Intraocular R.S.
Intraocular refractive surgery
Options for correction of presbyopia
Mar 25th
Options for correction of presbyopia
1. Commonly you need a pair of glasses. One is for viewing distance, the other is for viewing near. Fortunately, We got progressive glasses. This type of glasses could help you to see clearly at near and distant.
2. Soft contact lens. Bifocal or multifocal soft contact lens are in clinical trial.
3. Radial sclerotomy
4. Multifocal corneal refractive surgical procedures and monovision made by Lasik or PRK.
5. Single optic accommodating lens implants. Such as 1cu, Crystalens, Tetraflex, AT-45, AT-50
6. Dual optic accommodating lens implants. Such as Sarfarazi, the Synchrony,.
7. Curvature change IOLs. The powervision Fluidvision IOL and Smartlens.
8. Multifocal optic lens implants. Such as Restore, tecnis ZM, Rezoom and so on.
9. CK (conductive keratoplasty )
You have to alert that the glasses are the best safe. Surgery is another good option to you.
Can cataracts cause blindness?
Mar 18th
Can cataracts cause blindness?
Cataract would not cause blindness. The cataract is the lens opacity in our eyes. The reasons are congenital, trauma, diabetic or caused by some eye diseases such as high myopia, uveitis and so on. The cataract would cause color problems. In the early onset of cataract, the people would see more blur than before and the object are more yellowish. When the cataract is extracted, the patient view more blueish than pre-operation. That is because of the opacity lens is yellow. So many companies introduce many IOLs that could block blue-band light wave to protect macula from impairment, such as SN60AT.
Astigmatism treatment methods
Feb 7th
Astigmatism treatment methods
How to make a success with refractive lens exchange? It depends on the patient’s education, expectation, surfacial status of the eye, such as tear film, fundus of the eye and the rate of posterior capsule opacification. The most important is to reduce residual refracive error, especially the astigmatism.
Treatment methods:
1. Spectcles. Wear toric glasses.
2. Toric contact lens. Such as soft contact lens and RGP.
3. Corneal surgery.
Incision:
AK: Aracuate keratotomy
LRI: Limber relaxing incision
RK: Radial keratotomy
Incisional modification: 0.5-1.0D
Excimer Laser:
PRK: Photorefractive keratectomy
Lasik: Laser in situ keratomileusis
Lasek: Laser Epithelial Keratomileusis(Laser sub-epithelial )keratotectomy
Sbk-lasik: Sub-Bowman-Keratomileusis
Epi-lasik: Epipolis laser in situ keratomileusis
4. RLE: Refractive lens exchange
PIOL: Phakic intraocular lens
IC-PIOL:Toric Verisyse
AS-PIOL: Phakic6
TICL: Implantable Collamer Lens（Visian）
IOL: Toric IOL
There are four misconceptions regarding corneal incision: unpredictable, only useful for low astigmatism, regress and dangerous and difficulty of learn curve. There are also keys to overcome it: proper centration, periph clear cornea, perpendicular, cut deep and clean.
The pricinple of laser correction is bioptics. PRK is more excellent than Lasik as it is safe as soon as four weeks. So, what is the best in so many methods? It needs time.
Lens inside or ouside of your eyes?
Jan 10th
1. Spectacles (In the front of your eyes)
2. Contact lens (Soft or RGP? Touch your eyes)
3. Phakic 6 (Anterior chamber lens)
4. Verisyse, Artisan (Iris claw)
5. Implantable collamer lens (ICL)
6. Posterior lens (Cataract extration and ciliary groove implantable)
why we need implantable collamer lens (ICL)?
Jan 3rd
why we need implantable collamer lens (ICL)?
Simply speaking, common contact lenses are worn on the surface of your cornea, but the ICL is the contact lenses implanted in your eyes, so as to achieve the correction of myopia, hyperopia and astigmatism. Surgical safety and effectiveness are relatively high, with few complications.
As we know, Asia area has high rate of myopia, especially high myopia, which the incidence rate is more than western countries where high rate of hyperopia instead. We could operate LASIK, Epi-Lasik, PRK, LASEK on this type of patient. But some part of high myopia which is more than minus 12D could not be received the operation, the risk of surgery increases. How to figure out this problem? Intraocular refractive surgery is needed. First choice is implantable collamer lens. The second is iris claw lens, which representative product is verisyse.
The implantable collamer lens is suit for myope who refractive error ranges from -3.0D to -20.0D. Hyperope definitely could choose the surgery. No cataract. Sufficient anterior chamber depth of the eye. Age from 21 to 45 years old. Less than 4.0D astigmatism. If your astigmatism is more than 0.5D, you could prefer toric ICL for correction. The endothelial cells of cornea that are few affected by the lens should be check before surgery just in case. Not currently pregnant. The reason for this is the drugs or the psychic factors would affect your baby grows. Which I have to mention about is if you feel dry eye severely, or your corneal thickness is in suspicion of keratoconus or sub clinical keratoconus, you should drop this type of surgery. Because after implantation of the ICL, that won’t promote your vision acuity not for the factor of lens itself.
The ICL is implanted through a 3mm incision of corneal or limbus that cause negligible astigmatism. No iris function involvement, and is esthetic. The safety of implantation is proved by surgeons all over the world The best advantage of it, is it could be removable, which is not like the ablation of corneal surgery. The common complications met in clinical practise are cataract and glaucoma, which ophthalmologist could handle it out.
So it is a good alternation to patients and surgeons. Have no idea of ICL, read the first link below.
Types of phakic anterior chamber intraocular lenses
Dec 27th
In this article, I will give you, a brief summary of often clinical used phakic anterior chamber intraocular lenses (PAC IOL) types and their advantages and disadvantages.
- PAC IOL Vs. LASIK
PAC IOL
disadvatages:
postoperative astigmatism
refractive error caused by increments in length of the eyes
exact calculation of lens diopter
endothelium risk
infection
Advatages:
reversibility or adjustability
the preservation of accommodation
LASIK
disadvatages:
cornel ablated
small effective optical zones
the predictability and stability of the procedure
halos and glare
unreversibility or unadjustability
infection
Advatages:
the preservation of accommodation
less effection to intraocular system
- Classification
- Angle-Fixated
Strampelli was the first surgeon (in 1953) to implant this. The older products were ZB implant (Domilens Corp., Lyon, France) , ZB 5M (Domilens) and The Nuvita MA 20 (Bausch & Lomb, Claremont, CA) by Baikoff lens. The representative product was Phakic 6 (Ophthalmic Innovations International, Ontario, CA). Model ZSAL-4 (Morcher, Stuttgart, Germany) was similiar to ZB5M. The first foldable, phakic, angle-fixated anterior chamber IOL is the Vivarte lens, manufactured by Ioltech (La Rochelle, France) and distributed by CibaVision (Duluth, Ga) which could be insert to the eye by a 2mm incision. But this kind of lens have flexible haptics. Sometimes will cause problems. 
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- Iris-Fixated
Worst and Fechner’s phakic iris-claw lens is manufactured
and distributed by Ophtec (Gro¨ningen, Netherlands), under the name of Artisan. Do you know the first design of iris fixated lens was by worst? It is heard that the artisan is renamed to verisyse, am I right?
- PAC IOL Complications
- Corneal Endothelial Cell Loss
- Pupil Ovalization
- Retinal detachment (RD)
- Subclinical chronic inflammation
- Glare and halo effects
It is a sad trend that more and more doctors gives up the Angle-Fixated lens because it will damage the cornel’s function. Many papers proved that. The iris claw type seems good for patients. The ICL will cause cataract and secondary glaucoma, but incidence is very low.
Types of phakic posterior chamber intraocular lenses
Dec 27th
In this article, I will give you, a brief summary of often clinical used phakic posterior chamber intraocular lenses types and their advantages and disadvantages.
- Backgroud: to avoid the complication of anterior chamber intraocular lens, such as endothelium risk and pupil ovalization. The lens is inserted between iris and crystalline lens.the first implantation is done by Fyodorv in August 1986.
- Fyodorov and Chiron-Adatomed IOLs styles were designed to be fixated in the ciliary sulcus but, as the optic had the shape of a collar-button with a small diameter and protruded into the anterior chamber, the pupil could not constrict anterior to the lens optic. The optic and haptics were connected by a bridge through the pupillary opening.
- ICL, (PPCIOL), known as implantable contact lens produced by by Staar Surgical. The ICL is a single-piece plate design. The lens can be implanted through a corneal incision smaller than 3.0 mm. Surgical procedure is very simple.
- PRL, phakic refractive lens which manufactured by Medennium Inc. and distributed by CibaVision Corp. The PRL has spherical, thin, flexible haptics that are frosted in an attempt to reduce the incidence of postoperative halos or glare. And there has only a one-size-fits-all lens design, only the 11.3-mm model.
- The only most important complication is cataract formation. Others like pupillary block glaucoma leading to intraocular presure increased, pigment deposits, pigmentary dispersion, subjective edge glare and halos, decentration, monocular diplopia, inflammation and infection, Calculation of lens power. and so on. But incidences are low.
- There are many papers indicate the implantations appears to be an effective method for correcting moderate to high myopia, hyperopia, and extreme myopia when combined with surface refractive surgery such as LASIK, PRK. But we need even longterm and standardized clinical studies to determine the safety of this kind of implantation for refractive correction.