Dr. Bhushan Ghodke, G14425, Dr.Sachin Arya, Dr. Parmar Gautam Singh, Dr. Ashok Kumar Meena
INTRODUCTION :
Corneal transplantation in children has challenged ophthalmologists for decades.Once considered contraindicated in children less than 16 years of age, pediatric penetrating keratoplasty has become the standard of care for infants or children with corneal opacities that preclude the development or maintenance of normal visual function. Advances in surgical technique and postoperative care have led to higher rates of graft survival in selected group of patients.
The eye of the pediatric patient is smaller, the sclera and cornea are less rigid, with increased positive posterior vitreous pressure and a stronger inflammatory reaction. Follow-up is sometimes difficult owing to poor patient cooperation and the inability of young children to communicate postoperative symptoms.
Determining factors associated not only with graft survival but also with good visual outcome may be instrumental in improving vision after pediatric keratoplasty. Thus, the aim of our study is to evaluate outcomes of penetrating keratoplasty in children and determine factors related to graft survival in these patients.
METHODS:
It is a retrospective observational clinical study conducted at Sadguru Netra Chikitsalaya, Chitrakoot, India. Medical records of all patients less than 18 years of age between January 2010 and April 2017, who underwent pediatric penetrating keratoplasty(PPK) were reviewed.Preoperative assessment performed in all patients for evaluation of the corneal pathology and intraocular pressure measurement. All PPK surgeries were performed under general anesthesia. The study was approved by the Institutional Review Board of Sadguru seva sangh trust, and was performed in accordance with the tenets of the Declaration of Helsinki.
Parameters evaluated included demographic profile, indications of surgery, surgery-rejection period, rejection-reversal percentage, graft outcome, complicationsand duration of follow-up. Synechiolysis, anterior vitrectomy and cataract extraction were done wherever required. Topical steroid (1% prednisolone acetate) and antibiotic eyedrop (0.5% moxifloxacin – 4 times/day) were instilled in the immediate postoperative period along with cycloplegics (1% atropine sulphate eye ointment). All children were followed-up and factors like visual acuity, graft clarity, graft–host junction, sutural infiltrates, intraocular pressure, and signs of infection/rejection at each postoperative visit were evaluated. Selective suture removal was done for suture-related complications under strict aseptic conditions.
Graft rejection was defined by presence of anterior chamber reaction with cells and flare, keratic precipitates, endothelial rejection line along with corneal edema in a previously uninflamed eye, after a period of at least 2 weeks after the surgery. All cases of rejection were treated with intensive immunosuppression with topical prednisolone acetate 1 % drops half hourly while awake for 2 days and 1 hourly while awake for 1 week with a gradual taper thereafter. In addition, after a complete systemic workup, systemic steroid therapy was given in the form of intravenous dexamethasone 4-5 mg/kg body weight, diluted in 150 mL of 5% dextrose over 30-60 min. Monitoring of vital signs was done before, during, and after the infusions were given. Oral systemic steroids (1 mg/kg body weight) were prescribed after the initial pulse therapy in tapering doses. Rejection reversal was defined as resolution of all signs of rejection along with improvement in graft edema and visual acuity.
RESULTS :
A total of 29 pediatric penetrating keratoplasty surgeries were performed in 29 children(Boys-18,Girls-11).The mean age of children was 8.01 ± 5.5 years(1 year to 14 years).Mean follow-up for 74.2%grafts that remained clear was 38.3 months.
The major groups used to classify indications for keratoplasty were acquired non-traumatic, acquired traumatic, and congenital. In our study, acquired traumatic and acquired non-traumatic indications were equal in number(13/29 children – 44.87%) while all three cases in congenital group were of congenital hereditary endothelial dystrophy(CHED). In children, visual assessment can be difficult. Different methods were used to assess change in vision after surgery. Documentation of change in BCVA on Snellen or ‘‘E’’ chart was the preferred method if the child was cooperative. If visual assessment was not possible even when using these tests, subjective methods such as the child not resisting occlusion of the better eye and reaching out for things were used. In 30% of children in whom visual acuity testing was possible, there was 2 lines improvement in 30% of children. 25/29 grafts were clear at 6 months follow-up and the overall anatomical success rate in terms of graft clarity was 73.4%. Sutural infiltrate was the most common complication (6/29) followed by graft infiltrate (4/29). Graft failure rate was 25.8%.Mean Surgery-Rejection time was 6.5 ± 5.1 months.Percentage of Rejection Reversal was 30%.
DISCUSSION:
Corneal grafting in children is different from that in adults because of morphologic and functional aspects, and these differences are reflected in the overall outcome of the surgery. Also, there are regional differences regarding the indications and functional outcome of pediatric corneal transplantation surgery. Although congenital corneal opacification and corneal dystrophies are the major indications of pediatric corneal transplantation in the developed world, corneal scarring and perforation caused by ulceration are the major reasons of performing a corneal graft in children in this part of the world.In our study, 44.87% of patients belonged to the acquired non-traumatic group and healed or active infection was the most common indication for keratoplasty. Dana et al., have reported infectious keratitis to be the indication of corneal grafting surgery in only 18.5% of all cases. Among congenital causes, Peter’s anomaly is a major indication for pediatric keratoplasty in the western world. However, we observed that scarring secondary to congenital hereditary endothelial dystrophy was the most common congenital indication in our
study.Graft survival and restoration of optimal visual acuity are the 2 most important parameters of evaluating the success of any corneal transplantation surgery. Our overall 1-year graft survival was better than that of similar studies. This may be because most of our cases belonged to the acquired etiology group, and many of the patients had corneal grafting done at an older age than was the case with several other studies. A significantly better graft outcome was seen in children aged 6 years and above as compared to younger ones. Previous studies have also reported this fact and have said that the difference in the graft survival between younger and older children arises because examination in younger children is technically difficult. In our study, 25.8% of cases had graft failure, which is lower than that reported in the 2 major studies that had failure rates between 33% and 37%. In contrast to other studies that have reported graft rejection and secondary glaucoma as the most common causes of failure, we found that infection (suture and graft related) was the most common cause of graft failure in our patient base.
In a developing world like ours, factors other than just the indication for surgery affect the graft outcome. Regular follow-up and timely intervention can significantly alter the results.
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