Hyperopic Laser In Situ Keratomileusis Research Articles

Hyperopic LASIK and postoperative corneal steepness: revisiting the 49-diopter limit.

To compare corrected distance visual acuity (CDVA) outcomes of hyperopic laser in situ keratomileusis (LASIK) with a postoperative corneal steepness above vs below 49 diopters (D). Care-Vision Laser Centers, Tel-Aviv, Israel. Retrospective study. This study included consecutive patients who underwent hyperopic LASIK between January 2013 and December 2019. Hyperopic patients were divided into 2 groups based on postoperative corneal steepness with steep corneas defined >49.0 D and the control group ≤49.0 D. Adjustments were performed to account for differences in baseline and intraoperative parameters. Overall, 1703 eyes of 1703 patients were included. Mean age was 48.3 ± 10.0 years, and 45.3% were male. Preoperatively, the steep group (2.4%, n = 41/1703) had steeper mean (44.6 D vs 43.1 D, P < .001) and steep (45.1 D vs 43.5 D, P < .001) keratometry, worse logMAR CDVA (0.07 vs 0.04, P = .02), and higher sphere (4.9 D vs 2.9 D, P < .001). Intraoperatively, they had a higher spherical treatment (4.6 D vs 2.8 D, P < .001). After hyperopic LASIK, the steep group had worse logMAR CDVA (0.10 vs 0.06, P = .01). However, after accounting for differences in baseline and spherical treatment, no significant differences were found in postoperative logMAR CDVA (0.06 vs 0.06, P = .99). The factors that remained associated with worse postoperative CDVA were higher spherical treatment (0.01 logMAR per 1 D, P < .001) and preoperative CDVA (0.60 logMAR per 1.00 logMAR, P < .001). Postoperative corneal steepness greater than 49 D is not associated with worse visual outcomes after hyperopic LASIK. However, lower preoperative visual potential and higher spherical treatment applied are associated with worse outcomes. The 49 D cutoff should be revisited.

Factors Predicting Slow Visual Recovery Following Hyperopic LASIK.

To identify factors predicting slow visual recovery following hyperopic laser in situ keratomileusis (LASIK). The study included consecutive patients who underwent hyperopic LASIK between January 2005 and December 2019 at a single medical center. Patients were divided into two groups according to whether they experienced normal recovery of visual acuity (1-week visit) or slow visual recovery (1-month visit). Visual recovery was defined as achieving an efficacy index of 0.9 or greater. Efficacy index was calculated as postoperative uncorrected distance visual acuity / preoperative corrected distance visual acuity. A comparison of baseline and intraoperative parameters was performed. Binary logistic regression was performed to identify potential predictors of slow visual recovery. Overall, 861 eyes of 861 patients were included. Mean age was 48.0 ± 9.5 years and 55.9% were women. Two hundred forty-nine patients (28.9%) experienced slow visual recovery. Younger age (P = .01), a larger preoperative spherical equivalence (P = .002), and greater maximum ablation depth (P = .002) were predictors of slow visual recovery. In binary logistic regression, female gender (P = .036) and greater spherical equivalence (P = .007) remained significant predictors of slow visual recovery. Female gender and greater preoperative spherical equivalence were associated with slow visual recovery. Patients may be advised accordingly. [J Refract Surg. 2024;40(1):e42-e47.].

Transient Light Sensitivity Syndrome (TLSS) Incidence Following Femtosecond LASIK for Myopic and Hyperopic Eyes and Femtosecond SMILE for Myopic Eyes.

To evaluate and compare the incidence of transient light sensitivity syndrome (TLSS) after myopic laser in situ keratomileusis (LASIK), hyperopic LASIK, and myopic small incision lenticule extraction (SMILE). A retrospective analysis was performed of consecutive LASIK and myopic SMILE cases, performed with the VisuMax femtosecond laser and MEL 80 or MEL 90 excimer laser (both Carl Zeiss Meditec AG) between January 2010 and February 2021 at London Vision Clinic, London, United Kingdom. A chart review was performed to find cases of clinically significant TLSS, identified as patients prescribed anti-inflammatory medications between 2 weeks and 6 months after surgery to manage photophobia. The incidence of TLSS was calculated for three groups: myopic SMILE, myopic LASIK, and hyperopic LASIK. The incidence of TLSS was then calculated for three subgroups within each treatment type based on spherical equivalent refraction treated. For myopic SMILE and myopic LASIK, it was 0.00 to -4.00 diopters (D) (low), -4.01 to -8.00 D (moderate), and -8.01 to -14.00 D (high). For hyperopic LASIK, it was 0.00 to +2.00 D (low), +2.01 to +4.00 D (moderate), and +4.01 to +6.50 D (high). The range of treatment for myopia was similar between the LASIK and SMILE groups. The incidence of TLSS was 1.2% for the myopic SMILE group, 5.3% for the myopic LASIK group, and 9.0% for the hyperopic LASIK group. The difference was statistically significant between all groups (P < .001). For myopic SMILE, the incidence of TLSS was independent of spherical equivalent refraction for low (1.4%), moderate (1.0%), and high (1.1%) myopia (P > .05). Similarly, for hyperopic LASIK, the incidence was similar for low (9.4%), moderate (8.7%), and high (8.7%) hyperopia (P > .05). In contrast, for myopic LASIK, the incidence of TLSS was "dose-dependent" on refractive error treated, with an incidence of 4.7% for low, 5.8% for moderate, and 8.1% for high myopia (P < .001). The incidence of TLSS was higher after myopic LASIK than after myopic SMILE, higher after hyperopic than myopic LASIK, and "dose-dependent" for myopic LASIK but did not vary by correction in myopic SMILE. This is the first report describing the phenomenon of late TLSS occurring between 8 weeks and 6 months after surgery, [J Refract Surg. 2023:39(6):366-373.].

The Importance of Using Corneal Imaging to Determine Ablation Pattern for IOL Calculations After LASIK

PURPOSE: To report a case where inaccurate intraocular lens (IOL) calculations after laser in situ keratomileusis (LASIK) occurred due to misleading historical treatment data combined with suboptimal corneal imaging prior to cataract surgery. METHODS: Case report. RESULTS: A 70-year-old woman presented elsewhere for cataract surgery. She had a history of prior myopic LASIK in both eyes with subsequent hyperopic enhancement performed in the right eye to improve near acuity. The patient had her preoperative records, which indicated that prior to LASIK her refractive error was approximately −3.75 and −4.75 diopters (D) in the right and left eyes, respectively. Based on these records, the surgeon used the American Society of Cataract and Refractive Surgeons Post-Keratorefractive Intraocular Lens Power Calculator for eyes with prior myopic LASIK for a target of −1.75 D in the right eye. Postoperatively, the patient complained of blurred vision in the right eye. Manifest refraction was −3.75 D and the patient was referred for refractive management. Review of additional corneal imaging, including Placido and Scheimpflug tangential curvature maps, showed the presence of a hyperopic treatment pattern in the right eye. IOL exchange using IOL power calculations based on prior hyperopic LASIK yielded the appropriate refractive outcome. CONCLUSIONS: This case highlights the importance of using corneal imaging rather than patient history to determine the ultimate treatment pattern induced after prior corneal refractive surgery. Tangential curvature maps are particularly useful to determine the prior ablation performed and reduce IOL calculation errors in patients with a history of corneal refractive surgery. [ Journal of Refractive Surgery Case Reports. 2022;2(1):e22–e25.]

Case Report: Serial Topography Analysis After Acute Unilateral Diffuse Lamellar Keratitis

Abstract&#x0D; Significance: Diffuse lamellar keratitis (DLK) is a widely reported complication of laser in-situ keratomileusis (LASIK); however, serial topography tracking the resolution of the condition is sparse. This case illustrates the healing profile which may be expected following an episode of DLK, and the patient reassurances which may be appropriate.&#x0D; Purpose: To report the topography changes and refractive resolution associated with a case of acute unilateral diffuse lamellar keratitis following bilateral femtosecond-assisted hyperopic LASIK.&#x0D; Case Report: A healthy 53-year old male presented with grade two-plus diffuse lamellar keratitis (DLK) 11 days after undergoing successful bilateral wavefront optimized (Alcon, Fort Worth, USA), femtosecond-assisted hyperopic LASIK. Resolution of the DLK was achieved in three weeks with topical corticosteroids. Stabilization of the patient’s topography and refractive error was observed two months after the resolution of the DLK.&#x0D; Conclusions: This case suggests that improvements in corneal topography and refractive error can be expected long after the clinical signs of DLK have subsided. Corneal irregularities and residual refractive errors (usually hyperopia and astigmatism) which exist at the time of resolution on gross examination should be monitored regularly and patients may be reassured that improvements appear likely even after topical regimens have been completed.

The relationship between patient age and residual refractive error after uneventful laser in situ keratomileusis for moderate-to-high hyperopia.

To determine if the manifest sphero-cylindrical residual refractive error, at various time points over a 12-month postop period after laser in situ keratomileusis (LASIK) was associated with patient age at time of surgery. Patients with moderate to high hyperopia (3.00-7.00 DS) and astigmatism ⩽2 DC underwent LASIK using Wavelight Allegretto Eye Q (400 Hz). Treatments were centered on corneal vertex, flaps were made with Moria M2 mechanical microkeratome. Pre-and postoperative uncorrected and corrected distant visual acuity, best corrected spherical equivalent (SEQ) were measured. Measurements were taken at 1 week, 1, 3, 6, and 12 months after the surgery. Target refraction was emmetropia. Total of 161 patients were treated. In binocular cases, data from the right eyes were included for analysis. In this article, we report on refraction data only. Raw data were subjected to several permutations to elicit any links between refractive outcomes and patient age. The key findings were as follows y = postop SEQ (diopters), x = patient age (years), ln(x) = natural logarithm of patient age: At 1 month, y = x[0.049 -0.011.ln(x)] (R = -0.205, p = 0.001, n = 161). At 3 months, y = x[0.077 -0.017.ln(x)] (R = -0.355, p < 0.001, n = 161). At 6 months, y = x[0.088 -0.020.ln(x)] (R = -0.382, p < 0.001, n = 161). At 12 months, y = x[0.093 -0.021.ln(x)] (R = -0.409, p < 0.001, n = 161). There was no significant association between x and y at 1 week (p > 0.05). Residual postop refractive error after LASIK for hyperopia has a logarithmic association with patient age at time of surgery. In younger patients there is tendency toward undercorrection, the opposite occurs in older patients and this persists 1 year after treatment.

Refractive and Visual Outcomes of SUPRACOR TENEO 317 LASIK for Presbyopia in Hyperopic Eyes: 24-Month Follow-up.

To analyze the efficacy, safety, predictability, and stability in hyperopic presbyopic laser in situ keratomileusis (LASIK) surgeries with the TENEO 317 algorithm (Bausch & Lomb Technolas, Munich, Germany). Eighty eyes from 40 patients who underwent hyperopic and presbyopic LASIK in this retrospective, observational, and longitudinal study were included. All patients had a 24-month follow-up. Excimer laser treatment was performed with TECNOLAS Perfect Vision GmbH TENEO 317 software version 1.25 (Bausch & Lomb) with the PROSCAN platform for the distance dominant eye and the SUPRACOR mild platform for the near dominant eye. Mean age was 53.90 ± 4.84 years (range: 42 to 66 years). Postoperative uncorrected distance visual acuity (UDVA) was 0.00 ± 0.04 (20/19.97) for the dominant eye and 0.14 ± 0.05 (20/27.65) for the non-dominant eye. Postoperative uncorrected near visual acuity was 0.51 ± 0.17 (J9) for the dominant eye and 0.09 ± 0.06 (J1.5) for the non-dominant eye, whereas 2.5% of non-dominant eyes lost two lines of corrected distance visual acuity. Half of non-dominant eyes lost one line, and 2.5% of dominant and non-dominant eyes changed 0.50 D or more between 3 and 24 months. PROSCAN surgery in the dominant eye and SUPRACOR surgery in the non-dominant eye using the TENEO 317 algorithm demonstrated that the hyperopic presbyopic excimer laser surgery technique resulted in acceptable and stable outcomes after 24 months of follow-up. [J Refract Surg. 2019;35(9):591-598.].

Outcomes for Hyperopic LASIK With the MEL 90® Excimer Laser.

To report the outcomes of laser in situ keratomileusis (LASIK) for hyperopia using the Triple-A ablation profile with the MEL 90 excimer laser (Carl Zeiss Meditec, Jena, Germany). This retrospective analysis included 1,383 eyes treated by LASIK for hyperopia using the Triple-A ablation profile with the MEL 90 at London Vision Clinic, London, United Kingdom, between September 2013 and December 2016. Inclusion criteria were attempted hyperopic correction of +0.25 diopters (D) or higher and corrected distance visual acuity (CDVA) of 20/40 or better. Patients were observed for 1 year after surgery. Standard outcomes analysis was performed. One-year data were available for 1,350 (97%) eyes. Mean attempted spherical equivalent refraction (SEQ) was +2.77 ± 1.34 D (range: +0.13 to +6.50 D) and mean cylinder was -0.67 ± 0.66 D (range: 0.00 to -5.00 D). Mean age was 54 ± 11 years (range: 21 to 75 years), and 57% were female. Postoperative spherical equivalent was ±0.50 D in 73% and ±1.00 D in 93% of eyes. Uncorrected distance visual acuity was 20/20 or better in 75% of eyes, relative to 93% with preoperative CDVA of 20/20 or better. One line of CDVA was lost in 17% of eyes and two lines were lost in 0.6% of eyes. There was a clinically insignificant but statistically significant increase (P < .01) in contrast sensitivity at 3 and 6 cycles per degree (cpd) and no change for 12 and 18 cpd. LASIK for hyperopia with the MEL 90 excimer laser was found to satisfy accepted criteria for safety, efficacy, and stability. [J Refract Surg. 2018;34(12):799-808.].

Incidence and Clinical Characteristics of Post LASIK Ectasia: A Review of over 30,000 LASIK Cases

ABSTRACTPurpose: To report the incidence of postoperative ectasia after laser in situ keratomileusis (LASIK). Methods: A retrospective case review of 30,167 eyes (16,732 patients) was conducted following LASIK between August 2007 and August 2015. The follow-up was between 2 and 8 years. Tomography was performed after 2 years postop. After identifying cases of ectasia, the charts of these patients were examined to identify any common factors that may have predisposed them to develop ectasia. Results: Ten eyes of seven patients developed post-LASIK ectasia. Eight eyes had been treated for myopia and myopic astigmatism, two eyes for mixed astigmatism. There were no cases of ectasia after LASIK for hyperopia. All 10 cases of ectasia had a flap that was created using the Moria M2 mechanical microkeratome (average flap thickness 118.15 ± 12.88 µm) and refractive error corrected using the Wavelight Allegretto excimer laser. Retrospectively, most prevalent risk factors were thin cornea (≤ 500 µm, 50% of cases), anterior topographic map irregularities (e.g., asymmetric bow tie, 40% of cases), Ectasia Risk Score > 3 (40% of cases), percent tissue thickness alteration ≥ 40% (20% of cases) and low residual stromal bed (≤ 300 µm, 30% of cases). One eye had no identifiable risk factors. In the retrospective chart review 14.97% (4,506) of all the eyes had similar risk factors to the cases that went on to develop ectasia. Conclusion: The incidence of ectasia was 0.033% over 8 years. The incidence could be higher as some cases may destabilize beyond this period and some patients were lost to follow-up asymptomatic of any clinical signs. Other intrinsic factors may trigger the development of post LASIK ectasia. The current widely accepted risk factors are not sufficiently rigorous for screening out potential ectasia from developing after LASIK. There is a need to augment accuracy with higher sensitivity and specificity.

Refractive regression after laser in situ keratomileusis.

Uncorrected refractive errors are a leading cause of visual impairment across the world. In today's society, laser in situ keratomileusis (LASIK) has become the most commonly performed surgical procedure to correct refractive errors. However, regression of the initially achieved refractive correction has been a widely observed phenomenon following LASIK since its inception more than two decades ago. Despite technological advances in laser refractive surgery and various proposed management strategies, post-LASIK regression is still frequently observed and has significant implications for the long-term visual performance and quality of life of patients. This review explores the mechanism of refractive regression after both myopic and hyperopic LASIK, predisposing risk factors and its clinical course. In addition, current preventative strategies and therapies are also reviewed.

Outcomes of retreatment after hyperopic laser in situ keratomileusis

To evaluate the efficacy, predictability, and safety of laser insitu keratomileusis (LASIK) retreatment in eyes with hyperopia. Multicenter refractive surgery centers and University Hospital, Germany. Retrospective case series. This multicenter study included hyperopic patients with a preoperative difference between cycloplegic and manifest refraction of 1.00 diopter (D) or less who had LASIK retreatment based on manifest refraction. The refractive outcome was analyzed according to standard graphs for reporting the efficacy, predictability, and safety of refractive surgery. One hundred thirteen eyes of 113 consecutive hyperopic patients were enrolled. Efficacy (P<.001) and safety (P=.004) were statistically significantly improved by retreatment without being negatively influenced by preoperative manifest spherical equivalent (SE), manifest cylinder, or keratometry. In cases still showing a trend toward undercorrection, retreatment resulted in 88 eyes (78.0%) being within ±0.50 D of the attempted correction. The optical zone (OZ) diameter of the retreatment did not correlate with efficacy, predictability, or safety. Retreatment after hyperopic LASIK resulted in high efficacy, predictability, and safety outcomes. The efficacy and safety of the retreatment were not affected by preoperative manifest SE, manifest cylinder, keratometry, or OZ diameter.

Induced De Novo Astigmatism After Hyperopic LASIK Versus Myopic LASIK Surgery in Nonastigmatic Eyes.

To compare the astigmatism induced surgically (SIA) by spherical hyperopic laser in situ keratomileusis (H-LASIK) versus myopic laser in situ keratomileusis (M-LASIK) in nonastigmatic eyes. A retrospective study of patients who underwent LASIK surgery between 2005 and 2014 at the Care-Vision Laser Center, Israel. We calculated the mean absolute SIA and performed risk factor analysis for induced astigmatism. Differences between H-LASIK and M-LASIK were analyzed. Eyes of 3877 patients who underwent M-LASIK and of 549 patients who underwent H-LASIK were nonastigmatic preoperatively and received a nonastigmatic treatment. Three months after surgery, hyperopic treatment induced more SIA (0.49 ± 0.48 D) than did myopic treatment (0.36 ± 0.4 D) (P < 0.001). In the H-LASIK group, the risk factors for induced astigmatism of >0.5 D were a higher preoperative refractive error (P = 0.003) and larger optical zone (7 vs. 6 mm). In the M-LASIK group, eyes with SIA >0.5 D tended to have steeper corneas preoperatively (43.8 ± 1.5 vs. 43.6 ± 1.4 D; P = 0.001), a higher spherical equivalent (-3.43 ± 1.53 Vs. -3.07 ± 1.45 P < 0.001), and smaller treatment zones (6 vs. 7 mm). In H-LASIK, the mean induced astigmatic axis was at 74.6 degrees. There was a consistent trend toward more SIA in H-LASIK and in higher refractive error correction. In H-LASIK larger optical zones induce more SIA and in M-LASIK smaller ones caused it.

Role of percent peripheral tissue ablated on refractive outcomes following hyperopic LASIK.

ObjectivesTo determine the effect of hyperopic laser in situ keratomileusis (H-LASIK) on corneal integrity, by investigating relationships between proportionate corneal tissue ablated and refractive outcomes at 3 months.Methods18 eyes of 18 subjects treated with H-LASIK by Technolas 217c Excimer Laser were included in the study. Orbscan II Topography System was used to determine corneal volume and pachymetry 3mm temporally (3T). The volume of corneal tissue ablated was determined from the laser nomogram. Univariate associations between age, treatment, corneal volume, overall proportion of tissue removed, proportion of tissue removed at 3T, residual bed thickness at 3T and refractive outcomes 3 months post-LASIK were examined and independent factors associated with refractive outcomes determined using linear regression models.ResultsAt 3 months post-LASIK, the mean difference to expected refractive outcome was -0.20 ± 0.64 (Range -2.00 to +1.00). In univariate analysis, difference to expected refractive outcome was associated with proportion of tissue removed at 3T (P<0.01, r = -0.605) and total number of pulses (P< 0.05, r = -0.574). In multivariable analysis, difference to expected refractive outcome was associated with the proportion of tissue removed at 3T only.ConclusionSubjects undergoing H-LASIK, may present as either over or under-corrected at 3 months. The proportion of tissue removed at 3T was the single significant determinant of this outcome, suggesting unexpected biomechanical alterations resulting in corneal steepening. Future hyperopic LASIK procedures could consider proportionate volume of corneal tissue removed at 3T in addition to laser nomograms to achieve improved refractive outcomes.

Intraocular lens power calculations in eyes with previous hyperopic laser in situ keratomileusis or photorefractive keratectomy

To evaluate the accuracy of 7 intraocular lens (IOL) calculation formulas in patients with previous hyperopic laser in situ keratomileusis (LASIK) or excimer laser photorefractive keratectomy (PRK). Retrospective case series. Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, and private practice, Mesa, Arizona, USA. The 7 formulas evaluated were the adjusted Atlas 0-3, Masket, Modified Masket, Haigis-L, Shammas-PL, Barrett True-K, and Barrett True-K No-History. The Masket and Modified Masket were calculated using the single-K version of Holladay 1 and Hoffer Q formulas; the adjusted Atlas 0-3 was calculated using the double-K version of Holladay 1 and Hoffer Q. The IOL power predicted by each formula was calculated by targeting the postoperative manifest refraction. The IOL prediction error was obtained by subtracting the predicted IOL power from the implanted IOL power. The mean IOL prediction error, median absolute refractive prediction error, and percentages of eyes within ±0.50 diopter (D) and ±1.00 D of the predicted refraction were calculated. Twenty-one eyes of 21 patients were evaluated. There were no significant differences in the median absolute refractive prediction error or percentages of eyes within ±0.50 D or ±1.00 D of the predicted refraction between formulas or methods. The IOL mean prediction errors were comparable between the Holladay 1 and Hoffer Q calculations for all formulas except for a greater error for the double-K version of the Hoffer Q of the adjusted Atlas 0-3. In eyes that had hyperopic LASIK or PRK, there were no significant differences in the accuracy between the 7 IOL calculation formulas.

Safety and effectiveness of the SUPRACOR presbyopic LASIK algorithm on hyperopic patients.

BackgroundTo evaluate the safety and effectiveness of the Supracor excimer laser algorithm to treat hyperopic presbyopic patients using laser in-situ keratomileusis (LASIK).MethodsThis is a retrospective case review of patients diagnosed with hyperopia (Sphere ≥ +0.0 D and presbyopia reading add ≥ 1.0 D) who underwent Supracor excimer laser treatment on at least one eye for presbyopia correction from year May 2011 to May 2013. Binocular vision was further analyzed after patients were subdivided into three groups: Group A (n = 22 eyes, 11 patients) had Supracor on both eyes; Group B (n = 18 eyes, 18 patients) had Supracor in one eye and hyperopic LASIK on fellow eye; and Group C (n = 29 eyes, 29 patients) had Supracor in one eye and no treatment on the fellow eye.ResultsThis study evaluated 58 patients wherein 69 eyes underwent Supracor presbyopic LASIK. Preoperatively, mean manifest refraction spherical equivalent (MRSE) of all eyes that underwent Supracor was +1.37 ± 0.72 D with mean uncorrected distance visual acuity (UDVA), uncorrected intermediate visual acuity (UIVA), and uncorrected near visual acuity (UNVA) of 20/50 (0.35 logMAR), 20/50 (0.35 logMAR), and J9 (0.61 logMAR), respectively. At 6 months postoperatively, mean MRSE was −0.43 ± 0.59 D with mean UDVA, UIVA and UNVA of 20/25 (0.13 logMAR), 20/20 (0.01 logMAR), and J1 (0.05 logMAR), respectively. Loss of two lines of best-corrected distance visual acuity (BCDVA) was seen in 6% of eyes. Mean corneal steepening of 1.0 D at the 3 mm zone and 0.7 D in the 5 mm zone was observed. Mean vertical coma increased from −0.02 to +0.10 while mean 4th order spherical aberration became more negative from 0.20 to −0.14. Mean binocular UDVA, UIVA, and UNVA are 20/20, 20/20 and J1, respectively, in all treatment groups at the 6 month postoperative follow-up. No significant differences in binocular UDVA (p ≥ 0.36), UIVA (p ≥ 0.19) and UNVA (p ≥ 0.56) among groups were seen.ConclusionsSupracor excimer laser algorithm is safe and effective for the treatment of presbyopia in hyperopes. Monolateral and bilateral Supracor treatments yielded similarly good binocular vision outcomes.

Sixteen-year follow-up of hyperopic laser in situ keratomileusis

To assess the long-term efficacy and safety of hyperopic laser in situ keratomileusis (LASIK). Department of Ophthalmology, St. Thomas' Hospital, London, United Kingdom. Prospective cohort study. Hyperopic LASIK was performed using a mechanical microkeratome, an optical zone of 6.5mm, and a blend zone of 1.5mm. Simple hyperopia was treated. The mean patient age was 51.6years (range 34 to 60years). Preoperatively, the mean spherical equivalent (SE) was +3.74 diopters (D) (range +1.25 to +6.50 D). The mean attempted correction was +3.64 D (range +1.5 to +6.0 D). The mean follow-up was 16.5years. The mean SE was +0.28 D (range -1.0 to +1.5 D) at 12months, +0.84 D (range -0.75 to +3.35 D) at 5years, and +1.74 D (range -0.75 to +4.13 D) at 16years, representing an increase in hyperopia of +1.47 D±1.43 (SD) between 1year and 16years (P<.0001) and of +1.13±0.8 D between 5years and 16years (P<.03). The uncorrected distance visual acuity improved at 16years (P<.0001); corrected distance visual acuity (CDVA) was unchanged (P<.2). The efficacy index was 0.5 and the safety index, 1.09. One eye (3%) lost 2 lines of CDVA. Keratometry remained stable between 1year and 16years (P<1.0). Four eyes (12%) had cataract surgery, and 2 (6%) had laser iridotomy. There was no ectasia. After hyperopic LASIK, an increase in hyperopia occurred between 1 and 5years and 16years. At 16years, efficacy was limited but with no sight-threatening complications. Dr. Marshall was a consultant to Summit Technology, Inc. Dr. O'Brart holds a noncommercial research grant from Alcon Laboratories, Inc. None of the other authors has a financial or proprietary interest in any material or method mentioned.

Hyperopic laser in situ keratomileusis: Comparison of femtosecond laser and mechanical microkeratome flap creation

To evaluate and compare the refractive predictability and stability of laser in situ keratomileusis (LASIK) flap creation performed with a femtosecond laser and with a mechanical microkeratome to correct mild to moderate hyperopia. American University of Beirut Medical Center, Beirut, Lebanon. Retrospective case series. Patients who had hyperopic LASIK treatment using the Amaris excimer laser were included. Eyes in which the LDV femtosecond laser was used for flap creation were compared with eyes in which the Moria M2 microkeratome was used. The microkeratome group comprised 53 eyes and the femtosecond laser group, 72 eyes. Baseline characteristics were similar between groups (P > .05). The mean spherical equivalent (SE) deviation from target 1 week postoperatively was -0.08 diopter (D) ± 0.58 (SD) in the femtosecond laser group and -0.06 ± 0.87 D in the microkeratome group (P = .92). Thereafter, the mean SE deviation from target increased gradually and by 6 months postoperatively was +0.30 ± 0.50 D and +0.70 ± 0.71 D, respectively (P = .001). The correlation between the achieved and the attempted SE refraction was better in the femtosecond laser group (R(2) = 0.806) than the microkeratome group (R(2) = 0.671). Using the same nomogram, the short-term refractive outcomes of hyperopic LASIK with flap creation performed with the femtosecond laser were comparable to those for the microkeratome; however, the femtosecond group showed significantly better stability over the 6-month follow-up and better predictability, as reflected by a lower standard deviation and stronger Pearson correlation. Dr. Arba Mosquera is an employee of Schwind eye-tech-solutions GmbH and Co. KG. No other author has a financial or proprietary interest in any material or method mentioned.

The Accuracy of the Double-K Adjustment for Third-Generation Intraocular Lens Calculation Formulas in Previous Keratorefractive Surgery Eyes

To evaluate the effect of the double-K (DK) modification on third-generation formulas. Thirty-eight previously myopic and 24 previously hyperopic eyes that underwent phacoemulsification with intraocular lens (IOL) insertion after Laser in situ keratomileusis (LASIK) were evaluated. Pre-LASIK refraction and keratometry, post-LASIK topography, axial length (AL), IOL type and power, and 1-month postphacoemulsification refraction were recorded spherical equivalent after phacoemulsification (SE(postphaco)). Measured corneal power was adjusted using published and validated methods for postmyopic and posthyperopic LASIK. For each eye, and using SE(postphaco), different DK-IOL formulas were used to calculate the corresponding IOL power, the outcome measure, which was compared with the implanted IOL. DK-Holladay 1 yielded the highest Pearson correlation coefficient (PCC), 0.955 for myopes and 0.943 for high myopes (AL>26 mm). Mean error (ME) and mean absolute error (MAE) for myopes for DK Sanders-Retzlaff-Kraff theoretical formula [DK-SRK/T] were 0.44±0.84 D and 0.75±0.61 D for DK-SRK/T compared with -0.04±0.67 D and 0.52±0.40 D for DK-Holladay 1 (P<0.001 and P=0.016, respectively), and 0.03±0.88 and 0.64±0.58 for DK-Hoffer Q. For high myopes, ME and MAE were 0.75±0.81 D and 0.84±0.69 D for DK-SRK/T, and -0.05±0.74 D (P<0.0001) and 0.57±0.45 D (P=0.019) for DK-Holladay 1. About 29% of DK-SRK/T eyes with large AL had MAE>1.5 D, compared with 0% for DK-Holladay 1 and 14% for DK-Hoffer-Q. Eyes with previous hyperopic LASIK faired similarly for all formulas, with similar PCCs, and only 8% in each category with MAE>1.5 D. DK-SRK/T overestimates IOL power in eyes with large AL, especially with concomitant steep pre-lasik keratometry. Among third-generation formulas, DK-Holladay 1 seems more accurate to use in postmyopic LASIK eyes.

Long-Term Followup of LaserIn SituKeratomileusis for Hyperopia Using a 213 nm Wavelength Solid-State Laser

Purpose. To evaluate the long-term efficacy, accuracy, stability, and safety of hyperopic laser in situ keratomileusis (LASIK) using a 213 nm wavelength solid-state laser. Methods. This prospective noncomparative case series consisted of 34 eyes of 17 patients which underwent hyperopic LASIK using a 213 nm solid-state laser (Pulzar Z1, CustomVis) at an outpatient refractive surgery center in Manila, Philippines. The preoperative and postoperative examinations included uncorrected distance visual acuity (UDVA), subjective manifest refraction, corrected distance visual acuity (CDVA), cycloplegic refraction, slitlamp biomicroscopy, and keratometry (K). Main Outcome Measures. Accuracy, efficacy, stability, and safety of the refractive procedure. Results. Mean follow-up was 25.18 ± 13.79 months. At the end of follow-up, 26.47% had a UDVA of 20/20 and 94.12% had a UDVA of ≥20/40. Manifest refractive spherical equivalent (MRSE) was within ±0.50 D of the target refraction in 55.88% and within ±1.0 D in 85.30% of the study eyes. Refractive stability was noted in the 1st postoperative month while hyperopic regression was noted after the 3rd postoperative year. No eye lost more than 2 lines of CDVA. Conclusion. Our results show that the 213 nm solid state laser system is safe, effective, accurate, and predictable for the treatment of hyperopia.

The role of presbyopia-correcting intraocular lenses after laser in situ keratomileusis

There is a growing number of patients who wish to remain spectacle independent after cataract surgery, and this number includes some of the millions of people worldwide who have undergone laser in situ keratomileusis (LASIK). This article reviews the evidence of the use of presbyopia-correcting intraocular lenses (IOLs) in patients who have previously undergone LASIK. Small studies have demonstrated that the use of hybrid refractive-diffractive multifocal IOLs in eyes with previous myopic or hyperopic LASIK can result in good refractive results. However, refractive surprise can be common and may require further intervention, such as laser surgery enhancement, to achieve satisfactory results. The use of these IOLs can also result in lost lines of vision, and visual quality may be poorer under mesopic or glare conditions. No reports were found regarding the use of accommodating IOLs in such patients. There is a surprising paucity of literature on this topic, given the millions that have undergone LASIK. Further and timelier research is needed to assess the use of newer multifocal and accommodating IOLs in post-LASIK eyes, the effect of IOL asphericity on visual quality, and patients' experience, satisfaction and level of spectacle independence after surgery.