Childhood Lensectomy Is Associated with Static and Dynamic Reduction in Schlemm Canal Size

Incidence of and risk factors for suspected and definitive glaucoma after bilateral congenital cataract surgery: a 5-year follow-up

AIMS

To report the incidence and associated risk factors for developing suspected and definitive glaucoma after bilateral congenital cataract (CC) removal with a 5-year follow-up.

METHODS

Secondary analysis of a prospective longitudinal cohort study. Bilateral CC patients who had undergone cataract surgery between January 2011 and December 2014 at Zhongshan Ophthalmic Centre were recruited. Suspected glaucoma was defined as persistent ocular hypertension requiring medical treatment. Definitive glaucoma was defined as accompanied by the progression of glaucomatous clinical features. According to postoperative lens status in 5 years follow-up: 130 eyes in the aphakia group; 219 in the primary intraocular lens (IOL) implantation group and 337 in the secondary IOL implantation group. The Kaplan-Meier survival and Cox regression analyses were used to explore the cumulative incidence and risk factors for suspected and definitive glaucoma.

RESULTS

Three hundred fifty-one children (686 eyes) with bilateral CCs were enrolled in the study. The mean age at surgery was 1.82±2.08 years, and the mean follow-up duration was 6.26±0.97 years. Suspected and definitive glaucoma developed at a mean time of 2.84±1.75 years (range 0.02-7.33 years) postoperatively. The cumulative incidence of suspected and definitive glaucoma was 9.97% (35 of 351 patients), including 6.12% (42 eyes) for definitive glaucoma and 2.48% (17 eyes) for suspected glaucoma. Microcornea (HR 4.103, p<0.0001), CC family history (HR 3.285, p=0.001) and initial anterior vitrectomy (HR 2.365 p=0.036) were risk factors for suspected and definitive glaucoma. Gender, age at surgery, intraocular surgery frequency, length of follow-up and frequency of neodymium-doped yttrium aluminumaluminium garnet laser were non-statistically significant. Primary IOL implantation was a protective factor (HR 0.378, p=0.007).

CONCLUSIONS

Identifying suspected and definitive glaucoma after bilateral CC surgery can lower the risk of secondary blindness in children. Patients with related risk factors need to pay more attention and thus reach early intervention and treatment during clinical practice. Primary IOL implantation may be a potential protective factor, need more clinical trials to be verified.

TRIAL REGISTRATION NUMBER

NCT04342052.

Predicting the risk of glaucoma-related adverse events following secondary intraocular lens implantation in paediatric eyes: a 3-year study

AIMS

To establish and evaluate predictive models for glaucoma-related adverse events (GRAEs) following secondary intraocular lens (IOL) implantation in paediatric eyes.

METHODS

205 children (356 aphakic eyes) receiving secondary IOL implantation at Zhongshan Ophthalmic Center with a 3-year follow-up were enrolled. Cox proportional hazard model was used to identify predictors of GRAEs and developed nomograms. Model performance was evaluated with time-dependent receiver operating characteristic (ROC) curves, decision curve analysis, Kaplan-Meier curves and validated internally through C-statistics and calibration plot of the bootstrap samples.

RESULTS

Older age at secondary IOL implantation (HR=1.5, 95% CI: 1.03 to 2.19), transient intraocular hypertension (HR=9.06, 95% CI: 2.97 to 27.67) and ciliary sulcus implantation (HR=14.55, 95% CI: 2.11 to 100.57) were identified as risk factors for GRAEs (all p<0.05). Two nomograms were established. At postoperatively 1, 2 and 3 years, model 1 achieved area under the ROC curves (AUCs) of 0.747 (95% CI: 0.776 to 0.935), 0.765 (95% CI: 0.804 to 0.936) and 0.748 (95% CI: 0.736 to 0.918), and the AUCs of model 2 were 0.881 (95% CI: 0.836 to 0.926), 0.895 (95% CI: 0.852 to 0.938) and 0.848 (95% CI: 0.752 to 0.945). Both models demonstrated fine clinical net benefit and performance in the interval validation. The Kaplan-Meier curves showing two distinct risk groups were well discriminated and robust in both models. An online risk calculator was constructed.

CONCLUSION

Two nomograms could sensitively and accurately identify children at high risk of GRAEs after secondary IOL implantation to help early identification and timely intervention.

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.

[Glaucoma in infancy and childhood]

Glaucoma in infancy and childhood is a rare disease. An immediate diagnosis and treatment are absolutely necessary to prevent blindness of affected children. Childhood glaucoma is characterized by a heterogeneous phenotype: besides primary congenital glaucoma, secondary types often exist and the individualized treatment requires an experienced interdisciplinary team. The pathogenesis is not always discernible and genetic alterations sometimes cause the disease. A surgical procedure is usually necessary to lower the intraocular pressure. Refractive and orthoptic care are equally important to avoid amblyopia. This article gives an overview of childhood glaucoma and outlines the most important diagnostic and therapeutic aspects.

A Comprehensive Review of Pediatric Glaucoma Following Cataract Surgery and Progress in Treatment

Glaucoma following cataract surgery (GFCS) remains a serious postoperative complication of pediatric cataract surgery. Various risk factors, including age at lensectomy, intraocular lens implantation, posterior capsule status, associated ocular/systemic anomaly, additional intraocular surgery, and a family history of congenital cataract and GFCS, have been reported. However, the optimal surgical approach remains unclear. This review evaluates the diagnostic criteria, classification, risk factors, mechanism, and surgical management, especially the efficacy of minimally invasive glaucoma surgery, in GFCS, and aims to propose an optimal clinical management strategy for GFCS. The results of our review indicate that ab interno trabeculotomy (goniotomy) may be the most appropriate first-line treatment for GFCS.

Anterior segment optical coherence tomography findings in the Infant Aphakia Treatment Study (IATS): a secondary analysis of a randomized clinical trial

PURPOSE

To correlate the diagnosis of glaucoma among children in the Infant Aphakia Treatment Study (IATS) by age 10 years with anterior segment optical coherence tomography (AS-OCT) findings.

METHODS

A multicenter randomized controlled trial of 114 infants with unilateral congenital cataract who were 1-6 months of age at surgery. Data on long-term glaucoma-related status and outcomes were collected when children were 10.5 years old. Participants were randomized at cataract surgery to either primary intraocular lens (IOL) or no IOL implantation (contact lens [CL]). AS-OCT findings in eyes with glaucoma were compared to eyes which did not have glaucoma and to the fellow eyes, between fellow and treated eyes, and between the IOL and CL groups.

RESULTS

There were no significant differences in the mean nasal and temporal anterior chamber angle (ACA) or mean nasal and temporal angle opening distance (AOD) for nonglaucomatous, glaucomatous, and fellow eyes (P = 0.31, 0.16, 0.43, 0.08 resp.). There were also no significant differences in mean nasal and temporal ACA and AOD between fellow and treated eyes (P = 0.44, 0.67, 0.57, 0.38 resp.), or between IOL and CL groups (P = 0.36, 0.35, 0.49, 0.44, resp.).

CONCLUSIONS

AS-OCT confirmed that eyes with glaucoma in IATS had predominantly open angles with similar ACA and AOD to eyes without glaucoma and to fellow eyes. Furthermore, congenital cataract surgery with or without an IOL did not result in a significant difference in ACA or AOD compared to fellow eyes in IATS.

Infantile Aphakic Glaucoma: A Proposed Mechanism

PURPOSE

To review information pertaining to secondary glaucoma following infant lensectomy and provide evidence to support the mechanism responsible for this condition.

METHODS

Reported risk factors and proposed mechanisms for infantile aphakic glaucoma are reviewed. Laboratory studies and clinical observations in affected patients with glaucoma are described. Evidence of postoperative anterior chamber fibrosis is reviewed and interpreted.

RESULTS

Clinical evidence demonstrated the development of anterior chamber fibrosis following infant cataract surgery. Laboratory studies showed liberated lens epithelial cell transition to fibroblasts.

CONCLUSIONS

The review and assessment of laboratory and clinical evidence support the proposal that infantile aphakic glaucoma is caused, in part, by postoperative anterior chamber fibroization related to lens cell dispersion, cytokine activation, and epithelial-mesenchymal transition with resultant filtration angle fibrosis and secondary loss of filtration function. [J Pediatr Ophthalmol Strabismus. 2022;59(4):236-242.].

Approach to childhood glaucoma: A review

Childhood glaucoma represents a heterogenous group of rare ocular conditions that may result in significant sight threatening complications related to elevated intraocular pressure (IOP). It can be classified as either primary or secondary and the latter may have systemic associations. This review will be based on the work of the childhood glaucoma research network (CGRN) and will focus on the diagnosis and management of the most common types of childhood glaucoma. These include primary congenital glaucoma (PCG) and juvenile open angle glaucoma (JOAG) as well as secondary causes of glaucoma associated with non-acquired ocular anomalies (Axenfeld-Rieger anomaly; Peters anomaly and Aniridia), glaucoma associated with systemic disease (Sturge Weber syndrome and Neurofibromatosis), those due to acquired conditions (Uveitic glaucoma, trauma and tumours) and importantly glaucoma following cataract surgery.

Glaucoma following Infant Lensectomy: 2021 Update

PURPOSE

To review information pertaining to glaucoma following infant lensectomy surgery and to provide evidence to support the responsible mechanism of this condition.

METHODS AND RESULTS

Described risk factors and proposed mechanisms for infantile aphakic glaucoma were assessed. The clinical evidence observed in affected glaucoma patients was analyzed, and evidence of postoperative anterior chamber fibrosis was reviewed and interpreted.

CONCLUSION

The review and assessment of laboratory and clinical evidence support the proposal that infantile aphakic glaucoma is caused, in part, by postoperative anterior chamber fibroization related to lens cell dispersion and active epithelial-mesenchymal transition with resultant filtration angle tissue injury and loss of function.

Incidence and Risk Factors of Glaucoma Following Pediatric Cataract Surgery With Primary Implantation

PURPOSE

To determine the incidence and risk factors for glaucoma after pediatric cataract surgery with intraocular lens (IOL) implantation.

DESIGN

Retrospective, consecutive case series.

METHODS

In this single-center study, we reviewed 136 children (199 eyes) who underwent pediatric cataract surgery before 1 year of age with a minimum of 1 year of follow-up. The intervention used was pediatric cataract surgery with IOL implantation, and the primary outcome measure was the presence or absence of secondary glaucoma.

RESULTS

The mean age at surgery was 148 ± 93 days (range 30-359 days) with a mean follow-up of 6.3 ± 3.6 years (range 1.1-12.8 years). Glaucoma developed in 31 eyes (16%) with 5- and 10-year incidence rates of 12% and 28%, respectively. The incidence of glaucoma seemed to be bimodal, with a first peak occurring after a mean delay of 2.5 months (range 1.6-4.1 months) and a second peak occurring after a mean delay of 5.7 years (range 2.6-11.7 years). Younger age at surgery, shorter axial length, longer follow-up, use of trypan blue, reintervention, and bilateral surgery were associatied with a higher incidence of glaucoma. Multivariate analysis including the aforementioned variables indentified longer follow-up (odds ratio [OR] = 1.3 [95% confidence interval {CI} 1.1-1.6], P = .001), reintervention (OR = 4.1 [95% CI 1.2-13.4], P = 0.02), and the use of trypan blue (OR = 4.1 [95% CI 1.3-13.1], P = .02) as predictors for the development of glaucoma.

CONCLUSION

Glaucoma is a common complication after pediatric cataract surgery. It seemed to have a bimodal incidence. Risk factors for glaucoma development were reintervention, the use of trypan blue, and a long follow-up.

Angle Surgery in Pediatric Glaucoma Following Cataract Surgery

Glaucoma is a common and sight-threatening complication of pediatric cataract surgery Reported incidence varies due to variability in study designs and length of follow-up. Consistent and replicable risk factors for developing glaucoma following cataract surgery (GFCS) are early age at the time of surgery, microcornea, and additional surgical interventions. The exact mechanism for GFCS has yet to be completely elucidated. While medical therapy is the first line for treatment of GFCS, many eyes require surgical intervention, with various surgical modalities each posing a unique host of risks and benefits. Angle surgical techniques include goniotomy and trabeculotomy, with trabeculotomy demonstrating increased success over goniotomy as an initial procedure in pediatric eyes with GFCS given the success demonstrated throughout the literature in reducing IOP and number of IOP-lowering medications required post-operatively. The advent of microcatheter facilitated circumferential trabeculotomies lead to increased success compared to traditional <180° rigid probe trabeculotomy in GFCS. The advent of two-site rigid-probe trabeculotomy indicated that similar results could be attained without the use of the more expensive microcatheter system. Further studies of larger scale, with increased follow-up, and utilizing randomization would be beneficial in determining optimum surgical management of pediatric GFCS.

Objective quantification of lens nuclear opacities using swept-source anterior segment optical coherence tomography

Background/aims

The primary objective is to quantify the lens nuclear opacity using swept-source anterior segment optical coherence tomography (SS-ASOCT) and to evaluate its correlations with Lens Opacities Classification System III (LOCS-III) system and surgical parameters. The secondary objective is to assess the diagnostic performance for hard nuclear cataract.

Methods

This cross-sectional study included 1222 patients eligible for cataract surgery (1222 eyes). The latest SS-ASOCT (CASIA-2) was used to obtain high-resolution lens images, and the average nuclear density (AND) and maximum nuclear density (MND) were measured by a custom ImageJ software. Spearman’s correlations analysis was used to assess associations of AND/MND with LOCS-III nuclear scores, visual acuity and surgical parameters. The subjects were then split randomly (9:1) into the training dataset and validating dataset. Receiver operating characteristic curves and calibration curves were constructed for the classification on hard nuclear cataract.

Results

The AND and MND from SS-ASOCT images were significantly correlated with nuclear colour scores (AND: r=0.716; MND: r=0.660; p<0.001) and nuclear opalescence scores (AND: r=0.712; MND: r=0.655; p<0.001). The AND by SS-ASOCT images had the highest values of Spearman’s r for preoperative corrected distance visual acuity (r=0.3131), total ultrasonic time (r=0.3481) and cumulative dissipated energy (r=0.4265). The nuclear density had good performance in classifying hard nuclear cataract, with area under the curves of 0.859 (0.831–0.886) for AND and 0.796 (0.768–0.823) for MND.

Conclusion

Objective and quantitative evaluation of the lens nuclear density using SS-ASOCT images enable accurate diagnosis of hard nuclear cataract.

Schlemm Canal and Trabecular Meshwork Features in Highly Myopic Eyes With Early Intraocular Pressure Elevation After Cataract Surgery

PURPOSE

To investigate the morphologic features of the Schlemm canal and trabecular meshwork in highly myopic eyes with early intraocular pressure (IOP) elevation after cataract surgery.

DESIGN

Retrospective case-control study.

METHODS

Eighty-eight highly myopic eyes of 88 patients after uneventful cataract surgery were included, 31 of which had early postoperative IOP elevation and 57 of which did not. The morphologic features of the Schlemm canal and trabecular meshwork, collected with swept-source optical coherence tomography before surgery, were reviewed. Backwards stepwise multiple linear regression was used to investigate the anatomic risk factors for early IOP elevation in highly myopic eyes.

RESULTS

Highly myopic eyes with early postoperative IOP elevation had smaller Schlemm canal vertical diameter and area, as well as smaller trabecular meshwork thickness and width, in each quadrant than the non-elevation group. There was no significant difference in Schlemm canal horizontal diameter between the IOP elevation and non-elevation groups. In the highly myopic eyes, average Schlemm canal vertical diameter, Schlemm canal area, trabecular meshwork thickness, and width were all correlated negatively with the IOP elevation. A multivariate analysis showed that average Schlemm canal vertical diameter (β = -0.262, P = .004) and trabecular meshwork thickness (β = -0.173, P < .001) were significantly associated with early transient IOP elevation in highly myopic cataract eyes.

CONCLUSIONS

A smaller vertical diameter of Schlemm canal and a thinner trabecular meshwork are 2 anatomic risk factors for early IOP elevation after cataract surgery in highly myopic eyes.

[Timing of congenital cataract surgery : Amblyopia versus aphakic glaucoma]

A congenital cataract is a rare disorder, which is associated with a high risk of amblyopia. Ophthalmologists are faced with many diagnostic and surgical challenges in the management of this disease. Older children can undergo primary treatment with an intraocular lens, whereas children younger than 12 months of age usually initially remain aphakic. The most frequent long-term complication of aphakic eyes following congenital cataract surgery in connection with posterior capsulorrhexis and anterior vitrectomy is aphakic glaucoma, which in individual cases can lead to substantial impairment of vision. Many factors have been reported to increase the risk of postoperative glaucoma, including microphthalmos, fetal nuclear cataract, conspicuous family history and associated ocular malformations, such as persistent fetal vasculature (PFV). Cataract surgery during early infancy is well-established to be the most important factor for the formation of postoperative aphakic glaucoma. In individual treatment planning it has to be considered that although younger age at the time of cataract removal can provide better prerequisites for prophylaxis of amblyopia, it also confers a higher risk of development of aphakic glaucoma. Children undergoing congenital cataract surgery have to be regularly monitored given the lifelong risk for postoperative complications, such as aphakic glaucoma.

Iridocorneal Angle and Anterior Segment Structure of Eyes in Children with Cataract

OBJECTIVE

To evaluate the morphology of iridocorneal angle and anterior segment in eyes of children with cataract.

METHODS

In this prospective cross-sectional study, we included eyes of children with bilateral cataract as well as unilateral cataract and fellow eyes. The iridocorneal angle was evaluated using gonioscopy. We compared the preoperative structures of iridocorneal angle and anterior segment between cataractous eyes and fellow eyes. The grading of iridocorneal angle and anatomical changes were analyzed.

RESULTS

We finally recruited 55 eyes of 55 children with bilateral cataract and 41 cataractous eyes and 33 fellow eyes of 41 children with unilateral cataract. The fellow eyes were used as a control group. The iridocorneal angle was open in eyes with pediatric cataract when compared to control eyes. The eyes with cataract exhibited more pigments on the trabecular meshwork than control eyes did (unilateral cataract vs. control, p = 0.013; bilateral cataract vs. control, p = 0.002). The eyes with cataract exhibited a smaller cornea than control eyes (unilateral cataract vs. control, p = 0.031; bilateral cataract vs. control, p < 0.001).

CONCLUSIONS

The iridocorneal angle is open in the eyes of children with cataract. Eyes with increased pigments on the trabecular meshwork need to be carefully monitored and surgeons should to be on the alert for postoperative glaucoma.

Optical Coherence Tomography Findings After Childhood Lensectomy

Purpose

To explore the impact of childhood lensectomy on posterior segment development.

Methods

Cross-sectional observational study at children's eye clinics at a tertiary referral center in London, UK. We included 45 children age 4 to 16 years with healthy eyes and 38 who had undergone lensectomy. We acquired posterior segment optical coherence tomography scans of both eyes. We used parametric and nonparametric tests in SPSS24 for the comparison of parameters between groups and within individuals; a P value less than 0.05 was considered significant. The main outcome measures were foveal pit depth and subfoveal choroidal thickness (CT). Secondary outcomes were inner and outer ring CT and photoreceptor layer parameters, macular and peripapillary retinal nerve fiber layer thickness.

Results

Foveal pit depth and subfoveal CT are significantly reduced in eyes that have undergone lensectomy compared with nonoperated eyes. Inner ring CT and outer ring CT are reduced. Foveal inner retinal layer thickness is increased. Mean inner retinal and outer nuclear layer thickness are not affected.

Conclusions

Childhood lensectomy is associated with a reduction in developmental foveal pit deepening and lack of developmental thickening of the posterior choroid. Mechanical and optical disruption of foveal and subfoveal choroidal development may affect structural foveal development after childhood lensectomy.

Comparative Intraoperative Anterior Segment OCT Findings in Pediatric Patients with and without Glaucoma

PURPOSE

To compare the angle structures during surgery using anterior segment (AS) OCT in children with and without glaucoma.

DESIGN

Prospective comparative study, with single masked grader evaluating AS OCT images.

PARTICIPANTS

This study included a total of 44 eyes of 8 children with glaucoma and 14 children without glaucoma undergoing ophthalmic surgery with general anesthesia. The median age for the glaucoma group was 6 months (range, 0.5-108 months), and that for the nonglaucoma group was 42 months (range, 14-95 months).

METHODS

An Envisu C2300 handheld OCT with a high-resolution AS lens was used to capture videos of temporal and nasal quadrant anterior chamber angles from each eye. Still images of the temporal and nasal angles were selected and then graded by a masked ophthalmologist examiner to determine whether Schlemm's canal (SC) was visible, if abnormal tissue was present in the angle, and whether intrascleral lumens were present. Clinical correlation with severity of glaucoma was performed after AS OCT images were graded.

MAIN OUTCOME MEASURES

Presence or absence of SC on AS OCT in glaucomatous and nonglaucomatous eyes.

RESULTS

Schlemm's canal was present in 7 of 13 glaucomatous eyes compared with 27 of 27 nonglaucomatous eyes. In patients with unilateral glaucoma, absence of SC was noted only in the affected eye. Eight eyes with glaucoma showed abnormal tissue over the angle and SC. Intrascleral lumen and collector channels were found in both groups. Two patients with severe stenosis of SC during glaucoma angle surgery showed absent SC on AS OCT.

CONCLUSIONS

Intraoperative AS OCT identified differences in the presence and characteristics of SC and the anterior chamber angle in pediatric patients with and without glaucoma. Further studies are needed to determine clinical correlation.