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| ARTICLES |
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| Year : 1989 | Volume
: 37
| Issue : 2 | Page : 80-83 |
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Phakoemulsification cataract extraction with foldable IOLs-first 50 cases
Keiki R Mehtha
"Sea Side", 1 st Floor, 147, Colaba Road, Bombay - 400 005, India
Correspondence Address:
Keiki R Mehtha
"Sea Side", 1 st Floor, 147, Colaba Road, Bombay - 400 005
India
 Source of Support: None, Conflict of Interest: None  | Check |
PMID: 2583787 
Phakoemulsification as a procedure is only complete with flexible foldable lens Preliminary studies show good acceptace of the procedure though the injector is cumbersome. Phakoemulsification has now become a reality with advanced instrumentation techniques available. Phakoemulsification has to its greatest advantage the ability to remove a cataract though a 3mm opening. Not only does this enhance the safety and the speed of healing, but it reduces postoperative astigmatism significantly.
However, the very advantages listed above stand negated if the wound is to be opened to 6mm to accommodate an implant.
The extra effort needed as compared to regular extra capsular cataract extraction, the enhanced cost of the instrumentation, the more sophisticated technique needed and the superior magnification devices required were all rendered negative till the flexible lenses made their debut. With foldable lenses, phakoemulsification has come into its own.
Thomas Mazaco was first credited with the concept of folding and inserting lenses. The ocular lenses were foldable with a forcep (Faulker Folder) and inserted into the eye through a 4 mm incision. It was a tight fit and the compression exerted by the forceps often left a bend on the lens. These problems led to the manufacture of a injective inserter which was in essence a single metal syringe with a piston, either longitudinal pressure or screw movement. Of these the Bartel injector was perhaps the earliest. Now virtually every company making flexible lenses has come out with an injector.
The Staar Softrans injector has proven in my hands to be the most useful of all these devices.
as a procedure is only complete with flexible foldable lens. Preliminary studies show good acceptance of the procedure though the injector is cumbersome. Phakoemulsification has now become a reality with advanced instrumentation techniques available. Phakoemulsification has to its greatest advantage the ability to remove a cataract though a 3mm opening. Not only does this enhance the safety and the speed of healing, but it reduces postoperative astigmatism significantly. However, the very advantages listed above stand negated if the wound is to be opened to 6mm to accommodate an implant. The extra effort needed as compared to regular extra capsular cataract extraction, the enhanced cost of the instrumentation, the more sophisticated technique needed and the superior magnification devices required were all rendered negative till the flexible lenses made their debut. With foldable lenses, phakoemulsification has come into its own. Thomas Mazaco was first credited with the concept of folding and inserting lenses. The ocular lenses were foldable with a forcep (Faulker Folder) and inserted into the eye through a 4 mm incision. It was a tight fit and the compression exerted by the forceps often left a bend on the lens. These problems led to the manufacture of a injective inserter which was in essence a single metal syringe with a piston, either longitudinal pressure or screw movement. Of these the Bartel injector was perhaps the earliest. Now virtually every company making flexible lenses has come out with an injector. The Staar Softrans injector has proven in my hands to be the most useful of all these devices.
How to cite this article:
Mehtha KR. Phakoemulsification cataract extraction with foldable IOLs-first 50 cases. Indian J Ophthalmol 1989;37:80-3 |
| Material and Methods | |  |
Instrumentation :
Phakoemulsifier with magnetostrictive handpiece, 40 KHz titanium needles with peristaltic pump - while under dual 6053 computer control.
1. STAAR SOFI'RANS Injector
2. Faulkner Folder
3. Lenses:
Staar silicone lenses
Hydrophilic 1IEMA disc lenses
Adatomed Silicone lenses.
Surgical techniques utilised
(a)Incision: The posterior grey line is delinated for exactly 3.2mm with 2 step incision Keratome. Secondary incision at 3 O'clock faces away, lmm in size.
(b)Anterior Capsulotomy OR Canopener Capsulotomy
Neuman Capsulorhexis procedure to obtain a perfectly round capsulotomy.
(c)Phakoemulsification: Bimanual method
Carried out using the normal steps of nuclear sculpting followed by peripheral nucleus emulsification using a 30° titanium needle.
(d)Cortical removal:
Utilising automated irrigation aspiration available with the emulsifier with a 0.3mm pore.
(e)IOL Insertion: Visilon (methylcellullose) used to deepen chamber with extension of sections to 4mm and usage of a softrans injector.
(f) Positioning of the lens in the bag using a button hook, or a bent canula.
(g)Suture: 10'o monofilament, running suture with one loop on the primary site. Secondary site not sutured.
| Results | | |
The eyes have been accepting the lenses well with no untowered reaction. The most serious of the complications was a rise of IOP immediately post-operative, which could be attributed to the viscous substance utilised. This was controlled with acetazolamide since the technique was altered to completely flush out the visilon (methylcellulose), following insertion of I/A unit suction this problem has been almost eliminated.
Iris trauma occurs all too frequently following phako emulsification especially in beginners Cosmeticaly noticeable iris trauma occured in 7 cases.
Mild iritis was present due to the manipulation needed for setting "in" the silicone lens. This was in the first few cases as the manipulations had not stabilised.
Early opacity of the capsule was probably due to inadequate polishing of the capsule.
Adequate preop assessment with a Storz A scan had been carried out. We found the SRK rating of 116.4 was inadequate.
This was perhaps because the lens is much thicker than comparable PMMA lenses as specific gravity is less and thus the optical centre shifts backwards. Using a SRK rating of 117.6 proved to be more appropriate.
PARTICULAR PROBLEMS:
The injector is the only way to insert silicon lenses through a small incision. However, the Softrans injector needs to be loaded at the last minute. The lubrication has to be thorough, though used sparingly. The folding of the plastic holder has to be perfect or else the lens sticks and tears.
On its partial exit from the injector, the lens has to be properly positioned in the sulcus, or bag, as desired prior to total expulsion or else the manoeuvering becomes difficult.
The injector has no guide as to the amount of pressure involved. It often sticks and then suddenly releases the lenses in a burst.
A NEW TECHNIQUE WITH THE SOFI'RANS INJECTOR FOR FLEXIBLE IOL INSERTION IN EYE:
In an effort to diminish the "explosive exit of the silicone lens from the injector, many authors, including Shepard and Utrata have incised the nose cone. However, this only leads to endothelial damage as the sharp flap flips forward during delivery.
The author has developed a new technique in which a lens rotator is locked into the positioning hole of the IOL just prior to the exit of the lens. It has 3 advantages.
(a)There is no longer a sudden exit of the lens from the injector but a more controlled exit.
(b)The capsular bag now does not have to take the brunt of the impact which may lead to zonular dehiscence if friable.
(c)The IOL can be directed easily to the intra capsular location for proper bagging.
ANALYSES OF TYPES OF FOLDABLE LENSES USED:
There were 3 sets of lenses utilised:
30 lenses were of the stair silicone "bag" type lens. 8 lenses were of the silicone Loop type. 12 lensses were disc pattern HEMA lens.
(a) Silicone Staar Lenses (Model AA 4203 - Capsular Bag IOL )
These lenses are made from a silicone elastomer (RMZ-3) and have a biconvex optic of 6 mm diameter. They are single piece lenses with a specific gravity of 1.03. These lenses are injection cast and thus have perfectly shaped haptics or optics. Post-operatively the elastomeric material because of its softness, inertness and biocompatibility is expected to minimise long term intraocular trauma.
These lenses are inserted utilising the SOFTRAN inserter, an advance on the Novasoft injector, and have the advantage that they can be folded and inserted through a 3.2 mm incision.
Since antero posterior flexibility of a silicone lens is limited, it must be understood that here the iris is retracted with a hook and placed over the superior (proximal) haptic of the lens. Results are good and except for 2 lenses which were torn due to improper placement in the injector, no other problem; arose.
(b) Silicone 2 Loop Lenses - Adaptomed
These lenses, are made from medical grade silicone and are shaped like regular lenses with 2 loops at counter opposing areas. Here a Faulkner Folder or a strong suturing forcep with longitudinal groves is utilised to flex the lens and insert them in the eyes. However, the wound needs to be enlarged 4mm to accommodate the increase size of the forceps. Care has to be taken to release the forceps very slowly otherwise the lens "flips" open and is likely to "wipe" the endothelium leading to fairly severe striate keratopathy.
My personal view is that these lenses are far too thick and do not prove to be the answer required for the problem. Though they have antero posterior flexibility, this advantage is negated by the problems in insertion.
(c) Hema Disc Lens:
HEMA as a material for flexible IOL implantation has many advantages. The author published to the first series in the world on HEMA soft intra ocular lens along with Dr. Sathe and Karyekar. Here the disc lenses are made from 38.4% HEMA material of 9.00 mm diameter designed for bag placement.
The major advantages of these lenses are the extreme flexibility, and ease of insertion. However, the lenses are fragile and have to be handled with care.
HEMA lenses have an additional advantage that they shrink in their deydrated stage, though they tend to become friable if totally dry. Thus they can be easily inserted in a semi dry condition.
In addition, HEMA is virtually innocuous to the corneal endothelium and therefore can be used with relative safety.
[Figure - 1], [Figure - 2], [Figure - 3], [Figure - 4], [Figure - 5], [Figure - 6], [Figure - 7], [Figure - 8], [Figure - 9], [Figure - 10]
[Table - 1], [Table - 2]
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