AcrySof toric intraocular lens for post-keratoplasty astigmatism.

We report a 63-year-old male who had undergone left eye optical penetrating keratoplasty for central leucomatous corneal opacity 10 years earlier. The eye had clear donor graft with residual astigmatism of -6.50 diopter cylinder (DC) at 30°. The patient underwent clear corneal phacoemulsification with implantation of +6.0 D spherical equivalent AcrySof SN60T9 intraocular lens (IOL). Postoperatively, at 10 months, the patient had distance corrected visual acuity of 20/30 with -2.00 DC at 20°. AcrySof toric IOL offers an effective treatment option for post-keratoplasty high corneal astigmatism in patients with cataract.

Phacoemulsification with implantation of foldable toric intraocular lens (IOL) has become the preferred management option in patients with high corneal astigmatism with coexistent cataract. Various treatment options available for patients with post-keratoplasty high corneal astigmatism in patients with coexistent cataract are spectacles, toric contact lenses, rigid gas permeable lenses,[1] arcuate keratotomy with compression sutures[2] or astigmatic keratotomy with femtosecond laser,[3] photorefractive keratectomy,[4] laser-assisted in situ keratomileusis (LASIK),[56] intracorneal ring segments[7] and presently toric IOLs.[8-12] Artisan[89] and intraocular collamer lens (ICL)[1011] of STAAR Surgicals have been used for the post-keratoplasty high astigmatism. Phacoemulsification with minimal surgically induced astigmatism with AcrySof toric IOLs offers an effective management option in patients with coexistent cataract. AcrySof toric IOL with improved rotational stability is effective for high corneal astigmatism.[13] Various studies have shown the postoperative rotational stability of the AcrySof toric IOLs in patients with high astigmatism.[13] PubMed search showed ours as the first case report of phacoemulsification with implantation of AcrySof toric IOL for post-keratoplasty high corneal astigmatism.

Case Report

A 63-year-old male presented with complaints of gradually progressive painless diminution of vision in the left eye since last 1 year. The patient had undergone left eye optical penetrating keratoplasty 10 years back for leucomatous corneal opacity post corneal ulcer, managed medically.

The patient presented to us with visual acuity of 6/36 in the left eye with astigmatism of –6.50 diopter cylinder (DC) at 30° and unaided visual acuity of 6/9 in the right eye. Intraocular pressure measured with Goldmann applanation tonometer was 16 and 18 mmHg.

Slit-lamp examination of the left eye revealed clear, full thicknesscorneal graft of around 8 mm diameter with no graft edema, and cataract of nuclear colour (NC) and nuclear opalescence (NO) of grade 4. Early morning ultrasound pachymetry was 526 μm for the left eye and 546 μm for the right eye. A complete ophthalmological examination including refraction, pentacam for corneal topography, specular microscopy and pachymetry, biometry, IOL selection and systemic investigations were performed. Preoperative, endothelial cell count was 1450 cells/ mm2 on specular microscopy. IOL Master keratometry readings of K1 44.25 D at 55°, K2 54.0 D at 145° with preoperative corneal astigmatism of +9.75 DC at 145° and average keratometry reading of 49.13 D were used for IOL power calculation. As per the calculation, the IOL recommended was AcrySof SN60T9 spherical equivalent +6 D with residual cylindrical power of 5.48 D at 146° at the corneal plane [Fig. 1]. The patient underwent clear corneal phacoemulsification using Infiniti, Ozil system after markings for AcrySof toric IOL, with special surgical considerations for the corneal graft. Incision was placed at 110° with AcrySof toric IOL marks aligned along 146°. The preoperative 3, 6 and 9 o’ clock markings were made with Nuijts reference corneal marker under topical anaesthesia with the patient sitting upright. Upright reference markings were applied to avoid supine cyclo-torsion. Intraoperatively, location of the corneal incision and axis of IOL placement was marked using Mendez ring and Nuijts toric axis marker.

Figure 1

Preoperative intraocular lens power calculation for AcrySof SN60T9 was spherical equivalent +6 D with residual cylindrical power of 5.48 D at 146° at the corneal plane

Two clear corneal side-port incisions were made at 2 and 9 o’ clock hour positions. Graft endothelium was coated with Viscoat, Alcon (3% sodium hyaluronate + 4% chondroitin sulfate) and anterior chamber formed with Healon GV, AMO (Arshinoff soft shell technique). Triplanar clear corneal incision was made at 110°. Well-centered, approximately 5-mm continuous curvilinear capsulorrhexis was completed. Multiquadrant hydrodissection was done and nucleus rotated. In the bag, nuclear emulsification was done with direct chop technique followed by cortical material removal. Care was taken to avoid sudden decompression of the anterior chamber throughout the surgery. Capsular bag was filled with Healon GV and IOL implanted into capsular bag with the axis of the IOL aligned around 15° short of the final axis of alignment (146°). Viscoelastic removal was done along with final rotation of the IOL, and the axis aligned [Fig. 2]. Side ports and clear corneal incisions were hydrated. Postoperatively, the patient was reviewed on day 1, 3, 14 days, 6 weeks, 4 ½ months and 10 months. On the immediate postoperative day, the corneal graft was clear with well-formed anterior chamber with 1+ cellular reaction, and well-centered aligned IOL with an intraocular pressure of 13 mmHg in Goldmann applanation tonometer. Refraction 6 weeks postoperative was –2.0 DC at 20°, vision improving to 20/30 on Snellen visual acuity chart. There was clear corneal graft and no rotation of IOL was noted. The patient was examined at 10 months follow-up and has best-corrected visual acuity (BCVA) of 20/30 and no rotation of toric IOL [Fig. 3]. Endothelial cell count was 1110 cells/mm2. Intraocular pressure was 14 mmHg.

Figure 2

Capsular bag implanted toric intraocular lens (IOL) at the end of surgery after viscoelastic removal. Note the position of toric IOL marks on the optic

Figure 3

Postoperatively at 10 months, there was clear corneal graft and no rotation of intraocular lens was noted

Discussion

At present, toric IOL provides an effective management option for the correction of post-keratoplasty high astigmatism and cataract.[8-12]

Nuijts et al.[8] implanted Artisan phakic toric IOL for the correction of post-keratoplasty high corneal astigmatism in 36 eyes of 35 patients and achieved an average of 88.8% reduction of astigmatism. But there was continued loss of the endothelial cells till 3 years of follow-up. Two patients developed irreversible graft rejection while one developed corneal decompensation. Akcay et al.[10] reported the use of ICL, a posterior chamber phakic toric IOL, for post-keratoplasty astigmatism. They reported marked reduction of astigmatism. No serious complication or refractive shift occurred at 1 year post surgery follow-up. The above authors have used phakic toric IOLs.

In our patient with post-keratoplasty high corneal astigmatism with coexisting cataract, we used AcrySof toric IOL. This patient achieved BCVA of 6/9 with astigmatism of –2 DC at 20° (astigmatism reduced to roughly one third) with clear corneal graft. There was no postoperative rotation of IOL noted till 10 months post surgery. The better refractive result than that calculated can be explained as after keratoplasty, the biomechanical response of the corneoscleral tissue to the incision may be somewhat unpredictable, and a greater variability in surgically induced astigmatism may be seen.[8]

In conclusion, AcrySof toric IOL provides excellent correction of post-keratoplasty high corneal astigmatism in patients with coexistent cataract.