Retinoblastoma - A comprehensive review, update and recent advances.

Retinoblastoma is the most common pediatric ocular malignancy. It is triggered by a biallelic mutation in the RB1 gene or MYCN oncogene amplification. Retinoblastomas can be unilateral (60%-70%) or bilateral (30%-40%); bilateral tumors are always heritable and present at an earlier age as compared to unilateral ones (18-24 months vs. 36 months in India). High prevalence rates, delayed presentation, and inaccessibility to healthcare lead to worse outcomes in developing countries. The past few decades have seen a paradigm change in the treatment of retinoblastomas, shifting from enucleation and external beam radiotherapy to less aggressive modalities for eye salvage. Multimodality treatment is now the standard of care and includes intraarterial or intravenous chemotherapy along with focal consolidation therapies such as transpupillary thermotherapy, cryotherapy, and laser photocoagulation. Intravitreal and intracameral chemotherapy can help in controlling intraocular seeds. Advanced extraocular or metastatic tumors still have a poor prognosis. Genetic testing, counseling, and screening of at-risk family members must be incorporated as essential parts of management. A better understanding of the genetics and molecular basis of retinoblastoma has opened up the path for potential targeted therapy in the future. Novel recent advances such as liquid biopsy, prenatal diagnosis, prognostic biomarkers, tylectomy, and chemoplaque point to promising future directions.

Retinal laser - Protocols and practical tips.

Background: Many a young doctors in training find retinal laser photocoagulation a daunting task. However, if correct protocols are followed and checklists are observed, then it is not difficult to have a successful laser sitting with a happy patient. Most of the complications can be avoided with correct settings and techniques. Purpose: To enumerate the basic protocols of retinal laser photocoagulation and provide practical tips including laser settings and checklists for hassle-free laser experience. Synopsis: Laser settings for a pan-retinal photocoagulation (PRP) for proliferative diabetic retinopathy differ from those for a focal laser for macular edema. A fill in PRP is indicated when an active Proliferative diabetic retinopathy (PDR) is seen after the initial PRP is completed. The settings and protocols for laser photocoagulation for lattice degeneration are different, and various techniques of barrage laser are discussed. Practical tips and checklists are given, which will not be found in any textbooks. Highlights: Animated illustrations and fundus photos are used to explain the correct techniques of performing laser photocoagulation in different indications and scenarios. Detailed instructions and checklists are provided, which can be very useful to avoid complications and medicolegal problems. The practical tips and guidelines in an easy-to-understand manner make this video highly educational for the novice retinal surgeons who want to perfect their technique of retinal laser photocoagulation. Video Link: https://youtu.be/saQ4s49ciXI.

Study of Retinal Nerve Fibre Layer Thickness and Visual Contrast Sensitivity in HIV Positive Individuals.

INTRODUCTION: Measurement of Retinal Nerve Fibre Layer Thickness (RNFLT) by Optical Coherence Tomography (OCT) is a sensitive, non invasive and cheap method of detecting early retinal changes in a variety of diseases. In HIV infection, RNFLT is altered and this may have effect on other visual functions like Contrast Sensitivity (CS) and visual acuity. Such ocular pathology can affect the daily life and profession (especially driving) of HIV infected individuals. However, studies on this topic in HIV infected population are rare from India. AIM: To study RNFLT, CS and their correlation in a sample of HIV positive Indian population. MATERIALS AND METHODS: The present cross-sectional study was done in a tertiary care medical college hospital of Eastern India between May 2016 and September 2016. We did this study on HIV positive subjects with no clinically apparent ocular infection or other pathology. In this study, we have measured the RNFLT using the HRA-OCT Spectralis machine. The CS was tested using a smartphone version of the Pellie-Robson chart. CD4 count, visual acuity and colour vision were also tested. The data was analysed using SPSS version 20.0 for any correlation between these parameters. Pearson coefficient was used for continuous data and Spearman rank correlation was used for categorical data. A p-value <0.05 was considered significant. RESULTS: We had 17 patients, that is 34 eyes. RNFLT loss was found in 21% of the eyes and borderline thinning was found in a further 26%. Predominantly, the temporal quadrant was involved. The mean of log CS was 1.33±0.38. Taking 1.5 as the cut-off value for normalcy, 47% of the eyes tested showed decreased CS. Log CS showed significant correlation with RNFLT of the temporal quadrant only (r=0.37; 95% C.I. 0.041 to 0.631; p=0.02). Temporal RNFLT also showed statistical correlation with the CD4 count. The low CS was also significantly correlated with low visual acuity (r=0.5). CONCLUSION: In HIV infected persons, subtle ocular changes may occur and this may affect visual functions quite early. Hence, a comprehensive eye check-up should include parameters like CS and OCT.