The challenging management of pediatric corneal transplantation: an overview of surgical and clinical experiences

Pediatric corneal transplantation: techniques, challenges, and outcomes

Pediatric corneal transplant is a highly demanding and technically challenging procedure for the cornea surgeon in today's era. These cases pose unique challenges in clinical and surgical management. The indications of pediatric corneal transplant can be therapeutic, tectonic, optical, and cosmetic. Pediatric patients undergoing corneal transplants are at a high risk of graft infection, failure, rejection, dehiscence, and amblyopia due to young age, robust immune system, increased incidence of trauma, and compliance issues. The other factors contributing to graft failure can be allograft rejection, secondary glaucoma, corneal vascularization, multiple surgeries, vitreous prolapse, and lack of treatment compliance. A successful corneal transplant in children depends on meticulous preoperative evaluation, uneventful surgery, the expertise of a corneal surgeon, and regular and timely postoperative follow-up. Therapeutic and optical penetrating keratoplasty are the most commonly performed transplants in children. However, with the advancements in surgical technique and management protocol, the current focus has shifted toward lamellar keratoplasty. Lamellar keratoplasty offers early visual recovery and potentially fewer complications. Visual rehabilitation through corneal transplant in otherwise blind eyes can be a boon for the children. Recently, keratoprostheses have been promising in children with multiple graft failures. The current review gives insights into epidemiology, etiology, indications, clinical characteristics, investigations, management options, recent advances, and the future of pediatric corneal transplants. As surgical techniques continue to grow and comprehension of pediatric corneal transplants is improving, we can safeguard these eyes with the best possible anatomical and functional outcomes.

Penetrating Keratoplasty in Congenital Glaucoma

BACKGROUND

Childhood glaucoma is one of the most common causes of corneal opacity in childhood and is associated with various pathological corneal changes, including corneal enlargement, corneal clouding, and edema. Congenital glaucoma (CG) may cause a decrease in vision outcomes due to corneal opacity or clouding, which is often associated with stimulus deprivation amblyopia. Therefore, to create a balance between preventing amblyopia and sustaining corneal clearance, patients with CG can be managed with early penetrating corneal transplantation surgery along with advanced glaucoma management.

AIM

To investigate the graft survival rate and factors affecting graft survival in patients with congenital glaucoma who underwent penetrating keratoplasty (PKP).

STUDY DESIGN

Cross-sectional.

MATERIALS AND METHODS

Patients with congenital glaucoma who underwent PKP were retrospectively evaluated. The associations between age, corneal diameter, presence of ocular comorbidities, concurrent ocular surgeries with corneal graft, and visual outcomes were assessed.

RESULTS

Among the 30 eyes enrolled in the study, 6 (20%) had aniridia, 6 (20%) had Axenfeld-Rieger syndrome, and 18 (60%) were diagnosed with primary congenital glaucoma. Graft survival rates were 66.6% and 63.33% at 12 and 24 months, respectively. At the end of the follow-up, the overall graft survival rate was 60%. Statistical significance was observed between patient age at the time of surgery and graft failure (p = 0.02). Graft failure was associated with a younger patient age. Functional vision was achieved in 53.3% of patients.

CONCLUSIONS

The management of congenital glaucoma and its corneal complications is a delicate issue that requires great effort. PKP in congenital glaucoma was moderately successful in the present study. To provide functional vision, PKP could be the treatment of choice.

Update on Pediatric Corneal Diseases and Keratoplasty

Managing pediatric corneal disorders is challenging as the prognosis of pediatric keratoplasty depends on several factors. Advancements in the genetic basis of congenital corneal diseases and investigations in congenital corneal conditions provide a better understanding of pediatric corneal conditions. Surgeons performing keratoplasty in children now have a choice of various techniques. Evolving surgical techniques of anterior lamellar and endothelial keratoplasties has expanded the management interventions in these pediatric corneal morbidity conditions; however, considerable concerns still exist in association with corneal transplantation in infants and children. Outcomes in pediatric keratoplasty depend upon the preoperative indications, the timing of surgical intervention, intraoperative and postoperative factors including the patient/care givers' compliance. Factors such as low scleral rigidity, higher rate of graft failure, need for frequent examinations under anesthesia, and difficulty in optimal visual acuity assessment still remain a considerable challenge in pediatric scenarios. In children, deprivation amblyopia as a result of the corneal opacification can adversely affect visual development, causing dense amblyopia. Outcomes to surgical interventions for management of corneal opacification in children is further compromised by the pre-existing amblyopia apart from the concerns of refractive outcome of the graft. Graft rejection, graft infection, amblyopia, and glaucoma continue to be serious concerns. In recent years both anterior and posterior lamellar keratoplasty techniques are being increasingly performed in pediatric eyes, which offer advantages in the form of lower risk of graft rejection. The timing of surgery, careful case selection, cautious intraoperative approach, and optimal postoperative management can improve the anatomical and functional outcome in difficult cases.

Penetrating keratoplasty in children under 3 years old with congenital corneal opacities

AIM

To evaluate the graft rejection and visual outcomes after penetrating keratoplasty (PK) in the presence of various congenital corneal opacities in children.

METHODS

In this retrospective cohort study, children who underwent PK were then followed for 5y. The patient's medical records were collected from June 2014 until June 2019 and analyzed in December 2019. All patients were children under three years old with congenital corneal opacities with or without microcornea who came to a pediatric ophthalmologist and underwent PK in Jakarta Eye Center (JEC). Beforehand, all children have participated in a thorough evaluation for PK. In the case of severe microcornea was not advised to undergo surgery. The visual outcomes and graft survival rate were described in percentages. The graft survival plot was presented with Kaplan-Meier, while the visual acuity was analyzed using the Wilcoxon signed ranks test.

RESULTS

Sixteen eyes from eleven patients (seven girls and four boys) underwent PK. The graft survival rate of the first 6, 12, and 18 mo later of keratoplasty was 100%, 83.3%, and 66.7%, respectively. The overall mean survival time is 22mo (standard error 2.419), and no significant difference between the patients underwent PK before and after 36mo of their age (P=0.52). The graft failure was 50%, and post-surgery complications included cataract 43.7%, band keratopathy 12.5%, and scleromalasia 6.25%. Wilcoxon test analysis of visual acuity post keratoplasty was not statistically significant (P=0.34), while overall showed 44% improvements of visual outcome for 5y of follow-up. With a good survival at one year up to 22mo (83.3%), the visual acuity could be achieved (63%), and showed improvements (44%) during follow-up.

CONCLUSION

The complications are frequent for pediatric PK. Thus, corneal surgery on infants requires careful case selection, adequate pre-operative evaluation, skilled surgery (optical correction), very close cooperation family-physician, intensive post-operation care, and amblyopia management in the future.

Possible association between viral infection and poor survival of the corneal graft after penetrating keratoplasty in patients with congenital corneal opacity: a cohort study

BACKGROUND

Congenital corneal opacity (CCO) is a rare disorder. Penetrating keratoplasty (PK) is the main surgical option for CCO, but many factors affect graft survival. Therefore, this study aimed to perform a virological examination of CCO specimens after PK to explore the relationship between virological factors and graft survival after PK.

METHODS

This prospective study included consecutive patients (<6 months of age) diagnosed with CCO and treated with PK at Beijing Tongren Hospital from August 2017 to January 2018. Next-generation sequencing was used to detect viral DNA in the CCO specimens. The survival of the primary graft was analysed using the Kaplan-Meier method.

RESULTS

Overall, 24 eyes of 24 infants were treated with PK during the study period. The mean age at surgery was 4.8±1.1 months. Epstein-Barr virus DNA was detected in two specimens, varicella-zoster virus DNA in one specimen, herpes simplex virus DNA in three specimens and cytomegalovirus DNA in one specimen. In the virus-positive group, only one (14.3%) graft remained clear during follow-up. In contrast, in the virus-negative group (n=17), 13 (76.5%) grafts were still clear at the last follow-up. The mean survival of the grafts in the virus-positive group was significantly shorter than in the virus-negative group (11.0±9.8 months vs 27.1±7.7, p<0.001).

CONCLUSION

The presence of viral DNA in CCO specimens might be associated with poor graft survival after PK.

Miniscleral Contact Lens in Pediatric Age Group: Indications, Safety, and Efficacy

OBJECTIVE

To report indications, fitting feasibility, and safety of miniscleral design (MSD) lenses in children.

METHODS

Medical records of patients aged <18 years at the time of referral to Contact Lens Clinic of Farabi Eye Hospital, because of inadequate spectacle-corrected visual acuity, rigid gas-permeable or soft contact lens intolerance, and ocular surface disease were reviewed. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), best-corrected vision with the lens (CCVA), lens parameters, and comfortable daily wearing time (CDWT) were documented.

RESULTS

Seventy-two eyes of 52 pediatric patients were fitted with MSD lens over a 9-year period. The indications for MSD lens fitting were keratoconus (29 eyes), corneal scarring from ocular trauma (16 eyes), ocular surface diseases (25 eyes), and postkeratitis corneal scar (2 eyes). The average UCVA and the mean difference between CCVA and BSCVA were 1.20 and 0.55 logarithm of the minimal angle of resolution, respectively, which shows statistically significant improvement. This significant increase in vision was even seen in those who were referred for the management of ocular surface diseases. The mean CDWT for most patients was 10 hr/day.

CONCLUSION

Miniscleral design lens can be used as a safe and helpful modality to provide good vision and comfort in children experiencing ectatic disorders, traumatic corneal scars, and ocular surface diseases.

Pediatric Keratoplasty: The Success of a Tailor-Made Surgical Management

A Romanian 5-month-old girl was referred to our hospital after being diagnosed with congenital corneal opacities. She was sent in order to undergo penetrating keratoplasty (PKP) surgery on her left eye. The patient presented a natural tendency to esotropia. We took into account two different surgical techniques: PKP and lamellar keratoplasty. The latter was technically impossible to carry out because of the full-thickness corneal opacity. We conducted several tests to accurately obtain the patient's preoperative parameters and specifically decide the details of the surgical technique to be applied. For each step of the surgical procedure we carefully compared the individual results in the literature in order to ensure a stable and lasting result. In addition to this, we used an innovative suture technique: nylon thread, interrupted suture, alternating 11-0/10-0 threads. Six months after the operation, the functional result obtained was 4–5/10, with recovery of the fixation. Pediatric PKP, therefore, cannot follow a surgical standard, but requires careful case-by-case evaluation from the pre- to the postoperative phase, with the aim of maximizing stable visual acuity.

Organ donation from brain-dead pediatric donors in Korea: A 5-year data analysis (2013-2017)

In Korea, 2-4% of brain-dead organ donations are from donors <16 years of age. We aimed to identify the current status of and challenges in pediatric organ donation from brain-dead donors in Korea. We performed a retrospective analysis using data from KONOS between January 1, 2013, and December 31, 2017. Our research identified 107 pediatric donors aged <16 years, representing 4.4% of all donors in Korea between 2013 and 2017. The consent rate was higher in PDs than in adult donors (47.0% vs 44.9%). The most common cause of brain death in PDs was hypoxia (28.0%), followed by brain tumor and trauma, whereas that in ADs was brain hemorrhage/stroke (42.4%), followed by trauma and hypoxia (P < .001). In both groups, the kidney (PDs vs ADs: 75.7% vs 88.5%), liver (58.9% vs 46.2%), and heart (32.7% vs 29.7%) were the organs most commonly transplanted. However, pancreatic (PDs vs ADs: 30.0% vs 11.7%, P < .001) and small bowel transplantations (4.7% vs 0.2%, P < .001) were more common in PDs, whereas lung (7.5% vs 14.5%, P = .046) and corneal transplantations (14.0% vs 36.2%) were more common in ADs. Only a small proportion of organ donations in Korea are from PDs, but this rate has been maintained. Given the current status of brain-dead pediatric organ donation, a more active approach is required to bring about improvement.

Peters anomaly: A 5-year experience

BACKGROUND

Peters anomaly is a rare, congenital eye malformation characterized by an opaque cornea and blurred vision. Central corneal opacification can lead to delayed progression of visual development caused by defects in Descemet membrane and the posterior stroma. These children require several anesthetics for multiple eye examinations under anesthesia and corneal transplantation.

AIMS

We sought to review the anesthetic management of patients with Peters anomaly for ophthalmologic procedures at Westchester Medical Center, a major referral center for Peters anomaly.

METHODS

A retrospective chart review was completed which included pediatric patients who underwent ophthalmologic procedures related to Peters anomaly from 2013-2018.

RESULTS

The charts of 35 patients with Peters anomaly were reviewed: 14 patients with Peters anomaly Type I, 10 patients with Peters anomaly Type II, and 11 patients with Peters plus syndrome. Thirty patients required three procedures on average, two examinations under anesthesia pre- and post-transplant, and anesthesia for the corneal transplant itself. The youngest patient encountered for examination under anesthesia was 39-week postconceptual age. Anesthetic time for examination under anesthesia averaged 31 minutes using a laryngeal mask airway while corneal transplant averaged 104 minutes utilizing endotracheal intubation. Postanesthesia care unit stay averaged 51 minutes following examination under anesthesia and 65 minutes after corneal transplant. All examinations under anesthesia were successfully completed without adverse events with the use of a laryngeal mask airway. This case series includes two patients with Goldenhar syndrome and Al-Gazali syndrome accompanying Peters anomaly.

CONCLUSION

Although limited by its retrospective nature, this case series describes the cardiac and systemic implications of patients undergoing anesthesia with Peters anomaly. Our experience indicates that general anesthesia and airway manipulation are tolerated with minor postoperative concerns in these infants. Pediatric patients with Peters anomaly require multiple anesthetics for repeated ophthalmologic interventions. The laryngeal mask airway can be routinely utilized in infants less than 3 months of age for an eye examination under anesthesia with no airway complications noted. Perioperative providers should be aware of the multisystemic implications in patients with Peters plus syndrome.

Recent Surgical Trends in Pediatric Corneal Transplantation: A 13-Year Review

PURPOSE

Corneal transplantation is the standard of care for pediatric corneal opacities, but little consensus exists on optimal surgical management. Our goal was to evaluate cross-sectional data of donor and recipient characteristics collected from eye banks providing tissue for pediatric corneal transplant cases to assess surgical trends in pediatric keratoplasty over the past 13 years.

METHODS

We performed a retrospective review of recipient data, collected from 4 major eye banks, for pediatric patients (<18 years) who underwent corneal transplantation between January 2005 and December 2017. We analyzed trends in surgical indications, types of keratoplasty, and donor/recipient characteristics.

RESULTS

Our database included 2620 total pediatric cases. Penetrating keratoplasty (PKP) remains the most common surgery performed (79.8%), but more partial-thickness transplant cases [eg, endothelial keratoplasty (EK)] have been performed since 2008. The most commonly reported transplant indication was ectasias/thinnings (34.1%) overall and congenital opacities (17.0%) in children less than 5 years. Average donor age was significantly lower for the youngest recipient age group of less than 5 years (P < 0.001); endothelial cell count was also higher, and death-to-surgery time was lower for PKP and EK cases versus other keratoplasties.

CONCLUSIONS

Indications for transplant vary across age groups but are consistent with previous reports. Popularity of partial-thickness transplants has increased since 2008. Surgeons prefer younger donor tissue for younger patients and have higher thresholds for endothelial cell count for PKP and EK cases. Centralized tracking of pediatric keratoplasty cases is necessary for further investigation of long-term outcomes.

Optical Coherence Tomography-Guided Transepithelial Phototherapeutic Keratectomy for Central Corneal Opacity in the Pediatric Population

Purpose

To report the outcomes of optical coherence tomography- (OCT-) guided transepithelial phototherapeutic keratectomy (PTK) for central corneal opacity in the pediatric population.

Methods

The charts of 10 eyes of 8 children aged 9 to 17 with central corneal opacity from various pathologies who underwent a standardized OCT-guided transepithelial PTK technique at a single private practice institution were retrospectively reviewed. The corneal topographic findings, OCT measurements, and visual results with refractive outcomes were analyzed 6 months after the PTK treatment.

Results

All 10 eyes tolerated the procedure well without any significant intraoperative or postoperative complications. Uncorrected and best spectacle-corrected visual acuity (BSCVA) significantly improved postoperatively (p < 0.0001 and p=0.0045, respectively). The absolute value of spherical equivalent on cycloplegic refraction significantly improved postoperatively as well (p=0.0014), but there were no significant changes in topographic measurements. Seven out of the 10 eyes had complete resolution of the central corneal opacity on OCT imaging. None of the subjects lost any lines of BSCVA and developed recurrence of the corneal opacity from the primary disease condition or required keratoplasty during the follow-up period.

Conclusions

OCT-guided transepithelial PTK can provide excellent visual outcomes in pediatric patients with central corneal opacities.

Pediatric Corneal Transplants: Review of Current Practice Patterns

PURPOSE

To facilitate development of standardized guidelines for management of pediatric patients undergoing keratoplasty, particularly the youngest cohort, through a comprehensive survey assessing recent trends in practice patterns of corneal specialists and pediatric ophthalmologists.

METHODS

A cross-sectional, observational study of current practices pertaining to pediatric keratoplasty was performed by designing a 20-question survey focused on preoperative indications, surgical techniques, and postoperative management. This survey was sent electronically to corneal specialists and pediatric ophthalmologists. Results were compared with the findings of previous studies regarding pediatric keratoplasty.

RESULTS

Of the 80 ophthalmologists who responded, 51.3% currently perform pediatric keratoplasty; only 20% have performed >50 cases. The majority (73.8%) completed solely corneal fellowships; all perform penetrating keratoplasty, 35.2% also perform endothelial keratoplasty, and 37% also perform lamellar keratoplasty. Peters anomaly was the most common indication for transplantation (34.3%). The majority believe that 1 to 3 months is the optimal age range to perform keratoplasty for both monocular and binocular congenital corneal opacities, although 13% stated that they would never perform keratoplasty in a patient with a monocular opacity. All surgeons report modifying their intraoperative techniques for pediatric patients, but specific practices and postoperative management protocols vary. There is a consensus regarding the importance of amblyopia therapy in these patients.

CONCLUSIONS

Our results were consistent with the published literature regarding the indication and types of surgery performed. Variability among surgical techniques and postoperative management protocols highlights the necessity of creating standardized guidelines to optimize management of pediatric patients undergoing keratoplasty. Collaborative efforts between corneal and pediatric specialists are crucial for defining visual rehabilitation protocols to enhance visual outcomes.