This document discusses various vitreous substitutes and intraocular gases used to replace the vitreous humor after surgery. It describes the anatomy and composition of the natural vitreous and ideal properties for substitutes. Common substitutes discussed include gases like air, sulfur hexafluoride and perfluorocarbons; liquids like silicone oil, perfluorocarbon liquids and semi-fluorinated alkanes; and experimental polymers and implants. The document compares different options and provides details on how each works, associated complications, and appropriate uses.
Main physiologic function of cornea is to act as a major refracting medium, so that a clear retinal image is formed. • Normal corneal transparency is result of • 1.anatomical factor such as uniform and regular arrangement of corneal epithelium, peculiar arrangement of corneal lamella and corneal vascularity 2.Physiological factor [ie] relative state of corneal dehydration.
3. • Therefore, any process which upsets the anatomy or physiology of cornea will cause LOSS OF TRANSPARENCY to some degree.
4. FACTORS AFFECTING CORNEAL TRANSPARENCY • CORNEAL EPITHELIUM &TEAR FLIM • ARRANGEMENT OF STROMAL LAMELLA • CORNEAL VASCULARIZATION • CORNEAL HYDRATION • CELLULAR FACTORS AFFECTING TRANSPARENCY
Errors of refraction, also known as refractive errors, are common vision problems that occur when the shape of the eye prevents light from focusing directly on the retina. These errors can cause blurred or distorted vision, making it difficult to see objects clearly. Refractive errors are typically caused by abnormalities in the size or shape of the eyeball, cornea, or lens.
The main types of refractive errors include:
1. Myopia (Nearsightedness): People with myopia have difficulty seeing distant objects clearly, as light focuses in front of the retina instead of directly on it. This occurs when the eyeball is too long or the cornea is too curved.
2. Hyperopia (Farsightedness): Individuals with hyperopia have trouble seeing nearby objects clearly. In this case, light focuses behind the retina due to a shorter eyeball or flatter cornea.
3. Astigmatism: Astigmatism causes overall blurred vision due to an irregularly shaped cornea or lens. It occurs when the cornea is more curved in one direction than the other, causing light to focus unevenly on the retina.
4. Presbyopia: Presbyopia is a refractive error that affects near vision, particularly in individuals over the age of 40. It occurs due to a natural aging process where the lens of the eye loses flexibility, making it challenging to focus on close objects.
Refractive errors can often be corrected with eyeglasses or contact lenses. Eyeglasses work by bending light rays to compensate for the eye's refractive error, allowing the light to focus properly on the retina. Contact lenses function in a similar way, but they are placed directly on the eye's surface. Alternatively, refractive surgeries such as LASIK or PRK can be considered to reshape the cornea and correct the refractive error permanently.
Regular eye examinations with an optometrist or ophthalmologist are important to detect and correct refractive errors. These professionals can determine the specific refractive error and prescribe the appropriate corrective measures to improve visual acuity and overall eye health.
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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
Title: Sense of Taste
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 structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
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.
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.
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.
- Video recording of this lecture in English language: https://youtu.be/lK81BzxMqdo
- Video recording of this lecture in Arabic language: https://youtu.be/Ve4P0COk9OI
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2. Anatomy of vitreous1
• Gelatinous structure that
fills the space between lens
and retina
• Non homogenous
• Vitreous cortex
• Vitreous base
• Vitreo retinal interface
6. • VISCOELASTIC
• ALLOW MOVEMENT OF IONS AND ELECTROLYTES
• OPTICALLY CLEAR
• ONE TIME IMPLANTATION
• SELF RENEWABLE
• NON TOXIC, BIOCOMPATIBLE, NON
BIODEGRADABLE
• READILY AVAILABLE, REASONABLE COST AND
STORAGE
7. Classification2
Classification Example
Aqueous miscible
Low viscosity Balanced salt solution
High viscosity Chondroitin sulfate
Viscoelastic Hyaluronic acid, hydroxymethylcellulose
Aqueous immiscible Gases
Air, sulfur hexafluoride (SF6),
perfluoropropane (C3F8)
Liquids
Lighter than aqueous Silicone oil
Heavier than aqueous Perfluorocarbon liquids, Semiflourinated
alkanes,
Fluorinated silicone oil
10. • 1911 by Ohm.
• Rosengren used intravitreal air injection with drainage of
subretinal fluid and diathermy
• 1973, Norton used sulfur hexafluoride (SF6) gas for a longer
tamponade >air used for difficult retinal detachments,
particularly giant tears.
• Lincoff and associates then developed several perfluorocarbon
gases
13. • Surface tension –
between gas bubbles
and surrounding fluids
critical physical
property
of the gases in retinal
reattachment
• Electrostatic attractive
forces -van der Waals
forces -weaker and
longer range
14. • Buoyancy-ability to float
• Due to large difference in
specific gravity of fluid
and gas
• superior tear tamponaded
with a large air bubble
• Displaces fluid inferiorly
and away from the tear
• Flattens against the wall
of the eye.
15. • Buoyancy directs the
effectiveness of the
tamponade, gases -upward
gravitational direction.
• Large bubbles and face-
down positioning are
required to tamponade
inferior retinal breaks
apposition of the gas bubble against the
posterior pole and macula during face
down positioning.
16. • Solubility of a gas in the aqueous medium :
determining the reabsorption rate of a gas bubble
from the vitreous cavity
• If less soluble than nitrogen, expansion of the bubble
can occur
17. Biocompatibility
• SF6 and the perfluorocarbon gases have a purity of
99.8%
• Pure gases -chemically nonreactive, colorless,
odorless, and nontoxic
• SF6 may -0.3 ppm of hydrogen fluoride. regarded as
the most toxic contaminant found in SF6.
18. • When bubble is large enough , covers the back of the lens, a
cataract develops unless the patient is positioned so that a
layer of fluid covers the posterior surface of the lens
• On contact with corneal endothelium -causes increased
inflammation, >SF6 than perfluoropropane
• Persistent corneal edema and retro- corneal membrane -
interference with nutrition of the endothelium rather than to a
specific toxic effect
20. • Bubble Expansion-gas from surrounding fluid
enter the bubble
• Equilibrium with N2: partial pressures of both
compartments equilibrate: o2/co2 diffuse rapidly, N2
slowly, maximum in 6-8 hours
• Bubble dissolution: as gases diffuse out bubble
decreases in size
21. Role of Gas bubble
• Bubble larger than the break-surface tension of gas prevents it
from passing through the retinal break
• Gas bubble apposed to the posterior end of break
• Passage of fluid from the vitreous to SRF blocked
• SRF absorbed into RPE and choroid
22. • Sp gravity of gas lower than water
• Buoyant forces push retina against RPE (max at apex ) 10x >
silicone oil)
• Head position till chorio- retinal adhesion
Advantages:
• When visualisation of retina is difficult-optical window
• Allows fluid gas exchange
• Mechanical barrier-cellular elements & growth factors
“compartmentalisation”
24. Factors affecting dissolution
• Vitreous currents
• Surface area of bubble
• Gas solubility in fluid
• Diffusion coefficient of gas
• Partial pressures
• Ocular blood flow
25.
26. CHANGES IN THE VITREOUS
• In a non vitrectomised eye: collagen condensed and
compacted behind lens and at optic nerve head
• Hyaluronic acid expressed from vitreous space
• Lamellae - concave margins and rolled edges
• ? Formation of pre retinal membranes complicating
retinal detachment
30. Complications of gas use
• Cataract or corneal opacity
-Face-down or lateral positioning is necessary to
prevent continuous contact of the gas bubble with the
cornea and lens
• Glaucoma
-large bubble
-if the patient remains supine, fluid from the ciliary
body fills the posterior segment & air bubble blocks
fluid egress through the trabecular meshwork
-Medium size -peripheral anterior synechiae with total
angle closure
31. • Central Retinal Artery Occlusion
-Overfilling of the eye with expansile gas
• Laser treatment -undesirable burns
-Reflections of internal fluid–air and air–fluid surfaces.
-Avoid treatment through a gas–fluid or fluid–gas
interface
-Perpendicular to the interface: intensity of a reflected
beam increases as the angle of incidence decreases. -A
divergent beam should be used
• Endophthalmitis
32. • Subretinal gas
• New tears -7% to 23% of patients treated with
pneumatic retinopexy
• Dislocated intraocular lens implant
Gas injection into
vitreous base accidentally
A. Donut sign when gas
encircles the lens
posteriorly.
B. B. Sausage sign when
gas partially encircles
the lens posteriorly.
In both cases the gas
bubble is immobile
34. • Fluorine and carbon atoms - most biologically inert in the eye
• Surface tension of approximately 14 to 16 dynes/cm measured
against air –comparable to silicone oil
• Most remarkable property of the perfluorocarbon liquids is the
specific gravity, which is higher than that of water.
• specific gravities range from 1.7 to 2.03
35. • Enables the fluid to settle posteriorly, opening folds in the
retina while expressing subretinal fluid anteriorly through pre-
existing retinal breaks
• Perfluorodecalin & perfluorophenanthrene -high transparency
to light in the visible spectrum
• No obstacle to laser photocoagulation
• Perfluorooctylbromide is radiopaque, and it has potential
application as a contrast agent
36. Biocompatibility
• Inferior corneal endothelial loss with subsequent corneal opacity and
thickening
• Dispersion and droplet formation will develop
• Gial cell proliferation and retinal disorganization -1 month.
• 3 months-preretinal membranes, gliosis, and retinal disorganization
• 6 months, retinal detachments
• Perfluorotributylamine -a “moth-eaten appearance,” - irregularly
shaped defects in the outer segment discs in both the superior and
the inferior retina after 2 days
• Combined use of silicone oil and perfluoropolyether has shown a
tendency to reduce the emulsification PFC
37. 5 main indications:
• Giant retinal tears
• Detachments with complicated PVR
• Traumatic retinal detachments
• Removal of posterior lens fragments and posteriorly dislocated
intraocular lenses
• Macular rotation with a 360-degree retinotomy
• +ROP
38. • PVR: tamponade effect to
open up funnel detachment
exposing any areas of
residual membranes
• Giant retinal tears:
unfolding and displacement
of SRF and blood
39. • PPV removal of anterior
vitreous base
• Crystalline lens floated
anteriorly over ONH
• SRF displaced through
the break
• Posterior retina flattened
• Dislocated lens removed
with fragmatome/vit
cutter
40. DISADVANTAGES
• irreversible cell damage
• Disorganization of retinal
cell growth pattern, loss of
neurites
ADVANTAGES
• Specific gravity of PFCLs -
effective for the intraoperative
repair of complex retinal tears
• Anterior and posterior segment
complications are uncommon
• Low viscosity of PFCLs allow
for tissue manipulation,
injection, and removal
42. • Semifluorinated alkanes (SFAs),or partially fluorinated
alkanes (PFAs) or FA -first internal tamponade agents - used
beyond the intraoperative setting
• Low sp. gravity of SFA< PFCLs:so produce less retinal
damage
• Esp used for macular rotation surgery -press down on the
retina less , allowing rotation of the unfolded macular without
mechanical damage
• Using F6H8 and OL62 HV oligomers increases viscosity and
decreases droplet formation
• Ex: Perfluorohexyloctane(F6H8/O68),
Perfluorohexylethane(F6H2/O62)
• Complications: Glaucoma-Superior PI, Cataract ,Droplet
formation & dispersion
44. • Silicone oil chains - helix
with six silicium units per
turn.
• Pure 1,000-centistoke oil -
helix of 63 turns and a
5,000-centistoke oil a
helix of approximately
100 turns
• Interdigitation of the helix
& increasing molecular
weight -viscosity
linear chain coils into a helix,
composed of 6 (Si-O) units per turn.
For a molecular weight of 28,000
(1,000 centistokes), the helix will
have 63 turns in average
45. • Buoyancy:
• Difference in specific gravity of aqueous humor, vitreous and
hydrophobic polymer accounts for buoyancy
• Force is spread over an area max at apex and decreases to zero
at horizontal interface
• Directs the tamponade of the immiscible silicone oil upward.
46. Refractive state of the eye
• Higher refractive index compared to vitreous
• Refractive shift depends on lens status
• Phakic eye-oil forms a concave surface behind lens
Acts as a minus lens-making eye hyperopic-8D hyperopia
• Aphakic eye-convex surface as it bulges through pupillary
aperture-plus lens-myopic
Varies with pupillary aperture size-from +12.5 to +5.6D
• Contact lens –to minimise the anisoconia
• IOL-plano posterior surface preferred
49. B. Severe Proliferative Diabetic Retinopathy
• Silicone oil: decreased post op hemorrhage
• Rapid recovery
• Especially in patients with anterior segment
neovascularisation/anterior hyaloid proliferation
• Acts by impending movement of vasoproliferative factors
from posterior segment to anterior segment
• PDR with rhegmatogenous RD involving the macula
C. Macular Hole
• RD due to macular hole
• Idiopathic/Traumatic macular hole
50. D. Giant Retinal Tears
• Unfolding the tear
• Long term tamponade
E. Chronic uveitis with profound hypotony
F. Infectious retinitis
• RRD in CMV retinitis
• Gancyclovir implants with silicone tamponade
F. Endophthalmitis
• Increase concentration of intravitreal antibioticcs
• Antibacterial properties of silicone oil
• Stabilise atrophic retina
51. Complications of Silicone
Oil
• Cataract,
• Glaucoma,
• Keratopathy
• Absorption of silicone oil by silicone intraocular lenses,
• Migration of silicone oil into the optic nerve and rarely into the
brain, and
• Emulsification.
• Retinopathy
• Recurrent retinal detachments
52.
53. Emulsification of Silicone
Oils
• Smaller silicone oil droplets at the interface of oil droplet and intra
ocular fluids
• Factors promoting emulsification:
-Difference in density of two liquids
-Lower viscosity
-Decrease in interfacial tension
-Adsorption of surface active agents
-Ocular saccadic motion
(micro current in and outside the bubble)
1%-1month, 11%-3 months ,85% 6 months, 100%- 1 year 8
55. • Choice of IOL: heparin coated PMMA/ regular PMMA
• Silicone oil acts as a foreign substance and not reabsorbed by
the eye
• On removal-retinal redetachment 3-33%
• Indications for removal:
-Glaucoma
-Keratopathy
-reasonable chance that retina will remain attached
(followed by infusion of BSS / Air –fluid exchange)
56.
57. • Disadvantages
• can pass through retinal
breaks under traction
• Requires optical
adjustments
• tamponade of the inferior
retina is difficult
• Emulsification
• Complications
• Sticky silicone oil
o Advantages
• high surface tension, ease of
removal, low toxicity, and
transparency.
• tamponade effect on the
superior retina
• airplane or high elevation
travel is planned
• post-operative positioning is
difficult
58. • Combinations
“Double Fill”
• Double fill (DF) is a combination of SO and SFAs,
• light SO support the superior retina ,heavier SFA supports the
inferior retina,
• Tamponade agent and reduces dispersion
“Heavy Silicone Oil”
• SO and a PFA mixed in such a way as to create a homogenous
solution.
• More viscous, more stable
• Complex retinal detachments involving inferior proliferative
vitreoretinopathy
• HSO can be challenging to remove-heavier than water
60. vitreous molecular
structure
filling function,
to control
elasticity
pressure of the
eye
chemical and
physiological
properties
diffusion of
metabolites
and gases
Perfusion of
drugs
Interact with
intraocular
structures
61. A Natural Polymers
• Hyaluronic acid (HA) and collagen,
B Hydrogels “swell gels”
• hydrophilic polymers that form a gel network when cross-
linked & swell by absorbing several times their own weight in
water
• molecules as tamponades is coupled with the active action as
drug releasers or exchangers
62. • investigated include poly(vinyl alcohol),poly(1-vinyl-2-
pyrrolidone), poly(acrylamide), copoly(acrylamide), polyvinyl
alcohol methacrylate, poly(glyceryl methacrylate), poly(2-
hydroxythylacrylate), and poly(methyl-2-acrylamido-2-
methoxyacetate).
63. C. Transplants & Implants
• Transplant vitreal tissue
• Correctly stored, the vitreous body :maintain its structure
and also its enzymatic properties
• Low inflammatory reaction and interesting surgical
results on 40% of patients.
• Cataract, glaucoma, and more severe adverse events until
ocular atrophy
.
64. Implants
• artificial capsular bodies,
• silicone rubber elastomer and filled with a saline solution,
• silicone oil, controlled using a valve system
• FCVB
• Good mechanical, optical, and biocompatible properties
• PVA filling model
• X. Lin, J. Ge, Q. Gao et al., “Evaluation of the flexibility,
efficacy,and safety of a foldable capsular vitreous body in the
treatment of severe retinal detachment,” Investigative
Ophthalmology &Visual Science, vol. 52, no. 1, pp. 374–381, 2011.
65. Future??
A. VITREOUS SUBSTITUTES AS A DRUG DELIVERY
MEDIUM
• A proper vitreous substitute used as a long-term (>3
months) drug delivery system to reduce or eliminate the
need for multiple intra-vitreal injections
• Hydrogels may be a promising biomaterial for fragile
protein drug delivery
B. CELL CULTURE/GENE THERAPY: CAN WE GROW
VITREOUS?
66. REFERENCES
1. SURVEY OF OPHTHALMOLOGY VOLUME 56 NUMBER 4 JULY–AUGUST 2011
Vitreous Substitutes: A Comprehensive Review Teri T. Kleinberg, MS, MD,1 Radouil T.
Tzekov, MD, PhD,1 Linda Stein, MS,1 Nathan Ravi, MD, PhD,2 and Shalesh Kaushal,
MD, PhD1
2. Duanes Ophthalmology Volume 6 ,Chapter 54 Vitreous Substitutes MARK E.
HAMMER
3.Hindawi Publishing Corporation BioMed Research InternationalVolume 2014,
Article ID 351804, 12 pagesReview Article Vitreous Substitutes: The Present and the
Future Simone Donati,1 Simona Maria Caprani,1 Giulia Airaghi,1 Riccardo
Vinciguerra,1 Luigi Bartalena,2 Francesco Testa,3 Cesare Mariotti,4 Giovanni Porta,5
Francesca Simonelli,3 and Claudio Azzolini1
4.Intraocular gas in vitreoretinal Surgery Shaheeda Mohamed, FRCS, Timothy Y. Y.
Lai, MD, FRCS
5.Department of Ophthalmology & Visual Sciences, The Chinese University of Hong
Kong, Hong Kong
67. 5.Department of Ophthalmology & Visual Sciences, The Chinese University of
Hong Kong, Hong Kong
6.Swartz M, Anderson DR: Use of Healon in posterior segment surgery. J Ocul Ther
Surg , January-February, pp 26–28, 1984
7.Poole TA, Sudarsky RD: Suprachoroidal implantation for the treatment of retinal
detachment. Ophthalmology 93:1408, 1986
8.Stenkula S, Ivert L, Gislason I, et al: The use of sodiumhyaluronate (Healon) in the
treatment of retinal detachment. Ophthalmic Surg 12:435, 1981
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