Accuracy of preoperative imaging in predicting optic nerve invasion in retinoblastoma: A retrospective study

Purpose: Optic nerve invasion is an important cause of mortality in retinoblastoma. We aimed correlate preoperative imaging and surgical histopathology findings in enucleated eyes with retinoblastoma to determine the efficacy of preoperative imaging in predicting optic nerve invasion in retinoblastoma. Methods: A retrospective review of records of all patients undergoing primary enucleation for retinoblastoma at a tertiary eyecare system between March 2013 and December 2017 with all patients having undergone preoperative imaging, either CT scan or MRI. Data was analyzed statistically to determine the correlation between preoperative CT scan/MRI and histopathology. Results: Totally, 97 eyes of 97 patients were included in the study who underwent primary enucleation for unilateral retinoblastoma. The average age at presentation was 27.8 months with the chief complaint being leukocoria in all the cases. 14 patients (14.43%) had evidence of optic nerve involvement in preoperative imaging. 30 patients had optic nerve invasion on histopathology (laminar and retrolaminar). Spearman's rank correlation test revealed a significant correlation between MRI findings and HP and an insignficant correlation between CT findings and HP. The CT scan had a sensitivity of 20%, specificity of 88.89%, 50% positive predictive value and 66.67% negative predictive value. MRI had a sensitivity of 40%, specificity of 93.55%, positive predictive value of 66.67% and a negative predictive value of 82.86%. Conclusion: MRI showed significant moderate correlation with surgical histopathology for predicting optic nerve invasion in retinoblastoma whereas CT shows insignificant correlation with HPE. Therefore, we recommend MRI for predicting optic nerve invasion in cases of retinoblastoma.

Combined treatment modality for phthiriasis palpebrarum

Phthiriasis palpebrarum (PP) is the infestation of eyelids caused by the ectoparasite Phthirus pubis, frequently misdiagnosed as allergic conjunctivitis, blepharitis or dermatitis. There is no standard treatment of choice although various treatment modalities have been described. A 6-year-old male child with PP was successfully treated with local application of 20% fluorescein solution over the eyelashes and eyebrows of both the eyes, followed by the mechanical removal of all parasites and trimming of the eyelashes from the base and application of ophthalmic ointment.

Retinoblastoma discordance in families with twins

Retinoblastoma has an increased inheritance risk of germline RB1 mutations in offspring and siblings, especially twins. Three families, each having one retinoblastoma-affected twin, were selected for genetic analysis and DNA profiling. Germline RB1 mutations were found in all probands. DNA profiling carried on similar-looking twins of families I and II, proved them to be fraternal. This study demonstrates the importance of genetic analysis of RB1 gene for risk prediction in retinoblastoma families. It also emphasizes that DNA profiling is a mandate for genetic screening of families with twins, thus adding a new dimension in counseling of retinoblastoma.