Facilitation of amblyopia management by laser in situ keratomileusis in high anisometropic hyperopic and myopic children

PURPOSE: To assess the efficacy of laser in situ keratomileusis (LASIK) in facilitating amblyopia management of children from 6 to 14 years old, with high hyperopic and myopic anisometropia. PATIENTS AND METHODS: Between 2000 and 2005, 42 children with high hyperopic anisometropic amblyopia and 32 children with high myopic anisometropic amblyopia underwent LASIK to reduce their anisometropia. LASIK was performed under topical or general anesthesia. Pre- and postoperative best-corrected visual acuity, cycloplegic refraction, and binocular vision were recorded. Follow-up ranged from 6 months to 3 years, the averages of which were 17.45 months in the hyperopic group and 18.31 months in myopic group. RESULTS: Hyperopic anisometropia correction ranged from +3.50 D to +7.75 D, and the mean postoperative anisometropia was +0.56 +/- 0.75 D at 3 years. Myopic anisometropia correction ranged from -15.75 to -5.00 D and the mean postoperative anisometropia at 3 years was -2.20 +/- 1.05 D. The best-corrected visual acuity for distance and reading in the myopic group improved from 0.4 +/- 0.25 and 0.58 +/- 0.27, respectively, before surgery to 0.59 +/- 0.28 and 0.96 +/- 0.35, respectively, 3 years after surgery. In the hyperopic group, best-corrected visual acuity for distance and reading improved from 0.23 +/- 0.21 and 0.34 +/- 0.32, respectively, before surgery to 0.53 +/- 0.31 and 0.80 +/- 0.33, respectively, 3 years after surgery. The proportion of patients who had stereopsis increased from 19.1% preoperatively to 46.7% postoperatively in the hyperopic group and from 19% to 89% in the myopic group. CONCLUSIONS: LASIK reduced high hyperopic and myopic anisometropia in children, thus facilitating amblyopia management and improving their visual acuity and stereopsis.     

Long-term evaluation of hyperopic laser in situ keratomileusis

PURPOSE: To evaluate the efficacy, safety, and predictability of hyperopic laser in situ keratomileusis (H-LASIK). SETTING: Departments of Ophthalmology, Hadassah University Hospital, Jerusalem, and Assaf Harofeh Medical Center, Zerifin, Israel. METHODS: This prospective noncomparative case series studied the results of H-LASIK in the first 92 consecutive eyes of 50 patients with up to +10.25 diopters (D) of hyperopia. For analysis, the patients were divided into 3 groups based on preoperative hyperopia: low hyperopia (< +3.00 D), moderate hyperopia (> or = +3.00 to 6.00 D), and high hyperopia (> or = +6.00 D). RESULTS: Forty-two patients, 77 eyes (83.7%), were followed for at least 12 months. At 12 months, the mean manifest spherical equivalent was +0.33 +/- 0.65 D (93.1% of eyes within +/-1.0 D of the intended correction) in the low myopia group, +0.21 +/- 0.60 D (92.3% within +/-1.0 D of the intended correction) in the moderate hyperopia group, and +1.62 +/- 1.50 D (36.4% within +/-1.0 D of the intended correction) in the high hyperopia group. The uncorrected visual acuity (UCVA) was 20/40 or better in all eyes (100%), 24 eyes (92.3%), and 13 eyes (59.1%) in the low, moderate, and high hyperopia groups, respectively. Comparing the UCVA at the last examination with the best corrected visual acuity (BCVA) before surgery in all patients showed that 59 eyes (76.6%) were within +/-1 line and 18 eyes (23.4%) were within +/-2 or more lines of the preoperative BCVA. Three eyes (3.9%) in the high hyperopia group lost 2 or more lines of BCVA. Three eyes (3.9%) had flap- related complications. Eight patients (15 eyes) with a follow-up less than 12 months did not have intraoperative or postoperative complications. CONCLUSION: Laser in situ keratomileusis was a safe, effective, and predictable procedure for hyperopia up to +6.0 D and less predictable for higher hyperopia.     

Reoperations after myopic laser in situ keratomileusis

PURPOSE: To evaluate the results after enhancement of myopic laser in situ keratomileusis (LASIK) using the VISX Star excimer laser. SETTING: The Buzard Eye Institute, Las Vegas, Nevada, USA. METHODS: In this prospective study, 52 eyes of 40 patients had LASIK enhancement. The existing flap was lifted and the excimer laser treatment reapplied for the residual refractive error. The VISX Star excimer laser was used for the primary LASIK and the enhancement procedure. Retreatments for undercorrection, regression, and overcorrection were performed after 6 weeks and up to 40 weeks after the primary LASIK. Follow-up was 96% at 1 month, 67% at 6 months, and 71% at 12 months. RESULTS: Mean pre-enhancement spherical equivalent was -0.77 diopters (D) +/- 0.94 (SD) and mean uncorrected visual acuity (UCVA), 20/60. One year after the enhancement, mean spherical equivalent was -0.13 +/- 0.33 D, and mean UCVA was 20/25. Refraction remained stable during the 1 year follow-up, with no treatment required. After the enhancement, all patients had a UCVA of 20/40 or better. At 1 year, 3% of patients had lost 1 line of best corrected visual acuity and 32% had gained 1 line. No epithelial ingrowth was noted. CONCLUSION: Retreatment for LASIK beginning 6 weeks after the initial procedure proved to be effective with minimal complications and good results. The technique to raise and reposition the flap appeared safe, and complications were few.     

Photopic pupillometry-guided laser in situ keratomileusis for hyperopic presbyopia

PURPOSE: To evaluate a method of surgically treating presbyopia in hyperopic patients having laser in situ keratomileusis (LASIK) by selecting excimer ablation optical zone diameters based on the photopic pupil. SETTING: Private practice, Beverly Hills, California, USA. METHODS: This prospective analysis comprised 46 patients having hyperopic LASIK for presbyopia. The distance-dominant eye was treated with a standard 6.0 mm optical and 9.0 mm outer zone for full distance correction with no nomogram adjustment from the final preoperative manifest refraction. In the nondominant eye, an algorithm was used to select the optical and blend zone diameters and the optical zone size-dependent programmed amount of correction augmentation. Variables evaluated at the 6-month postoperative visit included preoperative and postoperative manifest refractive spherical equivalent (MRSE), refractive cylinder, and monocular and binocular near and distance uncorrected visual acuities. Patient satisfaction and spectacle dependence were also evaluated. RESULTS: In the near-corrected eye, the mean preoperative and postoperative MRSE was +1.10 diopters (D) +/- 1.20 (SD) and -1.30 +/- 0.56 D, respectively, and the mean refractive cylinder, -0.76 +/- 0.91 D and -0.36 +/- 0.33 D, respectively (P<.05). The mean uncorrected near acuity in the near-corrected eye was J10 preoperatively and J1 postoperatively (P<.0001) and the binocular mean uncorrected near acuity, J10 and J1, respectively (P<.0001). The mean uncorrected logMAR distance acuity in the near-corrected eye was +0.38 +/- 0.31 (20/50) preoperatively and +0.36 +/- 0.25 (20/50) postoperatively (P>.05). The mean binocular uncorrected logMAR distance acuity was +0.30 +/- 0.30 (20/40) and +0.01 +/- 0.08 (20/20) (P<.0001), respectively. The mean overall patient satisfaction score was 8.8 (scale 1 to 10). After LASIK, no patient reported using spectacles full time for near or distance and 15% reported part-time use. CONCLUSION: Photopic pupillometry-guided LASIK may be an effective option when considering surgical treatment of presbyopia in hyperopic patients.     

Corneal irregular astigmatism after hyperopic laser in situ keratomileusis

PURPOSE: To evaluate the changes in irregular astigmatism after hyperopic laser in situ keratomileusis (LASIK). METHODS: In a prospective case series, 15 eyes of 12 patients who had hyperopic LASIK were evaluated. Corneal topography was obtained before and after hyperopic LASIK. Corneal irregular astigmatism (asymmetry and higher-order irregularity) was calculated using Fourier harmonic analysis of the topography data. RESULTS: Hyperopic LASIK significantly increased the asymmetry component at 3 (P = 0.0085) and 6 months (P = 0.0307) postoperatively. The mean higher-order irregularity was not significantly changed at any postoperative time-point (P = 0.222). The achieved change in the spherical equivalent was significantly correlated with the post/preoperative ratio of asymmetry (R = 0.695, P = 0.0030). CONCLUSION: Hyperopic LASIK significantly increases the asymmetry component of the cornea, which is correlated with the achieved change in the spherical equivalent.     

Acute angle-closure glaucoma after hyperopic laser in situ keratomileusis

We report a case of acute angle-closure glaucoma 1 year after hyperopic laser in situ keratomileusis (LASIK). The glaucoma was resolved with laser iridotomy, and a prophylactic iridotomy was performed in the fellow eye. Corneal topography was performed 2, 5, and 18 weeks after the acute episode. A myopic shift occurred after the episode and resolved within 3 months. Hyperopic patients with narrow angles are at risk for angle closure and should be carefully monitored.     

Pseudo-Fleischer ring after hyperopic laser in situ keratomileusis.

A 37-year-old woman had bilateral hyperopic laser in situ keratomileusis (LASIK). Six months postoperatively, an epithelial pigmentation ring pattern was identified on both corneas. The appearance of the ring pattern was similar to the iron deposits of the Fleischer ring of keratoconus. While corneal iron deposits in various patterns have been reported after other forms of ocular therapeutic and refractive surgery, this is the first report of the association between hyperopic LASIK and a corneal iron line, which we have called the "pseudo-Fleischer ring."     

单眼行LASIK或LASEK术后疗效观察

目的:探讨单眼行准分子激光原位角膜磨镶术(laserin situkeratomileusis,LASIK)或准分子激光上皮下角膜磨镶术(laser epithelial keratomileusis,LASEK)治疗单眼近视所致屈光参差的效果。方法:采用对单眼等效球镜度>-2.50D的近视性屈光参差患者62例,进行单眼LASIK或LASEK手术。术眼及非术眼手术前后平均屈光度、屈光参差度数、最佳矫正视力和裸眼视力进行评价,术后随访6~24mo。结果:术眼术前平均等值球镜度数为-3.66(-2.50~-6.25)D,术后减少至-0.62(0.00~-1.00)D。LASIK或LASEK对平均等值球镜改变为-3.38(-2.50~-5.50)D。术前两眼平均屈光参差为-3.25(-2.50~-6.25)D,术后减少至-0.85(0.00~-1.75)D。术前术后最佳矫正视力(BCVA)范围均为0.6~1.0,平均最佳矫正视力从术前0.8提高到1.04;术后裸眼视力≥1.0者59眼,平均裸眼视力从术前的0.1提高至术后的1.0。非术眼术前平均等值球镜度数为-0.85(+0.25~-1.50)D,术后平均等值球镜度数为-1.85(-0.50~-3.50)D,平均裸眼视力从术前的0.5术后下降至0.1。结论:单眼LASIK或LASEK治疗近视性屈光参差虽然能提高患眼的最佳矫正视力和裸眼视力,解除单眼近视、散光所致的屈光参差对眼镜或角膜接触镜不能耐受的痛苦,而且对恢复双眼单视功能具有积极意义,但是同时我们也发现术后非术眼有近视加深的趋势,而且非术眼原近视度数越高近视加深越快越多。     

Valsalva-like retinopathy following hyperopic laser in situ keratomileusis.

A 50-year-old woman presented with unilateral acute loss of vision 15 hours after undergoing bilateral hyperopic laser in situ keratomileusis (LASIK). She denied "straining." Fluorescein angiography showed no retinal vascular abnormalities but demonstrated blocked fluorescence corresponding with subhyaloid, intraretinal, and subretinal hemorrhages seen clinically in the left eye. YAG laser vitreolysis was performed after noting posterior cortical vitreous thickening with a loculated subhyaloid hemorrhage. Best spectacle-corrected visual acuity was restored to 20/20 by the 2-month follow-up examination. Valsalva-like retinopathy, possibly the result of the rapid rise and fall of intraocular pressure during the microkeratome and suction ring operation, may occur following hyperopic LASIK surgery.     

Streptococcal keratitis after myopic laser in situ keratomileusis

A 24-year-old healthy male underwent uncomplicated laser in situ keratomileusis (LASIK) in left eye. One day after the surgery, he complained of ocular pain and multiple corneal stromal infiltrates had developed in left eye. Immediately, the corneal interface and stromal bed were cleared, and maximal antibiotic treatments with fortified tobramycin (1.2%) and cefazolin (5%) were given topically. The causative organism was identified as 'Streptococcus viridans' both on smear and culture. Two days after antibiotic therapy was initiated, the ocular inflammation and corneal infiltrates had regressed and ocular pain was relieved. One month later, the patient's best corrected visual acuity had returned to 20/20 with -0.75 -1.00 x 10 degrees, however minimal stromal scarring still remained. This case demonstrates that microbial keratitis after LASIK, if treated promptly, does not lead to a permanent reduction in visual acuity.     

单眼LASIK矫正近视性屈光参差疗效分析

目的探讨单眼准分子激光原位角膜磨镶术（LASIK）治疗单眼近视所致屈光参差的效果。方法采用对单跟等效球镜度-2．50D以上的近视性屈光参差42例，进行单眼LASIK手术前后平均屈光度、屈光参差度数、最佳矫正视力和裸眼视力进行评价，术后随访6～12月。结果术前平均等值球镜度数为-4．66D（-2．50D--9．25D），术后减少至-0．62D（0～-1．70D），LASIK对平均等值球镜改变为-4．38D（-2．00D～-8．00D）。术前两眼平均屈光参差为-5．23D（-2．5D～-9．25D），术后减少至-0．50D（0～-1．25D）。术前术后BCVA（最佳矫正视力）范围均为0．6～1．0，平均最佳矫正视力从术前1．0提高到1．04；术后裸眼视力≥1．0者39跟，平均裸跟视力从术前的0．13术后提高至1．0。结论单眼LASIK治疗近视性届光参差不仅能提高患眼的最佳矫正视力和裸眼视力，解除单眼近视、散光所致的屈光参差对眼镜或角膜接触镜不能耐受的痛苦，而且对恢复双眼单视功能具有积极意义。     

Posterior corneal surface changes after hyperopic laser in situ keratomileusis

PURPOSE: To evaluate posterior corneal surface topographic changes after hyperopic laser in situ keratomileusis (H-LASIK) using Orbscan I (Orbtek, Inc.). SETTING: Department of Ophthalmology, Nara Medical University, Nara, Japan. METHODS: In 25 eyes of 15 patients who had H-LASIK, the posterior corneal surface was measured with slit-scanning corneal topography (Orbscan I) preoperatively and 1 year postoperatively. The center as a fit zone and calculated posterior corneal surface changes were taken at 4 points: nasal, temporal, superior, and inferior sides in the 5.0 mm diameter. The posterior corneal topographic changes were analyzed using an analysis of variance. The postoperative:preoperative magnification ratio of the posterior corneal surface was calculated in a theoretical eye model. RESULTS: When a "+" reading was defined as the forward displacement and "-" was defined as the backward displacement, the mean posterior corneal topographic changes were -2.8 microm +/- 27.9 (SD) at the nasal side, -4.5 +/- 27.8 microm at the temporal side, -3.9 +/- 20.1 microm at the superior side, and -2.3 +/- 20.1 microm at the inferior side. The posterior corneal surface between any 2 examined points showed no significant difference after H-LASIK. In addition, the hypothetical change in the posterior cornea was -8.3 microm after +3.0 diopter H-LASIK, which was approximately closer to the study results. In each side, the amount of the attempted correction was significantly correlated with the posterior corneal topographic change. CONCLUSIONS: Clinical measurement of the posterior corneal displacement after H-LASIK with Orbscan revealed a backward shift. This change corresponded to the hypothetical artifactual changes with Orbscan; that is, changes in the magnification ratio.     

Factors that influence outcomes of hyperopic laser in situ keratomileusis

PURPOSE: To analyze the influence of preoperative corneal curvature, postoperative keratometric power, and the amount of correction on the outcomes of hyperopic laser in situ keratomileusis (LASIK). SETTING: Clínica Baviera, Instituto Oftalmológico Europeo, Madrid, Spain. METHODS: In this retrospective study, the records of 376 eyes that had LASIK for hyperopia using the Moria LSK-One microkeratome and the Technolas-Keracor 217C excimer laser were reviewed. The results were analyzed by preoperative hyperopia (5 subgroups) and by preoperative (more than and less than 43.0 diopters [D]) and postoperative (more than and less than 48.0 D) mean keratometry. RESULTS: A statistically significant keratometry regression was found in the +3.00 to +3.90 D range (P <.01), a significant decrease in predictability in the +4.00 to +4.90 D range (P <.05), and a significant worsening in safety in the highest range (+6.00 to +7.90 D; P <.05). Comparative analysis of the > or = +4.00 D and <+4.00 D groups showed statistically significant differences in most measurement parameters. The preoperative keratometry did not influence postoperative results with the exception of poorer predictability in the group of preoperative flat corneas in which a high degree of hyperopia was corrected; ie, spherical equivalents within +/-0.50 D were found in 40.4% and 61.0% of cases with flat and steep corneas, respectively (P <.05). The efficacy and safety in eyes that achieved a postoperative keratometry >48.00 D did not differ significantly from the efficacy and safety in eyes that had a lower final keratometric power. CONCLUSIONS: The factor that negatively influenced the outcome of hyperopic LASIK was the degree of hyperopia corrected. Preoperative keratometry did not significantly influence the postoperative results, and postoperative keratometry >48 D did not result in significant worsening of visual results when the attempted correction was less than +4.00 D.