated CV in the unilateral cataract group, underscoring the need for ophthalmologists to minimize corneal damage in these children.

Combined trabeculotomy-trabeculectomy for glaucoma after congenital cataract surgery: long-term results

OBJECTIVE

The aim of this study was to report on the long-term (>5 years) results of surgery for glaucoma after congenital cataract surgery.

DESIGN

Retrospective.

METHODS

A chart review was conducted of all children operated on for glaucoma after congenital cataract surgery in the Pediatric Ophthalmology Service of the Ophthalmology Department of Alexandria main University Hospital in Alexandria, Egypt, between 2005 and 2014 who completed 5 years of follow-up. Demographic, clinical, and operative data were retrieved from the medical records. Success was defined by stability and (or) reversal of optic nerve cupping in relation to presentation and, if this information was not available, by an intraocular pressure (IOP) less than the presenting IOP and less than 16 mm Hg with (true) or without (qualified) IOP-lowering therapy.

RESULTS

The records of 48 children were reviewed. Thirty-two eyes of 24 children had completed at least 5 years of follow-up and were included in the study. The mean age (±SD) of the study children was 11.6 ± 11.3 months (range, 3.2-52.0 months) at presentation, and the mean (±SD) follow-up was 105.5 ± 31.4 months (range, 60-156 months). Of 47 glaucoma surgical procedures in total, combined angle and filtering surgery with antimetabolite was the most common procedure performed (n = 30;63.8%). Annual success percentages from the fifth year onward to the thirteenth year were 69.6%, 68.8%, 77.8%, 50.0%, 71.4%, 60.0%, 50.0%, 83.3%, and 50.0%, respectively.

CONCLUSIONS

Surgery for glaucoma after congenital cataract surgery remains safe and successful for 13 years after surgery.

Corneal Structural Changes in Congenital Glaucoma

OBJECTIVE

To identify corneal structure differences on quantitative high-frequency ultrasound biomicroscopy (UBM) among subjects with congenital glaucoma compared with controls.

METHODS

This prospective case-control study evaluated 180 UBM images from 44 eyes of 30 subjects (18 control and 12 glaucoma, mean age 5.2±8.0 years, range 0.2-25.8 years) enrolled in the Pediatric Anterior Segment Imaging and Innovation Study (PASIIS). ImageJ was used to quantify a comprehensive set of corneal structures according to 21 quantitative parameters. Statistical analysis compared corneal measurements in glaucoma subtypes and age-matched controls with significance testing and mixed effects models.

RESULTS

Significant differences between congenital glaucoma cases and controls were identified in 16 of 21 measured parameters including angle-to-angle, central and peripheral corneal thicknesses, scleral integrated pixel density, anterior corneal radius of curvature, and posterior corneal radius of curvature. Eight parameters differed significantly between primary congenital glaucoma and glaucoma following congenital cataract surgery.

CONCLUSION

Multiple measurable corneal structural differences exist between congenital glaucoma and control eyes, and between primary and secondary congenital glaucoma, including but not limited to corneal width and thickness. The structural differences can be quantified from UBM image analysis. Further studies are needed to determine whether corneal features associated with glaucoma can be used to diagnose or monitor progression of congenital glaucoma.

Central corneal thickness measurements in phakic, pseudophakic, and aphakic children with ultrasound pachymetry and different non-contact devices

AIMS

Evidence for choosing a satisfactory device for central corneal thickness (CCT) measurement in children particularly pseudophakic and aphakic ones is insufficient. The aim of this study is to compare four differently measured CCTs obtained using ultrasound pachymetry (UP), Pentacam, partial coherence interferometry (PCI), and specular microscopy (SM) in phakic, pseudophakic, and aphakic children and assess the agreement between the six pairs of the methods.

METHODS

Children with history of cataract surgery at age six or younger and phakic children were recruited into this study. CCT was measured using UP (Optikon 2000, Rome, Italy), Pentacam (Oculus Inc, Wetzlar, Germany), PCI (IOLMaster 700, Carl Zeiss Meditec AG, Jena, Germany), and SM (Topcon SP-3000P; Topcon Corporation, Japan).

RESULTS

One-hundred two eyes (53 phakic, 29 pseudophakic, and 20 aphakic eyes) were included. The mean ages (± SD) of phakic, pseudophakic, and aphakic cases were 9.75 (± 3.3), 9.9 (± 2.3), and 8.2 (± 2.8) years, respectively. The mean CCTs (± SE) for phakic children using Pentacam, PCI, UP, and SM were 549.7 (± 5.0), 546.5 (± 4.5), 565.9 (± 5.5), and 506.2 (± 4.4) μm, respectively, for pseudophakic cases were 570.1 (± 6.4), 565.0 (± 6.1), 571.9 (± 6.3), and 524.3 (± 6.3) μm, respectively, and for aphakic participants were 635.3 (± 14.2), 635.4 (± 14.5), 649.0 (± 13.5), and 589.1 (± 13.3) μm, respectively.

CONCLUSION

Compared to Pentacam and PCI, SM underestimated CCT particularly in phakic and pseudophakic children, whereas UP slightly overestimated CCT especially in phakic and aphakic children. Furthermore, Pentacam and PCI had the closest agreement. By contrast, SM had the poorest agreement with the other three methods.

Postoperative Changes in Central Corneal Thickness and Intraocular Pressure in a Prospective Cohort of Congenital Cataract Patients

PURPOSE

To evaluate changes in central corneal thickness (CCT) and intraocular pressure (IOP) in children after surgery for congenital cataracts and to investigate the association between CCT and IOP.

METHODS

For this prospective observational cohort study, we recruited patients undergoing surgery for unilateral or bilateral congenital cataracts. CCT and IOP were measured before surgery and 1, 3, 6, 12, and 24 months after surgery.

RESULTS

Seventy-six children (152 eyes) were enrolled; 33 eyes were unaffected by cataracts, 77 were aphakic, and 42 were pseudophakic. In aphakic eyes, mean CCT increased by 31.14 ± 44.32 μm at 12 months postoperation and 33.09 ± 35.42 μm at 24 months postoperation; this increase was significantly higher than that in pseudophakic eyes 12 months after surgery (8.36 ± 19.91 μm; P < 0.001) and 24 months after surgery (0.31 ± 14.19 μm; P = 0.024). However, no significant differences in IOP were found between the different phakic states at 12 and 24 months postoperation (P = 0.672 and P = 0.080, respectively). There were also no significant differences in CCT and IOP before and after surgery in the unaffected eyes.

CONCLUSIONS

Mean CCT peaked at 12 months, and the mean IOP remained normal in both the aphakic and pseudophakic eyes during this study. CCT and IOP were positively correlated, regardless of the phakic status or age, a relationship which suggests that both parameters should be monitored closely in postsurgical patients for up to 12 months and in this time, may impact the ability to diagnose glaucoma.

A comparison of Icare PRO and Perkins tonometers in anesthetized children

AIM

To compare intraocular pressure (IOP) measurements obtained with the Perkins applanation tonometer and Icare PRO (ICP) rebound tonometer in anesthetized aphakic or strabismus children. Furthermore, intra-operator correlation and inter-operator correlation have been evaluated, along with the effects of central corneal thickness (CCT) on IOP measurements.

METHODS

Seventy children undergoing examination under anesthesia with sevoflurane for aphakic patients and for surgery for strabismus were included. IOP have been measured twice immediately after anesthesia induction with both Perkins applanation tonometer (PAT) and ICP in one eye and by two different operators with both devices in the fellow eye. Furthermore, CCT was measured with ultrasound pachymetry Pacline (Optikon). Agreement between the device measurements has been evaluated using Bland-Altman analyses. Repeatability and reproducibility of the device have been evaluated with intraclass correlation coefficient (ICC) with a value > 0.75 associated with excellent reliability. The relationship between IOP and CCT has been evaluated with Spearman's correlation coefficient r and determination coefficient r².

RESULTS

Mean difference in IOP measurements between ICP and PAT was 1.97 mmHg ± 1.23 mmHg (p < 0.05). This difference appeared to be higher in aphakic patients (mean difference 2.15 ± 1.35) than in patients undergoing strabismus surgery (mean difference 1.83 mmHg ± 1.12). Intraclass correlation coefficient (ICC) is used to evaluate repeatability and reproducibility, which are both high for PAT (repeatability 0.96, reproducibility 0.76) compared with ICP (repeatability 0.81, reproducibility 0.70). Correlation coefficient between CCT and IOP is 0.66 for both ICP and PAT.

CONCLUSION

ICP tends to overestimate IOP compared to PAT. Repeatability and reproducibility are both high for PAT as compared to ICP. A significant correlation between IOP and CCT for both instruments has been demonstrated.

Goldmann applanation tonometer versus ocular response analyzer for measuring intraocular pressure after congenital cataract surgery

PURPOSE

To compare intraocular pressure measured using the Goldmann applanation tonometer with that measured using the ocular response analyzer after congenital cataract surgery.

METHODS

This study included 113 eyes of 64 patients who underwent lensectomy and vitrectomy. In all, 36 eyes remained aphakic after surgery. Intraocular lens implantation was performed at the time of surgery in 47 eyes and secondarily in 30 eyes. Corneal hysteresis, corneal resistance factor, and cornea-compensated intraocular pressure were measured. The influences of independent factors on the difference between the cornea-compensated intraocular pressure and intraocular pressure measured with Goldmann applanation tonometer were investigated using linear regression analyses. Agreement between the two tonometers was investigated using the Bland and Altman and 95% limits of agreement analysis.

RESULTS

Central corneal thickness, corneal hysteresis, and corneal resistance factor were 591.2 ± 53.3 µm, 10.83 ± 2.27 mmHg, and 11.36 ± 2.14 mmHg, respectively. Cornea-compensated intraocular pressure (16.75 ± 4.82 mmHg) was significantly higher than intraocular pressure measured with Goldmann applanation tonometer (14.41 ± 2.27 mmHg, p < 0.001). Central corneal thickness (p = 0.02) and corneal hysteresis (p < 0.001) were identified as the main predictors of difference between cornea-compensated intraocular pressure and intraocular pressure measured with Goldmann applanation tonometer readings. A 95% limits of agreement for cornea-compensated intraocular pressure and intraocular pressure measured with Goldmann applanation tonometer was between -4.86 and 9.53 mmHg in the entire group. Cornea-compensated intraocular pressure showed the best agreement with intraocular pressure measured with Goldmann applanation tonometer in the primary pseudophakic subgroup as compared to the other subgroups.

CONCLUSION

The Goldmann applanation tonometer and ocular response analyzer cannot be used interchangeably for measuring intraocular pressure after congenital cataract surgery. The difference between the cornea-compensated intraocular pressure and intraocular pressure measured with Goldmann applanation tonometer was primarily affected by central corneal thickness and corneal hysteresis. Among the subgroups, the primary pseudophakic subgroup had the thinnest cornea and the highest corneal hysteresis values and demonstrated the best agreement between the two tonometers.

Effect of anesthesia on intraocular pressure measurement in children

Measurement of the intraocular pressure (IOP) is central to the diagnosis and management of pediatric glaucoma. An examination under anesthesia is often necessary in pediatric patients. Different agents used for sedation or general anesthesia have varied effects on IOP. Hemodynamic factors, methods of airway management, tonometry technique, and body positioning can all affect IOP measurements. The most accurate technique is one that reflects the awake IOP. We review factors affecting IOP measurements in the pediatric population and provide recommendations on the most accurate means to measure IOP under anesthesia based on the present literature.

Evaluation of corneal biomechanical properties using an ocular response analyser to examine aphakic and pseudophakic patients after congenital cataract surgery

PURPOSE

We evaluated corneal biomechanical properties in aphakic and pseudophakic patients after congenital cataract surgery and compared the data with those of age-matched normal subjects.

METHODS

We included 43 eyes of 43 aphakic or pseudophakic patients treated via congenital cataract surgery. As controls, 42 healthy age- and sex-matched subjects were enrolled. After a complete ophthalmic examination, central corneal thickness (CCT) and intraocular pressure (IOP) were determined. Corneal hysteresis (CH), corneal resistance factor (CRF), corneal-compensated IOP (IOPcc) and Goldmann-correlated IOP (IOPg) were recorded using an ocular response analyser.

RESULTS

In the study group, 18 eyes were aphakic and 25 eyes pseudophakic. We found a significant difference in CCT between the aphakic, pseudophakic and control groups (p < 0.001). No significant among-group differences were detected in CH or CRF (p > 0.05). We found significant differences in IOPcc, IOPg and IOP measured with Goldmann applanation tonometry (IOPGAT ) between the study and control groups (p < 0.001). In contrast, we found no significant differences within the two study groups in terms of these three IOP values (p > 0.05).

CONCLUSION

Although CCT increased after congenital cataract surgery, corneal biomechanical parameters, including CH and the CRF, were not affected by such surgery. Determination of the IOPcc did not provide any additional information on true IOP, which was independent of CCT in both aphakic and pseudophakic patients after congenital cataract surgery.

Association of Birth Parameters With Corneal Thickness in Prematurely Born and Full-Term School-Aged Children

PURPOSE

The objective of this study was to investigate and compare corneal thicknesses of prematurely born and full-term early school-aged children, who were grouped into birth weight categories according to gestational age.

METHODS

This cross-sectional study included 136 school-aged white children. They were grouped as premature (born before 37 weeks of gestation) and full term (born at or after 37 weeks of gestation). These 2 groups were further divided into birth weight groups according to gestational age as small, appropriate, and large for gestational age. Central corneal thickness (CCT) was measured by ultrasound pachymetry. The intraocular pressures of both groups were measured by a Goldmann applanation tonometer.

RESULTS

The study included right eyes of 136 children. There were 53 girls and 83 boys whose mean age was 6.5 ± 0.9 years (range: 5-8 yrs). Mean pachymetry of the small for gestational age group (526.8 ± 37.9 μm) in prematurely born children was significantly lower than that of appropriate for gestational age (554.6 ± 34.2 μm) (P = 0.039, mean difference 27.8, 95% confidence interval, 1.1-54.5). When prematurely born and full-term children are compared, the mean pachymetric values of the term children (574.5 ± 37.8 μm) were found to be significantly higher than those of the prematurely born children (545.4 ± 35.6 μm) (P ≤ 0.001).

CONCLUSIONS

Birth parameters affect CCT in early school-aged children. Prematurely born, small for gestational age children have lesser CCT. This should be kept in mind at their follow-ups.

Central corneal thickness in primary angle closure and open angle glaucoma

Purpose:

To quantitatively analyze central corneal thickness (CCT) in patients with primary angle closure glaucoma (PACG) and primary open-angle glaucoma (POAG), and to evaluate its correlation with severity of glaucoma.

Methods:

In this retrospective study, records of patients with previously diagnosed POAG or PACG at a tertiary glaucoma service were reviewed. CCT was measured by ultrasound pachymetry. Mean deviation (MD) on visual field (VF) testing was recorded for glaucoma severity determination. CCT and age- and sex-adjusted CCT were compared among the study groups using Student's t-test and analysis of covariance (ANCOVA), respectively. Univariate and multivariate regression models were used for correlation of age, MD and CCT.

Results:

A total of 115 patients with PACG, 215 with POAG, and 100 normal controls were included with mean age of 64.1 ± 10.4, 59.9 ± 10.5, and 62.04 ± 10.80 years, respectively. CCT was thicker in PACG eyes (545.5 ± 46.1 μm) as compared to POAG eyes (531.7 ± 37.3 μm) and controls (531.0 ± 38.3 μm) even after age and gender adjustment (ANCOVA, P = 0.05). CCT was found to decrease with increasing age only in the POAG group (β = -0.57, P = 0.01). Disease severity (MD of VF) was significantly and inversely correlated with CCT in both POAG and PACG eyes (β = 1.89, P = 0.02; and β = 1.38, P = 0.04, respectively) after age and sex correction.

Conclusion:

PACG eyes had thicker CCT as compared to POAG and normal healthy eyes in Iranian subjects. Severity of the disease was inversely correlated with CCT in eyes with both POAG and PACG.

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.

Intraocular Pressure Measurements by Three Different Tonometers in Children with Aphakic Glaucoma and a Thick Cornea

BACKGROUND

To evaluate the agreement in intraocular pressure (IOP) measurements by Ocular Response Analyzer (ORA) and Tono-Pen XL (TXL) with the Goldmann Applanation Tonometer (GAT) and to examine corneal biomechanical properties in aphakic glaucoma patients with a central corneal thickness (CCT) >600 µ.

METHODS

Thirty-six eyes of aphakic glaucoma patients (group 1) and 40 eyes of normal children (group 2) were studied. The mean ORA and TXL IOP values were compared with the GAT-IOP values. Regression analyses were used to evaluate the associations between IOP and CCT, corneal hysteresis (CH), and corneal resistance factor (CRF). Bland-Altman plots were used to evaluate the agreement between the tonometers.

RESULTS

The mean±standard deviations of the age and male/female ratio were 16.58±5.44 and 15.75±5.04 years and 14/22 and 18/22 in group 1 and group 2, respectively. CCT in group 1 was 651.1±42 and in group 2 was 567.3±32.4. In group 1, the mean TXL (22.4, P=0.004), IOPcc (corneal compensated) (27.8, P=0.005), and IOPg (Goldmann correlated) values (28.1, P<0.0001) were greater than GAT-IOP (20.6). In group 2, only IOPg value (16.4) was higher than GAT-IOP (14.8, P=0.04). IOP reading of all the tonometers were positively and negatively associated with CRF and CH in the multiple regression analysis, respectively.

CONCLUSION

The TXL had a greater agreement with the GAT, and the ORA overestimated IOP in aphakic glaucoma patients. The ORA and TXL seemed to be affected by CH and CRF.

Long-term risk of glaucoma after congenital cataract surgery

PURPOSE

To report the long-term risk of glaucoma development in children following congenital cataract surgery.

DESIGN

Retrospective interventional consecutive case series.

METHODS

We retrospectively reviewed the records of 62 eyes of 37 children who underwent congenital cataract surgery when <7 months of age by the same surgeon using a limbal approach. The Kaplan-Meier method was used to calculate the probability of an eye's developing glaucoma and/or becoming a glaucoma suspect over time.

RESULTS

The median age of surgery was 2.0 months and the median follow-up after cataract surgery was 7.9 years (range, 3.2-23.5 years). Nine eyes (14.5%) developed glaucoma a median of 4.3 months after cataract surgery and an additional 16 eyes (25.8%) were diagnosed as glaucoma suspects a median of 8.0 years after cataract surgery. The probability of an eye's developing glaucoma was estimated to be 19.5% (95% CI: 10.0%-36.1%) by 10 years after congenital cataract surgery. When the probability of glaucoma and glaucoma suspect were combined, the risk increased to 63.0% (95% CI: 43.6%-82.3%).

CONCLUSIONS

Long-term monitoring of eyes after congenital cataract surgery is important because we estimate that nearly two thirds of these eyes will develop glaucoma or become glaucoma suspects by 10 years after cataract surgery.

Congenital cataract surgery with intracameral triamcinolone: pre- and postoperative central corneal thickness and intraocular pressure

PURPOSE

To evaluate the change in intraocular pressure (IOP) and central corneal thickness (CCT) of children who underwent congenital cataract surgery with injection of triamcinolone acetonide into the anterior chamber at the end of the procedure.

METHODS

Fifty-three eyes of 34 children <2 years of age who underwent congenital cataract surgery with injection of 1.2 mg/0.03 mL of preservative-free triamcinolone acetonide into the anterior chamber at the end of the procedure were included in this study. IOP and CCT were measured preoperatively and at a mean of 2 and 12 months' follow-up.

RESULTS

The mean IOP was 8.7 ± 0.4 mm Hg preoperatively, 8.4 ± 0.6 mm Hg at the 2-month follow-up, and 8.1 ± 0.3 mm Hg at the 12-month follow-up. The mean CCT was 562 ± 11 μm preoperatively, 563 ± 10 μm at the 2-month follow-up, and 570 ± 10 μm at the 12-month follow-up. There was no significant change in either pre- or postoperative IOP (P = 0.700) or CCT (P = 0.419) over the study period.

CONCLUSIONS

Injection of 1.2 mg triamcinolone acetonide at the end of congenital cataract surgery in children <2 years of age did not significantly affect IOP or CCT in the first year after surgery.

[Aphakic and pseudophakic glaucoma following pediatric cataract surgery]

Modern surgical techniques allow congenital cataract surgery to be performed much more successfully. The development of a secondary glaucoma is the most dreaded postoperative complication (one third of all pediatric secondary glaucomas). Due to the limited value of the available literature, data on prevalence are unreliable. A 10-year postoperative incidence of 10-25% is given in the literature for developing secondary glaucoma and the frequency increases with the duration of follow-up. A major risk factor seems to be the age at the time of surgery. The younger the patient is at the time of surgery the higher the risk of secondary glaucoma. A microcornea seems to be another risk factor in multivariate analysis. The following postoperative changes might be involved in the pathogenesis: peripheral anterior synechia, high iris insertion and membranous material over the trabecular meshwork. Additionally postoperative inflammation, reaction to lens epithelial cells, perioperative barotrauma and loss of anterior segment architecture might also be responsible. In order to evaluate the optimal age window for congenital cataract surgery and risk factors for the development of secondary glaucoma, a prospective longitudinal study is mandatory.

Clinical and experimental advances in congenital and paediatric cataracts

Cataracts (opacities of the lens) are frequent in the elderly, but rare in paediatric practice. Congenital cataracts (in industrialized countries) are mainly caused by mutations affecting lens development. Much of our knowledge about the underlying mechanisms of cataractogenesis has come from the genetic analysis of affected families: there are contributions from genes coding for transcription factors (such as FoxE3, Maf, Pitx3) and structural proteins such as crystallins or connexins. In addition, there are contributions from enzymes affecting sugar pathways (particularly the galactose pathway) and from a quite unexpected area: axon guidance molecules like ephrins and their receptors. Cataractous mouse lenses can be identified easily by visual inspection, and a remarkable number of mutant lines have now been characterized. Generally, most of the mouse mutants show a similar phenotype to their human counterparts; however, there are some remarkable differences. It should be noted that many mutations affect genes that are expressed not only in the lens, but also in tissues and organs outside the eye. There is increasing evidence for pleiotropic effects of these genes, and increasing consideration that cataracts may act as early and readily detectable biomarkers for a number of systemic syndromes.

Glaucoma following infantile cataract surgery

PURPOSE

To examine incidence, risk factors, and outcomes of glaucoma following infantile cataract extraction.

METHODS

A retrospective chart review of all patients who underwent cataract extraction between January 1, 1993, and December 31, 2006, at the Children's Medical Center in Dallas.

RESULTS

Sixty-four eyes met inclusion criteria, of which 11 eyes (17.2%) developed glaucoma during a mean follow-up of 65.1 ± 4.3 months. Age younger than 3 months at cataract diagnosis (odds ratio 4.89, P = .05) or cataract extraction (odds ratio 4.4, P = .047) and the presence of anterior chamber anomalies (odds ratio 8.0, P = .01) were the only risk factors found to have statistical significance for the development of glaucoma. Eight of 11 eyes with glaucoma (72.2%) required at least one surgical intervention. Three of 10 eyes (30%) had a final best-corrected visual acuity below 20/400 and another 4 eyes (40%) demonstrated some degree of amblyopia.

CONCLUSION

Despite modern microsurgical techniques, infantile cataract surgery continues to pose a risk of secondary glaucoma. This was particularly true when cataract was diagnosed and/or extracted in patients younger than 3 months of age. Most eyes that developed glaucoma required surgical management and visual outcomes continue to be poor in this group.

Central corneal thickness in children and adolescents with pediatric glaucoma and eye disorders at risk of developing glaucoma

BACKGROUND

To investigate central corneal thickness (CCT) in children with glaucoma and at risk for glaucoma.

METHODS

The study included 139 children with glaucoma: 66 at risk for glaucoma (ie, aphakia, aniridia, or uveitis) and 66 normal children. CCT was measured by ultrasound pachymetry and intraocular pressure (IOP) by applanation. Analysis of variance was used to compare CCT between groups. Correlation analysis assessed associations between CCT and ocular factors including spherical equivalent, cup-to-disc ratio, glaucoma medications, and number of intraocular surgeries.

RESULTS

CCT was significantly higher for 141 eyes with glaucoma (mean: 0.598 mm, P < .001) and 76 eyes at risk for glaucoma (mean: 0.604 mm, P = .001) than for 66 normal eyes (mean: 0.558 mm). No significant difference was observed between at-risk (P = .989) and glaucoma eyes. Eyes with aphakia (0.653 mm) and aniridia (0.639 mm) had the thickest CCT values. Thinnest CCT was found in anterior segment dysgenesis and uveitis (mean: 0.541 mm). A significant positive correlation between CCT and spherical equivalent was found for glaucoma (r = 0.413; P < .001) and at-risk (r = 0.412; P < .0003) eyes, and between CCT and intraocular surgery for at-risk eyes (P = .0066). A significant negative correlation was found between CCT and cup-to-disc ratio for glaucoma eyes (r = -0.223; P = .01).

CONCLUSION

This is the largest series of CCT in pediatric glaucoma and related disorders. The data suggest caution in application of standard formulas for IOP-to-CCT correction when evaluating children with glaucoma because their mean CCT values extend far beyond values reported for normal eyes.

Acquired central corneal thickness increase following removal of childhood cataracts

PURPOSE

To evaluate central corneal thickness (CCT) in children with congenital/developmental cataracts before and after cataract removal, to correlate CCT with corneal diameters before cataract surgery in this same group, and to evaluate CCT over time in a separate group of children who were already aphakic or pseudophakic at study entry.

DESIGN

Longitudinal study.

METHODS

Children with cataract (Group 1, with pre-cataract-removal CCT) and aphakia/pseudophakia (Group 2, presenting after cataract removal) were included. CCT measurements were performed using ultrasound pachymetry. Normal fellow eyes of unilaterally affected cases served as controls. In bilateral cases, right eyes were used for analyses.

RESULTS

Group 1 comprised 66 children. Before cataract surgery, unilateral cases (n = 31) showed similar CCT and strong association between the affected and fellow eyes (552.0 ± 32.9 μm vs 550.9 ± 40.4 μm, respectively; r(2) = 0.71, P = .0001). After cataract surgery, affected eyes (n = 13) showed mean CCT increase of 29.7 ± 43.1 μm (P = .03) while fellow eyes remained unchanged. Similarly, before cataract surgery, bilateral cases (n = 35) showed similar CCT between the right and left eyes. After cataract surgery, mean CCT increase was 27.4 ± 39.4 μm for first operated eyes of bilateral cases (n = 17, P = .01). Group 2 comprised 50 aphakic/pseudophakic children lacking pre-cataract-removal CCT. CCT was higher in eyes with glaucoma vs those without, at both first and last measurements (ΔCCT 58.9 ± 27.0 μm at first examination, P = .034, and 56.4 ± 27.1 μm at last examination, P = .043, respectively). There was no statistically significant CCT change over the study interval (median 28 months) for either Group 2 eyes with or those without glaucoma.

CONCLUSIONS

CCT in children with cataracts increases after cataract surgery while the fellow eye remains stable. This increase seems to occur early after surgery, likely remaining stable thereafter, though glaucoma can accentuate the increase.

Changes of corneal central thickness of aphakia following congenital cataract surgery under the first six months of life

AIM

To observe the central corneal thickness (CCT) changes in infants and young children who had been undergone bilateral congenital cataract surgery, and to compare the changes with normal control group which was selected from healthy population.

METHODS

A cross section case-control study contained 28 cases (56 eyes) of bilateral aphakia (aphakic group) due to congenital cataract surgery combining with posterior continuous curvilinear capsulorhexis and with anterior vitrectomy during 2-6 months after birth. Fourteen children (28 eyes) of age-sex matched with the aphalic group were selected as normal control group. CCT and intraocular pressure (IOP) were measured postoperatively and the results were compared between groups.

RESULTS

The mean CCT was 653.5±82.4μm in the aphakic group and 579.6±39.2μm in the control group, with a significant difference (P=0.000). The mean value of IOP in aphakic group (22.0±1.6mmHg) was greater than that of control group (16.9±2.1mmHg), P=0.023. There was a negative correlation between age and CCT in normal control group (r=-0.531, P=0.026), and there was no correlation in bilateral aphakia group (r=-0.324, P=0.165)

CONCLUSION

Aphakic children due to congenital cataract surgery have a greater CCT than normal children. It is necessary to consider CCT in evaluating IOP for children after congenital cataract surgery.

Central Corneal Thickness in Microphthalmic Eyes with or without History of Congenital Cataract Surgery

Purpose

TO determine the central corneal thickness (CCT) in microphthalmic aphakic or Pseudophakic eyes as well as in microphthalmic eyes without any history of eye surgery.

Methods

Thirty-two patients with a mean age of 6.41 ±5.24 years after congenital cataract surgery with absolute microcornea, i.e., horizontal corneal diameter (HCD) <10 mm, or relative microcornea, i.e., HCD 10–11 mm but in the affected eye at least 0.5 mm smaller compared to the fellow eye, formed group A. Thirteen patients of mean age 0.94±1.22 years with absolute or relative microcornea plus another developmental anomaly of an eye without any history of eye surgery formed group B. The patients with corneal edema or scars were excluded. The control group consisted of 124 healthy school-aged children. Horizontal corneal diameter was measured with caliper and CCT with an ultrasound pachymeter. In infants, these measurements were performed under general anesthesia.

Results

In 48 eyes in group A and in 16 eyes in group B, the mean CCT was 635.13±65.35 μm and 642.31±93.07 μm, respectively, which was significantly greater (p<0.0001 and p=0.0018) in comparison with the mean CCT (553.58±33.12 μm) in the control group. Regression curve demonstrated the significant increase of CCT values along with the decrease of HCD in microphthalmic eyes.

Conclusions

Small corneas in microphthalmic eyes either with or without congenital cataract surgery have significantly higher CCT. The results demonstrate significant negative correlation between horizontal corneal diameter and CCT.

The incidence of glaucoma following paediatric cataract surgery: a 20-year retrospective study

AIMS

To analyse the incidence of glaucoma in children undergoing cataract surgery and determine whether early surgery is associated with increased risk of glaucoma.

METHODS

A retrospective chart review of all children aged 14 years or less who had surgery for congenital or developmental cataract at one unit over the last 20 years. The children were divided into three groups; group 1 consisting of children aged < or =50 days at surgery, group 2 those aged 51 days to 1 year, and group 3 aged 1-14 years.

RESULTS

We identified a total of 104 eyes of 74 children. The medical records for 100 eyes (71 children) were available for review. In all, 17 eyes (12 children) were aged < or =50 days at surgery, none of which have developed glaucoma. Group 2 consisted of 28 eyes (17 children) with one patient developing glaucoma in both eyes 11 years after surgery. Group 3 consisted of 55 eyes (42 children), none of which have developed glaucoma. After a median follow-up period of 4.9 years (range 0.6-19.6 years, mean 6.4 +/- 5.2 years) 2% of eyes had developed glaucoma. There was no significant difference in the length of follow-up between groups (H=2.979, P=0.22, Kruskal-Wallis Test).

CONCLUSIONS

There was a low incidence of glaucoma in our series and this was not increased in those having surgery in the first 6 weeks of life. Our findings contribute further evidence for the variability in prevalence of glaucoma after paediatric cataract extraction in the literature and suggest that factors other than age at surgery are important risk factors for this condition.

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.

Central corneal thickness: congenital cataracts and aphakia

PURPOSE

To evaluate central corneal thickness (CCT) in normal children (controls) and in those with cataracts, pseudophakia, and aphakia.

DESIGN

Prospective, observational case series.

METHODS

CCT was measured in 369 eyes of 223 children. Subjects with glaucoma, anterior segment abnormalities, or intraocular pressure of more than 30 mm Hg were excluded. Group means were compared for controls and for eyes with pediatric cataracts, pseudophakia, and aphakia.

RESULTS

The mean CCT of eyes with cataracts was more than that of controls (574 +/- 54 microm [n = 46] and 552 +/- 38 microm [n = 230], respectively; P = .001). After excluding from the cataract group those eyes with aniridia, Down syndrome, Marfan syndrome, or glaucoma surgery, the mean CCT (564 +/- 34 microm [n = 36]) was no longer greater than that of controls (P = .07). The mean CCT of pseudophakic eyes (598 +/- 56 microm [n = 29]) was greater than the mean CCT of controls (P < .001) and was similar to the mean CCT of eyes with cataracts (P = .06). The mean CCT of aphakic eyes (642 +/- 88 microm [n = 64]) was greater than the mean CCT of controls (P < .001), eyes with cataracts (P < .001), and eyes with pseudophakia (P = .003).

CONCLUSIONS

In the absence of factors known to affect CCT (Down syndrome, Marfan syndrome, and aniridia), CCT is similar in eyes with pediatric cataracts and normal controls and increases after cataract surgery.

Application of new ophthalmic technology in the pediatric patient

PURPOSE OF REVIEW

The present review will summarize briefly the recent advances in diagnostic tools, surgical techniques, and ophthalmic medications as they relate to the pediatric patient. The review will highlight results from studies that have investigated these new technologies and techniques.

RECENT FINDINGS

In the past several years there has been a plethora of literature on the application of new technologies and surgical techniques in children. New tools have been used for everything from gathering normative data about the pediatric eye to using the technologies to study diseases such as glaucoma and ocular tumors. Results of surgical techniques such as small-incision cataract surgery, sutureless vitrectomy, and refractive surgery are now reported with regularity in the pediatric ophthalmology literature.

SUMMARY

In the past 10 years pediatric ophthalmology has made significant advances. Technology has enabled us to qualify and quantify disease states more efficiently, and to explore new surgical techniques for disease processes that were formerly considered relatively untreatable.