Vertical fixation with fibrin glue-assisted secondary posterior chamber intraocular lens implantation in a case of surgical aphakia.

We report the first case of vertical fixation by fibrin glue-assisted secondary posterior chamber intraocular lens implantation in a case of surgical aphakia. Advantages of vertical fixation are discussed.

We report the first case of secondary intraocular lens (IOL) implantation in which vertical fixation of haptics of a 3-piece foldable IOL with fibrin glue was performed with successful outcome in a case of surgical aphakia. Advantages and rationale of using vertical fixation are discussed.

Case Report

A 55-year-old female patient presented to us on November 18, 2010. She had been operated in the left eye 5 years back elsewhere for cataract surgery. She was diabetic since 2 years and hypertensive since 11 years, controlled on treatment.

On examination the right eye had vision of 6/9 with -4.75 D Sphere and N6 with add of +3D. Left Eye was 6/12 with +8 D Sphere and N8 with +3 D add. Right eye showed a clear lens while left eye was aphakic with no capsule seen and intact vitreous face. Intraocular pressure (IOP) was 14 mm Hg right eye and 16 mm Hg left eye on applanation tonometry. Gonioscopy revealed open angles grade 4 in both eyes. Fundus examination showed myopic degenerative changes at macula with attached retina.

IOL Master (Version 5, Zeiss, Germany) readings were as follows. K1 45.61D @ 80°, K2 46.49D @ 170°, AL 24.81mm, IOL power +14 D (A constant 118.4).

The patient was operated for vertical glued secondary IOL implantation with temporal clear corneal incision and anterior vitrectomy.

Anesthesia

The surgery was performed with topical 0.5% Proparacaine (Sunways, Ahmedabad, India) and subtenons injection of preservative free 1% Lignocaine (Oculan, Sunways, India). After instillation of topical proparacaine, superonasal conjunctiva was cauterized and then conjunctiva and tenons were opened with sharp scissors. Two cc of 1% preservative free lignocaine was injected in the superonasal quadrant.

Surgical technique

A radial keratotomy marker was used to mark 2 diagonally opposite points exactly 180 degrees apart at 12 and 6 O″ clock. The conjunctiva was opened at the limbus and dissected to expose sclera adequately. A crescent knife was used to make partial lamellar scleral flaps of 2.5 × 2.5 mm centered at 12 and 6 O″ clock dissecting upto the limbus. A tunnelled clear corneal entry was made with a sideport knife and an anterior chamber maintainer was inserted at 8 O′ clock in the inferonasal quadrant. The infusion was turned on and this prevented globe collapse and hypotony in all subsequent surgical steps. Underneath the scleral flaps, an entry was made with 20 gauge micro vitreo-retinal (MVR) knife 1 mm from limbus at 12 and 6 O′ clock. The MVR knife was directed towards the centre of the globe and parallel entry was avoided so as to minimize risk of bleeding from the iris root. Anterior vitrectomy was performed with a 20 gauge vitrectomy cutter passed through the opening underneath the 12 O′ clock scleral flap. The IOL used was a 3 piece Sensar AR40e (AMO, USA) foldable implant (hydrophobic acrylic with UV absorber and blue PMMA modified C haptics). The IOL was injected via a temporal clear corneal tunneled incision of 2.8 mm. A 20 gauge intravitreal IOL holding forceps was introduced through the sclerotomy underneath the 6 O′ clock sclera flap till its tip could be visualized in the centre. Injection of the IOL was started and the leading haptic tip was grasped by the forceps. Exteriorization was done while injection of the IOL was gently continued. The leading haptic was grasped at the very tip so as to avoid snagging at the sclerotomy during exteriorization. Injection of the optic was completed while withdrawing the injector so that the trailing haptic remained outside the eye at the wound. The sponge tire of an iris retractor was used to plug into the exteriorized haptic at 6 O′ clock so that it did not slip back into the vitreous cavity while completing rest of the surgery. The intravitreal IOL holding forceps was then introduced through the sclerotomy port underneath the scleral flap at 12 O′ clock. A McPherson forceps was used to grasp the trailing haptic and this was flexed into the anterior chamber. The tip of this haptic was grasped with the IOL holding forceps and exteriorized at 12 o′clock. It was secured with another sponge tire of iris retractor. A partial thickness intra-scleral tunnel was created with a 26 gauge needle at the edge of the scleral flap parallel to limbus and along the haptic curve. The haptics were tucked into the scleral pocket. Centration of the IOl was adjusted by varying the degree of tuck of both haptics. The scleral bed was dried with a Weck-cel sponge, the infusion fluid being temporarily stopped. Vitrectomy was done at the sclerotomy ports to ensure that there was no incarceration of vitreous strands. Biological fibrin glue (Tisseel VH, Baxter AG, Vienna, Austria) was applied to the undersurface of the scleral flaps and the flaps were glued down. The conjunctiva at 12 and 6 o′clock was also closed with glue. The temporal clear corneal incision was hydrated. Intracameral injection of Moxifloxacin (Vigamox, Alcon, Fort Worth, TX, USA) 0.1 cc was given at the end of surgery. The patient was discharged without an eye patch.

Postoperatively the patient was prescribed Vigamox drops 4 times a day for one week, Prednisolone acetate (Alcon, USA) 4 times a day, and Nepafenac (Nevanac, Alcon, USA) 3 times a day for a period of 4 weeks. The postoperative period was uneventful. On the first postoperative day the patient had uncorrected vision of 6/36 improving to 6/12 with pinhole. The cornea showed minimal edema and Descemets folds. Anterior chamber showed 1+ cells. IOP with non contact tonometry was 16 mm Hg. Fundus examination showed few vitreous cells and normal disc with attached retina. At the end of 1 week, the patient had a vision of 6/12 with −1 D sphere and near vision was N8 with add of +3D sphere. Corneal edema and descemets folds had cleared. Anterior chamber showed occasional cells. The IOL was well centered with IOP of 14 mm Hg on Goldman applanation tonometry and a normal fundus. At 4 weeks completed follow-up the patient had a vision of 6/9 with −1 D sphere and −0.5 D cylinder at 90 and near vision of N6 with +3D add. The cornea was clear with quietanterior chamber. The IOL was stable and well centered with IOP of 16 mm Hg. Fundus examination was normal. Glasses were prescribed at 4 weeks. At the 6 month completed follow-up the patient was maintaining a corrected vision of 6/9 N6 with a quiet eye, IOP of 15 mm Hg, stable IOL and normal fundus. [Figs. 1-4].

Figure 1

Well centred IOL 6 months after surgery

Figure 4

Optic-haptic junctions seen in horizontal meridian

Discussion

There are various options for performing a secondary intraocular lens (IOL) implantation in aphakic patients. Posterior chamber IOL (PCIOL) can be placed in the sulcus if there is an intact capsulorrhexis rim with ruptured posterior capsule. Alternatively 4 point scleral fixation can be done with 10-0 prolene suture. Iris fixation on the anterior and posterior iris surface is another option. Open loop anterior chamber IOL's (ACIOL) are also used with success. There is insufficient evidence at present to demonstrate the superiority of one lens type or fixation site.[1]

Fibrin glue-assisted IOL fixation is a relatively new technique described by Agarwal et al.[2] One year results with this technique have shown a good outcome and minimal complications.[3]

In this study of 53 eyes, the early post-operative complication described was decentration in 5.6%, while the late complication was pigment dispersion (3.7%) and healed macular oedema (7.5%). No vision threatening complications such as retinal breaks, retinal detachment, or endophthalmitis were noted. No pseudophakodonesis, pseudophakic bullous keratopathy, or elevated IOP was seen in the follow-up visits. Donaldson KE et al. have reported elevated IOP in 38% of ACIOL and 42% of sutured PCIOL patients in their study.[4] They also noted complications like pseudophakic bullous keratopathy in ACIOL patients. Complications like cystoids macular edema, retinal detachment, and inflammation were noted in both ACIOL and sutured PCIOL patients. Suture erosion remains a concern in scleral fixated IOL patients and may lead to long term complications like subluxation or dislocation. Indeed in their study of 26 patients, Buckley EG noted 3 patients who developed subluxation due to spontaneous breakage of 10-0 polypropylene suture at 3.5, 8, and 9 years after surgery.[5] Fibrin glue-assisted scleral tunnel fixation may provide a technique with lesser complication rate and avoid suture related problems, though we would have to wait to get long term data on stability. Foldable IOL was selected so it could be injected through 2.8 mm incision, and 3 piece IOL was selected since haptics are more flexible to be grasped by forceps and exteriorized without breaking. Foldable acrylic haptic (hydrophobic or hydrophilic) is difficult to manoeuvre and grasp with forceps. Tucking this acrylic haptic into a scleral tunnel is more difficult than 3 piece IOL haptics. Single piece PMMA IOL will require larger incision with its disadvantages. Haptics of single piece PMMA IOL are more rigid and likely to break during exteriorization.

In the classical technique described for fibrin glue-assisted fixation, scleral flaps are made horizontally at 3 and 9 O′ clock (as also described for standard trans-scleral suture fixation procedures).

We report the first case where haptics were fixed in the vertical meridian underneath sclera flaps at 12 and 6 o′clock. We propose the following advantages of vertical fixation:

The scleral flaps are covered by upper and lower lids and congestion or hyperemia, which usually occurs in the postoperative period at sites of conjunctival and sclera flap dissection is less noticeable than in horizontal fixation.

White to white diameter is relatively constant vertically and not variable like horizontal white to white diameter.[6] Also, as the corneal diameter is less vertically, there is more haptic length available for tucking. The average horizontal diameter was noted to be 11.46 mm and vertical diameter was 10.63 mm in a study.[7] Secure tucking of haptics provides greater stability and prevents movement and tilt of IOL. This would be particularly helpful in myopic patients where horizontal white to white diameter is larger. In our patient, the corneal diameter was 12.25 mm horizontally and 11.75 mm vertically.

Surgeons who are used to temporal clear corneal incisions for routine cataract surgeries need not change their approach.

We hypothesize that surface problems like localized dryness or tear film distribution abnormalities may be reduced as the site of flaps would get compressed and flattened by upper and lower lids. This is also the reason why foreign body sensation would not be felt as the risk of getting a small bleb or bump is minimal. This can be seen in the post-operative photos in our case where the scleral flap sites are flat, smooth, and even [Figs. 2 and 3].

Figure 2

Inferior haptic underneath scleral flap at 6 o′clock

Figure 3

Superior haptic underneath scleral flap at 12 o′clock

Vertical fixation may be advantageous in patients who have had previous surgeries like pterygium or horizontal muscle squint surgery. In such patients scarring in the horizontal meridian at 3 and 9 o′clock may make dissection difficult and more bleeding would be encountered.

The anesthesia used in our case was localized subtenons injection of 1% Lignocaine. This provides adequate analgesia without akinesia and allows patient to move the eye up or down which aids the surgeon while dissecting scleral flaps and is especially useful in patients with narrow palpebral fissures. The additional advantage is that anaesthesia can be repeated during the surgery if required.

Post-operatively one line gain in vision on Snellen chart was observed and this can be ascribed to placement of IOL at the nodal point of the eye.

In conclusion, this technique of vertical fixation with fibrin glue assisted secondary IOL implantation can be successfully performed in carefully selected cases of aphakia with inadequate capsular support. As long term data on dislocation rates and stability is not available we do not recommend it in pediatric cases at this time.