This document discusses phakic intraocular lenses (IOLs), which are artificial lenses implanted in the eye to correct refractive errors while preserving the natural lens. There are two main types - anterior chamber IOLs fixed in the angle or iris, and posterior chamber IOLs resting in the ciliary sulcus. Anterior IOLs are easier to insert but can cause endothelial cell loss and glaucoma. Posterior IOLs like the Implantable Collamer Lens (ICL) rest on the ciliary processes and have fewer complications, though still risk cataract formation, inflammation, and elevated pressure. Careful patient selection and lens sizing are important to maximize benefits and minimize risks of
Artificial lenses implanted in the anterior or posterior chamber of the eye in the presence of the natural crystalline lens to correct refractive errors. Phakic IOLs an evolving technique in the field of refractive surgery for the correction of moderate to high refractive errors. Patients with high myopia (above -10 diopters) constitute only about 2% of the myopic population but 13-15% of patients presenting for refractive surgery belong to this group. The increased knowledge on anterior segment anatomy and availability of better imaging technologies along with improved IOL designs and surgical techniques have led to higher success rates with these lenses.
Compared to corneal refractive surgery , phakic IOLs compete favorably for the correction of high ametropias, with excellent predictability, efficacy, safety and quality of vision.
Artificial lenses implanted in the anterior or posterior chamber of the eye in the presence of the natural crystalline lens to correct refractive errors. Phakic IOLs an evolving technique in the field of refractive surgery for the correction of moderate to high refractive errors. Patients with high myopia (above -10 diopters) constitute only about 2% of the myopic population but 13-15% of patients presenting for refractive surgery belong to this group. The increased knowledge on anterior segment anatomy and availability of better imaging technologies along with improved IOL designs and surgical techniques have led to higher success rates with these lenses.
Compared to corneal refractive surgery , phakic IOLs compete favorably for the correction of high ametropias, with excellent predictability, efficacy, safety and quality of vision.
Boris Malyugin, M.D., PhD.'s presentation about Malyugin Ring® pearls. The key learning points of the presentation include the step-wise approach in managing small pupils, the main drivers for the decision to use pupil expander device, and the Malyugin Ring® implantation and removal pearls.
Update knowledge about Muntifocal IOL made by Asaduzzaman
Working as Associate Optometrist in Ispahani Islamia Eye Institute &Hospita, Dhaka 1215
Email:asad.optom92@yaho. com
Boris Malyugin, M.D., PhD.'s presentation about Malyugin Ring® pearls. The key learning points of the presentation include the step-wise approach in managing small pupils, the main drivers for the decision to use pupil expander device, and the Malyugin Ring® implantation and removal pearls.
Update knowledge about Muntifocal IOL made by Asaduzzaman
Working as Associate Optometrist in Ispahani Islamia Eye Institute &Hospita, Dhaka 1215
Email:asad.optom92@yaho. com
SPOTLIGHT ON THE PREMIUM CHANNEL – AcuFocusHealthegy
Presentation from OIS@ASCRS 2016
Nick Tarantino, OD, Chief Global Clinical & Regulatory Affairs Officer
Video Presentation:
https://www.youtube.com/watch?v=Nc4T9u62rBQ&list=PL1dmdBNnPTZJBhQxPOp0vdNg3s3wtN2yw&index=34
Th e use of premium IOLs requires more specifically than standard monofocal IOLs a thorough clinical and para clinical examination using modern equipments.
We will only mention micro-incision premium IOLs that are used
in our daily practice. All information regarding the characteristics of all available and especially multifocal IOLs are available in the SFO 2012 Report on presbyopia
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
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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.
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.
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
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2 Case Reports of Gastric Ultrasound
- 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
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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
5. History
In 1890, Fukala proposed and performed the extraction of the clear
crystalline lens for the correction of high myopia
1950 correct myopia by inserting concave lens to phakic eye
1988 Baikoff AC angle fixed IOL
1980s mid posterior chamber PIOL
1991 artisan worst claw lens
6. Types of Phakic IOLS
1. Anterior chamber angle fixated IOL e g. ZB M5, NuVita MA20,
Phakic 6.
2. Anterior chamber- Iris fixated IOL e g. VerisyseTM , Phakic IOL
(Artisan lens)
3. Posterior chamber sulcus fixated IOL e g. STAAR mplantable
contact lens and phakic refractive lens (PRL)
7. Angle supported anterior chamber PIOL
First generation angle supported IOLs were developed by Baikoff &
Joly 1997
The first model (ZB -DOMILENS) was a modified Kelman type lens
with a 4.0mm optic and 2 haptics with a 4-point fixation in theangle
Then ZBM5 4mm biconcave optic 20 degree angulated haptic
Nuvita MA20 4.5mm optic , large curved footplate
ZSAL4
8. BAIKOFF 1st generation and 2nd generation- associated with
endothelial cell loss,pupillary block
9. Nu vita-Baush and Lomb ie
Baikoff 3rd generation
ZSAL4- planoconvex
lens single PMMA
with Z haptic
11. Foldable - Vivarte
Zeiss
1 piece AC PIOL with 3 point
angle supported lens- tripod
support
Soft hydrophilic
Acrylic soft optic 5.5 mm and
rigid haptic
13. Calculate power of AC phakic IOL
white-to-white, a correction factor is added to determine the correct
length.
•1 mm in Phakic 6
•0.5-1.0mm in Vivarte
•1.5mm in Acrysof
power we use Van der Heijde nomogram, takes into account
oSpherical equivalent
oCorneal power
oAnterior chamber depth.
14. Advantage of Anterior Chamber PIOL
easy insertion
Excellent result
Placement away from crystalline lens- less chance of cataract
15. Problems of anterior chamber phakic IOLs
1. Endothelial cell loss - Intermittent endothelial touch
2. Pupillary ovalisation (4-42%)
a) Immediate post operatively - Iris tuck/ oversized IOL
b) Late onset - Iris root ischemia
3 Iris de pigmentation (2.3-4.5%) - Iris protrusion during surgery
4. Halos & glare - Small optic zones
5. Surgically induced astigmatism - Long incisions
6.IOP elevation – pupillary block, steroids/viscoelastic
16. Iris Supported Anterior Chamber Phakic IOLS
Iris fixated IOLs have
haptics in the form of lobster
claw that fixate the IOL to the
mid peripheral iris.
1.Artisan (Ophtec, Netherlands)
2. Verisyse( AMO).
17. The Artisan lens is a onepiece
UV wavelength absorbing PMMA
compression
molded lens with
Diameter- 8.5 mm
optic vaulted suitably (0.5mm) to
stay clear of the iris cone
5.0mm optic
Same size for all
18. Problems of Iris fixated phakic IOLs
1. Anterior chamber inflammation: early post-op- 6.4- 16% of eyes
(Fechner et al 1992)
2. Glaucoma
3. Iris atrophy: on fixation sites - 81% cases( Santonja et al)
4. Implant dislocation: lens instability & haptic disincarceration in
9.3% ( Santonja et al.)
5. Decentration : 23.4-56% (Manejo et al.)
6. Endothelial cell loss: mean endothelial cell loss 5.3%, 7.63%
&17.9% at 1, 2 &5 years respectively
19. Selection of patients for phakic IOLs-ICL
1. Age above 18 years (22-45)
2. Moderate to high myopes (>-9.00D) & hyperopes (> 4.5 D)
Hyperopia +5 D - +11 D
Myopia -10 to -23 D
3. Also indicated in lesser degrees of ametropias
if LASIK is contraindicated
Corneas thinner than 500 microns
Steep or flat corneas
Topographic change suggestive of keratoconus
20. 4. Endothelial cell density: at least 2250-2500 mm3
5. Pupil smaller than 6 mm in scotopic luminance.
6. Stable refraction for at least 1 year
7. Anterior chamber depth (excluding corneal thickness) at least 2.8mm
8. Angle width at least 30 degrees
9. AC angle Shaffers grading 3-4 in atleast 270 degree
10. No eye pathology except refractive
11. No systemic pathology such as diabetes, collagen diseases etc
23. Phakic IOL planning- AS OCT
ACD less than or equal 3.5 then
1.1 mm added to W-W diameter
ACD >3.5 add 1.6 to W-W till
maximum 13.7
anterior chamber depth – > 2.8 mm
25. 3.horizontal white to white diameter-Orbscan /digital caliper
Proper vaulting 500 microns or corneal thickness
If vault
•Too short lens vault small, more risk anterior capsular cataract
•Too long –excessive vault
angle crowding, increased change of angle closure
Iris shaffing and pigment dispersion glaucoma
27. Implantable collamer lens- ICL
Collamer – hybrid of silicone and
collagen
STAAR surgical
Recent Visian ICL –single piece foldable
lens-copolymer of HEMA (99%) &
porcine collagen (1%)
Planospherical
High biocompatibility
Toric version can correct upto 6 D
ICL rests on ciliary process than on
sulcus
28. The white arrow indicates the ICL and the blue
arrow indicates the crystalline lens