Long-term results of laser in situ keratomileusis for high myopia

Eleven-year follow-up of laser in situ keratomileusis

PURPOSE

To report the long-term (11-year) outcomes (stability and complications) of laser in situ keratomileusis (LASIK) in patients with high myopia.

SETTING

University refractive surgery center.

METHODS

Seven patients (4 with bilateral treatment and 3 with unilateral treatment) who had myopic LASIK and completed 11 years of follow-up were included in the study.

RESULTS

The mean age of the 2 men and 5 women was 41.7 years +/- 6.5 (SD) (range 34 to 50 years). The mean follow-up was 140.18 +/- 6.70 months (range 132 to 150 months). At 11 years, the spherical equivalent error was statistically significantly reduced, from a mean of -12.96 +/- 3.17 diopters (D) (range -19.00 to -10.00 D) before LASIK to a mean of -1.14 +/- 1.67 D (range -4.25 to 1.00 D) after (P<.001). Predictability of postoperative refraction 6 months and 11 years after LASIK showed that 6 eyes (55%) were within +/-1.00 D of intended correction. No late postoperative complications occurred. Five patients (8 eyes, 73%) were satisfied with the final outcome.

CONCLUSIONS

Laser in situ keratomileusis was moderately predictable in the correction of high degrees of myopia. After the sixth postoperative month, refractive and topographic stability were obtained. No long-term sight-threatening complications occurred during the follow-up period.

Implantation of Verisyse Phakic Intraocular Lens to Correct Myopic Refractive Error After Penetrating Keratoplasty in Pseudophakic Eyes

PURPOSE

We report 2 cases in which a Verisyse phakic intraocular lens (PIOL) was used to successfully treat high myopia after penetrating keratoplasty (PK) in pseudophakic patients.

METHODS

Case 1 involved a 69-year-old pseudophakic man with a manifest refraction (MR) of -6.50 + 1.75 x 048 and a best spectacle corrected visual acuity (BSCVA) of 20/40 approximately 16 months after PK in the right eye. Case 2 was a 78-year-old pseudophakic man who had an MR of -9.00 + 5.75 x 132 with a BSCVA of 20/100 approximately 24 months after PK in the left eye.

RESULTS

In case 1, 10 months after Verisyse PIOL implantation, the MR was pl +2.00 x 135 with a BSCVA of 20/30. Endothelial cell density (ECD) in this patient decreased from 1926.1 to 815.3 cells/mm over 17 months. In case 2, 24 months after Verisyse PIOL implantation, the MR was -3.25 + 3.50 x 105 with a BSCVA of 20/60. ECD in this patient decreased from 2108.4 to 753.8 cells/mm in 30 months.

CONCLUSION

The Verisyse PIOL may provide an alternative method to correct high myopia for anisometropia in pseudophakic patients after PK. In this report, PIOL implantation was associated with a decrease in ECD. Further studies are required to determine the long-term effects and ultimate safety of PIOL placement on the integrity of the cornea endothelium after corneal transplant in pseudophakic patients.

Laser in situ keratomileusis for different degrees of myopia

PURPOSE

To determine the efficacy, predictability, stability and safety of laser in situ keratomileusis (LASIK) in treating patients with different degrees of myopia.

METHODS

We enrolled 386 eyes of 200 consecutive patients who underwent LASIK and divided them into four groups according to their degree of preoperative spherical equivalent (SE). Group 1 eyes ranged between - 1.00 and - 3.99 dioptres (D) (low myopia). Group 2 eyes ranged between - 4.00 and - 5.99 D (moderate myopia). Group 3 eyes ranged between - 6.00 and - 9.99 D (high myopia). Group 4 eyes were over - 9.99 D (extreme myopia). Follow-up was at 1 day, 1 week and 1, 3, 6, 12 and 18 months postoperatively.

RESULTS

Our study included 386 eyes of 200 patients with SE ranging from - 3.00 to - 16.00 D (mean - 7.14 +/- 2.87 D). All eyes were seen at 1 day postoperatively. A total of 360 eyes (93%) were examined at 1 week, 330 eyes (85%) at 1 month, 281 eyes (73%) at 3 months, 247 eyes (64%) at 6 months, 199 eyes (52%) at 12 months and 142 eyes (37%) at 18 months. The postoperative data from 1 day to 12 months were used because of the low follow-up rate at 18 months postoperatively. Group 1 consisted of 30 eyes. The mean SE was - 3.52 +/- 0.43 D preoperatively and - 0.40 +/- 0.58 D at 1 month, - 0.46 +/- 0.60 D at 6 months and - 0.42 +/- 0.50 D at 12 months postoperatively. Uncorrected visual acuity (UCVA) was 20/40 or better in 95% of eyes at 1 day and in 100% of eyes at 6 and 12 months postoperatively. Group 2 consisted of 151 eyes. The mean SE was - 5.36 +/- 0.67 D preoperatively and - 0.54 +/- 0.78 D at 1 month, - 0.56 +/- 0.90 D at 6 months and - 0.55 +/- 0.82 D at 12 months postoperatively. Uncorrected VA was 20/40 or better in 95% of eyes at 1 day and in 100% of eyes at 6 and 12 months postoperatively. Group 3 consisted of 167 eyes. The mean SE was - 8.15 +/- 0.94 D preoperatively and - 0.58 +/- 0.90 D at 1 month, - 0.67 +/- 1.00 D at 6 months and - 0.64 +/- 0.95 D at 12 months postoperatively. Uncorrected VA was 20/40 or better in 90% of eyes at 1 day and in 98% of eyes at 6 and 12 months postoperatively. Group 4 consisted of 38 eyes. The mean SE was - 11.09 +/- 1.10 D preoperatively and - 1.25 +/- 1.20 D at 1 month, - 1.13 +/- 1.30 D at 6 months and - 1.20 +/- 1.25 D at 12 months postoperatively. Uncorrected VA was 20/40 or better in 78% of eyes at 1 day, in 94% at 6 months and in 90% at 12 months postoperatively. Intraoperative complications (free cap) occurred in two eyes and postoperative complications were observed in three eyes, making the total complications rate 1.29% (5/386). Seven eyes lost one Snellen line of BCVA, five lost two lines and two lost more than two lines (total: 3.64%, 14/386).

CONCLUSION

In conclusion, LASIK is effective, predictable and safe for correcting myopia but is more accurate for correcting myopia up to -10.00 D. With more improvement in algorithms and ablation profile, we believe that LASIK can offer better results for higher myopia.

5-year follow-up of LASIK for hyperopia

PURPOSE

To assess the long-term efficacy and stability of LASIK for hyperopia (+0.75 to +7.00 diopters [D]).

DESIGN

Retrospective follow-up study of a previous phase III multicenter clinical trial (unpublished data).

PARTICIPANTS

Patients who had been treated for hyperopia (33 individuals, 47 eyes) attended follow-up 5 years after surgery. The preoperative mean spherical equivalent at the spectacle plane was +3.58 D (range, +0.75 to 7.00 D), and the attempted mean spherical correction at the corneal plane was +3.18 D (range, +1.00 to +6.00 D).

INTERVENTION

Treatments were performed using a Moria LSK One microkeratome and a Summit Technology SVS Apex Plus excimer laser fitted with an Axicon.

MAIN OUTCOME MEASURES

Manifest refraction, uncorrected visual acuity, best spectacle-corrected visual acuity, corneal transparency, complications, and patient satisfaction were recorded.

RESULTS

At 5 years, for treatments between +1.00 to +3.00 D, 71.0% of eyes were within +/-1.00 D of the intended correction, and for treatments between +3.5 to +6.0 D, 37.5% of eyes were within +/-1.00 D of intended correction. From 12 to 54 months after surgery for all patients, there was a hyperopic shift of +0.53 D (range, -0.13 to +3.13 D), with 51.1% of eyes experiencing an increase of +0.50 D or more and 27.7% of eyes showing a hyperopic shift of more than +1.00 D. This hyperopic shift was +0.67 D (range, 0 to +1.125 D) for patients younger than 40 years of age and +0.44 D (range, -1.33 to +1.50 D) for patients between 43 and 55 years of age.

CONCLUSIONS

LASIK was moderately effective for the correction of low degrees of hyperopia. However, there was regression throughout the 5-year follow-up that was greater than would be expected as a result of aging. Long-term stability of hyperopic LASIK refractive corrections, therefore, is uncertain.

Combined ICRS insertion and LASIK to maximize postoperative residual bed thickness in high myopia

PURPOSE

To describe a new technique and early outcomes of combined intrastromal corneal ring segment (ICRS) insertion and laser in situ keratomileusis (LASIK) to treat patients with moderate to high myopia and thin corneas.

SETTING

University-based academic practice, Boston, Massachusetts, USA.

METHODS

Combined ICRS insertion and LASIK was performed in 2 stages: ICRS channel formation (stage I) followed by LASIK and ICRS insertion (stage II).

RESULTS

Fifteen eyes of 11 patients with a mean preoperative spherical equivalent of -9.98 diopters (D) +/- 2.60 (SD) (range -7.13 to -16.25 D) and mean preoperative astigmatism of 1.11 +/- 0.75 D (range 0.00 to -3.00 D) were treated with combined ICRS insertion and LASIK. The mean central pachymetry was 526.13 +/- 35.69 microm (472 to 579 microm). The uncorrected visual acuity was 20/40 or better in 7 of 15 eyes (46.67%) at 1 month, 6 of 12 eyes (50.00%) at 3 months, 5 of 12 eyes (41.67%) at 6 months, and 6 of 12 eyes (50.00%) at 12 months. The best spectacle-corrected visual acuity was 20/40 or better at all times. Postoperative maps confirmed the absence of ectasia. The postoperative spherical equivalent was within +/-1.00 D of the intended refraction in 11 of 15 eyes (73.33%) at 1 month, 9 of 12 eyes at 3 and 6 months, and 8 of 12 eyes (66.67%) at 12 months.

CONCLUSIONS

Results of combined ICRS insertion and LASIK in moderately to highly myopic patients with relatively thin corneas were good. Long-term studies are needed to determine whether this procedure will decrease the risk of LASIK-induced keratectasia in these patients.

A long-term study of photorefractive keratectomy; 12-year follow-up

OBJECTIVE

To evaluate long-term refractive stability of excimer laser myopic photorefractive keratectomy (PRK).

DESIGN

A long-term (12 years) prospective follow-up study.

PARTICIPANTS

Sixty-eight patients (56.6%) of the original cohort of 120 who participated in the first United Kingdom excimer laser clinical trial underwent detailed clinical assessment at 12 years after myopic PRK.

INTERVENTION

Myopic PRK was performed using the Summit Technology UV 200 excimer laser with a 4-mm ablation zone. Patients were allocated to 1 of 6 treatment groups based on their preoperative refraction. Each group received one of the following spherical corrections: -2, -3, -4, -5, -6, or -7 diopters (D). Patients in each group received an identical treatment, and therefore, emmetropia was not the primary aim.

MAIN OUTCOME MEASURES

Refractive stability, refractive predictability, best spectacle-corrected visual acuity (BSCVA), and corneal haze.

RESULTS

The postoperative refraction remained stable at 12 years, with no significant change in mean spherical equivalent refraction between 1, 6, and 12 years. Seventy-five percent of patients who underwent a -2-D correction and 65% of patients who received a -3-D correction were within 1 D of intended correction at 12 years. Fifty-seven percent of the -4-D group and 50% of the -5-D group were within 1 D, and this was further reduced to 25% and 22% in the -6-D and -7-D groups, respectively. Four percent had residual corneal haze, and 12% had persistent nighttime halos at 12 years. Dry eyes were encountered in 3% of patients, and none of the eyes developed corneal ectasia in the long term.

CONCLUSIONS

In myopic PRK, refractive stability achieved at 1 year was maintained up to 12 years with no evidence of hyperopic shift, diurnal fluctuation, or late regression in the long term. Corneal haze decreased with time, with complete recovery of BSCVA. Night halos remained a significant problem in a subset of patients due to the small ablation zone size.

Actual and theoretical risks for visual loss following use of the implantable contact lens for moderate to high myopia

PURPOSE

To estimate the actual and theoretical risks for visual loss associated with use of the implantable contact lens (ICL).

SETTING

Multicenter clinical trial data.

METHODS

An established model for estimating the risk for visual loss associated with retinal detachment (RD) following clear lens extraction (CLE) was modified to be applicable to the ICL. The risk for developing RD and the outcomes of RD surgery based on current lens extraction and RD repair techniques were updated. Non-RD-related risks for pseudophakia based on United States Food and Drug Administration (FDA) guidelines, actual visual loss data from the FDA ICL study, and calculated risks assuming a large future risk (10 times the current risk) of cataract development were also added.

RESULTS

The additional risk for visual loss due to cataract surgery is estimated at 0.19% and for subsequent RD assuming 10 times the current rate of cataract is 0.37%. Using an ultraconservative (high) model and adding the actual loss observed with the ICL, the total risk is 1.39%. The risk increases by 0.5% to 0.6% with each 10% increase in cataract incidence (eg, 10% to 20%, 20% to 30%). The risk for visual loss with CLE and/or laser in situ keratomileusis/photorefractive keratectomy in the same range of myopia is possibly 3.0% to 6.5%.

CONCLUSIONS

The ICL represents a viable alternative to currently available refractive procedures based on an analysis of the risk for visual loss.

Six-year follow-up of laser in situ keratomileusis for moderate and extreme myopia using a first-generation excimer laser and microkeratome

PURPOSE

To evaluate objectively and subjectively the long-term outcome of laser in situ keratomileusis (LASIK) in patients with high and very high myopia.

SETTING

Department of Ophthalmology, Philipps University, Marburg, Germany.

METHODS

Thirty-three eyes of 19 patients were followed for a mean of 76 months (range 50 to 84 months) after primary LASIK using the Keratom I excimer laser (Schwind) and the ALK microkeratome (Chiron). Refraction, glare, pachymetry, corneal topography, and tear-film secretion and stability were measured. At the last examination, patients also answered a 14-item questionnaire.

RESULTS

Preoperatively, the mean spherical equivalent was -13.65 diopters (D). At 1 year, it was -0.25 D and after 6 years, -0.88 D. Fifteen percent of eyes lost > or =2 lines of best spectacle-corrected visual acuity (BSCVA), and 9% gained > or =2 Snellen lines. At the end of the study, 46% of eyes were within +/-1.0 D of the attempted corrected and 88% were within +/-3.0 D. There were 5 microkeratome-associated complications; 3 resulted in loss of BSCVA. The latest pachymetry showed a mean corneal thickness of 498.5 microm (range 396 to 552 microm). There were no cases of keratectasia. Seventy-five percent of patients noted an increase in their quality of life. Seventy-one percent were satisfied with their postoperative visual acuity; however, 75% noticed glare and halos at night.

CONCLUSIONS

Laser in situ keratomileusis correction of very high myopia did not cause keratectasia in the long term provided the corneal thickness was respected. A flap thickness setting of 130 microm with a first-generation microkeratome resulted in a high number of cut failures. Most patients were happy with the results despite a modest level of accuracy and glare.

Tracker-assisted laser in situ keratomileusis for myopia using the autonomous scanning and tracking laser: 12-month results

OBJECTIVE

To determine the safety, efficacy, and predictability of the Autonomous scanning and tracking laser for the correction of myopia and myopic astigmatism with laser in situ keratomileusis (LASIK) procedure.

DESIGN

Retrospective, noncomparative case series.

PARTICIPANTS

The first 129 consecutive eyes with up to -13.00 diopters (D) of myopia and -5.00 D of astigmatism.

INTERVENTION

Myopic tracker-assisted LASIK (T-LASIK) using the Autonomous Laser (Alcon Summit Autonomous, Waltham, MA) and Hansatome microkeratome (Bausch & Lomb Surgical, Bracknell, England).

MAIN OUTCOME MEASURES

Uncorrected visual acuity (UCVA), manifest spherical equivalent (MSE), best spectacle-corrected visual acuity (BSCVA), and complications were studied.

RESULTS

At 12 months, the mean MSE was -0.02 +/- 1.01 D, with 79.1% of eyes within 0.5 D and 89.9% of eyes within 1 D of the intended correction. UCVA was 20/20 or better in 71.4%, 20/25 or better in 78.5%, and 20/40 or better in 92.8% of eyes. Two eyes (1.6%) lost 2 lines and five eyes (3.8%) gained 2 lines of BSCVA. Sixteen eyes (12.4%) required retreatment to correct residual myopia or astigmatism. After retreatment, 14 of 16 eyes were within 0.5 D of emmetropia. Nine eyes (6.9%) had minor flap complications; two eyes (1.6%) had grade 2 diffuse lamellar keratitis, of which one eye had associated peripheral flap melt. One eye showed slight decentration; this eye was rolling throughout the procedure. All eyes had some dryness, with 10% severe enough to require temporary punctual occlusion with plugs.

CONCLUSIONS

T-LASIK for myopic astigmatism with the Autonomous Laser is relatively safe, effective, and predictable. The tracker seems to be effective, and the complications are relatively few. Retreatment rates are acceptable and can be performed safely and effectively to improve visual outcome. The outcomes are comparable with other published data.