Intraocular lenses have evolved significantly from the early rigid lens designs implanted in the 1950s. Modern intraocular lenses are classified based on location, design, and material. Premium lens options include multifocal lenses that provide multiple focal points for both distance and near vision, toric lenses that correct astigmatism, and accommodating lenses designed to restore the eye's ability to focus on near objects. Proper patient selection is important for multifocal lenses, considering an individual's lifestyle and visual needs.
It describes about the procedure of Hess charting. it serves as a great tool to understand the concepts involved. Suitable for optometry course. This is not a routine procedure but an important procedure which is used in diagnosis.
It describes about the procedure of Hess charting. it serves as a great tool to understand the concepts involved. Suitable for optometry course. This is not a routine procedure but an important procedure which is used in diagnosis.
If the cornea is under 400 micron CXL cannot be performed safely.
The use of a hydrophilic contact lens adds 120 microns of corneal thickness and permits the treatment .
A systematic approach with practical tips to diagnose and manage optic disc pallor. Disc pallor is often encountered in the routine clinical practice and remains a diagnostic enigma for most ophthalmologist. I illustrate the relevant practical points to be looked out for to deal with disc pallor.
These simplified slides by Dr. Sidra Arshad present an overview of the non-respiratory functions of the respiratory tract.
Learning objectives:
1. Enlist the non-respiratory functions of the respiratory tract
2. Briefly explain how these functions are carried out
3. Discuss the significance of dead space
4. Differentiate between minute ventilation and alveolar ventilation
5. Describe the cough and sneeze reflexes
Study Resources:
1. Chapter 39, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 34, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 17, Human Physiology by Lauralee Sherwood, 9th edition
4. Non-respiratory functions of the lungs https://academic.oup.com/bjaed/article/13/3/98/278874
New Directions in Targeted Therapeutic Approaches for Older Adults With Mantl...i3 Health
i3 Health is pleased to make the speaker slides from this activity available for use as a non-accredited self-study or teaching resource.
This slide deck presented by Dr. Kami Maddocks, Professor-Clinical in the Division of Hematology and
Associate Division Director for Ambulatory Operations
The Ohio State University Comprehensive Cancer Center, will provide insight into new directions in targeted therapeutic approaches for older adults with mantle cell lymphoma.
STATEMENT OF NEED
Mantle cell lymphoma (MCL) is a rare, aggressive B-cell non-Hodgkin lymphoma (NHL) accounting for 5% to 7% of all lymphomas. Its prognosis ranges from indolent disease that does not require treatment for years to very aggressive disease, which is associated with poor survival (Silkenstedt et al, 2021). Typically, MCL is diagnosed at advanced stage and in older patients who cannot tolerate intensive therapy (NCCN, 2022). Although recent advances have slightly increased remission rates, recurrence and relapse remain very common, leading to a median overall survival between 3 and 6 years (LLS, 2021). Though there are several effective options, progress is still needed towards establishing an accepted frontline approach for MCL (Castellino et al, 2022). Treatment selection and management of MCL are complicated by the heterogeneity of prognosis, advanced age and comorbidities of patients, and lack of an established standard approach for treatment, making it vital that clinicians be familiar with the latest research and advances in this area. In this activity chaired by Michael Wang, MD, Professor in the Department of Lymphoma & Myeloma at MD Anderson Cancer Center, expert faculty will discuss prognostic factors informing treatment, the promising results of recent trials in new therapeutic approaches, and the implications of treatment resistance in therapeutic selection for MCL.
Target Audience
Hematology/oncology fellows, attending faculty, and other health care professionals involved in the treatment of patients with mantle cell lymphoma (MCL).
Learning Objectives
1.) Identify clinical and biological prognostic factors that can guide treatment decision making for older adults with MCL
2.) Evaluate emerging data on targeted therapeutic approaches for treatment-naive and relapsed/refractory MCL and their applicability to older adults
3.) Assess mechanisms of resistance to targeted therapies for MCL and their implications for treatment selection
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
The prostate is an exocrine gland of the male mammalian reproductive system
It is a walnut-sized gland that forms part of the male reproductive system and is located in front of the rectum and just below the urinary bladder
Function is to store and secrete a clear, slightly alkaline fluid that constitutes 10-30% of the volume of the seminal fluid that along with the spermatozoa, constitutes semen
A healthy human prostate measures (4cm-vertical, by 3cm-horizontal, 2cm ant-post ).
It surrounds the urethra just below the urinary bladder. It has anterior, median, posterior and two lateral lobes
It’s work is regulated by androgens which are responsible for male sex characteristics
Generalised disease of the prostate due to hormonal derangement which leads to non malignant enlargement of the gland (increase in the number of epithelial cells and stromal tissue)to cause compression of the urethra leading to symptoms (LUTS
- 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
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.
Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
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.
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Ve...kevinkariuki227
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
2. OVERVIEW • HISTORICAL ASPECTS
• PRESENT DAY IOLs
– Classification
– Design
– Material
• ASPHERIC IOLs
• MULTIFOCAL, ACCOMODATIVE, TORIC IOLs
• PHAKIC IOLs
• IOL IMPLANTATION IN SPECIAL SITUATIONS
• COMPLICATIONS RELATED TO IOLs
• RECENT ADVANCES AND THE FUTURE
• IOL POWER CALCULATIONs
• MANUFACTURING PROCESS
4. The Evolution of Intraocular Lenses*
*Yanoff & Duker: Ophthalmology, 3rd ed. Table 5-2-1, pg 394
5. HISTORY
• First IOL implantation
– Sir Harold Ridley
• November 29, 1949 at St. Thomas Hospital, London
• 49 year woman
• ECCE with in-the-bag placement
• Biconvex perspex (Transpex 1) disc; 138 mg
• Rayners Optical Company, Brighton
• Substantial post op myopia (-24.0 Ds/ +6.0 Dcyl X 30 degrees)
• IOL exchange in February, 1950
• Revealed only in 1951 at the Oxford Ophthalmic Congress
8.5 mm diameter, 2.4 mm thick, 108 mg
In 1795, Casamata implanted glass IOL
which sank posteriorly.
6. – INSPIRATION
• Inertness of intraocular plexiglass shards
• A medical student, Steve Perry questioned him why was he not
replacing the lens after removal
– Approximately 1000 Ridley IOLs implanted in the next 12
years
– Complications*
• Disclocation : approx 20%
• Glaucoma : 10 %
• Uveitis
– Went into disrepute
• Strongly opposed by Sir Duke-Elders
*Ridley H: Intraocular acrylic lenses—past, present and future. Trans Ophthalmol Soc UK 1964;84:5–14
7. EARLY ANTERIOR CHAMBER IOLs
• Rigid or semirigid AC-IOL
– Baron, in France; May 13, 1952
– Scharf and Strampelli
• Flexible or semiflexible AC-IOL
– Open haptic loops
– Closed haptic loops
– Peter Choyce
• Mark I to Mark VII
Strampelli Tripod AC-IOL (1953)
Choyce Mark I AC-IOL(1956)
Dannheim AC-IOL with closed haptics (1952)
Ridley Tripod AC-IOL (1957–60)
11. • Cornelius Binkhorst,
– Iris clip lens; four-loop (1957)
– Iridocapsular fixation; two loop (1965)
• Forerunner to capsular sac (in-the-bag)
fixation of modern posterior chamber
IOLs
• Fyodorov modification (1966)
– Fyodorov I
– Fyodorov II (Sputnik)
– Three haptics in front and three
behind the iris
12. • Jan Worst (Holland)
• Medallion IOL, mid-1970s
– Eliminating the anterior haptics while
retaining the horizontally oriented
posterior ones
– Prolene suture through the superior optic,
securing it to the iris
– Hydrolytic biodegradation of the nylon
stitches
Binkhorst 4-loop lens (1957/58),
Fyodorov iris clip Sputnik lens (1968),
Binkhorst 2-loop lens for iridocapsular
fixation (1965).
13. • Iris claw lens (lobster claw); by Worst in 1978
– Artisan/Artiflex Lens
– Slits in both haptics
– Clamped into the mid-periphery
14. ADVANTAGES
• Away from angle structures
• Rate of dislocation was less
• Less contact with corneal
endothelium
DISADVANTAGES
• Iris chaffing
• Pupillary distortion
• Transillumination defects
• Chronic inflammation
• CME
• Distortion on pupillary
dilatation
• Endothelial
decompensation
15. INTERMEDIATE ACIOLs
• Improved manufacturing techniques
– Tumble polishing of IOLs
• Flexible loops with multiple point of fixation
• More stable
• Anterior-posterior vaulting characteristics
• Elimination of sharp optic or haptic edges
• Fixation elements
– Spatula-like footplates
– Small-diameter lens loops
• Closed
• Open
21. ADVANTAGES OF IN-THE-BAG PLACEMENT
• Proper anatomical site
• Symmetrical loop placement
• Intraoperative stretching or tearing of zonules is avoided
• Minimimal magnification (<2%); (20-30% aphakic glasses, 7-12% aphakic contact lens,
ACIOL 2-5% )
• Low incidence of lens decentration and dislocation
• Maximal distance from the posterior iris pigment epithelium, iris root, and ciliary
processes
• Loop material alteration is less likely
• Safer for children and young individuals
• Reduced posterior capsular opacification
31. LENS CHEMISTRY
(Optic Materials)
• RIGID MATERIALS
– PMMA
(Polymethylmethacrylate)
– Water content <1%
– Refractive index 1.49
– Usually single piece
– May be penetrated by
aqueous humor known as
‘glistenings’ (very rare)
• FLEXIBLE MATERIALS
– Silicones
– Acrylics
• Hydrophilic
• Hydrophobic
– Hydrogels
– Collamer
32. FLEXIBLE MATERIALS
• Silicone
– Polymers of silicone and oxygen
– Since 1984; first material for foldable IOLs
– Hydrophobic (contact angle with water of 99°)
– 1.41 to 1.46
– 3 piece
– Thick optics (need larger incisons)
– Handling is difficult; loading into injector
– Bacterial adhesion
– Anterior capsule rim opacifies quickly
– Low PCO
– Lowest threshold for YAG laser damage
– Glistenings
– Adherence of silicone droplets
33. HYDROPHOBIC ACRYLIC
• Copolymers of acrylate and methacrylate
• 1993 (Acrysof 3-piece lens)
• Most successful IOLs today
• Angle of contact with water is 73°
• 3-piece or 1-piece designs
• 1.44 to 1.55
• Easy handling; prone to mechanical damage
• At least a 2.2-mm incision
• Low PCO rates
• Good resistance to YAG laser
• Photopsias
• Glistenings
• BSS packaging (reach 4% water content before implantation)
34. HYDROPHILIC ACRYLIC
• Mixture of hydroxyethylmethacrylate (poly- HEMA) and hydrophilic
acrylic monomer
• End of the 1980s
• 1.43
• 18 -26% water content
• Contact angle with water is lower than 50°
• Single piece
• Easiest to handle; less mechanical/YAG laser damage
• Sub-2-mm incisions
• Higher PCO rate
• Low resistance to capsular contraction
• Calcium deposits
35. HYDROGEL
• Swell in water
• 18% to 38% water content
• Copolymers of methacrylate esters
• Hydrophilic comonomer with a hydroxyl
functional group such as HEMA
36. COLLAMER
• STAAR Surgical
• Hydrophilic
• p-HEMA with 33% water and 0.2% porcine
collagen with a benzophenone UV blocker
37. UV ABSORPTION
• Additive
• Chemical bonding
– Hydroxybenzophenones
– Hydroxyphenylbenzotriazoles
• UV-absorbing chromophore
– Protective to macula
– Interference with melatonin cycle
43. HOW TO OVERCOME ?
• Strategy 1:
– Lens with negative spherical aberrations to
balance the normally positive corneal spherical
aberrations
• Strategy 2:
– Lens with minimum spherical aberrations so that
no additional spherical aberration is added to the
corneal spherical aberrations
44.
45. • Anterior prolate surface
– Tecnis, Advanced Medical Optics (AMO)
• Posterior prolate surface
– Acrysof IQ, Alcon Laboratories
• Both Anterior and Posterior prolate surfaces
– Akreos AO, SofPort AO and L161 AO, Bausch & Lomb
46.
47. ASPHERIC IOLs
• Need perfect centration
– Decentered IOLs can induce
coma
• Decreased depth
perception
• More expensive
• Need corneal topography
for optimal results
• Not much difference in
photopic conditions and in
older age group
• Not for previous hyperopic
refractive surgery
• Better contrast sensitivity
• Better mesopic vision
• Night time driving
– AcrySof® IQ Aspheric IOL
patients had an average
increase of 130+ feet (vs the
control lens) in which to stop
after identifying a warning
sign
• Better option for younger
patients
50. MULTIFOCAL IOLs
• Single IOL with two or more focal points
• Types
– Refractive
– Diffractive
– Combination of both
51. • Hoffer in 1982
• Patient with 6/6 vision in spite of an IOL that
was decentred by more than 50% of the
pupillary area
• Dr. John Pearce, 1986; bull’s eye style
• Pupil dependent
52. REFRACTIVE MULTIFOCAL IOLs
• Bull’s eye lens
– Concentric rings of different
powers
– Central addition surrounded by
distance optical power
• Annulus design
– 3-5 rings
– Central for distance vision
– Near vision ring
– Distance vision ring
53. 12345
Bright light/ Distance dominant zone
Large Near dominant zone
Low light/ Distance
dominant zone
Distance zone
Near zone Aspheric transition
REFRACTIVE MULTIFOCAL IOLs
54. • Silicone MIOLs
– Array multifocal IOL (AMO)
– First FDA approved foldable MIOL
• 5 concentric zones on its anterior surface
• 50% distance, 37% near, 15% for intermediate vision
• Acrylic MIOLs
– ReZoom multifocal IOL (AMO)
• Zone 1,3 and 5 : distance
• Zone 2 and 4 : near
• 60% distance, 40% near and intermediate
• PREZIOL (Acrylic)(Care Group)
– Manufactured by Indian company
– Also available as non foldable PMMA lens
59. Based on the average
corneal-surface
wavefront-derived
spherical aberration
60. • Tecnis Multifocal IOLs (AMO)
– ZM900 (Silicone)
– ZA00 (Acrylic)
• Optic Diameter 6.0 mm
• Optic Type
– Modified prolate anterior surface
– Total diffractive posterior surface
– Diffractive Power +4.0 diopters of near addition
(+3.0 Diopters at spectacle plane)
61. • Acrysof IQ ReSTOR (Alcon)
– Acrylic diffractive multifocal IOL with apodized design
– Optic diameter- 6 mm
– Refractive for distance, and a diffractive lens for near.
– 16 rings distributed over central 3.6 mm
– Peripheral rings placed closer to each other
– Central rings : 1.3 µm elevated, near vision
– Peripheral 0.2 µm elevated, distant vision
– Anterior peripheral surface is modified to act as
refractive design
– Near Addition +3.0 D at IOL plane (+2.5 D at spectacle
plane)
63. • Refractive lenses (pupil
dependent) ideal for
– Light to moderate readers
– Drive mostly during the day.
– Play sports,
– Use a computer frequently,
or
– Activities that rely heavily
on intermediate vision
• Diffractive IOLs (pupil
independent)for
– Spend a lot of time reading
– Detailed craft-work
– Scotopic activities
• Movies
• Night time driving
64. PATIENT SELECTION FOR MfIOLs
(most important factor)
• Strong desire to be spectacle independent
• Functional & occupational requirements
– Occupational night drivers (avoid)
• Pre-existing ocular pathologies
• Hypercritical & demanding patients
– strictly avoided
• > 1.0 D astigmatism; irregular astigmatism (avoid)
• Individuals with a monofocal lens in one eye
• History of previous refractive Surgery
• Previous PK
• Chances of IOL dislocation
65. INTRAOPERATIVE EXCLUSION
• Significant vitreous loss during surgery
• Pupil trauma during surgery
• Zonular damage
• Capsulorhexis tear
• Capsular rupture
• Eccentric CCC
66. SPECIAL CONSIDERATIONS FOR MfIOLS
• Counselling (most important)
• Accurate Biometry
– IOL master strongly recommended
– immersion biometry better than applanation biometry
• Power Calculation
– Plano to <+0.25
– newer formulae
• Surgical Technique
– Round, centered CCC completely overlapping the lens
optic
– Removal of all viscoelastic from behind the lens
67. MIXING AND MATCHING MULTIFOCAL IOLs
Stefan Pieh, MD; Herbert Weghaupt, Christian Skorpik MD; Contrast Sensitivity
and glare disability with diffractive and refractive multifocal IOL. J Cataract and
Refract Surgery 1998; 24-659-662.
68. • Loss of contrast sensitivity
• Glare and halos
– scattering of light at the dividing line of the different
zones
– improves with bilateral implantation, because of “a
bilateral summation” effect
• Less satisfactory visualization of fundus- difficulty in
vitreo-retinal procedures
• Requires Visual-Cortical Neuro-adaptation
69. ACCOMMODATIVE IOLs
• Monofocal IOL
• Changes position inside the eye as the eye's
focusing muscle contracts
• 1 mm of anterior movement of lens = 1.80 D
of accommodation
• Mimicking the eye's natural ability to focus
70. • Silicone
– Crystalens (Bausch & Lomb)
– Only FDA approved IOL for correction of
presbyopia
• Hydrophilic Acrylic
– BioComFold type 43E (Morcher GmbH)
– 1CU (HumanOptics AG)
– Tetraflex (Lenstec Inc.)
71.
72. Akkolens IOL (Akkolens,
Lumina IOL)
• Principle of the Alvarez lens
– Two sinusoidal optical surfaces slide across one another along the
horizontal axis
• Anterior element with a spherical lens
• Two cubic optical surfaces for varifocal effect
– fitted by spring-like haptics fused at the rim
– movement perpendicular to the optical axis
• Implanted in the sulcus
• 2 D to 5 D of near add power
73.
74. Synchrony Dual-Optic IOL (Visiogen)
• One piece Silicon foldable IOL
• Two optics
– high plus anterior
– posterior minus lens
• connected by spring like haptics.
• Zonular tension is released –
compression of optic-spring
haptic releases anterior optic
forward.
75.
76. TORIC IOLs
• 22% of patients undergoing cataract surgery
have substantial corneal astigmatism
• >1.25 D
77. • Staar Surgical Intraocular Lens
– First FDA approved (in 1998) toric IOL
– 2.00 and 3.50D
– Plate-haptic
– Poor rotational stability
– limited power range
78. • AcrySof IQ Toric IOL (Alcon Labs, USA)
– September 2005
– T3 to T9
– posterior surface has added cylindrical power and axis
markings
• Acri.Comfort 646TLC and Acri.LISA toric 466TD
– Carl Zeiss Meditec
– incision < 2 mm
• Rayner Sulcoflex toric 653T (Piggy back sulcus
lens)
81. • Marking The Eye
– reference marks at the 3- and 9-o’clock
– sitting upright
• Aligning the Toric IOL with the Axis
– Gross alignment,
– Viscoelastic removal,
– Final alignment
83. • For every 1 degree of axis rotation, 3.3% of
the lens cylinder power may be lost.
• At 30 degrees, all effect is lost
84. ROLLABLE IOLs
• Ultrathin ~100 µ
• Hydrophilic material
• Front surface curved
• Back surface: series of steps with concentric rings
• Open up gradually
• Implanted by phakonit technique
• Acrismart
• Thin Optx ultrachoice
• Slimflex lens
85. IOL IMPLANTAION IN SPECIAL SITUATIONS
• ABSENCE OF CAPSULAR SUPPORT
– Scleral fixation (suture/glue)
– Iris fixated
– ACIOLs
• PEDIATRIC AGE GROUP
– Heparin coated
– Multifocal IOLs
• DRUG ELUTING IOLs
– Triamcinolone acetonide
– Dexamethsone
– Antibiotic
– Diclofenac sodium (0.2 mg/mL)
– Mitomicin C (0.2 mg/mL)
– Colchicine (12.5 mg/mL) and 5-fluorouracile (10 mg/ml)
– Anti-VEGF
86. ANIRIDIA IOLs
• Various designs
– Overall size = 12.5 to 14 mm
– Optic diameter = 3.5 to 5 mm
– Central clear optic
– Surrounding colored diaphragm
88. PHAKIC IOLs
• Implantation of IOL without removing natural
crystalline lens.
• ADVANTAGE: Preserves natural
accommodation
– Mostly used in Myopic eyes: -5 to -20 DS
– Also used in Hyperopic eyes
• Concern in Hyperopes:
– More chances of endothelial damage
– Increased risk of angle closure glaucoma
– Life-long regular follow up required.
91. Implantable Collamer Lens (ICL)
• Pre-crystalline lens made of silicone or
collamer.
• Length of the lens = white-to-white limbal
diameter - 0.5 mm
– Overall size- 11-13 mm
– Otical zone - 4.5-5.5 mm
– Toric model also available
92. • COMPLICATIONS:
– Constant contact pressure
– Cataract
– Ciliary body reactions
– Prevent free passage of aqueous.- Iridectomy
required
– SPINNAKER EFFECT: Blowing sail of a boat
93. IRIS FIXATED PHAKIC IOL
• VERISYSE/ARTISAN (AMO/OPTECH)
– Made of PMMA
– convexo-concave
– Length = 7.2 – 8.5 mm
– Optic size = 5-6 mm
– Haptics fixed to iris –claws
94. IRIS FIXATED PHAKIC IOL
• ADVANTAGES OVER ICL:
– Customized smaller size possible
– Easier examination from end-to-end
• COMPLICATIONS-
– Early post op AC inflammation
– Glaucoma
– Iris atrophy on fixation sites
– Implant dislocation
– Decentration
– Endothelial cell loss
95. ANGLE FIXATED PHAKIC IOL
• TWO TYPES –
– 4 point fixation
• Baikoff’s modification of Kelman type haptic design
• NuVita MA20 (Bausch and Lomb)
– 3 point fixation
• Vivarte (IOL Tech)
• Separate optic and haptic
97. PIGGYBACK IOLs
• An intraocular lens that
“piggybacks” onto an existing
intraocular lens or two IOLs are
implanted simultaneously.
• First IOL is placed in the capsular
bag.
• The second (piggyback) IOL is
placed in the bag or sulcus.
98. • Easier to place 2nd IOL than to explant IOL &
replace it
– Lesser risk
– More predictable
– Can change power with time-by adding IOL or
explanting an IOL
– Better image quality
– Increased depth of focus
99. • COMPLICATIONS
– Interlenticular opacification
• (Interpseudophakos Elshnig’s pearls)
• (RED ROCK SYNDROME)
– Unpredictable final IOL position
100. COMPLICATIONS RELATED TO IOLs
• MALPOSITIONS
– Pupil capture
– Decentration
– Windshield wiper syndrome
– Sunset syndrome
• PCO
• Dysphotopsias
– Positive : night time glare and halos
– Negative : black ring more towards temporal field
101. • IOL material : acrylic > silicone
• Refractive index : negative dysphotopsia more
with higher refractive indices
• Smaller optic size
• Square edge
• Multifocal IOL
• Iris-optic distance
• Self resolving in a few weeks (cortical adaptation)
102. RECENT ADVANCES AND THE FUTURE
• LIGHT ADJUSTABLE IOL
• TELESCOPIC IOLs
• SMART IOLs
• ELECTRONIC IOLs
103. LIGHT ADJUSTABLE IOL
• Calhoun Vision
• Silicone lens with two C-PMMA haptics
• Photosensitive to the near-ultraviolet wavelength of
energy in a specific pattern
– myopic adjustment : periphery of the lens
• Final irradiation step locks in the power change
• ±2 D for sphere and 2.5 D for astigmatism at the
spectacle plane
105. IMPLANTABLE MINIATURE TELESCOPE
• Miniature implantable Galiliean telescope
– Implanted in posterior chamber
– Held in position by haptics loops
– Contain number of microlenses which magnify
objects in the central visual field.
– Improves central vision in ARMD.
106. • Telephoto system : 2-3 times magnification
• Images in the central visual field
– not be focused directly on the damaged macula
– over other healthy areas of the central and
peripheral retina
107. • DRAWBACKS:
– Surgically more challenging
– Difficulty due to the size and
weight of the implant
– Endothelial compromise
– Blocked peripheral retinal visibility
– Difficulty in future retinal laser
treatments
– Loss of peripheral vision
108. TELESCOPIC IOL
• Next generation of implantable miniature telescopes.
• Uses mirrors rather than glass lenses
• 25 X magnification of central images
• The LMI (Lipshitz Macular Implant)
– optics is 6.5mm
– slightly thicker than a standard IOL
• Contains 2 miniature mirrors
– 2.8 mm posterior doughnut shaped mirror that reflects light
anteriorly
– 1.4 mm central retina–facing mirror which in turn focuses the
light on retina).
• Does not affect peripheral vision.
111. IOL POWER CALCULATIONS
• Before 1980s,
– Best described as ‘educated guesses’
• The IDEM lens (ideal emmetropia lens)
– +17.0 D for an AC lens,
– +19.0D for an iris fixated lens
– +21.0D for a posterior chamber lens
• The Standard lens
– +1.25D added to the IDEM lens power
• The Emmetropia lens
– (pre existing refractive error) X 1.25 + IDEM lens power
112. IOL POWER PREDICTION FORMULAE
• First Generation - SRK- 1 and Binkhorst formulae
• Second Generation – SRK-2
• Third Generation – SRK T, Hollday. Hoffer-Q
• Fourth Generation – Hollday 2, HAIGIS
114. • human eye functions as a
dual lens system
• position of the cornea
and the retina is fixed
• effective IOL power
– Power of iol
– Postion
• “in the bag” IOL is 21.0D
• in the sulcus will function
as a 22.0 lens
115. THE ELPo
• Dr. Jack Holladay
• Anatomical factors
– axial length
– steepness of the cornea
– limbal white to white measurements
– preoperative
– anterior chamber depth
– lens thickness
• position of the capsular bag equator from the
corneal vertex : pre op ACD and 40% of the
crystalline lens thickness
116. • IOL and surgery related factors
– anterior angulation
– material of the haptic
– material of the optic
– Asphericity
• Individual Surgeon’s Technique
– CCC size and centration
– inadequate removal of visco-elastic from behind the
IOL
– Bag to Sulcus shift
117. MANUFACTURER’S LENS CONSTANT
• axial length of 23.5mm (applanation A scans)
• central corneal power 43.86D (manual
keratometry)
• limbal white to white diameter of 11.7mm
• 22.0mm – 26.0mm
• central corneal power of 41.0D – 46.0D
118. • The SRK formula
– IOL power = A – 2.5 L – 0.9 K.
– Donald Sanders, John Retzlaff and Kraff
– mid 1980’s.
– 6835 eyes
– 22.0m – 24.5mm
119. • SRK 2 formula
– Axial length 21-22mm, add 1 to A
– 20-21 add 2
– < 20 add 3
– Over 24.5mm subtract 0.5
120. • SRK T Formula
– third generation formula
– 1990
– John Retzlaff and Donald Sanders
– combines theoretical and regression formulae
– predicted post operative anterior chamber depth
– retinal thickness
– refractive indices of the cornea
– regression element is used to optimize the ‘A constant
121. • The Hoffer-Q formula
– Dr. Kenneth Hoffer in 1993
– P = f (A, K, Rx, pACD)
– short eye balls
122. • HAIGIS Formula
– also called the
GOW 70 formula
– Gernet, Ostholt
and Werner in
1970
123. • three ‘A constants’
– a0 : manufacturers lens constant
– a1 : pre operative ultrasonically measured ant
chamber depth (this has a default value of 0.4)
– a2 axial length measurements (default value of 0.1)
– enables customizationof each component
– entire range of axial length values
124. • Holladay 2
– 1998
– Accurate estimation of the ELPo
• Axial length.
• Central corneal power (K)
• Anterior chamber depth
• Lens thickness measurement
• Limbal white to white measurement
• Age of the patient
• Previous refraction of the patient