Yamane Intraocular Lens Fixation in a Patient with a Large Iris Defect
Title: Yamane Intraocular Lens Fixation in a Patient with a Large Iris Defect
Author: Austin S. Nakatsuka, MD; Mark D Mifflin, MD; Craig Chaya, MD
Keywords/Main Subjects: Cataract, secondary lens, intraocular lens, anterior segment, iris
Diagnosis: Aphakia with Traumatic Iris Defect
In this video, we present a few surgical pearls of performing the Yamane scleral fixated intraocular lens technique in a patient with a large traumatic iris defect.
First described by Dr. Shin Yamane, the Yamane technique is a method of direct haptic-scleral fixation of an intraocular lens without the use of sutures. We use a Zeiss CT Lucia ® 602 3-piece hydrophobic lens (formerly EC-3 PAL) because the polyvinylidene fluoride (PVDF) haptics have excellent flexibility and durability. In this case, the haptic was grasped through the iris defect to perform the handshake maneuver with a 30 gauge thin-walled TSK docking needle. The trailing haptic was fixated first, with the leading haptic externalized through a paracentesis incision to provide stability. After the haptic ends had been externalized, the iris defect provides a unique view of the inferior haptic as it enters into the scleral tunnel. Low temperature cautery of the haptic end forms a flange that secures the haptic within the scleral tunnel. Attempts were made to close the iris defect but this was abandoned due to lack of remnant iris tissue and no preoperative cosmetic concerns. The patient has done well postoperatively with uncorrected visual acuity of 20/25 and is not complaining of dysphotopsias.
Surgical Steps of this Case:
- Markings made at the limbus at 90 and 270 degrees with the Mendez ring
- Markings for scleral tunnel made 2mm from the limbus and 2mm horizontally for the scleral tunnel Inferior marking is made nasally and the superior marking is made temporally on this right eye
- Two paracentesis incisions are made nasally
- Dispersive viscoelastic is injected
- Bent TSK needle is used to tunnel into the sclera
- Anterior chamber maintainer was placed
- A 3.0 to 3.5 mm main incision is made
- IOL is injected (initially upside down, so we flipped it with a sinskey hook)
- Leading haptic is externalized through the nasal paracentesis incision
- Trailing haptic is grabbed with the micrograsper forceps, placed into the anterior chamber and then through the corectopic pupil.
- Trailing haptic is grasped ~0.5 mm from the haptic end through the iris defect and inserted into the needle
- Bent TSK needle is used to tunnel into the sclera superiorly
- Leading haptic is internalized through the paracentesis incision and inserted into the superior needle with the forceps
- Both haptics are externalized and the lens is centered by grasping the two haptics
- The haptic ends are trimmed about 0.5 to 1 mm and cauterized to form a flange (looks like a bulb)
- Each flange is buried into the end of the scleral tunnel
- The main incision is sutured with a 10-0 nylon suture, the anterior chamber maintainer is removed
- Brief anterior vitrectomy is performed
- All wounds are hydrated and sealed
-Anterior chamber maintainer
-(2) 30 gauge thin-walled TSK needles
-MST set with micrograsper forceps
-Handheld low-temp cautery unit
-3-piece intraocular lens
-Anterior vitrector set
-Blades for paracentesis and main incisions
-10-0 nylon suture
Areas of Improvement (for this case):
Some areas of improvement identified after the case had been completed include the following:
-An anterior vitrectomy was not performed in this case because the patient had a history of a previous vitrectomy and no vitreous was identified pre-operatively. However, this should always be considered, as it is very difficult to deal with vitreous after the lens has already been inserted.
-The anterior chamber maintainer should be placed in order to maintain pressure in the eye prior to inserting the first needle and creating a scleral tunnel. Otherwise, the needle is being placed in a soft eye, which can be very difficult and sometimes dangerous to try and create a scleral tunnel.
-In retrospect, the iris defect probably could have been repaired first. This way, we would not have had to worry about running into our haptics and destabilizing our lens during the repair.
Video Script of the Case:
Hi this is Austin Nakatsuka, cornea fellow at the Moran Eye Center and this is a case of a scleral fixated IOL with the Yamane technique in a patient with a large iris defect
The patient was aphakic with iris damage from a ruptured globe repair.
We chose to sit temporally for this case and markings were made 180 degrees away at 6 and 12 o’clock, with markings for the scleral tunnel 2 mm away from the limbus and 2mm horizontally for the tunnel itself.
Two paracentesis incisions are made nasally. A bent 30 gauge thin walled TSK needle is used to make the scleral tunnel. After the needle has been tunneled for two mm, make sure that the needle exits as perpendicular to the sclera as possible so that the needle points directly into the vitreous space. Here the needle gets slightly embedded in the remnant iris root, so I have to direct it more posteriorly before it comes out nicely.
An 3.0 to 3.5 millimeter incision is made temporally and the IOL is inserted. We use a CT Lucia 602 3 piece hydrophobic lens, formerly known as the EC3 PAL, which is great for Yamane because it has very flexible but durable haptics that do not easily dislodge from the optic. We do iol calcs with a target between the sulcus and bag. Unfortunately, I did inject it upside down so we identified that and flipped it.
Our technique involves docking the trailing haptic first, so we externalize the leading haptic through the paracentesis site to stabilize the lens.
One technique is to leave the trailing haptic outside of the main wound, then grasp the haptic from outside the wound the first before docking it in the eye in one swift movement such as seen here in another case. However, we could not do that due the large iris defect and pupil that would not completely dilate. Therefore, we first inserted the optic and trailing haptic into the eye and through the pupil. The trailing haptic was then grasped with the MST micrograsper forceps through the iris defect about 1.5 mm from the end and then slowly fed into the needle. Ergonomically, this is usually the most difficult part of the procedure, so take care not to damage the haptic end as you are doing this.
Once the haptic has been docked, the needle is kept within the scleral tunnel and the syringe is removed. This effectively secures the haptic.
The same thing is done with the leading haptic now.
In this case, through the iris defect, we get a unique view of what the haptic looks like just before it enters the scleral tunnel.
Once the haptics have been externalized, they can be grasped to position and center the lens.
The haptic ends are trimmed to size and then cauterized with handheld low temp cautery to form a bulb. The bulbs are then buried under the conjunctiva and ideally within the entrance of the scleral tunnel.
After consideration, we decided to leave the iris defect for now, both because the patient was not cosmetically bothered by it and because we did not want to risk dislodging our IOL. Additionally, when attempting to mobilize the iris tissue, there was very little remnant of the iris root. After the iol is structurally secure, we may consider secondary iris repair.
The patient is currently doing very well, with uncorrected visual acuity of 20/25 at post op week 1 and no issues with glare or dysphotopsias.
Faculty approval by: Mark D Mifflin, MD and Craig Chaya, MD
Disclosure (Financial or other): None