Indications and outcomes of keratoplasties in children during a 40-year period

Pediatric keratoconus epidemiology: a systematic scoping review

BACKGROUND

Pediatric keratoconus (pediatric KC) causes progressive deformation of the cornea in children and adolescents, leading to a gradual loss of vision and a need for rehabilitation. However, new treatments may halt the disease and prevent worse outcomes that require penetrating keratoplasty and its associated morbidity and high cost, irreversible loss of vision, and amblyopia. Few systematic reviews focus on keratoconus-and even fewer, on pediatric KC.

METHODS

Here, we report a systematic scoping review of pediatric KC epidemiology and discuss the studies reporting data on pediatric KC. We used PRISMA-ScR methodology and checklists in the elaboration of the manuscript. The inclusion criteria were: English language; publication between August 7, 1998, and August 7, 2019 (20 years); theme of the study pediatric KC epidemiology. The search strategy: searches of the PubMed-MEDLINE database and Cochrane Database of Systematic Reviews, using eight combinations of the following MeSH terms: keratoconus; child; incidence; prevalence; pediatrics; adolescent; epidemiology.

RESULTS

We charted and reviewed the selected articles. Initial searches included 1802 records; after the exclusion of article duplicates, we screened 777 records, read 97 articles in full text, and included 76 articles in this review.

CONCLUSIONS

Recent epidemiological studies with better methodologies demonstrated increased prevalence rates in comparison to the older literature. This effect may be due to better diagnostic methods and better sample selection than those in historical studies. Diagnosis remains a major challenge as the early disease is usually asymptomatic. Economic and social aspects of pediatric KC remain understudied in the pediatric literature. Global, inclusive, and proactive screening studies in schools are imperative to better understand the great impact of this disease in the young.

Classifications of anterior segment structure of congenital corneal opacity in infants and toddlers by ultrasound biomicroscopy and slit-lamp microscopic photographs: an observational study

BACKGROUND

The structural features have an impact on the surgical prognosis for congenital corneal opacity (CCO). The structural classification system of CCO, however, is lacking. Based on data from ultrasound biomicroscopy (UBM) findings in infants and toddlers with CCO, this research proposed a classification system for the anterior segment structure severity.

METHODS

Medical records, preoperative UBM images and slit-lamp photographs of infants and toddlers diagnosed with CCO at University Third Hospital between December 2018 and June 2022 were reviewed. According to the anterior segment structural features observed in UBM images, eyes were classified as follows: U1, opaque cornea only; U2, central anterior synechia; U3, peripheral anterior synechia combined with angle closure; and U4, aniridia or lens anomaly. The opacity appearance and corneal vascularization density observed in slit-lamp photographs were assigned grades according to previous studies. The extent of vascularization was also recorded. The corresponding intraocular anomaly classifications and ocular surface lesion severity were analysed.

RESULTS

Among 81 eyes (65 patients), 41 (50.6%) were right eyes, and 40 (49.4%) were left eyes. The median age at examination was 6.91 months (n = 81, 1.00, 34.00). Two (2.5%) of the 81 eyes were classified as U1, 20 (24.7%) as U2, 22 (27.2%) as U3a, 11 (13.6%) as U3b and 26 (32.1%) as U4. Bilateral CCO eyes had more severe UBM classifications (P = 0.019), more severe dysgenesis (P = 0.012) and a larger angle closure (P = 0.009). Eyes with more severe UBM classifications had higher opacity grades (P = 0.003) and vascularization grades (P = 0.014) and a larger vascularization extent (P = 0.001). Eyes with dysgenesis had higher haze grades (P = 0.012) and more severe vascularization (P = 0.003 for density; P = 0.008 for extent), while the angle closure range was related to haze grade (P = 0.013) and vascularization extent (P = 0.003).

CONCLUSIONS

This classification method based on UBM and slit-lamp photography findings in the eyes of CCO infants and toddlers can truly reflect the degree of abnormality of the ocular surface and anterior segment and is correlated with the severity of ocular surface anomalies. This method might provide meaningful guidance for surgical procedure design and prognostic determinations for keratoplasty in CCO eyes.

Association of Maternal and Neonatal Birth Outcomes With Subsequent Pediatric Transplants

BACKGROUND

We identified maternal and neonatal birth characteristics that were associated with organ or tissue transplants during childhood.

METHODS

We designed a retrospective cohort study of the population of children born between 2006 and 2019 in Quebec, Canada. The exposure included birth complications such as congenital anomaly, neonatal blood transfusion, and oligohydramnios. The main outcome measure was organ or tissue transplantation before 14 y of age. We categorized transplants according to type (major organs versus superficial tissues). To determine the association of birth characteristics with risk of pediatric transplant, we estimated hazard ratios (HRs) and 95% confidence intervals (CIs) using Cox proportional hazards models adjusted for potential confounders.

RESULTS

The cohort comprised 1 038 375 children with 7 712 678 person-years of follow-up, including 436 children who had transplants before 14 y of age. Birth complications were predominantly associated with major organ transplants. Congenital anomaly was associated with heart or lung (HR, 10.41; 95% CI, 5.33-20.33) and kidney transplants (HR, 13.69; 95% CI, 7.48-25.06), compared with no anomaly. Neonatal blood transfusion was associated with all major organ transplants, compared with no transfusion. Maternal complications were not as strongly associated with the risk of childhood transplant, although oligohydramnios was associated with 16.84 times (95% CI, 8.09-35.02) the risk of kidney transplant, compared with no oligohydramnios.

CONCLUSIONS

Adverse birth outcomes such as congenital anomaly, neonatal blood transfusion, and maternal oligohydramnios are associated with a greater risk of transplantation before 14 y of age. Maternal and neonatal birth outcomes may be useful predictors of transplantation.

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.

[Optical rehabilitation and pediatric ophthalmological care following keratoplasty for childhood corneal opacities]

BACKGROUND

The younger the children are at the time of corneal transplantation, the worse the survival prognosis of the graft.

PREOPERATIVE CONSIDERATIONS

Preoperative considerations are significant in terms of accurate parental education, ensuring adherence to treatment and choosing the appropriate surgical time frame (amblyopia versus graft failure, compliance of the patient). Parental education must include the reduced visual prognosis in young children, exceptions being later acquired corneal pathologies such as inflammatory corneal scars (herpes) and keratoconus.

POSTOPERATIVE CARE

A distinction must be made between morphological care after transplantation and refractive correction as well as treatment of amblyopia. The younger the children, the less favorable the prognosis for the transplant and the more often multiple examinations with anesthesia are necessary in order to detect complications, such as infiltrates or suture loosening at an early stage. Especially unilateral congenital pathologies often do not lead to a sufficient improvement of amblyopia (refractory amblyopia, poor compliance).

CONCLUSION

The prognosis after keratoplasty in childhood is already partly decided by the careful evaluation of indications (no surgery of a sclerocornea) and the detailed and realistic clarification for the parents (cooperation with long-term ocular and systemic treatment even if the child has poor compliance, frequent check-ups, reduced chances of amblyopia treatment). The younger the child is at the time of transplantation, the more frequent are graft failure and the development of complications. Later manifesting diseases in older children (herpetic corneal scars, keratoconus) have a better prognosis.

Current Perspectives on Corneal Transplantation (Part 2)

Disease of the cornea is the third leading cause of blindness worldwide. Corneal graft surgery is one of the most successful forms of solid organ transplantations in humans, with ever increasing developments in surgical technique. To date, approximately 4504 corneal transplants are performed in the UK each year. While full thickness transplantation was the most commonly performed keratoplasty over the last few decades, selective lamellar transplantation of the diseased layers of the cornea has been universally adopted. This comprehensive review aims to provide an updated synthesis on different types of corneal transplantations, their treatment outcomes, and the associated complications of each procedure both in adult and pediatric populations. In addition, we also present an up-to-date summary of the emerging therapeutic approaches that have the potential to reduce the demand for donor-dependent keratoplasty.

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.

Post-keratoplasty Infectious Keratitis: Epidemiology, Risk Factors, Management, and Outcomes

Post-keratoplasty infectious keratitis (PKIK) represents a unique clinical entity that often poses significant diagnostic and therapeutic challenges. It carries a high risk of serious complications such as graft rejection and failure, and less commonly endophthalmitis. Topical corticosteroids are often required to reduce the risk of graft rejection but their use in PKIK may act as a double-edged sword, particularly in fungal infection. The increased uptake in lamellar keratoplasty in the recent years has also led to complications such as graft-host interface infectious keratitis (IIK), which is particularly difficult to manage. The reported incidence of PKIK differs considerably across different countries, with a higher incidence observed in developing countries (9.2-11.9%) than developed countries (0.02-7.9%). Common risk factors for PKIK include the use of topical corticosteroids, suture-related problems, ocular surface diseases and previous corneal infection. PKIK after penetrating keratoplasty or (deep) anterior lamellar keratoplasty is most commonly caused by ocular surface commensals, particularly Gramme-positive bacteria, whereas PKIK after endothelial keratoplasty is usually caused by Candida spp. Empirical broad-spectrum antimicrobial treatment is the mainstay of treatment for both PKIK, though surgical interventions are required in medically refractory cases (during the acute phase) and those affected by visually significant scarring (during the late phase). In this paper, we aim to provide a comprehensive overview on PKIK, encompassing the epidemiology, risk factors, causes, management and outcomes, and to propose a treatment algorithm for systematically managing this challenging condition.

Keratoplasty for Keratoconus in Young Patients: Demographics, Clinical Features, and Post-transplant Outcomes

PURPOSE

To examine pretransplant findings and outcomes of corneal transplants for keratoconus in children.

DESIGN

Retrospective cohort (national registry) study.

METHODS

Data on all patients aged 16 or younger (n = 170) who had a first transplant for keratoconus between 2003 and 2018 in all corneal transplant centers in the UK were compared to adult patients aged 17 and older (n = 7,191). The influence of demographic variables, pretransplant corneal findings, and transplant type on 2-year visual, rejection-free, and transplant survival outcomes was examined.

RESULTS

Children had poorer pretransplant visual acuity and higher rates of corneal vascularization and ocular surface disease than adults. However, 2-year post-transplant corrected visual acuity reached 20/20 or better in 35% of children compared to 28% of adults (P = .1). Transplant rejection and failure rates were 11% (P = .79) and 3% (P = .31), respectively, for children, which were comparable to rates for adults. Endothelial rejection was reported following penetrating keratoplasty (PK) in 13% of children (10% in adults). Irreversible rejection was not recorded for any transplant in a child. Despite a lack of difference in transplant outcomes, there was a significant age effect in the Cox regression model for transplant rejection, such that for every 5-year increase in age there was a 6% reduction in the hazard of rejection. Transplant survival following anterior lamellar keratoplasty and PK in children was similar.

CONCLUSIONS

Young keratoconus patients have excellent transplant outcomes and visual results comparable to adults. Overall, the hazard of rejection was found to decrease with advancing age. However, in this large cohort of young patients with keratoconus and poor vision, there is no evidence of outcome advantage in delaying transplant until adult years.

Penetrating Keratoplasty in Infants With Peters Anomaly: Visual and Graft Outcomes

PURPOSE

To determine the prevalence of survival of corneal grafts and visual outcomes of primary penetrating keratoplasty (PK) in infants with Peters anomaly (PA) in Beijing, China.

METHODS

Twenty-nine patients (37 eyes) with PA who underwent PK before the age of 1 year were included. Optical correction for all eyes and occlusion therapy of amblyopia for a unilateral opacity were performed 2 weeks after suture removal. All infants underwent assessment of visual acuity after surgery using Teller Acuity Cards. Survival probabilities were estimated using the Kaplan-Meier method and log-rank test. Visual outcomes and prognosis factors were analyzed using the χ2 test.

RESULTS

The mean age of 29 infants undergoing primary PK was 5.7 ± 2.3 months. The mean follow-up duration was 18.0 ± 3.0 months. Twenty-seven (73.0%) of 37 grafts retained full clarity at final follow-up. Visual acuity above ambulatory was achieved in 67.6% (25/37) and >20/260 was achieved in 48.6% (18/37) of cases. Of all surgical indications, vascularized PA I (50.0%, 6/12) and PA II (18.2%, 2/11) showed a lower proportion achieving visual acuity >20/260 than nonvascularized PA I (71.4%, 10/14) (P = 0.030 < 0.05). There was no significant difference in the prevalence of graft survival and vision outcome between infants younger than 6 months and older than >6 months.

CONCLUSIONS

For infants with PA who underwent PK, the prevalence of graft survival and visual acuity were related mainly to the indication. The main risk factors were corneal vascularization and an abnormal lens.

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.

Bilateral phototherapeutic keratectomy for corneal macular dystrophy in an adolescent: case report and review of the literature

PURPOSE

Phototherapeutic keratectomy (PTK) with 193-nm excimer laser is a safe and effective procedure for the treatment of superficial corneal pathology. We aimed to review the use of PTK for the treatment of corneal macular dystrophy (MCD).

METHODS

Case report and literature review.

RESULTS

A 16-year-old boy presented to an ophthalmologist with a 4-year history of reduced vision, glare and photophobia in his left eye. He was diagnosed with corneal macular dystrophy and underwent sequencing of the CHST6 gene. Left excimer PTK with mitomycin C was performed. He remained relapse free until 18 months post procedure when his visual acuity declined and the stroma appeared more "milky". He underwent a penetrating keratoplasty in his left eye 24 month following the initial PTK.

CONCLUSION

Phototherapeutic keratectomy is an effective means of visual restoration in patients with macular corneal dystrophy and may delay penetrating keratoplasty. Patients should be counselled regarding the high risk of recurrence. This is the first reported case of a CHST6 gene positive patient with MCD that was treated with phototherapeutic keratoplasty.

Indications and Techniques of Pediatric Keratoplasty in Eastern China From 2008 to 2017

PURPOSE

To explore the transition of indications and surgical techniques of pediatric keratoplasty in Eastern China in the past 10 years.

METHODS

Medical charts of 1026 pediatric patients (1059 eyes) who underwent keratoplasties at the Eye, Ear, Nose and Throat Hospital of Fudan University from 2008 to 2017 were retrospectively reviewed. The indications for keratoplasty and the surgical techniques were collected and analyzed.

RESULTS

A total of 634 infants (≤3 years) (661 eyes), 207 toddlers and older children (4-12 years) (211 eyes), and 185 adolescents (13-18 years) (187 eyes) were included. The median age at the time of surgery was 2 years. The surgical indications were composed of congenital abnormalities (74.6%), acquired nontraumatic diseases (16.5%), acquired traumatic diseases (3.6%), and regraft (5.3%). Only congenital abnormality had a significant growing trend during this decade (P = 0.023). Keratoconus (67.2%) exceeded infectious keratitis (14.9%) and was the most common acquired nontraumatic cause in our study. The annual number of pediatric keratoplasties increased significantly from 40 cases in 2008 to 190 cases in 2017 (P < 0.001). Although penetrating keratoplasty was performed in 414 eyes (39.1%), its application in the treatment of keratoconus decreased significantly during this decade (P = 0.04). By contrast, deep anterior lamellar keratoplasty showed an increasing trend because of its popularization in the treatment of keratoconus (P = 0.003).

CONCLUSIONS

Congenital abnormalities have replaced infectious keratitis and have been the leading indications of pediatric keratoplasty in the past 10 years. Although the using of penetrating keratoplasty was still the predominant procedure to treat pediatric corneal pathologies, the adoption of deep anterior lamellar keratoplasty showed a significant increasing trend during the past decade.

[Keratoplasty in children : Indications and results]

Penetrating keratoplasty in children is associated with very specific difficulties for the surgeon as well as for the patient and the parents. Special features are specific pediatric indications, which do not occur in adults, a more difficult examination and treatment adherence depending on the parents. Diseases with a favorable prognosis include keratoconus and herpetic keratitis. Especially sclerocornea and the Peters' anomaly often have a limited prognosis regarding vision and graft survival due to secondary malformations of the eye. In addition, younger age represents a risk factor. This is most likely due to the impaired examination during follow-up and reduced compliance. For successful penetrating keratoplasty in children the timing for the operation, in which the risk for the graft is weighed up against the risk for amblyopia, is crucial.

Indications, Clinical Outcomes, and Survival Rate of Pediatric Penetrating Keratoplasty in Suburban Malaysia: A 10-year Experience

Purpose

To describe the demographics, indications, clinical outcomes and survival rate of penetrating keratoplasty in Malaysian children living in a suburban area, and discuss the literature on paediatric penetrating keratoplasty.

Methodology

A retrospective review of medical records was performed on children younger than 17 years of age who had undergone penetrating keratoplasty in Hospital Universiti Sains Malaysia from January 2008 to December 2017. We recorded demographic data, presenting visual acuity, indications, final visual acuity, and graft survival at 12 months into the postoperative period.

Results

Sixteen eyes of 14 children had penetrating keratoplasty. Mean age was 7.8 ± 5.9 years. Both genders were equally affected. The main indications were infective keratitis (56.25%), congenital corneal opacity (18.75%) and trauma (12.50%). There were 62.50% of patients who had a preoperative visual acuity worse than 6/60. Fifty percent had other combined procedures during the surgery, including lens aspiration, peripheral iridectomy, pupilloplasty and glaucoma tube implant. Best corrected visual acuity of 6/12 or better was achieved in 18.75% of patients. A hazy graft was noted in 68.75% of patients, and was attributed to graft rejection, glaucoma and graft failure. There was a statistically significant association between the presence of vascularized cornea, intraocular inflammation and combined surgery with survival rate of the graft at one-year postoperative period (p < 0.05).

Conclusions

Infective keratitis is the main indication for penetrating keratoplasty in our pediatric patients. Good visual outcome was documented in a small percentage of the patients. Amblyopia and hazy graft were the main barriers to success in this group of patients. Vascularized cornea, inflammation and combined surgery had significantly affected the survival rate of the grafts in our series.

Indications and Outcomes of Penetrating Keratoplasty in Infants and Children of Beijing, China

PURPOSE

To retrospectively investigate the indications and outcomes of pediatric penetrating keratoplasty (PKP) and to explore factors that affect graft survival.

METHODS

Patients who had undergone PKP from May 2010 to December 2016, aged ≤12 years were categorized as infants (≥3 months and <4 years) or children (≥4 years and ≤12 years). Clinical data including patient demographics, indications, surgical procedures, postoperative follow-up, and graft clarity were recorded and analyzed.

RESULTS

Among 160 eyes of 146 patients, 79 eyes and 81 eyes were treated from the infant and child groups, respectively, and followed up for 33.7 ± 21.7 months (range, 6 months to 7 years). The most common indication for PKP was congenital corneal opacity (71.9%). The survival rate of all corneal grafts was 68.1%. The rejection reaction rate was 33.8%. More children than infants underwent PKP that was combined with other intraocular surgeries (P < 0.05). The graft failures were in the regraft (52.0%), congenital opacities (30.4%), and acquired opacities (15.0%) groups. The rate of graft failure in patients who received PKP combined with other intraocular surgery (40.0%) was higher than those who received PKP only (30.0%). The univariate logistic regression analysis revealed that the graft failure was associated with the graft indication (P < 0.05).

CONCLUSIONS

The most common indication for PKP in children younger than 12 years was congenital corneal opacity in Beijing, China. The graft survival was 68.1%, with a mean follow-up of 33.7 months. Graft failure was associated with the indication.