This document discusses branch retinal vein occlusion (BRVO), including its pathogenesis, risk factors, clinical features, investigations, and management approaches. Some key points:
- BRVO is the second most common cause of vision loss due to retinal vascular disease, after diabetic retinopathy. It occurs most often in patients in their 50s-60s and is caused by obstruction of a branch retinal vein.
- Risk factors include hypertension, diabetes, hyperlipidemia, glaucoma, smoking, and age-related atherosclerosis. Laser treatment can help manage macular edema and neovascularization complications.
- Treatment aims to address modifiable risk factors and manage sight-threatening complications like macular edema,
Branched Retinal Vein Occlusion (BRVO) for undergraduate MBBS Students.
Covers the basics of Aetiology, pathophysiology, clinical features, types, associated conditions and management of BRVO.
Also encompasses salient points for PGMEE
Branched Retinal Vein Occlusion (BRVO) for undergraduate MBBS Students.
Covers the basics of Aetiology, pathophysiology, clinical features, types, associated conditions and management of BRVO.
Also encompasses salient points for PGMEE
Vitreous hemorrhage is the extravasation, or leakage, of blood into the areas in and around the vitreous humor of the eye.[1] The vitreous humor is the clear gel that fills the space between the lens and the retina of the eye. A variety of conditions can result in blood leaking into the vitreous humor, which can cause impaired vision, floaters, and photopsia.
It's an indepth presentation by Dr. Shah-Noor Hassan.
Retinal vein occlusion (RVO) is an obstruction of the retinal venous system by thrombus formation and may involve the central, hemi-central or branch retinal vein.
The most common aetiological factor is compression by adjacent atherosclerotic retinal arteries.
Other possible causes are external compression or disease of the vein wall e.g. vasculitis.
In this case-based presentation, Dr. Lori Myers unscrambles the alphabet soup of Diabetic Retinopathy, providing clear explanations and outstanding images to describe the diagnosis, risk stratification, and treatment of diabetic retinopathy.
The retina is the internal layer of the eyeball , which is a thin membrane having a purplish red color in living subject. This is a presentation by Dr. Shah-Noor Hassan regarding ANATOMY OF RETINA
Eye prophylaxis for retinal detachment (RD) is still a controversial issue since opinions are not unanimous regarding the kind of lesions to be treated or the method of treatment. This prospective clinical study aimed to follow the course of vitreoretinal conditions in 150 high risk fellow eyes.
Diabetic Macular Edema (DME) is an accumulation of fluid in the macula—part of the retina that controls our most detailed vision abilities—due to leaking blood vessels. In order to develop DME, you must first have diabetic retinopathy.
Retinoblastoma (Rb) is a form of cancer that rapidly develops from the immature cells of a retina, the light-detecting tissue of the eye. It is the most common primary malignant intraocular cancer in children, and it is almost exclusively found in young children.
Surgical management of Uveal Effusion Syndrome-A Case Report Dr. Shah Noor Hassan
The response to surgery in these eyes suggests that the approach is justified and provides further evidence that a scleral abnormality is the underlying cause of uveal effusion syndrome.
Pars Planitis is a disease of the eye that is characterized by inflammation of the narrowed area (pars plana) between the colored part of the eye (iris) and the choroid. This may lead to blurred vision; dark, floating spots in the vision; and progressive vision loss.
Fluorescein angiography, fluorescent angiography, or fundus fluorescein angiography is a technique for examining the circulation of the retina and choroid using a fluorescent dye and a specialized angiographic camera.
Endophthalmitis is an inflammation of the interior of the eye. It is a possible complication of all intraocular surgeries, particularly cataract surgery, with possible loss of vision and the eye itself.
Coats' disease, (also known as exudative retinitis or retinal telangiectasis, sometimes spelled Coates' disease), is a rare congenital, nonhereditary eye disorder, causing full or partial blindness, characterized by abnormal development of blood vessels behind the retina.
Approach to Disc Pallor and Automated Fields in Neuro-ophthalmology Dr. Shah Noor Hassan
Visual field assessment is important in the evaluation of lesions involving the visual pathways and should be performed at baseline and periodically in the follow-up. Standard automated perimetry has been shown to be adequate in neuro-ophthalmic practise and is now the technique of choice for a majority of practitioners.
Retinoblastoma is known to be a rare eye cancer, which occurs from the immature retina cells. It is one of the most common malignant cancer found in young children.
Endophthalmitis is an inflammation of the vitreous and the inner coats of the eye. This inflammation leads to infection which is caused by fungi or bacteria.
Diabetic maculopathy is a form of damage to the eye causing by diabetic macular oedema where fluids build up on the macula. It can be cured by laser surgeries.
Ocular Ultrasound is an ultrasound for eyes that uses high frequency sound waves to get detailed pictures of your eye and it's orbit. This procedure is usually done by Ophthalmologists.
These lecture slides, by Dr Sidra Arshad, offer a quick overview of physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar leads (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...Oleg Kshivets
RESULTS: Overall life span (LS) was 2252.1±1742.5 days and cumulative 5-year survival (5YS) reached 73.2%, 10 years – 64.8%, 20 years – 42.5%. 513 LCP lived more than 5 years (LS=3124.6±1525.6 days), 148 LCP – more than 10 years (LS=5054.4±1504.1 days).199 LCP died because of LC (LS=562.7±374.5 days). 5YS of LCP after bi/lobectomies was significantly superior in comparison with LCP after pneumonectomies (78.1% vs.63.7%, P=0.00001 by log-rank test). AT significantly improved 5YS (66.3% vs. 34.8%) (P=0.00000 by log-rank test) only for LCP with N1-2. Cox modeling displayed that 5YS of LCP significantly depended on: phase transition (PT) early-invasive LC in terms of synergetics, PT N0—N12, cell ratio factors (ratio between cancer cells- CC and blood cells subpopulations), G1-3, histology, glucose, AT, blood cell circuit, prothrombin index, heparin tolerance, recalcification time (P=0.000-0.038). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT early-invasive LC (rank=1), PT N0—N12 (rank=2), thrombocytes/CC (3), erythrocytes/CC (4), eosinophils/CC (5), healthy cells/CC (6), lymphocytes/CC (7), segmented neutrophils/CC (8), stick neutrophils/CC (9), monocytes/CC (10); leucocytes/CC (11). Correct prediction of 5YS was 100% by neural networks computing (area under ROC curve=1.0; error=0.0).
CONCLUSIONS: 5YS of LCP after radical procedures significantly depended on: 1) PT early-invasive cancer; 2) PT N0--N12; 3) cell ratio factors; 4) blood cell circuit; 5) biochemical factors; 6) hemostasis system; 7) AT; 8) LC characteristics; 9) LC cell dynamics; 10) surgery type: lobectomy/pneumonectomy; 11) anthropometric data. Optimal diagnosis and treatment strategies for LC are: 1) screening and early detection of LC; 2) availability of experienced thoracic surgeons because of complexity of radical procedures; 3) aggressive en block surgery and adequate lymph node dissection for completeness; 4) precise prediction; 5) adjuvant chemoimmunoradiotherapy for LCP with unfavorable prognosis.
Pulmonary Thromboembolism - etilogy, types, medical- Surgical and nursing man...VarunMahajani
Disruption of blood supply to lung alveoli due to blockage of one or more pulmonary blood vessels is called as Pulmonary thromboembolism. In this presentation we will discuss its causes, types and its management in depth.
Couples presenting to the infertility clinic- Do they really have infertility...Sujoy Dasgupta
Dr Sujoy Dasgupta presented the study on "Couples presenting to the infertility clinic- Do they really have infertility? – The unexplored stories of non-consummation" in the 13th Congress of the Asia Pacific Initiative on Reproduction (ASPIRE 2024) at Manila on 24 May, 2024.
- Video recording of this lecture in English language: https://youtu.be/lK81BzxMqdo
- Video recording of this lecture in Arabic language: https://youtu.be/Ve4P0COk9OI
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
Anti ulcer drugs and their Advance pharmacology ||
Anti-ulcer drugs are medications used to prevent and treat ulcers in the stomach and upper part of the small intestine (duodenal ulcers). These ulcers are often caused by an imbalance between stomach acid and the mucosal lining, which protects the stomach lining.
||Scope: Overview of various classes of anti-ulcer drugs, their mechanisms of action, indications, side effects, and clinical considerations.
1. Dr. Shah-Noor Hassan FCPS,FRCS
Consultant, Vitreo-Retina
Bangladesh Eye Hospital & Institute
2. INTRODUCTION
First described by LEBER in 1877.
KOYANAGI first described more
incidence in UT branch.
2nd most common cause of vision d/t
retinal vascular disease (after diabetic
retinopathy)
BRVO accounts for 69.5% of total RVO.
7. Pathogenesis
• Almost always occurs at AV crossings
• Retinal artery and vein share a common
adventitial sheath & in some cases a
common medium
• Artery located anterior to the vein at the
obstructed site; lumen of the vein
compressed upto 33 % at the obstruction
site
• Role of vitreous – eyes with decreased
axial length and and higher likelihood of
vitreomacular attachment at AV crossings
8. Turbulent flow at
the crossing site
causes focal
swelling of the
endothelium and
deeper vein wall
leading to venous
obstruction
Actual venous
thrombus at the
point of occlusion
10. CLASSIFICATION
1) Major BRVO :
-occlusion of 1st order
temporal branch at disc.
-occlusion of 1st order
temporal branch away from
disc, but involving branch
to macula.
2 ) Minor macular BRVO –
involving only a macular
branch
3 ) Peripheral BRVO – not
involving the macular
circulation
12. CLINICAL FEATURES
PRESENTATION
*macular involvement : sudden
blurred vn,metamorphopsia
,relative V F defect.
*peripheral involvement :
asymptomatic.
VISUAL ACUITY
-depends on macular involvement
-Orth & Patz : farther the site of
occlusion from disc better is
prognosis.
14. Fundus examination
EARLY STAGE :
Dilatation and tortuosity of the venous segment distal to the
site of occlusion and attenuation proximally
Flame shaped and dot-blot hemorrhages, retinal oedema and
cotton wool spots : usually in triangular pattern, apex of
which lies towards the site of obstruction.
15. Macular edema
5 – 15 % of eyes over 1 year period
18 % resolve by 4.5 months, 41% by 7.5
months
16. Course
• Resolve within 6 –
12 months
• Segmental
distribution of retinal
vascular
abnormalities pers
• Hard exudates,
venous sheathing
and sclerosis
peripheral to the site
of obstruction
17. Apparent on FA
• Capillary non-perfusion
• Microaneurysms
• Collateral vessel formation
18. Neovascularization
NVD – 10 %
NVE – 25 %
in cases with extensive
ischemia, >1/3 fundus
Serious complication – leads
to recurent pre-retinal and
vitreous hemorrhage
22. In late cases :in addition to
• nonfilling of the segment (CNP)
• collaterals (non-leaking) may be seen or NV (leaking)
Fluorescein column is narrowed at site of obstruction.
Clemette’s sign of focal hyperfluorescence at AV
crossing present from 6th to 12th week.
29. INVESTIGATIONS
BP, ECG
CBC, ESR
Fasting blood glucose & lipids
In young patients
• Autoantibodies
• ACE
• Homocysteine
• Thrombophilia screen
• Plasma protein electrophoresis
30. Management
2 main objectives
1. Identification of modifiable risk factors
(example HT, DM, CVS) and their
management – for other eye
2. Recognition and management of sight-
threatening complications
31. Anticoagulant therapy
Not beneficial in either prevention or
management
Associated with systemic complications
Theoretically, severity of intraretinal
hemorrhage in acute phase
32. BRVO with perfused periphery
& normal VA
Favourable prognosis
No therapy
Monitored monthly for 1st 3 months, then
every 2 months for the 1st year
34. Macular BRVO
Involves a small vein draining a sector of
the macular region
Favourable natural course
35. Laser photocoagulation
BVOS eligibility criteria
Grid laser recommended in eyes with
1. VA of 20/40 or less
2. Persistent macular edema > 4 mths
3. Resorption of macular hemorrhages
36. BVOS
TREATED
Gain of 2 or more
lines-65%
V/A of 6/12 or better-
60%
Mean gain of lines-
1.33
UNTREATED
37%
34%
0.23
MACULAR GRID LASER:
37. SCORE study
Recommended grid photocoagulation
for vision loss with macular edema
secondary to BRVO
However, leads to paracentral visual
field defects
39. Neovascularization
According to BRVO study group:
Scatter laser - if NVE is present (reduces chances of VH to
20%)
may not treat all cases with CNP areas as 78% may not
develop NVE & VH
40. BVOS
TREATED
VH incidence – 29%
NVE incidence –
12%(CNP > 5DD)
UNTREATED
61%
22%
Thus 78% cases do not progress
to NVE, hence laser not
recommended till NVE develops.
SECTORAL LASER
43. Surgical management
SHEATHOTOMY
OSTERLOH and CHARLES – 1988
Relieves the compression of artery on vein
OPREMCAK and BRUCE – 1999, 85% had
either same / improved V/A, 67 % improved
Mester,Dillinger et al –ILM peeling gives better
results
Shah et al – 2000
44. BMV with PVD induction
(+/- Sheathotomy)
Proposed mechanisms :
-removal of vitreo-macular traction
-removal of cytokines that increase
vascular permeability
-improvement of oxygen tension in
posterior retina
-faster development of collaterals- 6
months (normally 6-24 months)
46. BMV+PVD(+/-
Sheathotomy???) No significant difference
in improvement in VA in
eyes with reperfusion of
occluded vein and those
without - indicating that
the reopening of
occluded vein is not
essential for visual
recovery.
Improvement in macular
oedema but no effect on
macular function
Yamamoto et al AJO 2004
48. anti-VEGF
Safe and efficacious.
Unsustainad effect in some cases.
Does not alter the perfusion status
which determines the end result.
49. The benefit of any treatment has to be
compared with the natural course of the
disease.
50-60% maintain maintain initial V/A of
6/12 at 1-3 yrs followup. Thereafter natural
course remains relatively stable.
Conversely natural course of V/A<6/12 is
unfavourable without treatment.
( at 3 yrs 23% had V/A of 6/60 or worse &
only 37% gained 2 or more lines)
50. Treatment
Focused on management of vision-
limiting complications
Macular edema
Macular non-perfusion
Vitreous hemorrhage from
neovascularization
54. • More similarities than dis-similarities in the risk
factor profiles for BRVO, CRVO and HRVO
• Testing for patients with HT, DM and open-angle
glaucoma should be part of the evaluation of
patients with retinal vein occlusion
55.
56. Favorable safety and tolerability profile over 12
months of follow-up.
can be repeated with no new safety concerns after
the second treatment with regard to IOP
increases, although cataract progression does
seem to increase
57. Edaravone (MCI-186) is effective as a free
radical scavenger following arteriovenous
sheathotomy for treatment of macular
oedema associated with branch retinal vein
occlusion
T Maeno1,2, R Tano1, H Takenaka1, T Mano1
+Author Affiliations
1Tane Memorial Eye Hospital, Osaka, Japan
2Department of Ophthalmology, Osaka Medical
College, Takatsuki, Japan
58. •Stabilization and increase in visual acuity after laser
treatment did not correlate with an overall decrease in
scotoma size.
• Improved central visual function seen in 25% of treated
eyes appeared to be due to
•withdrawal of scotoma from the fovea.
59.
60. Sheathotomy
Principle steps
• Pars plana vitrectomy
• Overlying artery is separated from the
vein by creating an incision in the
adventitial sheath adjacent to the
arteriovenous crossing and then
separating the adhesions.
61. Although the study by Mason et al reported a benefi
cial effect on VA in those patients undergoing
surgery compared with those receiving laser or no
treatment, the
study was not randomized and was partly
retrospective, introducing sources of potential
bias. There is currently no evidence from RCTs
supporting the routine use of adventitial
sheathotomy to improve VA in eyes with BRVO
62. Plasminogen
Activator to Treat Macular
Edema
Associated With Branch
Retinal
Vein Occlusion
(Am J Ophthalmol 2006;142: 318–320
• After topical anesthesia was applied and a
paracentesis created
• tPA (40 k international units [IU]) injected into the
vitreous
• bedrest in the supine position for four hours
following treatment
Mechanisms - PVD induction & development of
collateral vessels
63. Multifocal ERG
Responses from multifocal
electroretinography demonstrate retinal
dysfunction in branch retinal vein
occlusion
64. Moreover, if repeat injections are required,
the use of a sustained release steroid
implant would obviate the need for
multiple injections, but also magnify the
risk of steroid related complications.
65. Although steroids have antiangiogenic, antifibrotic, and
antipermeability properties, the principal effects of
steroids
are stabilization of the blood-retinal barrier, resorption of
exudation, and down regulation of inflammatory stimuli.
Whereas it is clear that there is a break-down in the
blood
retinal barrier in BVO, studies have shown that there
may
also be an inflammatory component that would respond
to
steroids.
66. Endophthalmitis, sterile endophthalmitis,
pseudo-hypopyon, cataract, retinal
tears, retinal detachment, and vitreous
hemorrhage have all been described
after intravitreal steroid injections.
Additionally, steroid related complications
including cataract and increased
intraocular pressure (IOP) can occur.
Increased IOP was seen in 33% of
patients in the intravitreal injection group