Oversized grafts in children

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.

Anterior synechiae after penetrating keratoplasty in infants and children with Peters' anomaly

Background

To evaluate anterior synechiae after penetrating keratoplasty (PK) in patients with Peters’ anomaly using anterior segment optical coherence tomography (OCT).

Methods

A retrospective cross-sectional study was performed. The medical records of patients diagnosed with Peters’ anomaly who underwent PK between 2013 and 2018 were reviewed. In addition to basic ophthalmic examinations, images of anterior segment structures were obtained via spectral-domain OCT at baseline and during the postoperative follow-up period. The profiles of postoperative anterior synechiae and multiple potential risk factors were analyzed.

Results

Seventy-one eyes of 58 patients, aged 5 to 23 months, were included. Various extent of postoperative anterior synechiae was observed in 59 eyes (83.1%). OCT findings revealed graft-host junction synechiae, peripheral anterior synechiae, and a combination of both. Disease severity and malposition of the internal graft-host junction were significantly associated with the formation of postoperative synechiae. Multivariate regression analysis found that preexisting iridocorneal adhesion [odds ratio (OR) = 16.639, 95% confidence interval (CI) 1.494–185.294, p = 0.022] was positively correlated with postoperative anterior synechiae, whereas anterior chamber depth (OR = 0.009, 95% CI 0.000–0.360, p = 0.012) and graft size (OR = 0.016, 95% CI 0.000–0.529, p = 0.020) were negatively correlated with postoperative synechiae. In addition, quadrants of preexisting iridocorneal adhesion and width of the host corneal bed were identified as risk factors for increased postoperative anterior synechiae.

Conclusions

Anterior synechiae following PK is a relatively common occurrence in Peters’ anomaly patients and is found to be associated with preexisting iridocorneal adhesion, a shallow anterior chamber, small graft size, graft-host junction malposition, and graft closer to the corneal limbus. These data indicate the need for careful consideration when performing PK on these patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-022-02473-0.

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.

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.

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

PURPOSE

Pediatric keratoplasty is an immense challenge because of the technical complexity of the procedure and the high risk of rejection in young graft recipients. Our aim is to describe the major indications and appropriate timing of corneal transplantation intervention, including a report of our experience and surgical tips, in conjunction with the current literature.

METHODS

Review of the literature on indications for keratoplasty in pediatric patients classified as: congenital, traumatic and acquired non-traumatic opacities. We additionally explored the challenges corneal surgeons face in performing this type of surgery and review the most pressing transplant-related problems and their management.

RESULTS

Outcomes after pediatric keratoplasty, in terms of visual development, restoration and clarity of the graft, are influenced by peri-operative local and systemic conditions and factors, and by intraoperative management of the transplantation procedure itself.

CONCLUSION

Pediatric corneal transplantation is a critical tool for visual restoration and development in young patients with corneal opacities, particularly during the critical period of visual development. Successful management of the significant challenges associated with pediatric keratoplasty requires customized clinical and surgical management of each patient with particular attention paid to proper post-operative rehabilitation.

Structural and functional salvaging of eyes with anterior staphyloma using cyclodialysis with penetrating keratoplasty

PURPOSE

To evaluate the efficacy of a novel technique of anterior segment reconstruction and cyclodialysis in patients with anterior staphyloma.

METHODS

A prospective case series of 8 consecutive patients who underwent anterior segment restoration with penetrating keratoplasty and cyclodialysis was analyzed. The main parameters evaluated were structural success of the graft, improvement in visual acuity, and intraocular pressure.

RESULTS

The globe could be salvaged in all the cases, and 75% (6 of 8) of the cases had clear graft at 6-month follow-up. Best-corrected visual acuity (BCVA) ranged from hand motion close to face to 6/12. None of the patients developed glaucoma during the follow-up period.

CONCLUSIONS

Intraoperative creation of a cyclodialysis cleft can aid in adequate postoperative intraocular pressure (IOP) control and hence decrease the likelihood of graft failure because of raised IOP in eyes predisposed to development of postkeratoplasty glaucoma.

Comparison of the pig and feline models for full thickness corneal transplantation

PURPOSE

The goal of this study was to report on the advantages and limitations of the pig and feline models for experimental in vivo corneal transplantation.

METHODS

Ten healthy domestic pigs and ten healthy cats were used. Full thickness penetrating keratoplasty was performed using autologous (eight cases), allogeneic (seven cases) or human xenogeneic (three cases) tissue. In two other cases, the inflammatory response to partial thickness trephination (without transplantation) was evaluated. Eyes were assessed daily before and after surgery by slit-lamp, pachymetry, and tonometry. A transparency score ranging from 0 (opaque graft) to 4 (clear graft) was used, based on the slit-lamp examination. Optical coherence tomography, histology, and electron microscopy were performed postmortem.

RESULTS

In the pig, the mean (±SD) transparency score for the eight full thickness grafts was 0.88 ± 0.99, ranging from 0 to 3. In the feline model, the mean transparency score for the seven uncomplicated grafts was 3.93 ± 0.19, ranging from 3.5 to 4. Both negative controls without endothelium remained opaque at all time. Intraoperative tendency for iris incarceration into the wound, rapid corneal swelling, suture cheese wiring, and postoperative intraocular inflammation were the main factors jeopardizing the functional success of the corneal transplant in the pig model.

CONCLUSION

Suboptimal functional results were obtained after full thickness corneal transplantation in the pig model, while in the feline model, the same protocol yielded uneventful surgeries and clear transplants, with functional results similar to those achieved in human subjects.

The indications and outcome of paediatric corneal transplantation in New Zealand: 1991-2003

AIM

To evaluate patient characteristics, indications, surgical details, and outcome of paediatric keratoplasty in New Zealand.

METHODS

As part of a prospective longitudinal study, paediatric keratoplasty data collected by the New Zealand National Eye Bank (NZNEB) was analysed for the 13 year period 1991-2003.

RESULTS

During the study period the NZNEB supplied 2547 corneas for keratoplasty, of which 65 (3%) were used for paediatric patients (14 years or younger). The 65 keratoplasties were performed in 58 eyes of 52 patients (66% male, 34% female, mean age 10.6 years, SD 4.3 years). Indications were classified into three groups: congenital (16%, n = 9), acquired non-traumatic (74%, n = 43), and acquired traumatic (10%, n = 6). Peters' anomaly (7% of total), keratoconus (67%), and penetrating trauma (8%) were the most common indications in each group, respectively. 82% of keratoplasties with known outcome survived (clear graft) 1 year postoperatively, 16% failed, and one patient died. Keratoplasty for congenital indications had a lower 1 year survival rate (78%) compared to acquired non-traumatic (85%) and traumatic (100%) indications, although the difference was not statistically significant (p = 0.65). 38% of patients with known outcome had a 1 year postoperative best corrected Snellen visual acuity (BCSVA) of 6/9 or better, and 60% had a BCSVA of 6/18 or better. Visual outcome was significantly better for acquired compared to congenital indications (p = 0.03).

CONCLUSION

Analysis of the NZNEB database provided valuable information in relation to paediatric keratoplasty in New Zealand. In particular, this study highlighted an unusually high prevalence of keratoconus as an indication for keratoplasty. In addition, a high 1 year survival rate and good visual outcome were identified, especially in cases of keratoplasty for acquired conditions.

Keratoplasty for keratomalacia in preschool children

AIM

To study the results of surgical management of keratomalacia in children.

METHODS

A clinical case series of all children with keratomalacia, admitted to an Indian centre during the period from June 2000 to June 2001 is presented. The parameters evaluated were demographic data, systemic associations, and results of medical and surgical intervention.

RESULTS

29 children with keratomalacia ranging from 2 months to 5 years of age (mean 1.8 (SD 1.4) years) were included in the study. All children belonged to families of lower socioeconomic status. 27 patients (93.1%) had not been immunised at all. The systemic diseases precipitating the onset of keratomalacia included measles (41.37%), pneumonia (31.03%), and acute diarrhoea (37.93%). 36 eyes (66.7%) had total corneal melting and 11 (20.3%) eyes had paracentral corneal melting. In 15 eyes (27.8%) an emergency tectonic penetrating keratoplasty was performed of which only five grafts (33.3%) remained clear at a mean follow up of 7.3 (6.8) months (range 3-24 months). Seven eyes underwent optical penetrating keratoplasty, of which four grafts (57.14%) remained clear at a mean follow up of 6.4 (3.6) months (range 3-12 months). None of these could achieve a visual acuity better than 6/60.

CONCLUSIONS

Corneal grafting surgery in keratomalacia is associated with poor visual outcome.

Penetrating keratoplasty in infancy and early childhood

Penetrating keratoplasty in infants and young children is performed on an infrequent basis. The most common indication is visually significant congenital corneal opacity. Surgery must be performed early to avoid amblyopia. Surgical techniques differ from those used in adult penetrating keratoplasty because of the reduced ocular rigidity encountered in infants and young children. Use of a multispecialty team approach is important to improve visual outcome. Poor prognostic indicators include bilateral disease, concomitant infantile glaucoma, lensectomy and vitrectomy at the time of surgery, previous graft failure, extensive goniosynechiae, and extensive corneal vascularization. Prompt postoperative optical rehabilitation, combined with occlusion therapy when appropriate, is an important determinant of success.