Phakic intraocular lenses (IOLs) have been used since the late 1980s to correct refractive errors as an alternative to LASIK. There are three main types - anterior chamber angle supported, anterior chamber iris fixated, and posterior chamber IOLs. They are indicated for high myopia, hyperopia, or astigmatism when LASIK is contraindicated. Risks include endothelial cell loss, inflammation, glaucoma, and cataract formation. Recent advances include toric models, foldable designs, and potential future options like ultrathin or responsive "smart" lenses. Phakic IOLs can provide stable correction of a wide range of refractive errors while retaining accommodation.
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.
The recent updates about corneal collagen crosslinkingAmr Mounir
This concentrated presentation describes the recent advances in the topic of corneal collagen cross linking with interaction with the most recent publications about this topic.
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
The recent updates about corneal collagen crosslinkingAmr Mounir
This concentrated presentation describes the recent advances in the topic of corneal collagen cross linking with interaction with the most recent publications about this topic.
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
This presentation describes all the clinical aspects of keratoconus management
You can watch the illustrated presentation in this link :
https://www.youtube.com/watch?v=pYxwZPGm7e4&list=PLZ_mM13I_TrhWavjTmE9NjW1O5bGxkONO&index=13
MYOPIA , basics , causes , types and treatmentssuserde6356
Myopia, also known as near-sightedness and short-sightedness, is an eye disease[5][6][7] where light from distant objects focuses in front of, instead of on, the retina.[1][2][6] As a result, distant objects appear blurry while close objects appear normal.[1] Other symptoms may include headaches and eye strain.[1][8] Severe myopia is associated with an increased risk of macular degeneration, retinal detachment, cataracts, and glaucoma.[2][9]
Myopia results from the length of the eyeball growing too long or less commonly the lens being too strong.[1][10] It is a type of refractive error.[1] Diagnosis is by the use of cycloplegics during eye examination.[11]
Tentative evidence indicates that the risk of myopia can be decreased by having young children spend more time outside.[12][13] This decrease in risk may be related to natural light exposure.[14] Myopia can be corrected with eyeglasses, contact lenses, or by refractive surgery.[1][15] Eyeglasses are the simplest and safest method of correction.[1] Contact lenses can provide a relatively wider corrected field of vision, but are associated with an increased risk of infection.[1][16] Refractive surgeries like LASIK and PRK permanently change the shape of the cornea. Surgeries like Implantable Collamer Lens (ICL) implant a lens inside the anterior chamber in front of the natural eye lens. ICL doesn't affect the cornea.[
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
We all have good and bad thoughts from time to time and situation to situation. We are bombarded daily with spiraling thoughts(both negative and positive) creating all-consuming feel , making us difficult to manage with associated suffering. Good thoughts are like our Mob Signal (Positive thought) amidst noise(negative thought) in the atmosphere. Negative thoughts like noise outweigh positive thoughts. These thoughts often create unwanted confusion, trouble, stress and frustration in our mind as well as chaos in our physical world. Negative thoughts are also known as “distorted thinking”.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
4. INDICATIONS
Myopia > -8D and hyperopia > +5D
Severe astigmatism – toric models may be needed
When photoablation is contraindicated – corneal
thickness <500µ
Residual bed after LASIK <250µ.
AC depth > 3.2 mm for ACIOLs and 2.8mm for
PCIOLs
Endothelial cell count >2200/mm2
5. CONTRAINDICATIONS
Low endothelial cell count and altered morphology
Low AC depth
Cataract
Diabetic retinopathy
Abnormal iris and angle
Chronic uveitis
9. Two additional P-IOLs are currently in Phase 3
of clinical trials with a view to FDA approval:
1. The Veriflex - foldable P-IOL for the anterior
chamber with iris fixation also known as Artiflex
(OPHTEC).
2. The phakic AcrySof IOL for the anterior chamber
with angle support
The P-IOLs for anterior chamber and with angle
Support are the AcrySof and the Kelman Duet
10.
11. IMPLANTABLE CONTACT LENS
Available between -3.0 to -20.0 D and +1.50D to +20.0D
ICL – STAAR model
Single piece haptic design, made up of hydroxymethacrylate
copolymer
Optic – 5.5mm diameter
Myopia - anterior concave and posterior concave
Hyperopia – anterior convex/posterior concave
Optical zone 4.5 to 5.5mm
Sizing of posterior chamber PIOL – white to white measurement
between 3 and 9’o clock hrs or by direct sulcus measurement
13. Complications of posterior chamber phakic IOLs :
1. Cataract formation – most common
2. Pupillary block - Because of the PC phakic IOLs, the iris can
be pushed forward and narrow the anterior chamber angle, so a
pupillary block with acute glaucoma can appear - Prevented by
PI
3. ↑ IOP and pigment dispersion
4. Decentration and rotation of IOL – diplopia, glare and pigment
dispersion
14. IRIS SUPPORTED PHAKIC IOL
Artisan phakic lens is an iris-supported IOL
The lens haptics attach to the midperipheral,
immobile iris through a process called enclavation.
In this technique, the surgeon draws small knuckles
of peripheral iris into the pincer-like haptics.
Thus the optic lies just anterior to the iris plane.
15. Patient selection :
High myopia and high hyperopia
Toric phakic IOLs for high myopia and hyperopia with
astigmatism
>18 yrs of age with stabilized myopia or hyperopia
Sizing of iris fixated PIOL – one size fits all since it is
fixed to midperipheral iris.
Made up of PMMA with UV blocking
Total length 8.5mm
5mm optic - -3 to -23.5D
6mm optic - -3 to -15.5D
16.
17. COMPLICATIONS OF IRIS FIXATED AC IOL :
1. Endothelial cell loss
2. Chronic inflammation and uveitis
3. Astigmatism – iris claw is not foldable it requires an incision.
4. Intraocular lens rotation – less common
5. Pigment dispersion and lens deposits – less common
6. Glaucoma – less common, PI is mandatory to prevent
pupillary block
7. Cataract is less
21. ADVANTAGES OF PHAKIC IOLS
Potential to treat large range of myopic, hyperopic
and astigmatic refractive error
Allows the crystalline lens to retain its function
preserving accomodation
Removable and exchangeable
Results are stable
22. DISADVANTAGES
Risk of intraocular procedure
Nonfoldable models require large incisions that may
result in postop astigmatism
High ametropic patients may require additional
photorefractive surgery
Endothelial cell loss and cataract formation
Pupil ovalization, chronic uveitis, pupillary block,
pigment dispersion
23. REFRACTIVE OUTCOME OF PHAKIC IOLS
Refractive outcomes are very good
Phakic IOL surgery is also reasonably safe.
In this challenging set of eyes with high refractive
errors, the vast majority of patients do very well with
a significant portion gaining lines of BCVA
24. Myopia -1 to -10 D
Hyperopic +1 to +3D
Astigmatism up to 3D
corneal thickness atleast
250µ of posterior stroma
should be preserved
Total corneal thickness
atleast 410µ after LASIK
Myopia -10 to -22D
Hyperopia +4 to +10D
Astigmatism upto 3D
corrected with toric IOLs
corrects the full range of
refractive errors
Not associated with the
limitations of LASIK
LASIK PHAKIC IOLS
25.
26. BIOPTICS
Two different procedures in two different planes of
eye
1st procedure – intraocular
2nd procedure – LASIK, LASEK or PRK
Indicated in patients with refractive errors that are
suboptimally treated with a single procedure
Eg : high myopes, high hyperopes or with
significant astigmatism
27. FUTURE OF PHAKIC IOLS
Artisan phakic toric intraocular lens : correction of
regular astigmatism in combination with myopia or
hyperopia
Baush and lomb – testing a foldable version of
NuVita AC angle fixated PIOL
Artiflex – foldable version of iris fixated AC PIOL
28. Thinoptx – ultrathin intraocular lenses : thickness
ranging from 30 to 350 microns.
Ultrathin, rollable model designed using nanoscale
precision technology
Even in large diopters lens remains thin
29. Smart lens : made of a thermodynamic,
hydrophobic acrylic material.
At body temperature, the biconvex lens is 9.5 mm
in diameter and from 2 to 4 mm thick
The lens is highly flexible and completely elastic,
returning to its original shape when deforming
forces are released