Penetrating keratoplasty in children: visual and graft outcome

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.

Peters Anomaly: Novel Non-Invasive Alternatives to Penetrating Keratoplasty

BACKGROUND

Peters' anomaly (PA) is the most commonly encountered congenital corneal opacity (CCO) and displays a wide phenotypical range. The relatively recent adoption of high-quality anterior segment imaging in the form of high-frequency ultrasound biomicroscopy and anterior segment optical coherence tomography has aided in the accurate diagnosis of CCOs, facilitated distinction of PA from "pseudo-Peters' anomaly," and aided in prognostication and surgical risk stratification in PA. While the definitive management of PA, especially the more severe forms, is penetrating keratoplasty (PK), long-term success rates have overall been disappointing. This spurred the development of more non-invasive procedures, such as optical iridectomy and the more recently described selective endothelial removal, which represent viable alternatives to PK, at least in the less severe phenotypes of PA.

METHODS

Literature searches for the components of this review were performed using PubMed, in September 2021. The following keywords and their iterations were employed for the searches: "Peters' anomaly," "anterior segment dysgenesis," "kerato-irido-lenticular dysgenesis," "congenital corneal opacities." These were entered into the PubMed search engine, revealing 2852 related articles. The inclusion criteria included publications in the English language, specific to Peters' anomaly. Fifty-five studies that were published as systematic reviews or as nonrandomized comparative studies (cohort or case series) on the topic of Peters' anomaly were finally selected for this review.

RESULTS

This review provides a summary of Peters' anomaly in the context of advances in diagnosis, classification, and genotype-phenotype correlation of congenital corneal opacities, with a focus on penetrating keratoplasty, its outcomes, and non-invasive surgical options. While conservative therapies such as spontaneous clearing, mydriatic eye drops, and optical iridectomy may have variable success in milder variants of PA, penetrating keratoplasty in these eyes is fraught with several challenges and typically results in poor long-term functional outcomes. The management strategy depends on several variables such as phenotypical severity of PA, laterality, age at presentation, and capacity to adhere to the follow-up schedule. Notwithstanding the choice of treatment, it is essential that early and aggressive amblyopia therapy, a thorough systemic examination, and appropriate referral are undertaken for all patients of PA.

CONCLUSION

Peters' anomaly has seen recent advances in diagnosis, but treatment options remain limited. Focus directed towards less-invasive alternatives to keratoplasty may yield better functional outcomes.

Congenital Corneal Opacity in 22q11.2 Deletion Syndrome: A Case Series

PURPOSE

The purpose of this study was to describe the deep phenotype of congenital corneal opacities (CCO) in patients with 22q11.2 deletion syndrome (22q11.2 DS) and to identify putative regions or genes that could explain the CCO.

METHODS

A retrospective chart review was conducted to identify patients with 22q11.2 DS seen in the ophthalmology clinic of a tertiary referral children's hospital. Thirty patients were identified, with molecular confirmation. Twenty-six did not show structural anterior segment anomalies aside from posterior embryotoxon (n = 4), whereas 4 had bilateral CCO, of which 3 had preoperative images. We reviewed medical, operative, and pathology reports; anterior segment optical coherence tomography; high-frequency ultrasound; histopathologic slides; and genetic testing. To identify putative genes responsible for CCO, chromosomal breakpoints in patients with and without CCO were compared.

RESULTS

In the 3 patients with preoperative imaging and CCO, a pattern of paracentral corneal opacification with central clearing accompanied by iridocorneal or keratolenticular adhesions was observed. Anterior segment optical coherence tomography and histopathologic images showed central stromal thinning with a residual structure consistent with Descemet membrane. One patient presented at birth with unilateral corneal perforation, suggestive of likely stromal thinning. A comparison of the breakpoints across all cases failed to reveal unique regions or genes in patients with CCO.

CONCLUSIONS

22q11.2 DS can rarely be associated with CCO. We describe a consistent pattern of central clearing related to posterior stromal thinning, with or without ICA/KLA. Possible candidate genes for corneal opacification in 22q11.2 DS remain elusive.

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.

10-year experience with lamellar keratoplasty for the surgical Management of Paediatric Corneal Diseases

PURPOSE

To evaluate the outcomes of various lamellar keratoplasty techniques performed at our Institution in children aged 14 years or younger over the last decade.

METHODS

This single-centre study reviewed 72 eyes that underwent lamellar keratoplasty for various indications. Deep anterior lamellar keratoplasty (DALK) was performed in 19 eyes, mushroom penetrating keratoplasty (PK) in 27 eyes and Descemet stripping automated endothelial keratoplasty (DSAEK) in 25 eyes. The main outcome measures included best spectacle-corrected visual acuity (BSCVA), complications and rate of graft failure which was defined as any graft requiring repeat transplantation.

RESULTS

Best spectacle-corrected visual acuity (BSCVA) significantly improved after DALK, mushroom PK and DSAEK (all p < 0.05), with 50%, 60% and 56% of eyes reaching ≥20/40, respectively. Stromal rejection was observed in 1 eye (5.3%) after DALK, whilst endothelial rejection occurred in 1 eye after mushroom PK (3.7%) and 1 eye after DSAEK (4.0%). Overall survival was 100% after DALK (mean follow-up: 23.0 months), 92.8% after mushroom PK (mean follow-up: 42.3 months) and 96.0% after DSAEK (mean follow-up: 33.6 months).

CONCLUSION

Deep anterior lamellar keratoplasty (DALK), mushroom PK and DSAEK offer good visual outcomes for children with corneal pathology, with low rates of immunological rejection and graft failure.

A 10-Year Retrospective Case Series on Wound Dehiscence Following Corneal Transplant

Background and objective

Corneal transplants are associated with multiple well-known complications, one of them being wound dehiscence. It results in unfavorable outcomes, such as ocular structure damage, graft failure, repeated surgeries, and possibly a poor prognosis in terms of vision quality. Although the wound site may appear well-healed clinically, as the strength at the graft-host junction is weak, the site is susceptible to dehiscence. Wound dehiscence can be secondary to suture removal and/or trauma. In this study, we assessed the incidence of wound dehiscence secondary to trauma following corneal transplant and evaluated its occurrence in terms of patient age, type of corneal transplant performed, duration between corneal transplantation and wound dehiscence, mechanism of injury, and final outcome.

Methods

This was a case series that included all patients who suffered from wound dehiscence secondary to trauma post-corneal transplant between January 1, 2009, and December 31, 2019, at Hospital Kuala Lumpur.

Results

A total of 492 patients underwent corneal transplant surgery during the 10-year study period. Based on specified inclusion and exclusion criteria, only 13 patients were eligible for inclusion in this study. The incidence of wound dehiscence secondary to trauma post-penetrating keratoplasty (PK) was low (2.64%). Twelve patients had undergone PK, while one patient had undergone deep anterior lamellar keratoplasty (DALK). Blunt ocular trauma post-transplant can cause wound dehiscence regardless of patient age and duration post-corneal transplantation. Males are at a higher risk as their active lifestyle contributes to higher exposure to ocular injury.

Conclusion

As corneal transplant patients are at life-long risk of wound dehiscence post-transplant, they must be counseled about this possible risk and the need to take adequate precautions in their daily lives. Based on our findings, the use of newer technologies and partial- rather than full-thickness corneal transplants should be explored further.

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.

Penetrating Keratoplasty Versus Deep Anterior Lamellar Keratoplasty in Children and Adolescents With Keratoconus

PURPOSE

To compare the outcomes of penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty (DALK) for pediatric keratoconus.

DESIGN

Retrospective comparative interventional case series.

METHODS

This study included consecutive pediatric keratoconus cases (≤18 years of age) who received PK (n=45) or DALK (n=54) in 2 different time periods. Postoperative best spectacle-corrected visual acuity (BSCVA), refraction, and complications were compared between the study groups.

RESULTS

The mean follow-up was 83.3±46.1 and 63.3±45.6 months in the PK and DALK groups, respectively (P = .10). Postoperatively, BSCVA was 0.20±0.19 logMAR in the PK group and 0.26±0.19 logMAR in the DALK group (P = .11), with a BSCVA of ≥20/40 in 91.1% and 83.3% of eyes, respectively (P = .25). Two groups were comparable regarding postoperative refractive outcomes. Graft epitheliopathy and suture-associated complications were more commonly encountered after DALK, which was attributable to the effect of low-quality grafts on the clinical outcomes of DALK. Ten PK eyes (22.2%) and 9 DALK eyes (16.7%) experienced at least 1 episode of graft rejection within 5 years of corneal transplantation (P = .49). Rejection was reversible in 93.1% and 100% of episodes in the PK and DALK groups, respectively (P = .63). At the postoperative year 5, 95.6% of grafts in the PK group and 98.2% in the DALK group remained clear (P = .45).

CONCLUSION

No significant difference was observed in the outcomes between PK and DALK in pediatric keratoconus. Low-quality donor tissues in DALK increased the incidence of graft epithelial problems and suture-related complications as compared to PK.

Pediatric keratoconus - Current perspectives and clinical challenges

Keratoconus is an ectatic corneal disease characterized by progressive stromal thinning, irregular astigmatism, and defective vision. It can be unilateral or bilateral with asymmetric presentation. It starts at puberty and either progresses rapidly to an advanced stage of the disease or stops in case of delayed onset and slow progression. Pediatric keratoconus is more aggressive than in adults and the management protocols differ because of various rationales such as accelerated progression, advanced stage of disease at the time of diagnosis and co-morbidities. It poses a burden to the society as it affects the quality of life, social, and educational development in children. Hence early diagnosis, recognition of progression, and timely intervention with collagen crosslinking is imperative to arrest the worsening. Association with systemic syndromes and ocular comorbidities can be of concern in pediatric keratoconus. Severe ocular allergy when associated hastens progress and complicates timely intervention of crosslinking treatment and compliance to contact lens wear. Keratoplasty in pediatric keratoconus has good outcomes but can encounter frequent suture-related concerns. This article discusses the epidemiology, etiopathogenesis, clinical challenges, and current perspectives of management of pediatric keratoconus.

Histopathological examination of congenital corneal staphyloma and prognosis after penetrating keratoplasty

The aim of this study was to investigate the histopathological manifestations of congenital corneal staphyloma accompanied by anterior segment dysgenesis and evaluate the prognosis after penetrating keratoplasty with an ultralarge button graft.We retrospectively studied 8 pediatric patients with large congenital corneal staphylomas in the Department of Ophthalmology of Peking University Third Hospital, China, between September 2014 and December 2018. All patients underwent penetrating keratoplasty with ultralarge button grafts, as well as additional operations according to the abnormality of each eye. Pathological investigations of all samples obtained during penetrating keratoplasty were performed with hematoxylin and eosin staining.The main clinical characteristic of congenital corneal staphyloma was an extremely opaque and ectatic cornea. Histopathological examination showed abnormal corneal epithelia and stroma and an absence of Bowman membrane, Descemet membrane, and the endothelium. Different severities of anterior segment dysgenesis, presenting as various histopathological manifestations, were observed in all cases. Several postoperative complications occurred after penetrating keratoplasty in some of the patients; however, the complications were discovered and treated accordingly in a timely manner. Six patients achieved good visual outcomes and a satisfactory cosmetic appearance after penetrating keratoplasty. One patient eventually lost the transparency of the button because of corneal neovascularization, and 1 patient lost visual function because of retinal detachment.Congenital corneal staphyloma combined with anterior segment dysgenesis can exhibit various manifestations on histopathological examination. Penetrating keratoplasty with an ultralarge button graft seems to be a suitable treatment for congenital corneal staphyloma to obtain good functional and aesthetic prognoses.

Anatomic and visual outcomes of corneal transplantation during infancy

PURPOSE

To determine the effect of age at penetrating keratoplasty (PKP) on graft survival and visual outcome in children with corneal opacities transplanted during infancy.

METHODS

In this two-center retrospective consecutive cohort study, the medical records of infants who underwent unilateral or bilateral PKP during the first year of life between 2004 and 2011 were reviewed retrospectively. PKP was categorized as early (age 0-90 days) or late (age 91-365 days). Main outcome measures were graft survival and vision (classified as poor, fair, or good, considering both testing method and age norms).

RESULTS

A total of 62 eyes of 52 infants were included: 19 eyes underwent early PKP; 43 eyes, late PKP. Of the 62 eyes, 61 had central congenital corneal opacities; 1 was acquired. Median follow-up was 38.1 months (range, 12.2-150.5 months). Kaplan-Meier graft survival estimates were 0.92 at 1 year (95% CI, 0.81-0.96) and 0.61 at 5 years (0.44-0.74). Graft survival (early PKP, 73.7%; late PKP, 65.1% [P = 0.57]) did not differ between groups. Of the 55 eyes with recorded visual acuities, no significant difference existed in proportion with ambulatory or better vision at latest follow-up between early and late PKP (42.1% vs 55.6%; P = 0.61).

CONCLUSIONS

Visual outcomes were better for PKP performed during infancy compared to results of prior reports of late PKP; however, clearing of congenital opacities in the first 3 months of life did not improve visual outcomes compared to later PKP. One-half of grafts survived >5 years. Early PKP did not worsen graft survival, but PKP may be technically easier to perform later in infancy.

Primary Pediatric Keratoplasty: Etiology, Graft Survival, and Visual Outcome

PURPOSE

Interventional study to evaluate the etiology, visual outcome and survival of corneal transplantation in children and to identify the risk factors associated with graft failure.

DESIGN

Retrospective, interventional consecutive case series.

METHODS

Medical records of every child 7 years of age or younger who underwent primary penetrating keratoplasty at Department of Ophthalmology, Federal University of São Paulo were reviewed. The parameters evaluated were indications for keratoplasty, graft survival, and postoperative visual acuity (VA) improvement. Children underwent ophthalmologic examination before and after corneal graft, including VA, assessed by the preferential looking test and visual evoked potential. The analysis of transplant survival was performed using the Kaplan-Meier method.

RESULTS

Fifty-six penetrating transplants were performed in 51 eyes of 43 children. The patients were divided into 2 groups: congenital (72.5%) and acquired (17.5%) corneal opacity. The main indication was congenital glaucoma (29.4%). The overall Kaplan-Meier graft survival rates were 64.7% in the postoperative average follow-up period of 24 months. There was no significant difference in graft survival between the congenital and acquired groups (Mantel-Cox P = .1031). There was significant improvement in VA in both groups (P = .0022 for congenital and P < .0001 for acquired). Rejection and diagnosis of congenital glaucoma were risk factors for graft failure.

CONCLUSIONS

Congenital glaucoma was the main indication for corneal transplantation and despite the difficulties, prolonged survival and improved VA can be achieved in pediatric transplant. Complications such as rejection and early glaucoma were significantly associated with graft failure.

Outcomes of big-bubble deep anterior lamellar keratoplasty for pediatric keratoconus

PURPOSE

To evaluate the outcomes and complications of deep anterior lamellar keratoplasty (DALK) performed for pediatric keratoconus.

METHODS

This retrospective study enrolled 44 consecutive eyes of 39 keratoconus-affected children (≤ 18 years of age). All patients underwent big-bubble DALK from March 2004 to June 2016. The outcome measures included postoperative best spectacle-corrected visual acuity (BSCVA), manifest refraction, keratometry readings, and complications.

RESULTS

The mean participant age was 16.8 ± 1.4 years, and the mean follow-up period was 68.5 ± 39.9 months. Successful big bubble was achieved in 33 eyes (75.0%), while the surgical technique was predescemetic DALK in 11 (25.0%). The mean BSCVA changed from 1.34 ± 0.49 LogMAR preoperatively to 0.24 ± 0.10 LogMAR postoperatively (P < 0.001). The mean keratometry decreased from 59.54 ± 5.17 D preoperatively to 46.23 ± 2.17 D postoperatively (P < 0.001). The complications encountered during the study period were intraoperative Descemet's membrane perforation (n = 5, 11.4%), the Urrets Zavalia syndrome (n = 1, 2.3%), graft epithelial problems (n = 3, 6.8%), subepithelial graft rejection (n = 5, 11.4%), high intraocular pressure (n = 8, 18.2%), and traumatic wound dehiscence (n = 2, 4.6%). Suture-related complications included premature loosening (n = 13, 29.6%), broken sutures (n = 12, 27.3%), suture-tract vascularization (n = 6, 13.6%), suture-associated abscesses (n = 5, 11.4%), and suture cheese wiring (n = 2, 4.6%). A clear graft was found in 40 eyes (90.9%) at the last follow-up examination.

CONCLUSION

This study showed promising results with big-bubble DALK in keratoconus-affected children. A frequent and close follow-up with dedicated parental involvement is essential for the early recognition and management of postoperative complications.

Risk factors for graft failure after penetrating keratoplasty

The objective of our study was to define principal risk factors for graft failure in patients who underwent penetrating keratoplasty (PK).Retrospective data obtained from a cohort of 895 penetrating keratoplasties performed between 2001 and 2006 were analysed. Recipient related factors, graft characteristics, and surgical technique were assessed in a univariate analysis and with a multivariate proportional hazard model to detect principal risk factors for definitive graft failure.Multivariate analysis showed clear significance for diagnosis and number of previous grafts and border line significance for the oldest donor age group. Patients with keratoconus had the best 10-year survival estimate (95%), followed by endothelial and stromal dystrophies (both 55%), infectious leukomas (49%), trauma (33%) and chemical burns (14%). Primary PK grafts had a survival rate of 81%, second grafts of 33% and third or more grafts of 16%. Overall 10-year survival estimate based on univariate analysis was found to be 65%.In conclusion, we found that primary diagnosis and previous graft failures in the recipient are the most important risk factors of graft failure after a PK.

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.

Changing Indications in Penetrating Keratoplasty: A Systematic Review of 34 Years of Global Reporting

BACKGROUND

Penetrating keratoplasty (PK) ranks among the oldest and most common kinds of human tissue transplantation. Based on the hypothesis that reported indications for PK significantly vary between global regions and over time, the present systematic review aimed to provide a thorough overview of global PK indications as reported in peer-reviewed manuscripts.

METHODS

A literature search of PubMed and MEDLINE was conducted to retrieve articles published from January 1980 to May 2014. Indications for PK within 7 global regions were compared using a modified classification system for PK indications and analyzed via multivariate regression.

RESULTS

A total of 141 publications from 37 countries were included, recording 180 865 PK cases. Postcataract surgery edema was the predominant indication in North America (28.0%) and ranked second in Europe (20.6%), Australia (21.1%), the Middle East (13.6%), Asia (15.5%), and South America (18.6%). Keratoconus was the leading indication in Europe (24.2%), Australia (33.2%), the Middle East (32.8%), Africa (32.4%), and South America (22.8%). It ranked third in North America (14.2%). Keratitis was the primary indication in Asia (32.3%). Fuchs endothelial corneal dystrophy was the fourth most common indication in North America (12.9%) and Europe (10.2%) and fifth in South America (3.8%). Multivariate analysis supported these results and revealed individual regional changes over time.

CONCLUSIONS

Systematic analysis reveals characteristic chronological and regional differences in reported global PK indications. Leading reported indications for PK between 1980 and 2014 were keratoconus (Europe, Australia, the Middle East, Africa, and South America), pseudophakic bullous keratopathy/aphakic bullous keratopathy (North America), and keratitis (Asia).

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

PURPOSE

To report the indications and the outcomes of keratoplasties in children over four decades.

METHODS

A retrospective cohort study of patients aged 16 years or younger who underwent keratoplasty in the Helsinki University Eye Hospital during 1968-2011. Diagnosis, preoperative status, age at the time of surgery, surgical technique, complications and follow-up time were registered. Main outcome measures were visual acuity and graft survival as assessed by Kaplan-Meier analysis. The independent role of risk factors on outcomes was evaluated by Cox multivariate regression analysis.

RESULTS

Forty-eight keratoplasties, 42 penetrating and six lamellar, were performed in 44 eyes of 39 children at the age of 4.5 months to 16 years (median, 12 years). Five patients had bilateral grafts, and five grafts were regrafts. The indication for keratoplasty was injury for 13 grafts, non-traumatic acquired corneal opacities for 11, keratoconus for eight, corneal dystrophy for seven, congenital corneal opacities for six and aniridia for three grafts. The cumulative proportion of clear grafts was 46% at 5 years postoperatively, and the median follow-up time of clear grafts was 5.1 years (range, 0.4-29 years) for 41 penetrating allografts (PKP). Simultaneous intraocular surgery at the time of grafting [hazard ratio (HR) 9.7], corneal vascularization (HR 8.1) and regrafting (HR 5.4) were the main independent risk factors for graft failure in this PKP cohort. The cumulative proportion of clear grafts was 84% at 5 years in the absence of any of these risk factors. PKP for keratoconus and corneal dystrophy yielded clear grafts in 83% of the eyes, and a visual acuity ≥0.3 (Snellen) in 75% of the eyes. Seventeen of the 20 graft failures were due to rejection.

CONCLUSIONS

Favourable graft survival was obtained in primary keratoplasties for non-vascularized corneal opacities performed without any other simultaneous intraocular surgery. Visual outcome was favourable in keratoconus and corneal dystrophies and poor in most eyes with injury.

Results of Deep Anterior Lamellar Keratoplasty for Advanced Keratoconus in Children Less Than 18 Years

PURPOSE

To evaluate the outcomes of deep anterior lamellar keratoplasty (DALK) in children with advanced keratoconus.

DESIGN

Retrospective noncomparative interventional case series.

METHODS

A retrospective analysis was conducted of 20 eyes of 16 patients who underwent deep anterior lamellar keratoplasty at a tertiary eye care center for advanced keratoconus. The main preoperative parameters measured were decimal uncorrected visual acuity (UCVA), decimal best-corrected visual acuity (BCVA), and average keratometry. The average keratometry was taken as an average of the flat and steep keratometric readings. The follow-up ranged from 24 to 105 months. The main outcome measures were UCVA, BCVA, steep and flat simulated keratometry, refraction, graft clarity, and complications.

RESULTS

At the final follow-up, 18 patients had clear grafts in the visual axis area. Mean decimal UCVA changed from 0.06 ± 0.08 to 0.24 ± 0.09. Mean decimal BCVA changed from 0.12 ± 0.19 to 0.45 ± 0.24. The average keratometry decreased from 64.15 diopter (D) to 45.7 D after surgery. The complications noted in the patients were graft rejection (1), shield ulcers (2), graft infection (2), and interface vascularization (4). They were managed accordingly and only 1 patient needed penetrating keratoplasty.

CONCLUSIONS

DALK is an effective therapeutic modality for the management of advanced keratoconus in children.

Intraocular myofibroblastoma in an infant: a case report

BACKGROUND

Myofibroblastoma is a benign tumor composed of spindle cells and bands of hyalinized collagen. Intraocular myofibroblastoma in infancy is rarely encountered.

CASE PRESENTATION

The present study reports the case of a 4-month-old female baby with intraocular myofibroblastoma. She was suspected as corneal perforation due to the rupture of a corneal neoplasm in the right eye. The anterior segment was also involved according to the Color Doppler ultrasonography. A surgical exploration was performed and the protuberant part of the mass was resected. Conventional HE staining showed numerous spindle-shaped cells with bands of collagen beneath multilayers of well-differentiated corneal epithelia. Immunohistochemical staining demonstrated the tumor cells were strong positive for vimentin and smooth muscle actin, while negative for S-100 protein. The mass was confirmed as myofibroblastoma. After 12 month follow-up, there was no apparent growth of the tumor.

CONCLUSIONS

Myofibroblastoma is a very rare type of intraocular neoplasm, which may have complicated manifestation and could be misdiagnosed as dermoid or Peter's anomaly. Histopathological and immunohistochemical staining is crucial to form a precise diagnosis.

Treatment options for advanced keratoconus: A review

Traditionally, the mainstay of treatment for advanced keratoconus (KC) has been either penetrating or deep anterior lamellar keratoplasty (PK or DALK, respectively). The success of both operations, however, has been somewhat tempered by potential difficulties and complications, both intraoperatively and postoperatively. These include suture and wound-healing problems, progression of disease in the recipient rim, allograft reaction, and persistent irregular astigmatism. Taken together, these have been the inspiration for an ongoing search for less troublesome therapeutic alternatives. These include ultraviolet crosslinking and intracorneal ring segments, both of which were originally constrained in their indication exclusively to eyes with mild to moderate disease. More recently, Bowman layer transplantation has been introduced for reversing corneal ectasia in eyes with advanced KC, re-enabling comfortable contact lens wear and permitting PK and DALK to be postponed or avoided entirely. We offer a summary of the current and emerging treatment options for advanced KC, aiming to provide the corneal specialist useful information in selecting the optimal therapy for individual patients.

Graft rejection in pediatric penetrating keratoplasty: Clinical features and outcomes

PURPOSE

Early presentation of rejection facilitates early initiation of treatment which can favor a reversible rejection and better outcome. We analyzed the incidence, clinical features including rejection-treatment period and outcomes following graft rejection in our series of pediatric corneal graft.

MATERIALS AND METHODS

Case records of pediatric penetrating keratoplasty (PK) were reviewed retrospectively, and parameters noted demographic profile, indication of surgery, surgery-rejection period, rejection-treatment interval, graft outcome, and complications.

RESULTS

PK was performed in 66 eyes of 66 children <12 years, with an average follow-up of 21.12 ± 11.36 months (range 4-48 month). The median age at the time of surgery was 4.0 years (range 2 months to 12 years). Most of the children belonged to rural background. Scarring after keratitis (22, 33.4%) was the most common indication. Graft rejection occurred in eight eyes (12.12%) (acquired nontraumatic - 3, congenital hereditary endothelial dystrophy [CHED] - 2, nonCHED - 1, congenital glaucoma - 1, regraft - 1). The mean surgery-rejection period was 10.5 ± 7.3 months and mean rejection-treatment interval was 10.9 ± 7.02 days.

CONCLUSION

This study showed irreversible graft rejection was the leading cause of graft failure of pediatric PK. Though, the incidence (12.1%) of graft rejection in current study was not high, but the percentage of reversal (25%) was one of the lowest in literature because of delayed presentation and longer interval between corneal graft rejection and treatment. In addition, categorization of the type of graft rejection was very difficult and cumbersome in pediatric patients.

The outcomes of primary pediatric keratoplasty in Singapore

PURPOSE

To evaluate the long-term corneal graft survival and risk factors for graft failure in pediatric eyes.

DESIGN

Retrospective, interventional consecutive case series.

METHODS

Unilateral eyes of 105 patients aged 16 years and below were included from the Singapore Corneal Transplant Study between April 4, 1991 and April 4, 2011. Corneal graft survival was calculated using Kaplan-Meier survival analysis, and survival distributions were compared using log-rank test.

RESULTS

Mean recipient age was 8.38 ± 5.63 years (range 0.18-15.92 years). Mean follow-up time was 34.16 ± 39.10 months. Main diagnoses were corneal scar (22.9%), limbal dermoid (21.9%), anterior segment dysgenesis (15.2%), and keratoconus (14.3%). Forty-four eyes (41.9%) underwent penetrating keratoplasty (PK), 37 (35.2%) underwent anterior lamellar keratoplasty (ALK), 22 (21.0%) underwent lamellar corneal patch graft, and 2 (1.9%) underwent Descemet stripping automated endothelial keratoplasty (DSAEK). Kaplan-Meier survival rates for PK were 92.8% at 1 year, 88.9% at 2-4 years, and 80.9% at 5-16 years; survival rates for ALK were 88.0% at 1 year and 84.3% at 2-7 years; survival rates for corneal patch graft were 100% at 1-3 years and 90% at 4-10 years; these were not statistically significant (P = .362). Deep corneal vascularization (P = .012), preexisting active inflammation (P = .023), preexisting glaucoma drainage device (P = .023), and preexisting ocular surface disease (P = .037) were associated with reduced graft survival in a univariate analysis.

CONCLUSIONS

We report good long-term graft survival following pediatric keratoplasty for various indications. Lamellar keratoplasty, when indicated, should be the procedure of choice in high-risk keratoplasties.

Corneal Allograft Rejection: Immunopathogenesis to Therapeutics

Corneal transplantation is among the most successful solid organ transplants. However, despite low rejection rates of grafts in the ‘low-risk’ setting, rejection can be as high as 70% when grafted into ‘high-risk’ recipient beds. Under normal homeostatic conditions, the avascular cornea provides a unique environment that facilitates immune and angiogenic privilege. An imbalance in pro-inflammatory, angiogenic and lymphangiogenic mediators leads to a breakdown in corneal immune privilege with a consequent host response against the donor graft. Recent developments in lamellar and endothelial keratoplasties have reduced the rates of graft rejection even more, while providing improved visual outcomes. The corneal layer against which an immune response is initiated, largely determines reversibility of the acute episode. While epithelial and stromal graft rejection may be treated with topical corticosteroids with higher success, acute endothelial rejection mandates a more aggressive approach to therapy due to the lack of regenerative capacity of this layer. However, current immunosuppressive regimens come with the caveat of ocular and systemic side effects, making prolonged aggressive treatment undesirable. With the advent of biologics, efficacious therapies with a superior side effect profile are on the horizon. In our review we discuss the mediators of ocular immune privilege, the roles of cellular and molecular immune players in graft rejection, with a focus on human leukocyte antigen and antigen presenting cells. Furthermore, we discuss the clinical risk factors for graft rejection and compare rates of rejection in lamellar and endothelial keratoplasties to traditional penetrating keratoplasty. Lastly, we present the current and upcoming measures of therapeutic strategies to manage and treat graft rejection, including an overview of biologics and small molecule therapy.

Rotational autokeratoplasty in pediatric patients for nonprogressive paracentral corneal scars

OBJECTIVE

To report the outcomes of ipsilateral rotational autokeratoplasty (RAK) for nonprogressive paracentral corneal opacities in children <16 years of age.

DESIGN

Retrospective, consecutive, interventional case series.

PARTICIPANTS

Thirty-three eyes of 33 children aged <16 years undergoing RAK for nonprogressive paracentral scars.

METHODS

Medical records were retrospectively reviewed for the primary etiology of corneal opacity, time of onset, duration of opacity, preoperative visual acuity, formula used for calculation of trephine size, size of the trephine used, and duration of follow-up. Any intraoperative and early and late postoperative complications were noted for all patients. Postoperative visual acuity and astigmatism were noted. Visual acuity was converted to logarithm of the minimum angle of resolution units for analysis.

MAIN OUTCOME MEASURES

Primary outcome was postoperative visual acuity. Graft clarity and complications were analyzed as secondary outcomes.

RESULTS

The mean age at surgery was 7.2 ± 3 .9 months. The mean follow-up duration was 27 ± 37 months. The commonest etiology of corneal opacity was trauma (62.5%), followed by resolved microbial keratitis (21.9%). Postoperative visual acuity (1.25 ± 0.84) was significantly better (P<0.001) than preoperative visual acuity (2.05 ± 0.96). The mean astigmatism at last visit was 4.04 ± 2.21 diopters. Postoperative visual acuity was better in older children (β = -0.01; P = 0.03) and had a shorter delay in presentation (β = 0.02; P = 0.05). At the last follow-up, the graft was clear in 27 cases (81.25%). The cumulative probability of graft survival was 85% at 2 years and 65% at 5 years. Complications included wound leak in 4 eyes, secondary glaucoma in 2 eyes, graft infiltrate and traumatic dehiscence in 1 eye each.

CONCLUSIONS

Rotational is a autokeratoplasty viable alternative surgical option to allogenic keratoplasty. Graft survival at 2 years seems to be better than allogenic keratoplasty. Younger age and delay in presentation contribute to poorer visual outcomes after surgery.

FINANCIAL DISCLOSURE(S)

The authors have no proprietary or commercial interest in any of the materials discussed in this article.

Boston Keratoprosthesis: expanding the boundaries

The Boston Keratoprosthesis (KPro) has enjoyed good results in the adult population, particularly through its rapid clearing of the visual axis, its excellent retention rate, and the paucity of postoperative complications in recent years. Design modifications, enhanced surgical technique, and improved postoperative management have made keratoprosthesis surgery a reality in the twenty-first century and an excellent alternative for poor PK candidates.

Early outcomes of primary pediatric keratoplasty in patients with acquired, atraumatic corneal pathology

PURPOSE

To evaluate the early outcomes of pediatric corneal transplantation in patients with acquired, nontraumatic corneal pathology.

METHODS

In this retrospective series, the records of children 15 years of age or younger who underwent optical penetrating keratoplasty for acquired nontraumatic corneal pathologies between December 2008 and June 2010 were reviewed. Demographic features, etiology of opacification, visual acuity, and other clinical findings were recorded.

RESULTS

Nineteen eyes of 19 children (10 females) were included. Mean age at time of surgery was 9.1 ± 3.01 years (range, 5-15 years). Adherent leukoma secondary to healed infectious keratitis (n = 12, 63%) and keratoconus (n = 7, 37%) were the leading indications for surgery. The mean follow-up period was 10.2 ± 3.3 months (range, 6-18 months). Postoperatively, clear grafts were seen in 15 cases (79%). Graft failure was noted in 4 eyes secondary to allograft rejection (n = 1), graft infection (n = 1), primary graft failure (n = 1), and uncontrolled glaucoma (n = 1). The most common cause of moderate or poor visual outcome was amblyopia (80%). Overall, 13 patients (68%) had postoperative visual acuity better than the preoperative vision.

CONCLUSIONS

Penetrating keratoplasty can yield good anatomic results in children with acquired, nontraumatic causes of corneal scarring, but amblyopia limits the visual outcomes.

Long-term visual outcome of penetrating keratoplasty in infants and children with Peters anomaly

PURPOSE

To determine the long-term visual outcome of penetrating keratoplasty for Peters anomaly and to identify prognostic factors affecting final vision.

METHODS

The records of children 12 years of age or younger who underwent penetrating keratoplasty for Peters anomaly between January 1, 1971 and December 31, 1992 at Emory University were reviewed. Characteristics of the recipient, eye, donor, and surgical procedure were examined with the use of multivariate analyses.

RESULTS

One hundred forty-four keratoplasties in 72 eyes of 47 children who were followed for a minimum of 3 years from the date of first keratoplasty (median, 11.1 years) were reviewed. Visual acuities ranged from 20/25 to no light perception. Twenty-nine percent of eyes achieved 20/400 or better visual acuities, whereas 38% had light perception or no light perception. Stromal vessels (p < 0.001) and larger donor corneas (p < 0.001) were independent predictors of poor outcome. Postoperative complications included graft failure (n = 44), cataract (n = 15), glaucoma (n = 14), retinal detachment (n = 16), and phthisis (n = 22). More than half of the eyes (n = 18) without graft failure, retinal detachment and/or phthisis saw 20/400 or better.

CONCLUSIONS

Less than one-third of eyes with Peters anomaly undergoing keratoplasty achieved a visual acuity of 20/400 or better. Stromal vessels and large corneal grafts (>or=8 mm) were the only independent predictors of a poor visual outcome.

Optical iridectomy in children with corneal opacities

BACKGROUND

Optical iridectomy creates a clear entrance pupil, improving vision in patients with segmental corneal opacities. An area of clear peripheral cornea can produce retinal images compatible with good visual acuity.

MATERIALS AND METHODS

The records of 22 children who underwent optical iridectomy from January 2002 to June 2004 were reviewed retrospectively. The optical iridectomy site was selected after slit-lamp examination. Visual acuity was assessed pre- and postoperatively by an age-appropriate method.

RESULTS

Twenty-two children with central corneal opacities underwent the procedure. Mean age was 10.4 +/- 12.6 months (range, 8-24 months). Mean follow-up period was 22.2 +/- 56.2 months (range, 8-140 months). No intraoperative or postoperative complications were observed. Visual acuity improved to near normal in 4 children (18.2%). However, 4 children (18.2%) did not show any improvement, and 1 child lost vision. Two patients (9.1%) showed no improvement in vision despite maintaining a clear line of sight.

CONCLUSIONS

Optical iridectomy is an alternative when penetrating keratoplasty cannot or should not be performed.

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.

Pediatric keratoplasty in India: indications and outcomes

PURPOSE

To analyze the indications and outcomes of pediatric corneal transplantation surgery in a tertiary eye care center in the developing world.

METHODS

In this longitudinal, retrospective study involving continuous cases, the records of 168 eyes of 154 children undergoing keratoplasty at a tertiary care center's specialized keratoplasty clinic during a 7-year period (1998-2004) were reviewed. The demography, etiology of opacification, visual acuity, and other findings were recorded. Intraoperative and postoperative details were reviewed. Major postoperative outcomes analyzed were visual acuity, graft survival, causes of graft failure, and follow-up duration.

RESULTS

Infectious keratitis (43%) was the most common indication for keratoplasty, followed by congenital glaucoma (16.6%) and corneal trauma (11.2%). Overall 77% graft survival was seen at 36 months, and better graft outcome was associated with younger age and longer regular follow-up. Postoperatively, a best-corrected visual acuity (BCVA) > 20/200 could be achieved in only 30.1% of eyes at the last follow-up. Graft failure was seen in 18.4% of eyes, with graft infection being the most frequent cause (50%). Moreover, graft infection was the most common cause of graft failure in all age groups.

CONCLUSIONS

In the developing world, infectious keratitis is the most common indication for pediatric keratoplasty and the most frequent cause of its failure.

Pediatric Keratoprosthesis

OBJECTIVE

To describe the authors' experience using keratoprosthesis to treat pediatric corneal opacity.

DESIGN

Nonrandomized, consecutive, retrospective interventional series.

PARTICIPANTS

Twenty-two eyes of 17 children with opaque corneas as a result of primary congenital disease and or previous failed keratoplasty.

METHODS

A retrospective review of pediatric patients with a history of corneal opacification treated with keratoprosthesis surgery.

MAIN OUTCOME MEASURES

Intraocular pressure, inflammation, clarity of the visual axis, visual acuity, refraction, complications, and retention of the prosthesis.

RESULTS

Twenty-two eyes of 17 patients 1.5 to 136 months of age underwent 23 keratoprosthesis procedures. The follow-up period was 220 patient months (range, 1-37 months; mean, 9.7 months). In both cases implanted with the AlphaCor (Argus Biomedical Pty. Ltd., Perth, Australia), the keratoprosthesis was not retained. In one instance, the prosthesis sustained traumatic dislocation and was replaced with a cadaver cornea. In the second instance, the intralamellar implant began to extrude and was replaced with a Boston keratoprosthesis. In all 21 Boston cases, the prosthesis was retained without dislocation or extrusion. The visual axis remained clear in 100% of cases, although retroprosthetic membranes were removed in 5 eyes. Reoperation was necessitated for management of concurrent glaucoma (n = 3) or retinopathy (n = 2). There were no instances of surface infection or endophthalmitis. In 7 instances where patient age was 4 years or more, visual acuity ranged from counting fingers to 20/30. In the remaining cases, all infants were able to follow light, fingers, and objects. Intraocular pressure was controlled in all cases.

CONCLUSIONS

Implantation of the Boston keratoprosthesis rapidly establishes and maintains a clear optical pathway and does not prejudice management of concurrent glaucoma or retinopathy. The device is retained without extrusion or rejection and is appropriate for the management of pediatric corneal opacity.

Acuité visuelle un et deux ans après kératoplastie transfixiante pour kératocône

PURPOSE

To quantify the visual outcome obtained in patients operated on for penetrating keratoplasty for keratoconus (KC) after 1 and 2 years.

PATIENTS

and methods: The files from consecutive keratoconus patients operated on for PKP after more than 2 years of follow-up were retrospectively studied. The demographic charts, the KC stage, and the surgical features were noted. The best corrected visual acuities (BSCVA) were analyzed at the initial examination and after 1 and 2 years of follow-up.

RESULTS

One hundred and two eyes from 98 patients were analyzed, including 83 grade 4 (81%) and 19 grade 3 (18%) cases of KC. The mean preoperative BSCVA was 0.08 on the decimal chart, which increased to 0.5 and 0.6 1 and 2 years after penetrating keratoplasty (p<0.001, respectively). The mean keratometric astigmatism was 3.80+/-2.9 D and 3.94+/-2.3 D for the grade 3 and 4 KC, respectively, after 1 year and 2.52+/-1.9 D and 3.34+/-2.2 D after 2 years (NS). At this time point, 81% of the eyes had less than 5 D astigmatism.

CONCLUSION

One and 2 years after penetrating keratoplasty, a mean BSCVA of 0.5 and 0.6 could reasonably be expected in keratoconus patients and three-quarters of patients can be expected to see better than 0.5 after 2 years.