Penetrating keratoplasty in infancy and early childhood

General Treatment and Ophthalmic Management of Peters' Anomaly

Peters' anomaly (PA) is a manifestation of complex disorders in the development of the anterior segment of the eye. The most recognizable feature of the disease is a doughnut-shaped central corneal opacity and adhesions between the opacity and underlying iris. Glaucoma is observed in 30-70% of patients, with up to 50% of the patients showing concomitant vision-threatening disorders. Up to 60% of patients have systemic abnormalities or developmental delays. Being a rare malformation, PA is one of the most common congenital indications for corneal transplantation in infants. Penetrating keratoplasty is used as the primary method of treatment in cases with corneal opacification of a degree that forbids visual development in both eyes. The heterogeneity of co-occurring ophthalmic and systemic malformations in the spectrum of PA determines the wide range of success, defined by various endpoints: graft clarity or visual acuity. Although surgical advancement has made corneal grafting possible in younger children, it has a higher graft failure rate and worse visual prognosis than adult keratoplasty. Optical sector iridectomy, pupil dilation, or cornea rotation can alternatively be performed. Satisfying results of pediatric keratoprosthesis in particular cases of PA have been described. Postoperative treatment of PA aims to maintain a clear optical pathway and prevent amblyopia. This article therefore aims at reporting the ophthalmic treatment and need for multidisciplinary management of PA, including pharmacological and surgical treatment.

Update on Suture Techniques in Corneal Transplantation: A Systematic Review

Effective suturing remains key to achieving successful outcomes in corneal surgery, especially anterior lamellar keratoplasty and full thickness transplantation. Limitations in the technique may result in complications such as wound leak, infection, or high astigmatism post corneal graft. By using a systematic approach, this study reviews articles and conducts content analysis based on update 2020 PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria). The aim of this paper is to summarize the state of the art of corneal suturing techniques for every type of corneal transplant and patient age and also their outcomes regarding astigmatism and complications. Future developments for corneal transplantation will be also discussed. This is important because especially the young surgeon must have knowledge of the implications of every suture performed in order to achieve consistent and predictable post-operative outcomes and also be aware of all the possible complications.

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.

Indications and outcomes of pediatric keratoplasty in a tertiary eye care center: A retrospective review

To evaluate indications and outcomes of pediatric keratoplasty in a tertiary eye center, and identify factors that affect visual outcomes.We performed a retrospective review of penetrating keratoplasty in children aged 0 to 18 years between 1995 and 2011 in the Asociación para Evitar la Ceguera en México IAP, Hospital "Dr. Luis Sánchez Bulnes".A total of 574 penetrating keratoplasties were performed during the study interval. Median follow-up was 5.0 years. Main indications included keratoconus (55.58%), postherpetic scarring (9.58%), traumatic opacities (7.49%), and bullous keratopathy (6.09%). Rejection rates at 5 years were 27% overall, and among indications, keratoconus showed the best graft survival at 60-months follow-up (85%). The percentage of patients with best corrected visual acuity (BCVA) posttransplant >20/400 at 5 years in the nonrejection group was 81.25% and 82.74% in < and > 10 years of age (YOA) groups, respectively, versus a BCVA posttransplant > 20/400 at 5 years in the rejection group of 53.68% and 51.72% in < and > 10 YOA groups, respectively. There was a statistically significant reduced rejection rate between genders at 18 months of follow-up, favoring males.Despite being considered a high-risk procedure in children, penetrating keratoplasty can achieve good results, especially in patients with keratoconus. It can achieve significative improvements of visual acuity, provided there is an adequate follow-up and treatment adherence.

Clinical results of 40 years of paediatric keratoplasty in a single university eye clinic

PURPOSE

  To evaluate indications for paediatric keratoplasty in recipients aged ≤16 years and assess long-term clinical outcome.

METHOD

  Recipients were identified from records of the Danish Cornea Bank. Data were collected from patient journals, clinical follow-up examinations and questionnaires and stratified into pre-, peri- and postoperative variables. Diagnoses were classified into acquired traumatic, acquired nontraumatic and congenital groups. Recipients were divided into groups of <8 and ≥8 years. Data were analyzed using relative percentages and Kaplan-Meier survival plots.

RESULTS

  Thirty-three out of sixty identified recipients (73 keratoplasties in 63 eyes) were invited. Twenty-four accepted, seven still attended follow-up in our clinic. Follow-up data reached 95% of the eligible recipients (median follow-up 11 years). Twenty-three per cent were <8 years and 77%≤8 years. Diagnoses were mainly acquired nontraumatic (69%), acquired traumatic (12%) and congenital (7%). Indications were primarily optical (52%) or tectonic (41%). Graft survival was best in the acquired nontraumatic group (except regrafts) (median survival 15-20 years) and poorest in the regraft subgroup as well as the acquired traumatic and congenital groups (median survival 1-2 years). Graft failure was higher in the youngest with predisposing risk factors and in combined procedures. In terms of indications, visual improvement and eye preservation was achieved in 70%.

CONCLUSION

  Paediatric keratoplasty was successful regarding indication. Graft survival was best in the acquired nontraumatic group and poorest in the congenital group. Vascularization and/or combined risk factors, additional surgeries and young recipient age influenced negatively on graft survival.

Short-term azithromycin treatment promotes cornea allograft survival in the rat

Background

Any inflammatory response following corneal transplantation may induce rejection and irreversible graft failure. The purpose of this study is to analyze the anti-inflammatory effect of azithromycin (AZM) following experimental keratoplasty in rats.

Methods

Corneal transplants were performed between Fisher-donor and Lewis-recipient rats. Recipients were postoperatively treated three times daily with AZM, miglyol, ofloxacin or dexamethasone eye drops. As an additional control, AZM was applied following syngeneic keratoplasty. Furthermore, short-term treatments with AZM for seven days perioperatively or with AZM only three days prior to the transplantation were compared to appropriate controls. All transplants were monitored clinically for opacity, edema, and vascularization. Infiltrating CD45⁺, CD4⁺, CD8⁺, CD25⁺, CD161⁺ and CD163⁺ cells were quantified via immunohistochemistry.

Results

AZM significantly promoted corneal graft survival compared with miglyol or ofloxacin treatment. This effect was comparable to topical dexamethasone. No adverse AZM effect was observed. Histology confirmed a significant reduction of infiltrating leukocytes. The short-term application of AZM for three days prior to transplantation or for seven days perioperatively reduced corneal graft rejection significantly compared with the controls.

Conclusions

Along with antibiotic properties, topical AZM has a strong anti-inflammatory effect. Following keratoplasty, this effect is comparable to topical dexamethasone without the risk of steroid-induced adverse effects. Short-term treatment with AZM three days prior to the transplantation was sufficient to promote graft survival in the rat keratoplasty model. We therefore suggest further assessing the anti-inflammatory function of topical AZM following keratoplasty in humans.

Inhibition of corneal inflammation following keratoplasty by birch leaf extract

The objective of this study was to determine the effect of birch leaf (Betula pendula) extract (BPE) on corneal inflammation following keratoplasty in the rat model. T cells were stimulated in vitro in the presence of BPE. Proliferation, activation phenotype and the number of apoptotic/necrotic cells in cell culture were analyzed by flow cytometry. Corneal transplantation was performed between Fisher and Lewis rats. Recipient rats were either treated with cyclosporine A at a low dosage (Low-dose CsA=LDCsA) or received LDCsA in combination with BPE (2×1ml/day). Clinical signs for corneal inflammation and rejection time points were determined. Infiltrating leukocytes were analyzed histologically. BPE specifically inhibited T cell proliferation in vitro by inducing apoptosis. The phenotype was not affected. In vivo, BPE significantly delayed the onset of corneal opacification (p<0.05). The amount of infiltrating CD45(+) leukocytes and CD4(+) T cells (p<0.001) was significantly reduced by BPE, whereas infiltration of CD163(+) macrophages was not significantly different between the two groups. BPE selectively induces apoptosis of activated T cells. Accordingly, BPE treatment significantly reduces infiltrating T cells and subsequent corneal opacification following keratoplasty. Our findings suggest BPE as a promising anti-inflammatory drug to treat corneal inflammation.

Penetrating keratoplasty in a newborn: case report and analysis of current surgical trends in Italy

PURPOSE

The aims of this study were to describe bilateral penetrating keratoplasty (PK) in a newborn and to analyze the data of PKs performed in Italy during the 5-year period 1999-2003 in children under 4 years of age.

METHODS

A male newborn had PK at age 3 months and 5 months for near-blindness secondary to severe congenital corneal clouding in both eyes. The infant''s explanted corneas were subjected to histochemical and ultrastructural analyses. Data regarding the number of PKs performed in Italy on 0-4-year-olds were obtained from the Web site of the Italian Ministry of Health.

RESULTS

The postoperative courses were uncomplicated, and 42 months of follow-up data show bilateral graft transparency and substantial improvement in visual acuity despite high-grade myopia and nystagmus. At the ultrastructural level, the main alterations involved the endothelial cells and Descemet membrane. A total of 45 PKs were performed in Italy on patients 0-4 years old from 1999 through 2003; only nine involved babies under 1 year of age.

CONCLUSIONS

In babies with congenital corneal opacities, early PK can reduce severe amblyopia. However, the risk of intra- and postoperative complications in PK is high. Based on the 42-month follow-up, the anatomic and functional results achieved in the current patient are satisfactory despite the presence of nystagmus and postoperative high-grade myopia. This study shows that PKs are rarely performed, in Italy, in children aged 0-4 years, and very few are done during the first year of life.

Differential contribution of natural killer cells to corneal graft rejection in 3-week-old versus mature rats

BACKGROUND

The aim of this study was to compare immunologic graft rejection in adult and 3-week-old immature recipients in the rat keratoplasty model.

METHODS

Forty orthotopic penetrating keratoplasties were performed in four different donor-recipient combinations. Group 1 consisted of adult Fisher donors and adult Lewis recipients, group 2 consisted of adult Fisher donors and immature Lewis recipients, group 3 consisted of adult Lewis donors and recipients, and group 4 consisted of adult Lewis donors and immature Lewis recipients. An immunohistologic evaluation of the grafts was performed on day 14.

RESULTS

Grafts in both allogeneic groups (groups 1 and 2) showed infiltration with CD4+ cells, CD8+ cells, natural killer (NK) cells, interleukin-2-receptor+ cells, macrophages, and intercellular adhesion molecule-1+ cells. The density of infiltrating CD4+, CD8+, interleukin-2-receptor+, and intercellular adhesion molecule-1+ cells in the graft stroma, however, was statistically significantly lower in the immature group (group 2) than in the adult group (group 1). The density of CD161+ NK cells, in contrast, was statistically significantly higher in the immature group than in the adult group. There were no or only a few infiltrating inflammatory cells in grafts of both syngeneic groups (groups 3 and 4).

CONCLUSIONS

We were able to establish for the first time an animal model for keratoplasty in infants that showed that the mechanism of graft rejection in young recipients seems to be different from that in mature rats. In adult recipients, alloreactive T cells are the main mediators of rejection, whereas NK cells seem to play a more dominant role in immature recipients.