Analysis of Graft Failure After Primary Penetrating Keratoplasty in Children With Peters Anomaly

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.

Clinical Analysis of Repeat Penetrating Keratoplasty in Children

(1) Background: To analyze the indications, graft survival, and graft failure-related risk factors of repeat penetrating keratoplasty (RPK) in children. (2) Methods: In this case series, children younger than 12 years who received RPK at Beijing Tongren Hospital were reviewed. The indications for RPK, postoperative complications, and graft survival were analyzed. The analysis of the potential variables associated with graft survival was performed using Cox proportional hazards regression. (3) Results: A total of 30 RPK eyes of 29 children were included in this study. The mean follow-up time was 26.98 ± 18.75 months. The most common indication for RPK was a vascularized corneal scar (86.67%). Postoperative complications occurred in 27 eyes (90%), including immune rejection (46.67%), epithelial defects (36.67%), and glaucoma (26.67%). About 60% of the regrafts remained clear one year after RPK, while the overall graft survival rate was 30% at the last visit. The most common cause of regraft failure was irreversible immune rejection (8/21). The significant risks of graft failure included an age of less than 60 months at surgery (p = 0.009), corneal vascularization (p = 0.018), and a postoperative epithelial defect (p = 0.037). (4) Conclusions: A vascularized corneal scar is the most common indication of RPK in children. Immune rejection is the most prevalent complication, and irreversible immune rejection always causes regraft failure.

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.

Selective Endothelialectomy in Peters Anomaly: A Novel Surgical Technique and Its Clinical Outcomes in Children

PURPOSE

This study describes the surgical outcomes of selective endothelialectomy in Peters anomaly (SEPA), a relatively new technique to manage Peters anomaly (PA).

METHODS

This study included 34 eyes of 28 children who had a visually significant posterior corneal defect due to PA and underwent SEPA between 2012 and 2019. A selective endothelialectomy from the posterior corneal defect was performed while preserving Descemet membrane. The primary outcome measure was the resolution of corneal opacification. The secondary outcome measures were functional vision, complications, and risk factors for failure.

RESULTS

At a mean postoperative follow-up of 0.96 ± 0.20 years, 29 eyes (85.3%) maintained a successful outcome. Mean preoperative and postoperative best-corrected visual acuities were 2.55 ± 0.13 and 1.78 ± 0.13 ( P < 0.0001), respectively. Ambulatory functional visual improvement was seen in 97%, and 23% attained vision ranging between 20/190 and 20/50. Corneal opacification failed to clear in 5 eyes (15%). Risk factors associated with surgical failure were female sex ( P = 0.006), disease severity ( P < 0.0001), glaucoma ( P = 0.001), and additional interventions after SEPA ( P = 0.002). In multivariate analysis, only disease severity (ie, a type 2 PA) was a significant risk factor for the failure of SEPA. There were no sight-threatening complications.

CONCLUSIONS

SEPA is a safe and effective technique in select cases of posterior corneal defect due to PA. SEPA could be a potential surgical alternative to pediatric keratoplasty or optical iridectomy in children with central corneal opacification smaller than 7 mm due to PA.

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.

Selective endothelial removal: A case series of a phase I/II surgical trial with long-term follow up

Peters anomaly is a congenital condition which results in a central corneal opacity from birth. Selective Endothelial Removal (SER) is a novel surgical technique and a form of regenerative therapy, which encourages clearance of the central corneal opacity by the patient’s own corneal endothelial cells, and it may potentially be beneficial for the treatment of Peters anomaly. We have performed a phase I/II surgical trial, evaluating the safety of SER in four eyes (three patients) with Peters Anomaly. These patients underwent SER at between 9 and 39 months of age, each demonstrating clearance of central corneal opacities and improvements in vision post-operatively. No complications occurred in any of these eyes, at a minimal post-operative follow-up duration of 48 months. We conclude that SER for Peters anomaly is a safe surgical procedure. While encouraging efficacy outcomes have been observed, these findings should be further evaluated in a larger scale Phase II/III surgical trial.

Phenotypic Spectrum of Peters Anomaly: Implications for Management

PURPOSE

The aim of this study was to characterize the wide phenotypic spectrum of Peters anomaly and to suggest a management algorithm based on disease phenotype.

METHODS

The charts of all children diagnosed with Peters anomaly between January 2000 and December 2013 were reviewed retrospectively. Anterior segment color photographs, anterior segment optical coherence tomography, and ultrasound biomicroscopy images were used to phenotype disease severity and to guide management. Disease severity was categorized to Peters anomaly type I and II according to lens involvement. Peters anomaly type I and II were further categorized from mild to severe disease according to the size and location of corneal opacity. Associated systemic findings were also documented.

RESULTS

Eighty eyes of 54 patients with Peters anomaly were identified, of which 28 (51.9%) had unilateral disease. Peters anomaly type I was present in 40 patients (57 eyes, 71.2%) and Peters anomaly type II in 14 patients (23 eyes, 28.8%). Nine eyes (11.3%) had phenotypic features that required observation only, 24 eyes (30%) were amenable to pupillary dilation, 43 eyes (53.8%) with large, dense central opacity required penetrating keratoplasty, and 4 eyes (5.0%) had no intervention because of very poor prognostic features. Associated systemic abnormalities occurred frequently in Peters anomaly (n = 20, 37.0%), with congenital heart defect being the most common morbidity (n = 10, 18.5%).

CONCLUSIONS

Peters anomaly presents with a variable phenotype ranging from minimal peripheral corneal opacity to extensive iris and lens adhesions with dense central corneal opacity detrimental to vision. Management can be standardized and guided by an algorithm based on phenotypic severity. Systemic abnormalities should be ruled out, regardless of the severity of Peters anomaly.

Descemet Stripping Automated Endothelial Keratoplasty in Pediatric Age Group: A Decade of Our Experience

PURPOSE

This study was to report the outcomes of Descemet stripping automated endothelial keratoplasty (DSAEK) in managing corneal endothelial disorders in children less than 14 years of age.

METHODS

Medical records of 180 DSAEK performed, between 2008 and 2020, on 167 eyes of 111 children who had a visually significant endothelial dysfunction were retrospectively reviewed for the primary etiology of corneal decompensation, time of the onset and duration of cloudiness, preoperative visual acuity, the technique of endothelial keratoplasty, surgical modifications, and reintervention.

RESULTS

Median age at surgical intervention was 7.9 years (interquartile range, 5.2-11.2 years). At a median postinterventional follow-up of 2.5 years (interquartile range, 0.9-3.4 years), 86.2% (144 of 167 eyes, 95% confidence interval 79.9%-90.1%) maintained a clear graft. Median best-corrected visual acuity (logarithm of the minimum angle of resolution) improved from 1.45 ± 0.70 preoperatively to 0.90 ± 0.06 at the last follow-up visit (P < 0.0001). The cumulative overall long-term graft survival was 92.7%, 86.5%, and 77.7% at 1, 3, and 7 years, respectively. Cox proportional hazards regression analysis showed that the indication for DSAEK (P = 0.007; hazards ratio: 2.17 ± 0.62), age at surgery (P = 0.02; hazards ratio: 0.87 ± 0.05), and any subsequent intervention after DSAEK (P = 0.003; hazards ratio: 0.11 ± 0.08) were significant risk factors for DSAEK failure. The endothelial cell loss was 40.1% at 6 months, 45.4% at 1 year, 55.2% at 5 years, and 61.9% at 7 years.

CONCLUSIONS

DSAEK is a safe and effective surgical strategy in managing endothelial disorders among the pediatric age group.

Advances in corneal graft rejection

PURPOSE OF REVIEW

Immune rejection after corneal transplantation is a major risk for graft failure. We aim to summarize recent advances in the understanding and management of graft rejection.

RECENT FINDINGS

Immune rejection remains the leading cause of graft failure in penetrating keratoplasty (PKP). While ABO blood type and sex match between donor and recipient may reduce rejection, human leucocyte antigens class II matching in a randomized study did not reduce the risk of rejection in high-risk PKP. Compared with PKP, deep anterior lamellar keratoplasty, descemet stripping automated endothelial keratoplasty, and descemet membrane endothelial keratoplasty have lower immune rejection rates of 1.7-13%, 5-11.4%, and 1.7-2.8%, respectively, based on long-term (5 years and more) studies. Whether immune rejection is a major risk factor for graft failure in these lamellar keratoplasties is unclear. While there have not been major advances in the systemic management of graft rejection, topical nonsteroid agents such as tacrolimus and anti-vascular endothelial growth factor have shown promise in high-risk cases.

SUMMARY

Immune rejection remains the leading cause of graft failure in PKP. Lamellar keratoplasties have significantly lower rejection rates compared with PKP. The significance of rejection in the failure of lamellar grafts warrants further investigation.

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.