Lomb Technolas Research Articles

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.].

Endothelial cell changes after photorefractive keratectomy with graded usage of mitomycin C.

To compare differences in the endothelial cells before and after photorefractive keratectomy (PRK) for myopia with refractive error graded mitomycin C (MMC) application. In a prospective randomized clinical trial, forty-eight myopic patients referred to Khatam-al-Anbia Eye Hospital, Mashhad, Iran, for PRK. Patients were treated with PRK by a Bausch and Lomb Technolas 217z excimer laser (Bausch and Lomb, Rochester, NY). MMC was applied after PRK 5s for each diopter of spherical equivalent myopic refractive error corrected. The manifest refraction, visual acuity, MMC treatment length, corneal pachymetry and specular microscopy were evaluated preoperatively and at 1 and 6months postoperatively. A total of 48 cases (96 eyes, 68.75% female) were treated, with a mean age of 26.70±4.89years (range, 18-34years). Postoperative cell density, cell size and polymegathism did not significantly change. On the other hand, standard deviation (SD) of cell size (P=0.008), pleomorphism (P=0.003) and coefficient of variation (CV) (P=0.016) were significantly increased. None of these parameters was related to the length of MMC application. Corneal thickness decreased significantly after the operation but it increased 6months postoperatively compared with the first month (P<0.001). MMC application for PRK in myopia can affect the endothelial cells, but in early follow-ups, it does not affect the cell density or size. Cell size was changed but it was obvious not in mean cell size, but in SD and CV. MMC time below the 30s was not significant on endothelial cell changes.

Stereoacuity after photorefractive keratectomy in myopia

PurposeStereopsis, as a part of visual function, is the ability of differentiating between the two eyes' views (binocular disparity), due to the eyes' different positions. The aim of this study was to compare stereoscopic vision before and after photorefractive keratectomy (PRK) in myopia. MethodsIn a prospective interventional case series study clinical trial, forty-eight myopic individuals (age range: 18–34 years) who had undergone PRK surgery by a Bausch & Lomb Technolas 217z excimer laser were included. In all patients, stereoscopic vision was assessed using TNO test charts at 40 cm distance preoperatively and at 3 and 6 months postoperatively. ResultsA total of 48 cases (96 eyes, 69% female) with a mean age of 26.70 ± 4.89 years (range: 18–34 years) were treated. Uncorrected visual acuity (UCVA) was improved and refraction was corrected significantly after PRK surgery. The stereoscopic vision in patients was 246.56 ± 98.43 s of arc before PRK surgery. Postoperatively, the stereoacuities were recorded as 365.38 ± 112.65 s of arc and 343.51 ± 88.96 s of arc at 3 and 6 months, respectively. These differences were statistically significant (p < 0.001). ConclusionPRK was successful and safe in improving refractive error and UCVA, but it may deteriorate the stereoscopic vision. It may be due to an increase in higher order aberrations.

Stereopsis and Patient Satisfaction in Myopic and Hyperopic Individuals Selecting Monovision Correction by LASIK or LASEK

Purpose: This study was designed to measure binocular function, patient satisfaction and to evaluate postoperative outcomes of presbyopic patients selecting monovision correction either by laser in situ keratomileusis (LASIK) or Laser Assisted Sub-Epithelial Keratomileusis (LASEK). Methods: We carried out a Retrospective chart review of 86 selected patients 40 years and older, treated with refractive laser monovision correction by LASIK or LASEK. Laser was performed with a Baush & Lomb Technolas 217 (Zyoptix or PlanoScan) Excimer laser. All patients had the dominant eye corrected for distance. The parameters used were distance & near corrected visual acuity, manifest refraction before and after surgery and near stereopsis postoperatively. Patient satisfaction was evaluated by questionnaire. Results: Eighty six patients (51 hyperopes, 35 myopes) were included. Hyperopic mean refractive spherical equivalent (MRSE) in the distance-corrected eye was +1.90 ± 0.79 D and for the eye corrected for near vision MRSE +2.62 ± 0.93. Myopic (MRSE) in the distance corrected eye was -4.15 ± 1.06 D and for the eye corrected for near vision MRSE -2.37 ± 1.06 D. All hyperopes and 7 myopes were treated with LASIK and the rest were treated with LASEK. After surgery 94% had distance binocular uncorrected visual acuity of 0.00 logmar or better and 93.2% of the patients had near binocular uncorrected visual acuity of N6 of better. The mean near steroacuity was 248 ± 244S D seconds of arc. All patients chose their dominant eye to be corrected for distance. Of 35 myopes treated one patient underwent enhancement of the near eye to distance vision and one underwent enhancement for near after 4 months. Eighty-two patients were happy with their vision. Sixty-five percent of all patients had a mean near stereoacuity of ≥ 100 seconds of arc. Despite this eighty two patients are happy with their vision, satisfaction graded with a standardized questionnaire. Conclusion: There is no ideal surgical approach to presbyopia. The ideal procedure is still at present monovision after LASIK or LASEK, although it is a long way off reduces stereopsis it results in high satisfaction for both myopic and hyperopic presbyopic individuals.

Aspheric Ablation Depth as the Target Depth for Enhanced Wavefront-Guided Myopic Retreatments After Laser-Assisted In Situ Keratomileusis.

To propose a new adjustment method and present the clinical result of wavefront-guided myopic laser-assisted in situ keratomileusis (LASIK) retreatment with an aspheric program-targeted central ablation depth to avoid refractive overcorrection. Thirty-two eyes (of 20 consecutive patients) that underwent wavefront-guided LASIK myopic retreatment between January 2009 and February 2012 after primary wavefront-guided LASIK for myopia were included. Wavefront-guided retreatments were performed using the Bausch and Lomb Technolas 217z100 excimer laser system. Wavefront-guided retreatments were adjusted by setting the ablation depth corresponding to the ablation depth determined by the aspheric program. The refractive outcome, visual outcome, and outcome of high-order aberrations (HOAs) were analyzed. Linear mixed models were also used to evaluate the predicting factors for retreatment offset. Mean age was 29.5 ± 3.1 years. Spherical equivalent (SE) before retreatment was -1.0 ± 0.44 diopters (D) (range, -2.25 to -0.5). Twelve months postoperatively, SE was -0.03 ± 0.12 D, and 31 of 32 eyes had an uncorrected visual acuity 20/20 or better. All eyes were within ±0.5 D. None of the eyes had lost >2 lines of Snellen visual acuity. Safety and efficacy indices were 1.03 and 1.00, respectively. Total HOA, coma, and trefoil were reduced significantly (P = 0.028, P = 0.036, P = 0.034, respectively). Predictive factors for the amount of offset required are significantly related to preoperative SE (P = 0.006) and spherical aberration (P = 0.03, adjusted by SE). Setting the target ablation depth using the aspheric program provided high refractive predictability with a satisfactory visual outcome, significant reduction of HOAs, and no overcorrections.

Evaluation of the influence of corneal biomechanical properties on the central corneal curvature after a SUPRACOR procedure

PurposeSUPRACOR™, performed with the Technolas Excimer Workstation 217P (Bausch + Lomb Technolas), creates a small zone of high refractive power in the central cornea, the « bump », to facilitate near focus. The aim of this study is to evaluate the influence of corneal biomechanics on this « bump ».MethodsThis retrospective study included 46 eyes of 23 patients. The Supracor ablation pattern was applied, to create hyperprolate shape resulting about 2 D near addition. The periphery was treated with hyperopic ablation in a 6 mm zone, using 9.5 mm suction ring, under 120 µm flap created by the IntraLase FS60 femtosecond laser (AMP, USA). Every patient underwent a corneal topography (Pentacam, Oculus, Germany) before and 1 month after surgery to evaluate the importance of the “bump”, and a biomechanical evaluation with the Ocular Response Analyser (ORA, Reichert, NY). CH (Corneal Hysteresis) and CRF (Corneal Resistance Factor) were evaluated. Spearman's rank correlation coefficient was used to analyze the relationship between the parameters of the ORA and the « bump ».ResultsThe mean patient age was 55.5 ± 3.94, ranging from 50 to 62 years. Pre‐operative spherical equivalent were 1.57 ± 0.77 D. Mean corneal thickness was 548 ± 44 µm. CH and CRF were respectively 10.53 ± 1.63 mmHg and 10.90 ± 2.12 mmHg. Mean “bump” was 2.25 ± 0.98 D, ranging from 0.50 to 4.64 D. A correlation was found between the CH and the bump (r = 0.34; p = 0.022) and also between the pachymetry and the bump (r = 0.45; p = 0.004). A strong correlation was found between corneal thickness and the CH (r = 0.62; p = 0.001).ConclusionsIn this study, the “bump” is correlated with the corneal thickness and the CH. The corneal thickness appears to be sufficient to predict the “bump” in hyperopic patients undergoing Supracor. These results should be confirmed in a larger sample of patients.

Validation of an Objective Scoring System for Forme Fruste Keratoconus Detection and Post-LASIK Ectasia Risk Assessment in Asian Eyes.

To investigate the efficacy of the SCORE Analyzer (Bausch+Lomb TechnoLas, Germany) in detecting forme fruste keratoconus (FFKC) in Asian eyes and validate its usefulness as a risk assessment system for post-laser in situ keratomileusis (LASIK) keratectasia. We retrospectively evaluated corneal topographies with the Orbscan IIz system and independently tested them with the SCORE Analyzer through masked investigators. Eyes were classified into 2 groups: (1) The FFKC group included clinically and topographically normal eyes with definite keratoconus in the contralateral eye. (2) The control group included normal preoperative topographies of patients with LASIK performed at least 4 years before with no resultant keratectasia. The main outcome measures were accuracy indicators: sensitivity, specificity, positive, and negative predictive values. Parameters in the calculation of the SCORE including irregularity at 3 mm, thinnest pachymetry, the difference between central and thinnest pachymetry (CP - TP), vertical decentration of the thinnest point, maximum posterior elevation, and anterior elevation of the thinnest point were compared in both groups. We analyzed 128 Orbscans of 128 Asian patients. There were 24 FFKC eyes and 104 control eyes. SCORE was negative in 7 eyes (false negative) in the FFKC group and was positive in 2 eyes in the control group (false positive). The sensitivity was 70.8%, specificity 98.1%, positive predictive value 89.5%, and negative predictive value 93.6%. Irregularity at 3 mm, thinnest pachymetry, CP - TP, thinnest point decentration, maximum posterior elevation, and anterior elevation of the thinnest point were significantly different in both groups. The SCORE Analyzer algorithm, developed and validated in eyes of white subjects, was found to be valid and consistent in Asian eyes, showing good sensitivity and specificity in FFKC detection, and to be useful in objectively identifying cases at risk of post-LASIK keratectasia.

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

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

Angle kappa changes after photorefractive keratectomy for myopia

The goal of this study was to compare differences in the mean angle kappa and its intercepts before and after photorefractive keratectomy (PRK) for myopia. In a prospective controlled study, myopic patients were treated with aspheric wavefront-guided (personalized) PRK with a Bausch & Lomb Technolas 217z excimer laser. The manifest refraction, visual acuity, and angle kappa were evaluated preoperatively and at 1 and 6months postoperatively. The same operator performed all angle kappa measurements using Orbscan IIz. A total of 48 cases (96 eyes, 68.75% female) with a mean age of 26.70±4.89years (18-34years) were treated. The preoperative and postoperative mean angle kappa values were not significantly different (4.97±1.24 vs 4.99±1.10 at 6months). The average horizontal distance (x-intercept) between the visual axis and pupillary axis intersection on the corneal surface measured before surgery (-0.562±0.074mm) did not significantly differ from the values measured at 1 and 6months after surgery (-0.559±0.048 and -0.554±0.055mm, respectively). Similarly, the average vertical distance (y-intercept) values did not differ before and at 1 and 6months after surgery (0.156±0.225, 0.142±0.040, and 0.149±0.33mm, respectively). No differences in the angle kappa or its corneal intercepts were observed between pre- and post-PRK. This finding implies that PRK does not change the corneal vertex locations.

Short term LASIK outcomes using the Technolas 217C excimer laser and Hansatome microkeratome in 46 708 eyes treated between 1998 and 2001

PurposeTo report the outcomes of a high-volume, multi-surgeon, multicentre LASIK corporation between 1998 and 2001.Methods46 708 eyes of 24 138 consecutive patients with myopic astigmatism had undergone LASIK using the...

Ten year follow up of laser in situ keratomileusis for all levels of myopia

Editor, In 2004, we performed a retrospective study assessing the refractive and visual outcome of patients 5 years post laser in situ keratomileusis (LASIK) surgery for all levels of myopia (O’Doherty et al. 2006). All 49 patients (94 eyes) in the original study were invited to attend for a 10-year review. Thirty patients (54 eyes) attended for examination. The original range of myopia treated was from −1.5 to −13 dioptres. The eyes were grouped into mild (<−3 D), moderate (−3 to −6 D) and high (>−6D) myopia. All surgery was performed by one experienced surgeon (MO’K) using the Bausch and Lomb Technolas 217 laser platform (Bausch & Lomb, Surrey, UK). The treatment algorithm used was the plano programme. Flaps were cut to a depth of 140 μm using the Hansatome microkeratome (Bausch and Lomb) and hinged superiorly with a flap diameter of 8.5–9.5 mm. The ablation zone ranged from 6 to 7 mm. At 10-year follow-up, uncorrected (UCVA), best corrected visual acuity (BCVA), manifest refractive spherical equivalent (MRSE), corneal topography and aberrometry were measured. Patients completed a questionnaire regarding satisfaction with LASIK. Questions asked included those relating to symptoms of dry eye and night vision problems such as glare and haloes. Regression was measured in this study as eyes that had regressed more than 0.5 dioptres. Of the 94 eyes originally included (49 patients), 54 eyes of 30 patients were examined. Nineteen women and 11 men of mean age of 42.8 years (range 30–65) were assessed 10 years post-LASIK. There were seven eyes in the mild, 29 in the moderate and 18 in the highly myopic groups. The original cohort of patients (94 eyes) had 23 mild, 49 moderate and 22 highly myopic eyes. Therefore, 30% of mild myopes, 59% of moderate myopes and 82% of high myopes returned for the follow-up study. At 10-year postoperative review, 52% were within ±0.50 D and 87 within ±1.0 D of emmetropia. Fifty-six per cent of eyes had UCVA better than or equal to 6/6 and 82% better than or equal to 6/9. Fifteen eyes (27.8%) had regressed. The overall mean regression (MRSE) was −1.6D. Mean regression in the mild, moderate and high myopic groups were −1.15, −0.93 and −1.94 D, respectively. Eleven eyes (20.4%) underwent retreatment during the 10-year follow-up period with a mean time to retreatment from the original surgery of 6.1 years. Of these, 4 (36%) were retreated prior to 5-year review and 7 (64%) between 5 and 10 years. The mean overall retreatment refractive error (MRSE) was −1.77 D. The mean retreatments performed in the low, moderate and high myopic groups were −1.15, −0.88 and −1.89 dioptres, respectively. The retreatment rate was greatest in the highly myopic group. No eye was retreated more than once (see Table 1). Four eyes of three patients regressed but no retreatment was performed. Two patients with unilateral regression had useful monovision. The third patient with bilateral regression returned to wearing glasses and declined further treatment. In the 43 eyes that were not retreated, 56% had a vision of 6/6 or better and 89% had a vision of 6/9 or better. During the 10-year follow-up period, three eyes were treated for retinal tears and one underwent retinal detachment repair. Ten patients reported glare. Seven patients reported the symptoms of dry eye. There was no topographical evidence of corneal ectasia. On questioning, all patients stated to be very happy with their original decision to undergo LASIK surgery. In our study, we found that better results were achieved in mild and moderate myopia and poorer outcomes were achieved in high myopia. These findings are similar to those of Zalentein (Zalentein et al. 2009). The trend towards regression may be explained by both corneal and non-corneal changes. Clearly changes in the corneal mechanics such as ectasia and corneal epithelial thickness could be one explanation. Non-corneal causes such as increase in axial length secondary to vitreous chamber elongation have been shown to increase myopia in adulthood (Kinge & Miledfart 1999; Jorge et al. 2007) In the twelve-year follow-up after PRK, we reported a continuous small regression (O’Connor et al. 2006). There is a reasonable inference from these studies that it is very likely that non-corneal changes over time will induce an increase in myopia. Those undergoing LASIK for high myopia and younger patients who are highly myopic should be advised of this potential and that they may indeed need retreatment in the future. This study shows LASIK to be a safe procedure associated with high patient satisfaction. Long-term stability was found in low to moderate myopia; however, a much greater tendency towards regression was seen in highly myopic patients with the need for retreatment.

Aspheric laser in situ keratomileusis for the correction of myopia using the technolas 217z100: Comparison of outcomes versus results from the conventional technique

To compare postoperative outcomes of a new aspheric laser in situ keratomileusis (LASIK) system, which applies an index for corneal asphericity (Q-value), with outcomes of the conventional LASIK procedure. Twenty-eight eyes of 15 consecutive patients (mean age, 36.4 +/- 5.8 years) underwent aspheric LASIK (As-LASIK group), and 33 eyes of 18 consecutive patients (mean age, 32.9 +/- 8.3 years) underwent conventional LASIK (Con-LASIK group) at Sanno Hospital (Tokyo, Japan). Both procedures were performed with a Moria LSK-One microkeratome and a Bausch and Lomb Technolas 217-z100 excimer laser. Preoperative mean spherical equivalent refraction values were -5.13 +/- 1.23 diopters (D) and -5.63 +/- 0.88 D in the As-LASIK and Con-LASIK groups, respectively. Higher order aberrations were measured and contrast sensitivity was assessed at 3 months after the procedure, and these, along with safety, efficacy, and predictability, were compared between the two procedures. Conventional LASIK significantly increased higher order aberrations and reduced contrast sensitivity, whereas As-LASIK did not increase spherical-like aberrations or alter contrast sensitivity. Aspheric LASIK may be a better laser technique than Con-LASIK, with less postoperative increase in spherical-like aberrations and better control over contrast sensitivity.

Comparison of Corneal Aberration Changes After Laser In Situ Keratomileusis Performed With Mechanical Microkeratome and IntraLase Femtosecond Laser: 1-Year Follow-up

To compare corneal aberration changes 1 year after myopic laser in situ keratomileusis (LASIK) performed with a mechanical microkeratome and IntraLase femtosecond laser. Twenty four eyes of 15 patients underwent LASIK with the Hansatome microkeratome, and 23 eyes of 13 patients underwent LASIK with the IntraLase femtosecond laser. A standard ablation was performed with the Bausch & Lomb Technolas 217 excimer laser. Topography data were used to calculate corneal aberrations with a 3.0 mm and 5.00 mm pupil, before and 12 months after surgery. The increasing factor (IF), defined as the ratio between the postoperative and preoperative mean value of the optical aberration, was calculated. The method of Mulhern et al was used to evaluate the centration of ablation. The comalike aberration was correlated with the decentration of ablation. The Student t test was used for the statistical anaylsis. The postoperative mean decentration of ablation was <0.5 mm. The comalike aberration appeared to be positively correlated with the decentration of ablation in both groups with a 5.0-mm pupil (P < 0.05). With a 3.00-mm pupil, the comalike aberration changed in the Hansatome group, whereas with a 5.00-mm pupil, all aberrations statistically significantly changed in both groups (P < 0.05). The IF similarly increased in 2 groups for spherical-like aberration, whereas IF greatly increased for total and comalike aberrations in the Hansatome group. Wavefront corneal aberrations change significantly 1 year after myopic LASIK performed with the Hansatome microkeratome as well as with IntraLase femtosecond lasers. Both of the procedures induce higher-order aberrations in the anterior corneal surface, but the amount of comalike aberration increases more with the Hansatome mechanical microkeratome.

Intraocular straylight and contrast sensitivity after LASIK

Abstract Purpose: To give a review about the effect of refractive surgery on glare, intraocular straylight and contrast sensitivity and to present the results of a study at the Centro de Oftalmología Barraquer. Methods: Altogether 50 eyes of 33 patients (mean age 31 years; refractive error range 3.5 to ‐7.5 D) were treated for LASIK with Bausch &amp; Lomb Technolas Z100 and studied pre‐op and two month post‐op. Intraocular straylight was measured with the Oculus C‐quant and contrast sensitivity with the CSV‐1000 (at 3, 6, 12, 18 cycles/degree). Results: In our study at the Centro de Oftalmología Barraquer, pre‐op mean log(s) straylight parameter of 0.98 (+/‐0.06 confidence interval [CI]) did not change at two month post‐op 0.97 (+/‐0.05 CI). Only two eyes out of 50 had straylight values increased by more than 0.2 log units. There was no significant change in contrast sensitivity at all four spatial frequencies. Conclusions: This and one earlier study by Beerthuizen showed no change of the mean values of intraocular straylight at one or two month post‐op after refractive surgery, but a few cases had a more than 0.2 log units increase. Results with regard to contrast sensitivity are not consistent in the literature, with improvement or decrease depending on post‐op time, illumination level and type of refractive procedure.

Effect of Preoperative Keratometric Power on Intraoperative Complications in LASIK in 34,099 Eyes

To evaluate the effect of preoperative keratometric power on the intraoperative complications in LASIK for myopia, hyperopia, and astigmatism. In this retrospective study, the records of 34,099 eyes of 17,388 patients who underwent LASIK for myopia, hyperopia, and astigmatism using the Moria LSK One manual microkeratome and the Bausch & Lomb Technolas 217 Z excimer laser were reviewed. One thousand three hundred thirty-eight (3.92%) intraoperative microkeratome complications were identified in the total number of eyes: 571 (1.67%) free caps, 320 (0.93%) epithelial abrasions, 282 (0.82%) thin/irregular flaps, 126 (0.36%) incomplete flaps, and 39 (0.11%) flap buttonholes. When eyes were stratified according to preoperative keratometric power, eyes with flatter corneas usually had more free caps and incomplete flaps than eyes with steeper corneas (P < .05), whereas eyes with steeper corneas usually had more epithelial abrasions and thin/irregular flaps than eyes with flatter corneas (P < .05). The risk of free caps, incomplete flaps, and epithelial abrasions was greater when bigger keratome rings (H) were used than when smaller rings (-1) were used (P < .05). The incidence of buttonholes was independent of the preoperative keratometric power, keratome plate (100 or 130 microm), and keratome ring (-1, -2, or H). No statistically significant relationship was found between preoperative keratometric power and incidence of flap buttonholes in this series. Eyes with flatter corneas tended to have more free caps and incomplete flaps, whereas eyes with steeper corneas tended to have more epithelial abrasions and thin/irregular flaps.

LASIK in the Presbyopic Age Group: Safety, Efficacy, and Predictability in 40- to 69-Year-Old Patients

To report the safety, efficacy, and predictability of LASIK in a presbyopic population and to examine possible differences between age groups. Retrospective, descriptive, comparative consecutive case series. Seven hundred ten eyes of 424 patients between 40 and 69 years of age who underwent LASIK by the same surgeon between January 1999 and September 2005. Patients had manifest refractive spherical errors ranging from -10.5 to +6 diopters (D) and cylinder of up to 2.50 D. LASIK was performed with IntraLase femtosecond laser or Hansatome microkeratomes and VISX Star (S4 or S2; VISX Inc., Santa Clara, CA) or Baush & Lomb Technolas 217z (Zyoptix or PlanoScan; Bausch & Lomb, Claremont, CA) excimer lasers. There were 511 myopic eyes (spherical equivalent [SE], -5.03+/-2.02 D) and 199 hyperopic eyes (SE, +2.21+/-1.21 D). Patients were divided into 3 groups: group 1 (40 to 49 years old; n = 359 eyes), group 2 (50 to 59 years old; n = 293 eyes), and group 3 (60 to 69 years old; n = 58 eyes). Uncorrected visual acuity (UCVA) and best spectacle-corrected visual acuity (BSCVA), retreatment rates, safety, efficacy, and predictability. The mean age of patients in groups 1, 2, and 3 was 45, 53, and 63 years, respectively. With increasing age, there was a trend toward higher retreatment rates and more myopic end points. Safety, efficacy, and predictability were comparable between all groups. At the final follow-up (mean+/-standard deviation, 10.4+/-7.4 months), 80% to 100% of eyes had 20/30 or better UCVA and 81% to 90% were within +/-1.00 D. No eyes lost more than 2 lines of BSCVA, and only 9 eyes (1.3%) lost 2 lines. Subgroup analysis of eyes with a follow-up of 12 months or more was performed. The results were compared with those with shorter follow-up. Both subgroups had comparable outcomes; the duration of follow-up did not affect the visual outcomes. Despite a trend toward worse final BSCVA and higher retreatment rates in older patients, a greater risk of visual loss after LASIK was not observed. LASIK for myopia and hyperopia has reasonable safety, efficacy, and predictability profiles in the 40- to 69-year-old presbyopic population.

Zyoptix Wavefront-Guided versus Standard Photorefractive Keratectomy (PRK) in Low and Moderate Myopia: Randomized Controlled 6-Month Study

To evaluate the refractive and aberrometric outcome of wavefront-guided photorefractive keratectomy (PRK) compared to standard PRK in myopic patients. Fifty-six eyes of 56 patients were included in the study and were randomly divided into two groups. The study group consisted of 28 eyes with a mean spherical equivalent (SE) of -2.25+/-0.76 diopters (D) (range: -1.5 to -3.5 D) treated with wavefront-guided PRK using the Zywave ablation profile and the Bausch & Lomb Technolas 217z excimer laser (Zyoptix system) and the control group included 28 eyes with a SE of -2.35+/-1.01 D (range: -1.5 to -3.5 D) treated with standard PRK (PlanoScan ablation) using the same laser. A Zywave aberrometer was used to analyze and calculate the root-mean-square (RMS) of total high order aberrations (HOA) and Zernike coefficients of third and fourth order before and after (over a 6-month follow-up period) surgery in both groups. Preoperative and postoperative SE, un-corrected visual acuity (UCVA), and best-corrected visual acuity (BCVA) were evaluated in all cases. There was a high correlation between achieved and intended correction. The differences between the two treatment groups were not statistically significant for UCVA, BCVA, or SE cycloplegic refraction . Postoperatively the RMS value of high order aberrations was raised in both groups. At 6-month control, on average it increased by a factor of 1.17 in the Zyoptix PRK group and 1.54 in the PlanoScan PRK group (p=0.22). In the Zyoptix group there was a decrease of coma aberration, while in the PlanoScan group this third order aberration increased. The difference between postoperative and preoperative values between the two groups was statistically significant for coma aberration (p=0.013). No statistically significant difference was observed for spherical-like aberration between the two groups. In the study group eyes with a low amount of preoperative aberrations (HOA RMS lower than the median value; <0.28 microm) showed an increase of HOA RMS while eyes with RMS higher than 0.28 microm showed a decrease (p<0.05). Zyoptix wavefront-guided PRK is as safe and efficacious for the correction of myopia and myopic astigmatism as PlanoScan PRK. Moreover this technique induces a smaller increase of third order coma aberration compared to standard PRK. The use of Zyoptix wavefront-guided PRK is particularly indicated in eyes with higher preoperative RMS values.

Analysis of the efficacy, predictability, and safety of LASEK for myopia and myopic astigmatism using the Technolas 217 excimer laser

Purpose: To evaluate the efficacy, predictability, and safety of laser-assisted subepithelial keratectomy (LASEK) for the treatment of myopia and myopic astigmatism. Setting: Stanford University Eye Laser Center, Stanford, California, USA. Methods: This retrospective analysis comprised 102 eyes that had LASEK for myopia using the Bausch & Lomb Technolas® 217 excimer laser. Primary outcome variables including uncorrected visual acuity (UCVA), best spectacle- corrected visual acuity (BSCVA), manifest refraction, and complications were evaluated at 3, 6, and 12 months. Vector analysis was performed on eyes that received astigmatic correction. Results: The mean spherical equivalent was −7.03 diopters (D) ± 2.61 (SD) preoperatively, +0.19 ± 0.64 D at 3 months, +0.23 ± 0.82 D at 6 months, and +0.03 ± 0.63 D at 12 months ( P<.001). At 3, 6, and 12 months, the UCVA was 20/20 or better in 66%, 67%, and 83% of eyes, respectively, and 20/40 or better in 98%, 99%, and 100%; 74%, 70%, and 83%, respectively, were within ±0.5 D of emmetropia, and 89%, 86%, and 97%, respectively, were within ±1.0 D. No eye lost more than 2 lines of BSCVA. At 3, 6, and 12 months, 10.0%, 8.7%, and 0% of eyes, respectively, had trace corneal haze. Vector analysis found a success rate of approximately 78% to 80% in achieving the astigmatic surgical correction at the 3 postoperative visits. Conclusions: Laser-assisted subepithelial keratectomy was an effective, predictable, and safe procedure for the treatment of myopia and myopic astigmatism. Further studies are needed to determine the role of LASEK in the refractive surgery spectrum.

Outcomes after laser in situ keratomileusis retreatment in high myopes

PURPOSE: To evaluate the refractive and visual performance after laser in situ keratomileusis (LASIK) retreatment. METHODS: A retrospective study was performed on 33 eyes of 23 patients who underwent LASIK (Bausch & Lomb Technolas 217C) retreatment for residual myopia with or without astigmatism. Parameters evaluated were uncorrected and best spectacle-corrected visual acuity, spherical equivalent refraction, contrast sensitivity, glare acuity, and pachymetry, preoperatively and at 1, 3, and 6 months postoperatively. RESULTS: The mean spherical equivalent refraction before primary LASIK was -9.89 ± 4.00 D and before retreatment was -2.85 ± 2.17 D. Although contrast sensitivity and glare acuity decreased significantly after primary LASIK (P<.05), no significant change in these parameters was observed after retreatment. Smaller ablation zones were associated with decreased contrast sensitivity and glare acuity after primary LASIK as well as following retreatment. Contrast sensitivity and glare acuity following primary LASIK were significantly better in eyes with ablation zones ≥5 mm than those with <5 mm (P<.05). Eyes in which the ablation zone was the same as that for primary LASIK had significantly better contrast sensitivity than those with different ablation zones (increased or decreased) during retreatment. Attempted refractive correction during primary LASIK and retreatment had a significant negative correlation with contrast sensitivity and glare acuity following primary LASIK as well as retreatment. CONCLUSION: The ablation zones following primary LASIK and retreatment should be ≥5.00 mm and remain unchanged to improve visual performance.

Electron Microscopy of Surface Smoothness of Porcine Corneas and Acrylic Plates With Four Brands of Excimer Laser

This study compares ablation smoothness patterns produced on four different excimer laser devices available for photorefractive surgery. VISX calibration plastic and porcine cornea were ablated with standard -3.00-D, -6.00-D, and -9.00-D settings using four different excimer lasers: VISX S2 Smooth Scan, Nidek EC-5000, Autonomous Ladar Vision System, and Bausch and Lomb Technolas. Electron microscopy and laser interferometry were used for qualitative evaluation of the ablated surfaces. Corneal ablation surface smoothness was graded by ten independent observers. Calibration plastic ablated surfaces were evaluated quantitatively for smoothness by laser interferometry. The independent observer assessment of corneal ablation surface smoothness demonstrated that the Autonomous small spot Gaussian profile laser produced the smoothest ablation surfaces, followed by the other broad beam lasers. In comparing ablation smoothness among various refractive powers (-9.00 D, -6.00 D, and -3.00 D), a trend was observed that indicated a correlation of higher refractive settings with decreasing surface smoothness. However, this trend was not statistically significant. The quantitative laser interferometry measurements supported the independent observer ranking of the Autonomous flying small spot ablation profile as the smoothest. However, there were differences between the laser interferometry smoothness rankings and independent observer smoothness rankings. There were significant differences in ablation surface smoothness among the four excimer lasers tested.