Laser in situ Keratomileusis After Penetrating Keratoplasty

Laser in situ keratomileusis versus Artisan lens implantation in correcting ametropia after penetrating keratoplasty for keratoconus

PURPOSE

To compare the long-term safety and efficacy of laser in situ keratomileusis (LASIK) with Artisan phakic intraocular lens implantation to correct refractive errors after penetrating keratoplasty (PK) for keratoconus.

METHODS

This retrospective comparative interventional case series included a total of 33 consecutive keratoconus eyes that had previous PK and received subsequent LASIK (n = 16) or Artisan lens implantation (n = 17) were included in this study. Outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refractive error, and complications.

RESULTS

Postoperatively, the UDVA of ≥20/40 was achieved in none of the LASIK group compared to 62.5% of eyes in the Artisan group (P < 0.001); the respective values for CDVA of ≥20/40 were 87.5 and 94.1% (P = 0.51). Spherical equivalent refraction decreased from - 6.97 ± 1.50 D preoperatively to - 4.20 ± 2.05 D postoperatively in the LASIK group (P < 0.001) and from - 10.79 ± 2.15 D preoperatively to - 2.13 ± 1.23 D postoperatively in the Artisan group (P < 0.001). There was no significant change in the refractive astigmatism in LASIK group (P = 0.30) or Artisan group (P = 0.11). The efficacy and safety indices were significantly better for Artisan (0.82 ± 0.34 and 1.13 ± 0.30, respectively) than for LASIK (0.22 ± 0.17 and 0.85 ± 0.24, respectively, P ≤ 0.006 for both comparisons). While refractive error changed significantly from postoperative year 3 to the final visit in the LASIK group, it remained stable in the Artisan group through follow-up period. No significant complications were observed in any group.

CONCLUSION

Artisan lens implantation provided superior and stable visual outcomes compared to LASIK for the management of post PK refractive errors in keratoconus eyes.

Management of post-keratoplasty ametropia

Even after a successful corneal transplant, patients experience severe refractive errors, impeding their rehabilitation and satisfaction. Refractive errors can be caused by recipient pathology and corneal thickness, as well as intraoperative factors such as donor-host discrepancy, recipient's eccentric trephination, vitreous length, wound apposition, technique of suturing, and suture material. Also, wound healing and the interim between keratoplasty and suture removal contribute to astigmatism. Lamellar keratoplasty outperforms penetrating keratoplasty in terms of endothelial cell loss and endothelial graft rejection, yet the risk of developing refractive errors is comparable. Nonsurgical interventions such as spectacles and lenses fail to provide desirable vision in cases with high astigmatism and corneal irregularity. When these limitations are encountered, surgical interventions including incisional keratotomy, wedge resection, laser refractive surgeries, intracorneal segments, and intraocular lens implantation are employed. However, occasionally, none of these approaches deliver the desired effects, leading to the need for a repeat keratoplasty.

Post-penetrating keratoplasty astigmatism

Postoperative astigmatism is one of the common complications affecting visual outcomes after a penetrating keratoplasty. It can result from various factors related to host, donor and surgical technique, resulting in suboptimal visual outcome. While some of the measures taken during preoperative planning and during actual surgery can reduce the magnitude of postoperative astigmatism, postoperative correction of astigmatism is often required in cases with high degrees of astigmatism. When spectacles and contact lenses fail to provide optimal visual outcomes, various surgical techniques that include astigmatic keratotomy, compression sutures, toric intraocular lens placement, and laser refractive procedures can be considered. When none of these techniques are able to achieve a desired result with in the acceptable optical range, a repeat keratoplasty is considered a last option. We discuss the various causes and management of complication of postoperative astigmatism occurring after a full thickness corneal transplantation surgery.

Femtosecond astigmatic keratotomy for postkeratoplasty astigmatism

PURPOSE

To evaluate the initial outcomes of femtosecond laser arcuate keratotomies (AK) to correct high astigmatism after keratoplasty.

METHODS

This retrospective non-comparative interventional study included 52 consecutive patients (52 eyes) who underwent Intralase-enabled arcuate keratotomies. Changes in uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BCVA), mean refractive and keratometric astigmatism, preoperative and postoperative manifest refraction and complications were the main outcome measures.

RESULTS

The mean follow-up period was 13.77 ± 4.17 months. Mean BCVA and UCVA improved statistically significantly from 0.30 ± 0.18 LogMAR and 0.90 ± 0.43 LogMAR preoperatively to 0.20 ± 0.14 and 0.60 ± 0.39 postoperatively respectively (P < 0.05, all comparisons). Mean subjective cylinder decreased statistically significantly from 7.15 ± 1.32 D preoperatively to 5.19 ± 2.25 D at the last postoperative visit (P = 0.0002). Two eyes (4%) lost one line or more of BCVA. Three patients (5.8%) had corneal perforation and only one eye required resuturing of the AK wound. Twelve patients (23%) were overcorrected.

CONCLUSIONS

AK performed with the femtosecond laser was relatively easy to perform, safe, and effective for treating post-keratoplasty astigmatism. There was a significant improvement in UCVA and BCVA with a very low rate of complications. A larger series is required to refine the nomogram to achieve a greater reduction in cylinder.

Visual outcomes of Femto-LASIK for correction of residual refractive error after corneal graft

PURPOSE

To evaluate the outcomes of the Femto-LASIK method in the treatment of refractive errors following penetrating keratoplasty (PK) at the Persian Eye Clinic, Isfahan, Iran

METHODS

In a prospective, non-comparative case series, 34 consecutive symptomatic eyes of 34 patients after corneal graft, were operated on. Tissue-saving (TS) Femto-LASIK (n = 16), and Zyoptix Personalized Treatment Advanced (PTA) Femto-LASIK (n = 18) were performed using the Bausch & Lomb Technolas 217z excimer laser and Zyoptic algorithm. Uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), manifest refraction, contrast sensitivity, and HOAs were evaluated preoperatively and 12 months after enhancement treatment.

RESULTS

At 12 months, the mean preoperative myopic spherical equivalent refraction (SE) decreased from -6.50 ± 2.8 D to -1.6 ± 1.8 D, and mean hyperopic SE from +3.2 ± 2.20 D to 0.37 ± 1.2 D. The safety index was 1.42 (1.2 in the TS group and 1.5 in the PTA group). In the TS group, 100% of eyes achieved 20/80 or better UCVA and 50%, 20/40 or better and in the PTA group, 100% of eyes achieved 20/80 or better UCVA and 77.7%, 20/40 or better. The efficacy index was 1.08 (0.9 in TS group and 1.21 in the PTA group). Patients obtained statistically significant lower values of root mean square (RMS) of HOAs with spherical aberrations (p < 0.05).

CONCLUSIONS

Femto-LASIK method with Zyoptic programs after PK was safe, effective, and predictable for correction of spherical and cylindrical components of the refractive error.

Femtosecond LASIK combined with astigmatic keratotomy for the correction of refractive errors after penetrating keratoplasty

BACKGROUND AND OBJECTIVE

To evaluate the outcomes of femtosecond laser in situ keratomileusis (LASIK) compared to combined LASIK and astigmatic keratotomy in the treatment of refractive errors following penetrating keratoplasty.

PATIENTS AND METHODS

A retrospective review was performed on 18 eyes of 16 patients who underwent LASIK for visual rehabilitation after penetrating keratoplasty. Seven eyes (38.8%) had undergone paired relaxing incisions with topographic guidance prior to LASIK performance.

RESULTS

Preoperative uncorrected visual acuity was 20/100 or worse in 13 eyes (72.2%) and best-corrected visual acuity (BCVA) was 20/40 or better in 15 eyes (83.3%). After LASIK, uncorrected visual acuity was 20/40 or better in 10 eyes (55.5%) and BCVA was 20/40 or better in 17 eyes (94.4%). Three eyes (16.6%) had a loss of 1 to 2 lines of BCVA. No difference in visual outcomes was noted in eyes undergoing LASIK and astigmatic keratotomy versus LASIK alone. An increased complication rate was noted in patients who also underwent astigmatic keratotomy and was associated with flap creation.

CONCLUSION

Femtosecond LASIK is effective in reducing ametropia after penetrating keratoplasty. Astigmatic keratotomy might complicate flap creation in LASIK; therefore, photorefractive keratectomy should be considered for patients who had previous astigmatic keratotomy to reduce astigmatism.

Toric implantable collamer lens for patients with moderate to severe myopic astigmatism: 12-month follow-up

PURPOSE

To report on the 12-month follow-up of 77 eyes with moderate to high myopic astigmatism implanted with toric implantable collamer lenses (ICLs).

METHODS

Retrospective case-note review of 77 eyes from 42 patients undergoing toric ICL placement by one surgeon. Preoperative mean spherical equivalent -2.50 dioptres (D) to -15.00 D myopia and 1.00 D to 7.00 D astigmatism.

RESULTS

At 12 months, mean manifest refractive cylinder (MRC) decreased 81% from 2.38 D to 0.44 D. MRC within 1.00 D occurred in 99% (76/77) of eyes, whereas 86% (66/77) had MRC within 0.75 D. 99% (76/77) had postoperative best-corrected visual acuity (BCVA) better than or equal to preoperative values, whereas 78% (60/77) gained up to one line BCVA and 1% (1/77) lost one line BCVA. Uncorrected binocular vision of 6/6 or better occurred in 90% (38/42) of patients compared with binocular BCVA of 6/6 or better in 67% (28/42) preoperatively. One ICL was replaced due to low vaulting. Two eyes with astigmatism of 3.25 D and 3.50 D received subsequent laser in situ keratomileusis (LASIK) to reduce residual small refractive errors. Indications for ICL were: myopia too high for LASIK (73%), cornea too thin for LASIK (44%) and contact lens intolerance (33%). Night halos were reported in 10% (8/77) of eyes at 12 months. One ICL was removed due to unrecognized preoperative glaucoma. There were no cases of cataract formation, or endophthalmitis.

CONCLUSION

This study is the largest reported series of toric ICL implantation in New Zealand. It supports the safety, efficacy and predictability of toric ICLs to treat myopic astigmatism.

Topographically guided two-step LASIK and standard LASIK in the correction of refractive errors after penetrating keratoplasty

PURPOSE

To evaluate in a long-term period the effectiveness and safety of topographically guided two-step laser in situ keratomileusis (LASIK) and standard LASIK technique in the correction of refractive errors after successful penetrating keratoplasty (PKP) for keratoconus.

METHODS

At least 2 years after PKP and 6 months after removal of all sutures, 15 eyes of 15 patients (Group 1; mean manifest refraction spherical equivalent (MRSE) -7.23 D -/+ 3.42 SD) were submitted to standard LASIK and 15 eyes of 15 patients (Group 2; mean MRSE -4.37 D -/+ 1.97 SD) to a topographically guided two-step LASIK procedure (first the flap and at least 2 weeks later the laser ablation). In all cases, a superior hinged corneal flap(160 microm/9.5 mm) was created.

RESULTS

After a follow-up of 36 months, in Group 1 the mean uncorrected visual acuity (UCVA) was 0.51 logarithm of the minimum angle of resolution (logMAR) -/+ 0.41 SD and the mean best-corrected visual acuity (BCVA) was 0.03 logMAR -/+ 0.05 SD, with a mean MRSE of -1.57 D -/+ 2.65 SD. In Group 2, the mean UCVA was 0.28 logMAR -/+ 0.24 SD and the mean BCVA was 0.01 logMAR -/+ 0.03 SD, with a mean MRSE of -0.07 D -/+ 1.00 SD. In both groups, no complications were observed.

CONCLUSIONS

After a long follow-up period, both topographically guided two-step LASIK and standard LASIK could be considered effective and safe tools in the correction of refractive errors after successful PKP for keratoconus.

IntraLase-enabled astigmatic keratotomy for postkeratoplasty astigmatism

PURPOSE

To report on the outcomes of IntraLase-enabled astigmatic keratotomy (IEAK) and to compare it with manual astigmatic keratotomy (AK) for the management of postkeratoplasty astigmatism.

DESIGN

Retrospective, comparative case series.

METHODS

Forty eyes of 39 patients treated at a cornea clinic at the Toronto Western Hospital were included. Twenty eyes underwent manual AK and 20 eyes underwent IEAK. The main outcome measures included preoperative and postoperative manifest refraction, uncorrected and best-corrected visual acuity (UCVA, BCVA), corneal topography, high-order ocular aberrations, and complications.

RESULTS

In the manual AK group, UCVA (logarithm of the minimum angle of resolution) improved from 1.08 +/- 0.29 before surgery to 0.93 +/- 0.45 after surgery (P = .09), and in the IEAK group, UCVA improved from 1.14 +/- 0.42 before surgery to 0.82 +/- 0.44 after the procedure (P = .004). BCVA improved from 0.63 +/- 0.40 to 0.44 +/- 0.38 (manual AK; P = .16) and from 0.52 +/- 0.38 to 0.29 +/- 0.26 (IEAK; P = .01), respectively. Mean cylinder reduction was 3.23 +/- 4.69 diopters in the manual AK group and 4.26 +/- 1.72 diopters in the IEAK group (P = .36). Two eyes in each group lost one line of BCVA. Three patients (15%) in the manual AK group had corneal perforation and required resuturing of the AK wound (P = .23) Overcorrection occurred at a similar rate in the two groups.

CONCLUSIONS

Treatment of postkeratoplasty astigmatism with IntraLase is a safe and effective surgical procedure and resulted in a significant improvement in UCVA and BCVA compared with manual AK. A larger sample series is needed to refine further this new technique of AK and to compare it with accepted manual techniques.

Topographic Customized Photorefractive Keratectomy for Regular and Irregular Astigmatism After Penetrating Keratoplasty Using the LIGI CIPTA/LaserSight Platform

PURPOSE

To evaluate the use of a software ablation program (Corneal Interactive Programmed Topographic Ablation [CIPTA]) that provides customized photorefractive keratectomy (PRK) to correct astigmatism after keratoplasty.

METHODS

In this prospective, noncomparative, consecutive case series, 44 eyes underwent CIPTA for correction of astigmatism after penetrating keratoplasty. Eighteen eyes were treated for regular astigmatism and 26 eyes were treated for irregular astigmatism after penetrating keratoplasty. Orbscan II topography (Bausch & Lomb) and a flying-spot laser (LaserScan 2000; LaserSight) were used. Epithelial debridement with alcohol was performed before PRK in 16 eyes and transepithelial PRK was performed in 28 eyes. Mean target-induced astigmatism was 8.19 +/- 2.68 diopters (D) and 7.68 +/- 4.50 D in the regular and irregular astigmatism groups, respectively.

RESULTS

Mean follow-up was 25.4 +/- 13 months. At last postoperative follow-up, 13 (72.2%) and 18 (69.2%) eyes in the regular and irregular astigmatism groups, respectively, had uncorrected visual acuity (UCVA) better than 20/40. Four (22.2%) and 8 (30.7%) eyes in the regular and irregular astigmatism groups, respectively, had UCVA of 20/20. Fourteen (77.7%) and 18 (69.2%) eyes in the regular and irregular astigmatism groups, respectively, were within 1.00 D of attempted correction in spherical equivalent manifest refraction. No eye lost Snellen lines of best spectacle-corrected visual acuity. Mean surgically induced astigmatism was 7.66 +/- 2.70 D and 6.99 +/- 3.80 D for the regular and irregular astigmatism groups, respectively. Index of success of astigmatic correction was 0.138 and 0.137 for the regular and irregular astigmatism groups, respectively. Haze developed in three eyes.

CONCLUSIONS

Topography-driven PRK using CIPTA software is a suitable solution for correcting regular and irregular astigmatism after penetrating keratoplasty.

Flap-induced Refraction Change in LASIK After Penetrating Keratoplasty

PURPOSE

To further analyze the refractive and topographic changes occurring with microkeratome lamellar keratotomy and to investigate possible factors associated in eyes with previous penetrating keratoplasty (PK).

METHODS

The Hansatome microkeratome was used to create a lamellar corneal flap in 21 eyes of 19 patients after PK. The laser ablation was not performed in the first stage. Pre- and postoperative refractions and corneal topographies were compared to evaluate possible changes induced by the keratotomy.

RESULTS

Twenty-one eyes were analyzed in this study. Mean time between PK and lamellar keratotomy was 36.63 +/- 28.23 months (range: 12 to 120 months). No microkeratome-related flap complications occurred. Previous to the keratotomy, the mean spherical equivalent refraction was -4.26 +/- 3.41 diopters (D), mean refractive astigmatism was -4.71 +/- 2.27 D, and mean topographic astigmatism was 5.28 +/- 2.94 D. After keratotomy, eyes showed statistically significant changes in spherical equivalent refraction from preoperative values (P = .025), with 3 eyes showing changes > 2.00 D. Average refractive and topographic astigmatism did not change significantly from before to after keratotomy. However, surgically induced astigmatism (SIA) calculated through vector analysis was > 1.01 in 11 (52.4%) eyes. A statistically significant correlation was found between the SIA values and preoperative refractive astigmatism (P = .025).

CONCLUSIONS

Lamellar keratotomy as part of two-stage LASIK in eyes with prior PK led to refractive changes that justify the use of this technique, especially in eyes with high degrees of preoperative astigmatism.

Three-Year Follow-up Analysis of Artisan Toric Lens Implantation for Correction of Postkeratoplasty Ametropia in Phakic and Pseudophakic Eyes

PURPOSE

To determine the 3-year follow-up of efficacy and safety of Artisan toric iris-fixated lens implantation after penetrating keratoplasty (PK) to correct high ametropia and astigmatism.

DESIGN

Prospective noncomparative case series with a minimum follow-up of 1 year.

PARTICIPANTS

Artisan toric lens implantation was performed in 36 eyes of 35 patients who were contact lens intolerant or unable to wear glasses due to anisometropia and/or high astigmatism.

INTERVENTION

Thirty-six eyes of 35 consecutive patients received Artisan toric lens implantation for postkeratoplasty astigmatism and/or anisometropia.

MAIN OUTCOME MEASURES

Manifest refraction, uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), and corneal topography were determined or performed before surgery and at 3, 6, and 12 months and yearly intervals up to 4 years after surgery. Efficacy, safety, percent reduction of refractive astigmatism, anisometropia of defocus, and the astigmatism correction index were determined. A patient satisfaction questionnaire and specular microscopy were assessed.

RESULTS

The mean +/- standard deviation of preoperative refractive cylinder was -7.06+/-2.01 diopters (D) (range, -3.0 to -11.0), which was reduced to -1.73+/-1.25 D, -1.69+/-1.15 D, -1.94+/-1.68 D, -2.02+/-1.93 D, and -2.00+/-1.53 D at 6 months (n = 36), 1 year (n = 36), 2 years (n = 29), 3 years (n = 15), and the last follow-up examination (28.5+/-12.5 months, n = 36), respectively (P<0.001 for all time points, paired t test). The spherical equivalent was reduced from -3.19+/-4.31 D (range, +5.5 to -14.25 D) preoperatively to -1.03+/-1.20 D (range, +1.0 to -5.25 D) at the last follow-up. The UCVA and BSCVA were > or =20/40 in 31.6% and 80.6%, respectively. There was a loss of BSCVA of >2 lines in 8.3% of eyes and a gain of at least 2 lines in 8.3% of eyes. Percent reductions in refractive astigmatism and anisometropia of defocus were 88.8%+/-29.5% and 77.8%+/-19.3%, respectively. The astigmatism correction index was 96.0%+/-24.2%. Satisfaction increased from 3.6 to 8.0 (scale, 0-10) after implantation. The endothelial cell loss as compared with preoperatively was 13.8%+/-18.7% (n = 34), 21.2%+/-21.8% (n = 33), 29.6%+/-27.3% (n = 26), 30.4%+/-32.0% (n = 18), and 34.8%+/-26.3% (n = 6) at 6 months (P = 0.001), 1 year (P<0.001), 2 years (P<0.001), 3 years (P = 0.001), and 4 years postoperatively (P = 0.1), respectively. In 2 patients, irreversible graft rejections occurred, and in 1 patient, gradual endothelial decompensation occurred.

CONCLUSION

Artisan toric lens implantation after PK was effective for reduction of refractive astigmatism and ametropia. All patients were suitable for spectacle correction after implantation. There was continuing endothelial cell loss from 6 months to 3 years postoperatively. In 3 cases, corneal graft failure developed.

Laser in situ keratomileusis outcomes following radial keratotomy, astigmatic keratotomy, photorefractive keratectomy, and penetrating keratoplasty

PURPOSE

To evaluate the safety and efficacy of laser in situ keratomileusis (LASIK) to enhance refractive status following other corneal surgical procedures.

SETTING

Clinical office-based practice.

METHODS

Seventy-one eyes of 57 patients had LASIK for refractive errors following radial keratotomy (n = 22), astigmatic keratotomy (n = 13), photorefractive keratectomy (n = 18), and penetrating keratoplasty (n = 18). A Moria LSK-1 microkeratome was used with a Visx S2 or Wavelight Allegretto excimer laser. Data were acquired by retrospective chart review of all appropriately qualified patients.

RESULTS

The mean preoperative manifest refractive spherical equivalent (MRSE) was -3.93 diopters (D) +/- 2.83 (SD) in myopic eyes and +1.43 +/- 1.79 D in hyperopic eyes. The mean time from the initial corneal surgical procedure to LASIK was 65.0 months. The mean post-LASIK follow-up was 9.40 months (range 1 to 42 months). Postoperatively, the mean MRSE was -0.85 +/- 1.42 D in myopic eyes (P<.0001) and -0.16 +/- 1.09 D in hyperopic eyes (P<.0001). Enhancement by LASIK was required in 14% of eyes.

CONCLUSION

In eyes that have had a variety of previous corneal surgeries, LASIK offers a safe and predictable method for enhancing refractive results.

Two-step LASIK With Topography-guided Ablation to Correct Astigmatism After Penetrating Keratoplasty

PURPOSE

To assess the efficacy, predictability, stability, and safety of a two-step LASIK procedure using topography-guided ablation to correct astigmatism after penetrating keratoplasty.

METHODS

Fifteen eyes of 15 patients underwent a two-step LASIK procedure at the Maggiore Hospital of Bologna, Italy. In the first step, a flap was created using the Hansatome microkeratome. In the second step, topography-guided ablation using the LaserSight LSX was planned with interactive software (CIPTA) once topographical and refractive stabilization had been obtained. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), cylindrical correction, gain of lines of BSCVA, spherical equivalent refraction, and complications were analyzed.

RESULTS

Minimum follow-up was 12 months (range: 12 to 30 months). Uncorrected visual acuity improved in all 15 (100%) eyes. At the last postoperative examination, 11 (73%) eyes had UCVA > or = 20/40. Nine (60%) eyes were within 1.0 diopter (D) of the attempted correction. Mean postoperative astigmatism was -1.67 (range: -3.5 to 0; standard deviation: 1.26). Index of success of astigmatic correction was 0.26. No patient lost Snellen lines of BSCVA. Intraoperative complications included two buttonhole flaps, and postoperative complications included one flap retraction. No further laser treatment was needed.

CONCLUSIONS

The two-step LASIK procedure using topography-guided ablation reduces spherical and cylindrical refractive error due to penetrating keratoplasty. Topography-guided ablation also proved to be effective in correcting irregular astigmatism.

Post-LASIK corneal flap displacement following penetrating keratoplasty for bullous keratopathy

OBJECTIVE

To report 3 patients who experienced late flap dislocation after laser in situ keratomileusis (LASIK) in eyes that had undergone prior penetrating keratoplasty (PKP) for bullous keratopathy.

METHODS

Retrospective chart review of 2 referral corneal and refractive surgery practices, case reports, and literature review.

RESULTS

Three patients (mean age 58.3 years, 2 male, 1 female), all status post-corneal transplant for bullous keratopathy, had residual myopic astigmatism and underwent LASIK for correction of their significant anisometropia. Flap dislocation occurred at a mean of 7 days (range 3 to 14 days) following the LASIK procedure. All patients had peripheral corneal edema in their recipient bed. All 3 patients required an additional surgical procedure for visual rehabilitation.

CONCLUSION

Flap displacement may occur following LASIK in patients who have undergone PKP for bullous keratopathy. The endothelial pump function, which is vital to maintaining flap adherence, may be compromised in these patients. We suggest that patients with a history of PKP and endothelial compromise who undergo LASIK wear protective shields for a longer than normal period and be followed closely to reduce the risk of flap slippage.

Torische Kunstlinsen zur Korrektur eines persistierenden kornealen Astigmatismus nach perforierender Keratoplastik

PURPOSE

Cataract extraction with implantation of toric intraocular lenses (tIOL) is a new surgical option for correction of residual astigmatism following penetrating keratoplasty and cataract with only minimal direct manipulation of the graft.

PATIENTS AND METHODS

We implanted an individually manufactured backtoric tIOL in 11 eyes of 9 patients. TIOL power calculation was done using vergence transformation in a paraxial space.

RESULTS

Implantation and intraoperative alignment of tIOL were uneventful in all patients. Uncorrected visual acuity increased from 0.1+/-0.06 preoperatively to 0.47+/-0.18 (p=0.006) postoperatively. Best-corrected visual acuity changed from 0.23+/-0.18 preoperatively to 0.6+/-0.14 postoperatively (p=0.002). The refractive cylinder could be reduced from 7.0+/-2.6 D to 1.63+/-1.5 D (p=0.001) after surgery. We observed a small mean deviation from the target axis of 4.1+/-2.9 degrees (0-8 degrees ) after a mean follow-up time of 3.5 (2-7) months.

CONCLUSION

TIOL implantation is a promising option for correction of high astigmatism following penetrating keratoplasty with only minimal direct surgical manipulation of the graft. Regular and symmetric corneal topography is essential for successful implantation of tIOL.

Long Term Analysis of LASIK for the Correction of Refractive Errors After Penetrating Keratoplasty

PURPOSE

To determine the long-term safety and effectiveness of laser in-situ keratomileusis (LASIK) in the treatment of refractive errors following penetrating keratoplasty (PK).

METHODS

A retrospective review was performed of 57 eyes of 48 patients with anisometropia or high astigmatism who were unable to wear glasses or a contact lens after PK and who underwent LASIK for visual rehabilitation. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BCVA), and corneal transplant integrity were recorded before surgery as well as up to 60 months after LASIK.

RESULTS

The mean follow-up after the LASIK was 21.4 +/- 14.2 months (range 3 to 60 months). Mean preoperative spherical equivalent (SE) was -4.19 +/- 3.38 D. The mean preoperative astigmatism was 4.67 +/- 2.18 D. Preoperative BCVA was 20/40 or better in 42 eyes (74%). At 2 years the mean SE was -0.61 +/- 1.81 D, and mean astigmatism was 1.94 +/- 1.35 D for the 28 eyes with follow-up. UCVA was 20/40 or better in 12 eyes (43%), and BCVA was 20/40 or better in 24 eyes (86%) at 2 years. A gain in BCVA of 1 line or more was seen in 8 eyes (29%). Two eyes (7%) had loss of 2 or more lines of BCVA at 2 years. There were 9 eyes (16%) that developed epithelial ingrowth. Five eyes (9%) in this series had repeat corneal transplants.

CONCLUSIONS

LASIK is effective for reducing ametropia after PK. Proper patient counseling is necessary because the results of LASIK after PK are not as good as, and complications are more frequent than in eyes with naturally occurring myopia and astigmatism. Complications are especially common in patients with mismatch of the donor and host cornea or in those with poor endothelial cell function.

Effect of hinged lamellar keratotomy on post-keratoplasty astigmatism and vision

PURPOSE

To show that hinged lamellar keratotomy alone affects refraction and vision in post-keratoplasty eyes.

METHODS

A retrospective, non-comparative, interventional case series was conducted on 28 eyes of 26 patients who had two-stage laser in situ keratomileusis (LASIK) after penetrating keratoplasty. Records were reviewed with respect to the hinged lamellar keratotomy component of the procedure. The interval between keratoplasty and keratotomy was at least 1 year, and the follow-up period averaged 29 +/- 10 days. The Automated Corneal Shaper with nasal hinge was used. In addition to basic empirical astigmatism calculations, the Alpins method of astigmatism analysis was also employed to ensure that the influence of changes in cylinder axis were correctly taken into account when calculating the refractive change.

RESULTS

Surgically induced astigmatism from hinged lamellar keratotomy was not statistically significant in this series; however, the range in values (-9.06 to +7.57 D) has potential clinical ramifications. Nearly 70% of cases studied experienced surgically induced astigmatism of at least 2 D. Mean preoperative uncorrected vision was logMAR 1.06 +/- 0.41, which improved marginally postoperatively to logMAR 1.03 +/- 0.44 (P = 0.36). Best spectacle-corrected visual acuity averaged logMAR 0.21 +/- 0.16 preoperatively, improving to logMAR 0.09 +/- 0.15 (range -0.18 to 0.42) postoperatively, which was a statistically significant improvement (P < 0.01). No difference in refractive or visual outcomes was identified when those with keratoconus were compared to those with other underlying corneal disease processes.

CONCLUSION

Although mean surgically induced astigmatism was not statistically significant, hinged lamellar keratotomy caused considerable changes in astigmatism in nearly 70% of post-keratoplasty eyes studied. This suggests that clinically significant inaccuracies may result if a one-stage LASIK procedure is performed on such patients. The authors suggest that reassessment of refraction after keratotomy may improve refractive outcomes.

Five-Year Results of Laser In-Situ Keratomileusis (LASIK) After Penetrating Keratoplasty

OBJECTIVE

To study the long-term refractive results of LASIK after penetrating keratoplasty.

PLACE

Clinica Barraquer de América.

METHODS

Retrospective review of 46 eyes of 38 patients that underwent LASIK for the correction of refractive errors after penetrating keratoplasty.

RESULTS

The mean interval between keratoplasty and LASIK was 7 years. The preoperative defocus equivalent refraction (DEQ) was 2.0 to 7.0 D in 56% (26/46) of eyes and 8.0 to 24.0 D in the remaining 20 eyes. Five years after LASIK, DEQ was 1.0 to 7.0 D in all eyes. Seventy-five percent of eyes had a refractive error within 2.00 D of emmetropia. Thirty-two percent had uncorrected visual acuity of 20/40 or better, and 59% of eyes gained more than 1 line of best spectacle-corrected visual acuity at 5 years. Vector analysis showed a success index of 60% at 5 years. The refraction in eyes with keratoconus remained stable.

CONCLUSION

LASIK is safe and effective for the correction of refractive errors in eyes that have previously undergone corneal transplantation.

Laser in-situ keratomileusis after penetrating keratoplasty

Laser in situ keratomileusis (LASIK) after penetrating keratoplasty has been used more commonly for the correction of myopia or myopic astigmatism and less so for hypermetropia or hyperopic astigmatism. The primary goal after LASIK in such cases is resolution of sufficient myopia and astigmatism to allow spectacle correction of the residual refractive error and decrease anisometropia. All sutures should be removed prior to LASIK and the interval between penetrating keratoplasty and LASIK should be a minimum of 1 year. Preoperative evaluation includes refraction, slit-lamp biomicroscopy, corneal topography, and specular microscopy. The technique of LASIK surgery after penetrating keratoplasty is similar to the standard procedure. However, many variations have been described. These include maneuvers during surgery such as augmentation with arcuate cuts on the stromal bed and topographically guided LASIK. Other variations are relaxing incisions followed by LASIK surgery and sequential treatment by LASIK, that is, raising of the flap as a first stage procedure followed by ablation if required, 4 to 6 weeks later after relifting the flap in the second stage. Improvement in both uncorrected visual acuity and spectacle-corrected visual acuity, as well as a decrease in spherical equivalent, cylinder, and anisometropia, has been reported in various studies. All grafts were clear and no occurrence of wound dehiscence has been reported. Intraoperative complications include hemorrhage, microkeratome failure, flap buttonhole, dislocation, and perforation. Postoperative complications include undercorrection, decentered ablation, and regression. Re-enhancements after LASIK following keratoplasty are possible with acceptable visual outcome.

Two-stage Laser in situ Keratomileusis to Correct Refractive Errors After Penetrating Keratoplasty

PURPOSE

To evaluate the effect of a two-stage laser in situ keratomileusis (LASIK) procedure on eyes with high astigmatism and/or anisometropia after penetrating keratoplasty.

METHODS

Eleven postoperative penetrating keratoplasty eyes were included in a prospective, non-controlled study. All patients had at least 4.00 D of astigmatism and/or at least 3.00 D of anisometropia and were spectacle and contact lens intolerant. Two-stage LASIK was performed; in the first stage a hinged corneal flap 160 microm in thickness and 9 mm in diameter was created. After stabilization of corneal shape (1 to 3 months after keratotomy), the corneal flap was lifted and laser refractive treatment (second stage) was performed.

RESULTS

After the first stage, a statistically significant reduction in refractive astigmatism (P<.01) was recorded. In all eyes but one, best spectacle-corrected visual acuity was maintained or improved after the procedure. Three months after the second stage, refractive astigmatism in 8 of 11 eyes (73%) was within +/- 1.00 D, and spherical equivalent refraction in 9 of 11 eyes (82%) was within +/- 1.00 D of intended correction. Preoperative irregular astigmatism persisted in three patients (3 eyes) who could not be corrected within +/- 1.00 D of refractive astigmatism and/or +/- 1.00 D of intended spherical equivalent refraction. In one eye, an interface infiltrate developed shortly after creation of the flap, and resulted in limited melting.

CONCLUSIONS

A two-stage LASIK procedure improved visual acuity and refraction in postoperative penetrating keratoplasty eyes with high astigmatism and/or anisometropia. Complications were uncommon but can lead to loss of vision.

Laser in situ keratomileusis combined with topography-supported customized ablation after repeated penetrating keratoplasty

I report the case of a 32-year-old woman who had penetrating keratoplasty (PKP) in both eyes because of keratoconus. After PKP, a high degree of spherical myopia and irregular astigmatism prevented optical correction. The patient then had laser in situ keratomileusis (LASIK) combined with topography-supported customized ablation (TOSCA) in both eyes. The procedure resulted in a significant reduction in spherical myopia and astigmatism. A tissue-sparing algorithm was used to plan the refractive treatment. There were no intraoperative or postoperative complications, and the treated corneas maintained transparency. TOSCA-supported LASIK is a useful method for dealing with specific refractive problems after PKP.

Astigmatism and LASIK

Although laser in situ keratomileusis (LASIK) enjoys a high success rate, postoperative residual or induced astigmatism may limit uncorrected visual acuity and cause starbursts and glare at night. Irregular astigmatism can also cause loss of best-corrected visual acuity, monocular diplopia, and ghosting of images. Astigmatism may be measured by keratometry and refraction, while corneal topographic techniques help to define irregular astigmatism, in particular. Further information may be obtained regarding induced higher-order aberrations with aberrometry. Because astigmatism has both direction and magnitude, its analysis is more complex than that of the spherical component of the treatment. There are multiple approaches to the analysis of surgically induced astigmatism, including vector analysis, conversion to a Cartesian coordinate system, matrix formalism, and linear optics. Both excimer laser and incisional techniques may be used to correct astigmatism after LASIK, but the treatment of irregular astigmatism requires selective zonal ablation techniques or customized corneal ablations, using topographic or wavefront derived data.

Subclinical inflammation after laser in situ keratomileusis in corneal grafts

PURPOSE

To evaluate postoperative inflammatory reaction in the eye after laser in situ keratomileusis (LASIK) in corneal grafts.

SETTING

Department of Ophthalmology, Helsinki University Central Hospital, Helsinki, Finland.

METHODS

Ten eyes of 9 patients with penetrating keratoplasty (PKP) and significant postoperative refractive errors and astigmatism had LASIK 22 months or more after the PKP. All patients were treated with the VISX Star excimer laser and the Bausch & Lomb Hansatome microkeratome. Preoperative and early postoperative inflammation was evaluated by quantifying the aqueous flare intensity with a laser flare photometer (Kowa FM-500). A full ophthalmic assessment was also performed before LASIK and up to 6 months postoperatively.

RESULTS

The inflammatory response was mild and limited to the first postoperative hour. The mean anterior chamber flare increased from 6.0 photons/millisecond (ph/ms) preoperatively to 14.0 ph/ms at 1 hour and then decreased to 6.7 ph/ms (hour 3), 6.8 ph/ms (day 1), and 8.2 ph/ms (day 7). The mean spherical equivalent (SE) refraction decreased from -3.81 diopters (D) (range -9.63 to -0.25 D) to -0.46 D (range -1.13 to +0.38 D), and the mean preoperative astigmatism decreased from 3.0 D (range 6.5 to 0.5 D) to 0.7 D (range 0.0 to 2.0 D). At the last examination, 9 eyes were within +/-1.0 D (6 within +/-0.5 D) and all were within +/-1.5 D of the intended SE refraction. Three eyes achieved full cylinder correction, and 7 were within +/-1.0 D of the intended correction. Eight eyes had a best corrected visual acuity of 20/40 or better (unchanged or gain of 1 to 4 lines [6], loss of 1 line [1], and loss of 3 lines [1]), and 8 had an uncorrected visual acuity of 20/50 or better.

CONCLUSIONS

Uneventful LASIK induced subtle, short-lasting anterior chamber flare when measured by the laser flare meter. In corneal grafts, LASIK appeared to be a safe and effective procedure for residual refractive errors.

Effect of hinged lamellar keratotomy on postkeratoplasty eyes

PURPOSE

To evaluate the effect of a hinged lamellar keratotomy on refraction, vision, and corneal topography of postkeratoplasty eyes with high-degree astigmatism.

DESIGN

Noncomparative, interventional case series.

PARTICIPANTS

A hinged lamellar keratotomy was performed on nine eyes of nine patients at least 9 months after penetrating keratoplasty and with high-degree astigmatism. All patients were spectacle and contact lens intolerant.

INTERVENTION

A superiorly hinged lamellar keratotomy (corneal flap), 160 microm in thickness and 9 mm in diameter, was created on all eyes included in this study. Each patient was examined 1 day, 1 month, and 3 months after surgery.

MAIN OUTCOME MEASURES

Uncorrected visual acuity, best spectacle-corrected visual acuity, refraction, computerized analysis of corneal topography.

RESULTS

At each postoperative examination time, there was a significant reduction in both average spherical equivalent (P < 0.05) and average absolute value of astigmatism (P < 0.01) over mean preoperative values. The major changes were seen as early as 1 day after surgery, but both progression and regression of the effect were documented at later postoperative examinations. In all patients best spectacle-corrected acuity was maintained or improved after the procedure. Postoperatively, four patients could be successfully corrected either with spectacles (n = 2) or with gas-permeable contact lenses (n = 2). There were no surgical flap or corneal graft complications.

CONCLUSIONS

Hinged lamellar keratotomy improves vision and refraction of postkeratoplasty eyes with high-degree astigmatism. In some cases it may be so effective as to make planned excimer laser treatment unnecessary.

Laser in situ Keratomileusis in Children 8 to 15 Years Old

PURPOSE

To determine the safety, efficacy, predictability, and stability of laser in situ keratomileusis (LASIK) to correct high myopia or high myopic astigmatism in patients with high anisometropia in whom conventional treatments have failed.

METHODS

Nine eyes of nine patients, three boys and six girls with high anisometropia (>3.50 D), were included in this study. Patient age was 8 to 15 years. Minimum follow-up was 12 months. All patients were treated with the Chiron Technolas 217 excimer laser.

RESULTS

Three months after LASIK, uncorrected visual acuity improved by at least five Snellen lines in all eyes. Three eyes (33.3%) were 20/40 or better without correction. Due to dense amblyopia, no eye had uncorrected visual acuity of 20/20 or better. The mean spherical equivalent refraction decreased from -7.66 to -0.22 D, and mean preoperative astigmatism decreased from -3.11 to -0.69 D. Eight eyes (88.8%) were within +/-1.00 D of emmetropia. Two eyes (22.2%) were within +/-0.50 D of the desired outcome. All patients were able to function binocularly.

CONCLUSION

In this study of selected older children, LASIK was a safe and effective option for the correction of high anisometropia and for improved binocularity, when conventional therapies had failed. Further study is necessary to determine the long-term refractive stability in these young patients.