Faculty Bibliography

PURPOSE/OBJECTIVE:To facilitate development of standardized guidelines for management of pediatric patients undergoing keratoplasty, particularly the youngest cohort, through a comprehensive survey assessing recent trends in practice patterns of corneal specialists and pediatric ophthalmologists. METHODS:A cross-sectional, observational study of current practices pertaining to pediatric keratoplasty was performed by designing a 20-question survey focused on preoperative indications, surgical techniques, and postoperative management. This survey was sent electronically to corneal specialists and pediatric ophthalmologists. Results were compared with the findings of previous studies regarding pediatric keratoplasty. RESULTS:Of the 80 ophthalmologists who responded, 51.3% currently perform pediatric keratoplasty; only 20% have performed >50 cases. The majority (73.8%) completed solely corneal fellowships; all perform penetrating keratoplasty, 35.2% also perform endothelial keratoplasty, and 37% also perform lamellar keratoplasty. Peters anomaly was the most common indication for transplantation (34.3%). The majority believe that 1 to 3 months is the optimal age range to perform keratoplasty for both monocular and binocular congenital corneal opacities, although 13% stated that they would never perform keratoplasty in a patient with a monocular opacity. All surgeons report modifying their intraoperative techniques for pediatric patients, but specific practices and postoperative management protocols vary. There is a consensus regarding the importance of amblyopia therapy in these patients. CONCLUSIONS:Our results were consistent with the published literature regarding the indication and types of surgery performed. Variability among surgical techniques and postoperative management protocols highlights the necessity of creating standardized guidelines to optimize management of pediatric patients undergoing keratoplasty. Collaborative efforts between corneal and pediatric specialists are crucial for defining visual rehabilitation protocols to enhance visual outcomes.

PURPOSE:This review summarizes the conclusions and recommendations of the new National Council on Radiation Protection and Measurements (NCRP) Commentary No. 26 guidance on radiation dose limits for the lens of the eye. The NCRP addressed radiation protection principles in respect to the lens of the eye, discussed the current understanding of eye biology and lens effects, reviewed and evaluated epidemiology, and assessed exposed populations with the potential for significant radiation exposures to the lens while suggesting monitoring and protection practices. CONCLUSIONS:Radiation-induced damage to the lens of the eye can include the loss of clarity resulting in opacification or clouding several years after exposure. The impact is highly dependent on the type of radiation, how the exposure of the lens was delivered, the genetic susceptibilities of the individual exposed, and the location of the opacity relative to the visual axis of the individual. The preponderance of epidemiological evidence suggests that lens damage could occur at lower doses than previously considered and the NCRP has determined that it is prudent to reduce the recommended annual lens of the eye occupational dose limit from an equivalent dose of 150 mSv to an absorbed dose of 50 mGy. Significant additional research is still needed in the following areas: comprehensive evaluation of the overall effects of ionizing radiation on the eye, dosimetry methodology and dose-sparing optimization techniques, additional high quality epidemiology studies, and a basic understanding of the mechanisms of cataract development.

PURPOSE:To assess which surgical teaching methods are used for residency surgical training and which methods residents find most useful. SETTING:Wilmer Eye Institute, Baltimore, Maryland, USA. DESIGN:Retrospective observational cross-sectional study. METHODS:A survey was developed and sent to residents at accredited ophthalmology training programs in the United States. The survey asked about demographics, program characteristics, surgical training methods, perceived initial preparedness, eventual competence, and difficulty with the steps of cataract surgery. The correlation between surgical training methods was compared with perceived preparedness, competence, and difficulty. RESULTS:One hundred sixteen residents completed the survey. Discussing surgical procedures with senior surgeons or using surgical simulators preoperatively improved resident-perceived surgical competency in several areas, such as paracentesis. Residents who had preoperative discussions with senior surgeons were statistically less likely to report difficulty with surgical procedures, such as performing a clear corneal incision. The presence of a supervised wet lab or surgical simulator in a residency was also associated with improved resident-perceived surgical competency. CONCLUSION:Educational resources, such as surgical simulators and supervised wet labs, tended to be associated with greater resident-perceived competency for steps in cataract surgery.

PURPOSE OF REVIEW/OBJECTIVE:Pediatric keratoplasty poses unique challenges in clinical and surgical management. However, successful transplantation can afford a child vision in an otherwise poorly seeing eye. This review will provide an update on recent advances in pediatric keratoplasty. RECENT FINDINGS/RESULTS:Although children who receive corneal transplants remain at increased risk of rejection, infection, and graft dehiscence compared with adult corneal transplant recipients, new surgical techniques, and advances in clinical management have led to better outcomes. Surgical modifications in penetrating keratoplasty (PKP) offer increased stabilization of the delicate pediatric eye. Lamellar surgery, including endothelial keratoplasty and deep anterior lamellar keratoplasty, can target specific diseased tissue in children with potentially fewer complications. The keratoprosthesis can be used successfully in children when the chance of success with PKP is especially low. SUMMARY/CONCLUSIONS:As our knowledge of prognostic indicators and surgical techniques continues to grow, we can offer children safer and more targeted surgeries for some of the most challenging corneal diseases. Ultimately, successful transplantation with long-term graft survival can be obtained by a multidisciplinary approach, with care across ophthalmic specialties, and a commitment to long-term follow-up by the patient's family.

Previous National Council on Radiation Protection and Measurements (NCRP) publications have addressed the issues of risk and dose limitation in radiation protection and included guidance on specific organs and the lens of the eye. NCRP decided to prepare an updated commentary intended to enhance the previous recommendations provided in earlier reports. The NCRP Scientific Committee 1-23 (SC 1-23) is charged with preparing a commentary that will evaluate recent studies on the radiation dose response for the development of cataracts and also consider the type and severity of the cataracts as well as the dose rate; provide guidance on whether existing dose limits to the lens of the eye should be changed in the United States; and suggest research needs regarding radiation effects on and dose limits to the lens of the eye. A status of the ongoing work of SC 1-23 was presented at the Annual Meeting, "Changing Regulations and Radiation Guidance: What Does the Future Hold?" The following represents a synopsis of a few main points in the current draft commentary. It is likely that several changes will be forthcoming as SC 1-23 responds to subject matter expert review and develops a final document, expected by mid 2016.

PURPOSE/OBJECTIVE:To report 2 interventional cases of dedifferentiated chondrosarcoma with orbital involvement after radiotherapy performed in childhood and to review the literature on chondrosarcoma in the orbit following radiation treatment. METHODS:Retrospective analysis of medical records of 2 patients with chondrosarcoma of the orbits with review of the literature. RESULTS:The first patient developed chondrosarcoma of the orbital and maxillary sinus 36 years after external beam radiation therapy to the OS to treat retinoblastoma. The second patient developed a large orbital chondrosarcoma 35 years after external beam radiation therapy in the treatment of craniofacial fibrous dysplasia. CONCLUSIONS:These cases highlight the risk of secondary chondrosarcoma in patients following radiotherapy and the importance of lifetime monitoring.

Nonarteritic anterior ischemic optic neuropathy (NAION) causes sudden profound loss of vision with no known cause or cure. Various treatment modalities, both surgical and pharmacologic, have been tried without success. The purpose of our retrospective study was to evaluate the effect of intravitreal bevacizumab (Avastin) as a treatment option for NAION. We evaluated demographics of 5 patients and compared visual acuity and automated visual fields prior to and following intravitreal bevacizumab injection. Visual acuity at presentation was 20/20 in 4 of 5 patients and 20/150 in 1. Visual acuity improved to 20/40 in the patient who presented with decreased acuity and decreased slowly in 3 patients and rapidly in 1. All patients presented with variable visual field defects: 1 improved slightly, 3 progressed, and 1 remained stable. One patient subsequently developed NAION in the fellow eye. These results are consistent with the natural course of the disease, and bevacizumab did not appear to have a dramatic effect on the clinical outcome in this small series of patients with NAION.

Ocular imaging technologies continue to evolve and play increasingly important roles in both the diagnosis and management of corneal pathology. In addition to improved documentation of exam findings using increasingly better resolution photographs, newer modalities, including specular and confocal microscopy, can facilitate diagnosis by imaging single cell layers within the cornea. Anterior segment optical coherence tomography (OCT) and ultrasound biomicroscopy (UBM) can image structures in the cornea and anterior segment which may not otherwise be visible. This is particularly useful in patients with opaque corneas. The ability to topographically map the cornea allows for more accurate pre- and post-operative planning, especially in patients with corneal ectasia. As these technologies develop, their use in specific patient populations, such as children, must be optimized. In this report, we provide an updated analysis of selected imaging modalities used in the diagnosis and management of pediatric corneal pathology.