Topic

#Macular Diseases

38 articles
  1. Students Gallery 1 Apr 2021 27 min read

    Instruments Used in Vitreoretinal Surgery: A Comprehensive Guide for the Post Graduates

    History : While writing about the instrumentation of retinal surgery, the first name came in my mind was the none other than the Jules Gonin, who not only identified the Retinal tear as a prerequisite for the retinal detachment in the way back in 1904 in his first paper with series of 3 cases but also described the management of the same later on after constant hard work over the next two decade. He made major contribution and impact in the field of retinal surgery, immediately after his major presentation at the International Congress of Ophthalmology in 1929, and hence it is worth starting the topic recalling him. From the Gonin era to date, there were three major events in terms of development. 1st – improvement in instrumentation used to evaluate vitreoretinal pathology. 2nd – Evolution of the methods to create a chorioretinal adhesion around retinal breaks. 3rd – the development of a variety of techniques to tackle the vitreoretinal adhesion and hence to close the break permanentl

    Dr. Pratik Shah
  2. Articles 1 Apr 2021 8 min read

    Slit-lamp Biomicroscopy

    A slit-lamp is a binocular microscope used for eye examination using a slit-like light beam. In 1911, Allvar Gullstrand a Swedish Ophthalmologist designed table-mounted binocular eyepiece for 3-dimensional visualization of optically clear eye structures. Later Otto Henker, combined Gullstrand slit lamp with Czapski’s binocular microscope resulting in first slit lamp biomicroscope, allowing hand-free examination of an eye.1 The optical design of the Slit-Lamp Biomicroscope (SLB). Due to the miniature size of the anterior segment of the eye, we need high magnification and clarity to appreciate finer details. This can be achieved by having 2 convex lenses at the observer end (eyepiece) separated at its focal distance (astronomical telescope type alignment) and, a concave-convex combination (Galilean telescope type alignment) at the examinee’s end for further magnification of the image. Telescopic arrangements of lenses need to be focused at near, hence a plus power objective lens is fixed

    Dr. Nagesha C K · Dr. Shruthi M N
  3. Articles 1 Apr 2021 5 min read

    Ten Pearls for Performing Vitrectomy in Diabetic Retinopathy

    Important terms: Truncation: To relieve all the surrounding traction 360 degree Segmentation: Dividing a larger membranes/FVP into smaller islands of FVP by 360-degree truncation around them. Delamination: Separation of these membranes/FVP from the retinal surface to which they are firmly adherent by creating a plane of dissection between them. Pearl #1 When not to perform vitrectomy in diabetic retinopathy? Answer: In cases of extramacular tractional retinal detachment (TRD) when the fovea is attached and the patient has a comparative good vision the extramacular TRD can be observed. Charles and Flinn reported only 21% of extramacular TRD extending into macula without any surgical intervention. Also, DRVS (Diabetic retinopathy vitrectomy study) reports that only 23% of eyes with TRD developed severe visual loss at 2 years. Also, early intervention in such extramacular TRD’s can sometimes lead to more harm than benefit owing to the surgery itself. Pearl #2 First step should always be c

    Dr. Raja Narayan
  4. Articles 1 Apr 2021 43 min read

    Visual Electrophysiology Made Simple for the Postgraduates

    Visual electrophysiology is an extremely useful tool to study the retinal function objectively. It assesses the functional aspects of not only the retina but also the visual pathway as a whole. Even in this era of advanced imaging, one cannot ignore the importance of the functional aspects of the cellular network in the retina. The commonly used tests with their salient applications are enumerated in Table 1. S.no Test Application 1. Electroretinogram(ERG) Elicits mass response from the Retina 2. Electro-oculogram(EOG) Assesses the function of the Retinal pigment epithelium 3. Pattern ERG(PERG) Differentiates macular and optic nerve pathology 4. Multifocal ERG(MfERG) Picks up focal retinal pathology and maps out the topography 5. Photopic Negative Response(PhNR) Tests the function of retinal ganglion cells 6. Visual Evoked Potentials(VEP) Assesses the visual pathway up to the occipital cortex 7. Multifocal VEP(MfVEP) Picks up focal dysfunction of the visual pathway and maps the topogra

    Dr. Parveen Sen · Karthika Pandurangan · +1 other
  5. Interesting Reads 1 Apr 2021 16 min read

    Ten Clinical Trials in Retinal Diseases Every Postgraduate Should Know

    1. CATT (Comparison of Age-related Macular Degeneration Treatments Trials)1 Description A prospective, multicenter, single-blind, noninferiority randomized clinical trial. 1208 patients with neovascular AMD were enrolled from February 2008 and randomly assigned to receive intravitreal injections of ranibizumab (0.5 mg/0.05 ml) or bevacizumab (1.25 mg/0.05 ml) on either a monthly schedule or as needed with monthly evaluation. Patients aged ? 50 years with active, subfoveal CNV, fibrosis < 50% of total lesion area, visual acuity 20/25-20/320 and at least 1 drusen (>63?) in either eye or late AMD in fellow eye were eligible. The primary outcome was the mean change in visual acuity at 1 year, with a noninferiority limit of 5 letters on the eye chart. Results At one year, all four groups had similar improvements in visual acuity. Groups had similar rates of adverse events, though patients receiving bevacizumab had more occurrences of ?1 serious adverse event than those in the ranibizumab gr

    Dr. Neha Goel, MBBS MS MNAMS DNB FRCS (Glasgow)
  6. Articles 1 Apr 2021 30 min read

    Clinical Applications of Multicolor Imaging

    Multicolor imaging (MCI) is a non-invasive retinal imaging modality available in the Spectralis platform (Heidelberg Engineering, Heidelberg, Germany). It simultaneously acquires three reflectance images of the retina using three individual lasers of different wavelengths: blue (488 nm), green (515 nm), and infrared (820 nm). These penetrate the tissue to different depths, simultaneously capturing and depicting information originating from different retinal structures. The infrared reflectance (IR) image visualizes structures at the level of the outer retina and choroid. The green reflectance (GR) image allows imaging of retinal blood vessels, hemorrhages, and exudates. The blue reflectance (BR) particularly provides details of the inner retina and the vitreoretinal interface such as epiretinal membranes, retinal nerve fiber layer (RNFL) thinning, and macular pigment changes. The information from these three images is integrated to form a composite multicolor image.1 Color fundus photo

    Dr. Sugandha Goel · Dr. Rupak Roy
  7. Interesting Reads 1 Apr 2021 11 min read

    Understanding Retinal Imaging

    Retinal imaging has come a long way today. From times of appropriately concentrating the fluorescein dye from scratch in the lab itself to times where we have a dye-free angiography system, technology has covered vast boundaries. There is a platter of different modalities in the market today, each having their own ebb and flow. And what the future beholds for us is certainly inexplicable. To throw a light on these modalities, we have a special interview with someone who continues to extensively work on these technologies and modalities day in and out, Dr. Manish Nagpal Dr. Nagpal is practicing as a vitreoretinal consultant at Retina Foundation, Ahmedabad, since 1999. He completed his Ophthalmology training at M & J Institute of Ophthalmology, Ahmedabad in 1996 and further went on to accomplish the FRCS (Ed) at the UK in 1997. He is a recipient of the prestigious Distinguished Service Award of APAO in 2007, the Achievement award of APAO in 2012, the American Academy’s Achievement award

    Dr. Dhaivat Shah
  8. Articles 1 Apr 2021 4 min read

    Ten Things You Should Know about Brolucizumab

    1. Brolucizumab is a humanized, single-chain variable fragment (scFv) antibody with a molecular mass of approximately 26 kDa that inhibits VEGF-A.[1] (An scFv is an autonomous binding agent that is no longer dependent on a heavy molecular support structure but still retains the full binding capacity to its target). Mechanism of Action of Brolucizumab Unique Properties of Brolucizumab 2. The pharmacokinetics of a single intravitreal (IVT) injection of Brolucizumab in cynomolgus monkeys revealed a mean terminal half-life of 2.4 ± 0.3 days in all ocular compartments. It was cleared from the serum with a mean half-life of 51 hours (approximately 2 days).[2] Brolucizumab Bevacizumab Ranibizumab Aflibercept Molecule Short-chain variable fragment Full antibody (IgG) Monoclonal humanized antibody format Fusion protein Clinical dose in neovascular ARMD 6 mg 1.25 mg* 0.5 mg 2 mg Equivalent Molar dose 11.2-13.3 0.4-0.5 0.5-0.6 1.0 Table: Molecular properties of anti-VEGF agents (ARMD= Age-related

    Dr. Anmol Naik

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