Optimized Artificial Intelligence for Enhanced Ectasia Detection Using Scheimpflug-Based Corneal Tomography and Biomechanical Data.

PURPOSE: To optimize artificial intelligence (AI) algorithms to integrate Scheimpflug-based corneal tomography and biomechanics to enhance ectasia detection. DESIGN: Multicenter cross-sectional case-control retrospective study. METHODS: A total of 3886 unoperated eyes from 3412 patients had Pentacam and Corvis ST (Oculus Optikgeräte GmbH) examinations. The database included 1 eye randomly selected from 1680 normal patients (N) and from 1181 "bilateral" keratoconus (KC) patients, along with 551 normal topography eyes from patients with very asymmetric ectasia (VAE-NT), and their 474 unoperated ectatic (VAE-E) eyes. The current TBIv1 (tomographic-biomechanical index) was tested, and an optimized AI algorithm was developed for augmenting accuracy. RESULTS: The area under the receiver operating characteristic curve (AUC) of the TBIv1 for discriminating clinical ectasia (KC and VAE-E) was 0.999 (98.5% sensitivity; 98.6% specificity [cutoff: 0.5]), and for VAE-NT, 0.899 (76% sensitivity; 89.1% specificity [cutoff: 0.29]). A novel random forest algorithm (TBIv2), developed with 18 features in 156 trees using 10-fold cross-validation, had a significantly higher AUC (0.945; DeLong, P < .0001) for detecting VAE-NT (84.4% sensitivity and 90.1% specificity; cutoff: 0.43; DeLong, P < .0001) and a similar AUC for clinical ectasia (0.999; DeLong, P = .818; 98.7% sensitivity; 99.2% specificity [cutoff: 0.8]). Considering all cases, the TBIv2 had a higher AUC (0.985) than TBIv1 (0.974; DeLong, P < .0001). CONCLUSIONS: AI optimization to integrate Scheimpflug-based corneal tomography and biomechanical assessments augments accuracy for ectasia detection, characterizing ectasia susceptibility in the diverse VAE-NT group. Some patients with VAE may have true unilateral ectasia. Machine learning considering additional data, including epithelial thickness or other parameters from multimodal refractive imaging, will continuously enhance accuracy. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Immediate Sequential Bilateral Cataract Surgery: Opinions among Refractive Surgeons in the United States and a Comparative Analysis with European Consultants.

Purpose: To analyze the perspectives of practicing refractive surgeons regarding the implementation of Immediate Sequential Bilateral Cataract Surgery (ISBCS) in the United States (US) and to compare their perspectives with those of European colleagues. Setting. Online refractive surgery forum. Design: A survey-based questionnaire. Methods: An electronic survey was emailed to all surgeon members of the Refractive Surgery Alliance (RSA) in the US. Participants were prompted to score their impressions regarding various aspects regarding ISBCS. Responses were compared to published reports conducted among European surgeons. Results: The electronic link to the survey was emailed to US-based surgeon members of the RSA, where 107 participated (44.6%). Twenty-seven (25.2%) reported that they currently perform ISBCS. Twenty-three (22.5%) of the respondents indicated they felt ISCBCS should be offered as a standard of care for routine cataract surgery. For surgeons that do not perform ISBCS, the most important factors were related to medicolegal issues and decreased reimbursement, whereas evidence of effectiveness and complications related to ISBCS were less important. Compared to practitioners abroad, 67.2% of European ophthalmic surgeons, compared to 25.2% of US surgeons, perform ISBCS (p < 0.0001). Conclusions: While US refractive surgeons often perform bilateral corneal procedures, many significant barriers exist to the widespread adoption of ISBCS. Concerns reported by US surgeons mirror those reported by surgeons in Europe. The majority of the US refractive surgeons in this survey indicate that ISBCS should not be the standard of care in routine cases, with the prevailing reason being concerns about decreased physician reimbursement and potential medicolegal issues, not safety.

Prevalence of laser vision correction in ophthalmologists who perform refractive surgery.

PURPOSE: To determine the prevalence of laser corneal refractive surgery (laser vision correction [LVC]) among ophthalmologists who perform these procedures and to assess the willingness of these ophthalmologists to recommend LVC to immediate family members. SETTING: Online survey with results analyzed at Surgivision Consultants, Inc., Scottsdale, Arizona, USA. DESIGN: Prospective randomized questionnaire study. METHODS: The 22-question Global Survey on Refractive Surgery in Refractive Surgeons was sent by e-mail to 250 ophthalmologists randomly selected from a database of 2441 ophthalmologists known to have performed LVC at some point in the past decade. Responses were solicited by e-mail, with subsequent telephone reminders to nonresponders. RESULTS: Responses were received from 248 (99.2%) of 250 queried individuals, of which 232 (92.8%) met the protocol criteria of currently working as refractive surgeons. Of the 232 subjects, 161 (69.4%) reported that they had refractive errors potentially amenable to treatment with LVC, not including presbyopia. Of the 161 ophthalmologists with treatable refractive errors, 54 (33.5%) reported they were not candidates for LVC for a variety of reasons and 107 (66.5%) reported they were candidates for LVC. Of the LVC candidates, 62.6% reported that they had an LVC procedure in their own eyes. Of the overall 232 subjects, more than 90% recommend LVC for adult members of their immediate family. CONCLUSIONS: Ophthalmologists who perform LVC were significantly more likely than the general population to have LVC in their own eyes. The prevalence of refractive errors was significantly higher among ophthalmologists performing refractive surgery than in the general population. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Phakic intraocular lens implantation in United States military warfighters: a retrospective analysis of early clinical outcomes of the Visian ICL.

PURPOSE: To assess short-term clinical outcomes after implantation of phakic intraocular lenses (Visian ICL, STAAR Surgical Co) in US military warfighters who are not good candidates for laser vision correction. METHODS: A retrospective interventional consecutive case series analysis of all eyes that underwent ICL surgery during a 14-month time period was performed. Main outcome measures included indications for surgery, efficacy, predictability, and early adverse events. RESULTS: Three-month postoperative visual data were available for 135 eyes of 69 patients who underwent ICL implantation during the study period. Indications included abnormal corneal topography (37%), thin predicted residual bed following LASIK (32%), history of dry eye (13%), thin corneal thickness (11%), or other (7%). Mean patient age was 30.9 ± 6.6 years. Mean preoperative spherical equivalent refraction was -6.00 ± 1.92 diopters (D) (range: -2.63 to -11.50 D). Three months postoperative, uncorrected distance visual acuity of 20/20 or better was found in 129/135 (96%) eyes and 91/135 (67%) were 20/15 or better. Manifest refraction and corrected distance visual acuity (CDVA) data were available for 128 eyes. Forty-two (33%) eyes had improvement of one or more lines of CDVA. One hundred fifteen eyes (90%) were within ± 0.50 D of emmetropia, and predictability within ± 0.75 D was found in 127/128 (99%) eyes. No significant intra- or postoperative complications were observed. CONCLUSIONS: This retrospective analysis of 3-month outcomes suggests that Visian ICL implantation in myopic warfighters provides excellent refractive and visual results. Further study is needed to evaluate long-term results.

LASIK for -6.00 to -12.00 D of myopia with up to 3.00 D of cylinder using the ALLEGRETTO WAVE: 3- and 6-month results with the 200- and 400-Hz platforms.

PURPOSE: To report the refractive results after LASIK for high myopia and cylinder at one center with one surgeon comparing two laser platforms. METHODS: A total of 206 eyes of 121 patients were treated for -6.00 to -12.00 diopters (D) of spherical equivalent refractive error with up to 3.00 D of cylinder. All eyes underwent LASIK with the ALLEGRETTO WAVE 200-Hz (n=141) or 400-Hz (n=65) laser (Alcon Laboratories Inc) between 2003 and 2009. Corneal flaps were created with the IntraLase femtosecond laser (Abbott Medical Optics) at an intended thickness of 100 or 110 µm in all cases. RESULTS: At 3- and 6-month follow-up in the 200-Hz group, 77% (109/141) and 86% (121/141) of eyes, respectively, were within ±0.50 D of intended correction. In the 400-Hz group, 98.5% (64/65) and 100% (65/65) of eyes were within ±0.50 D of intended correction at 3 and 6 months postoperatively. At 3- and 6-month follow-up, 84% (119/141) and 77% (109/141) of eyes, respectively, in the 200-Hz group and 80% (52/65) and 92% (60/65) of eyes, respectively, in the 400-Hz group had 20/20 or better uncorrected distance visual acuity. At 6-month follow-up, refractive predictability and visual acuity were statistically superior in eyes in the 400-Hz group (chi square, P<.01). No eyes underwent retreatment as a secondary procedure during the time of analysis. CONCLUSIONS: LASIK with the ALLEGRETTO WAVE 200- and 400-Hz laser is effective and predictable for the treatment of high myopia with astigmatism in appropriately selected patients. The acuity and predictability of refractive results may be slightly better when using the 400-Hz platform.

LASIK for mixed astigmatism using the ALLEGRETTO WAVE: 3- and 6-month results with the 200- and 400-Hz platforms.

PURPOSE: To report the refractive results after LASIK for mixed astigmatism at one center with one surgeon comparing two laser platforms. METHODS: A total of 137 eyes of 69 patients were treated with LASIK for mixed astigmatism up to 3.33 diopters (D) using either the ALLEGRETTO WAVE 200- or 400-Hz laser (Alcon Laboratories Inc) between April 2006 and December 2009. The degree of astigmatism was higher in the 400-Hz group. Corneal flaps were created with the IntraLase femtosecond laser (Abbott Medical Optics) in all cases. RESULTS: The refractive outcomes with both laser systems were statistically similar. At 6 months, 78% of eyes had 20/20 or better uncorrected distance visual acuity (UDVA) with all but one eye achieving 20/30 or better UDVA. At 6 months, 10% of eyes treated with the 200-Hz system lost one line of corrected distance visual acuity (CDVA) whereas no eyes treated with the 400-Hz system lost any lines of CDVA. Residual astigmatism was <0.50 D for all eyes treated with both platforms. CONCLUSIONS: Both laser platforms provided predictable and effective treatment of mixed astigmatism in the patient populations treated, with over 90% of eyes achieving UDVA of 20/25 or better 6 months after surgery.

Circular keratotomy to reduce astigmatism and improve vision in stage I and II keratoconus.

PURPOSE: To report the use of circular keratotomy in eyes with stage I and II keratoconus to reduce astigmatism. METHODS: A retrospective analysis was performed of all eyes operated from 1993 to 2006 by one surgeon using circular keratotomy for stage I and II keratoconus. Results were evaluated for reduction of corneal astigmatism, refractive stability, and change in best spectacle-corrected visual acuity (BSCVA). RESULTS: Forty-six eyes in 36 patients were evaluated. Corneal (keratometric) astigmatism and refractive astigmatism were significantly reduced, particularly in eyes with preoperative astigmatism > or = 2.00 diopters (D). Preoperative astigmatism correlated with reduction of astigmatism (R = 0.81). Astigmatism stabilized after 1 year in 64% of 28 eyes that were seen both within the first year after surgery and then at some time point > or = 2 years after surgery. In this group, astigmatism changed < or = 2.00 D in 94% of eyes between 1-year follow-up and the last examination. Mean BSCVA improved from 20/44 to 20/33 (P < .01), with 20 (43%) of 46 eyes gaining 2 lines or more, 22 (48%) of 46 eyes changing by less than 2 lines, and 4 (9%) of 46 eyes having a worse BSCVA at the last examination compared with preoperatively. CONCLUSIONS: Circular keratotomy provides significant reduction in astigmatism, improved BSCVA, and stabilization of astigmatic changes in most eyes, although some eyes show limited benefit. Eyes with higher preoperative astigmatism appear to be more likely to benefit from the procedure than those with lower preoperative astigmatism. Circular keratotomy also resulted in reasonable clinical results for the treatment of stage I and II keratoconus.

Wavefront-optimized versus wavefront-guided LASIK for myopic astigmatism with the ALLEGRETTO WAVE: three-month results of a prospective FDA trial.

PURPOSE: To compare visual outcomes using the WaveLight ALLEGRETTO WAVE to administer either wavefront-optimized (standard LASIK) or wavefront-guided (custom LASIK) treatments in myopic eyes. METHODS: In this prospective, open-label, multicenter study conducted in the United States, 374 eyes were randomized by alternating enrollment to receive either wavefront-optimized or wavefront-guided LASIK treatments with this laser platform. Bilateral treatments were administered, with both eyes of each patient receiving the same treatment. Corneal flaps were created using the IntraLase femtosecond laser. RESULTS: In this FDA clinical trial, results at 3 months postoperatively revealed that 93% of eyes in both cohorts receiving either wavefront-optimized or wavefront-guided treatments attained an uncorrected visual acuity (UCVA) of 20/20 or better. Seventy-six percent of eyes with the wavefront-optimized treatment and 64% of eyes with the wavefront-guided treatment achieved UCVA of 20/16 or better. None of the eyes that received either treatment lost two lines or more of best spectacle-corrected visual acuity (BSCVA). In addition, 58% of eyes with wavefront-optimized treatment and 62% of eyes with wavefront-guided treatment gained one line or more of BSCVA. None of the eyes in either treatment group underwent retreatment. CONCLUSIONS: In the majority of eyes, no statistically significant differences were found between either treatment group in regard to visual acuity and refractive outcomes. Wavefront-guided treatments are not required in most cases with this laser, but may be considered if the magnitude of preoperative root-mean-square (RMS) higher order aberrations is >0.35 microm. In this study population, 83% of eyes had preoperative RMS higher order aberrations of <0.3 microm.

Four-year postoperative results of the US ALLEGRETTO WAVE clinical trial for the treatment of hyperopia.

PURPOSE: To evaluate the long-term refractive stability after LASIK for hyperopia with the WaveLight ALLEGRETTO WAVE Excimer Laser System. METHODS: All 151 patients enrolled in the 2000-2002 FDA study of the ALLEGRETTO WAVE laser were contacted by the investigators approximately 4 years after study completion to be evaluated for refractive stability. RESULTS: A total of 127/290 (43.8%) eyes in 68/151 (45%) patients presented for re-examination. Mean time from the examination taken at the 6-month follow-up stability endpoint in the FDA trial (Stability Exam) to the Post-Approval Exam was 3.9+/-0.39 years (range: 3.2 to 4.9 years). Stability of the manifest refraction spherical equivalent (MRSE) within +/-1.00 D or less was seen in 119/127 (93.7%) eyes. Regression of effect of >1.00 D was seen in 6/127 (4.7%) eyes and progression of effect was seen in 2/127 (1.6%) eyes. Weak correlation of refractive changes with keratometry readings were seen in eyes that underwent >2.00 to 4.00 D treatment (R=0.31) and >4.00 D treatment (R=0.33), implying corneal remodeling may have played a role in the refractive change observed. CONCLUSIONS: Refractive stability within +/-1.00 D MRSE after hyperopic LASIK with the ALLEGRETTO WAVE excimer laser was seen in 93.7% of eyes at > or =3 years after surgery compared with 6-month follow-up, supporting the conclusion in the FDA trial that refractive stability occurred by 6 months postoperatively. Refractive changes associated with keratometry changes were not significant in eyes that underwent < or =2.00-D treatment.

Systematic evaluation of wavefront-guided outcomes.

PURPOSE: To present a format for reporting outcomes of aberrometer-guided refractive procedures. SETTING: SurgiVision Consultants, Inc., Scottsdale, Arizona, and Food and Drug Administration, Center for Devices and Radiological Health, Rockland, Maryland, USA. METHODS: Reports of standard refractive and visual outcomes (uncorrected visual acuity, manifest refractive spherical equivalent, best spectacle-corrected visual acuity) should be provided for any refractive surgery report. Comparison of postoperative uncorrected visual acuity to preoperative best spectacle-corrected visual acuity should be included. Aberration reports should convert 2nd-order terms to refractions (measured in diopters) and use standard refractive reporting methods. Changes in coma, spherical aberration, and root-mean-square changes should be described using statistical methods for aggregate data. Underlying statistics should be reported. RESULTS: Aberration changes are well described by the mean error of the attempted versus achieved outcomes, comparison of the mean changes, and stability over time. Ancillary plots include histogram representation of the postoperative scores. Additional reports of visual function should be included, as appropriate. CONCLUSION: Use of standardized tables and graphs permits qualitative and quantitative comparison of outcomes of refractive treatment with wavefront-guided lasers. Modifications of the recommended formats can be expected over time.

Femtosecond laser versus mechanical keratome flaps in wavefront-guided laser in situ keratomileusis: prospective contralateral eye study.

PURPOSE: To compare the outcomes of wavefront-guided laser in situ keratomileusis (LASIK) performed using the IntraLase femtosecond laser with the outcomes using the Hansatome mechanical microkeratome. SETTING: Private clinic, Overland Park, Kansas, USA. METHODS: In a prospective contralateral-eye study performed under institutional review board supervision, 51 consecutive patients (102 eyes) had bilateral wavefront-guided LASIK for myopia using the Alcon LADARVision laser. One eye of each patient was randomized to have the flap created with the IntraLase femtosecond laser and the other flap using a standard compression head Hansatome microkeratome. All other treatment parameters were the same. RESULTS: The IntraLase group had significantly better mean uncorrected visual acuity (UCVA) at all intervals from 1 day to 3 months postoperatively. The mean spheroequivalent at 3 months was more myopic with the Hansatome (-0.34 diopter [D] +/- 0.28 [SD]) than with the IntraLase (-0.19 +/- 0.24 D) (P<.01). The mean residual astigmatism at 3 months was also significantly higher in the Hansatome group than in the IntraLase group (0.32 +/- 0.25 D and 0.17 +/- 0.20 D, respectively) (P<.01). The differences in UCVA persisted after spheroequivalent outcomes were controlled for but equilibrated when the analysis was modified to control for manifest postoperative astigmatism. Aberrometry showed significantly higher astigmatism and trefoil in the Hansatome group. Recovery of corneal sensation and epithelial integrity was similar between groups. CONCLUSIONS: The statistically better UCVA and manifest refractive outcomes after LASIK with the IntraLase femtosecond laser may be the result of differences in postoperative astigmatism and trefoil. These findings are consistent with previous findings of better astigmatic outcomes with the IntraLase laser and may have clinical significance for wavefront-guided treatments.

Subjective assessment of mesopic visual function after laser in situ keratomileusis.

The authors' study evaluated subjective reports of mesopic visual function after LASIK for spherical and spherocylindrical myopia and evaluated whether age, pupil size, treatment amount, residual postoperative refractive error, or other factors correlated with subjective findings. Preoperative, 3-month, and 6-month subjective patient questionnaires were administered. Results for questions about glare with night driving and glare with bright lights were tallied and evaluated using standard statistical methods. The results indicated that subjective reports of mesopic visual function after myopia LASIK improve overall. Worsened symptoms are most likely to occur in eyes with poor refractive outcomes. Correction of residual refractive errors may improve night driving and glare symptoms after LASIK.

Comparison of the IntraLase femtosecond laser and mechanical keratomes for laser in situ keratomileusis.

PURPOSE: To compare laser in situ keratomileusis (LASIK) results obtained with the femtosecond laser (IntraLase Corp.) to those obtained using 2 popular mechanical microkeratomes. SETTING: Private practice, Greensboro, North Carolina, USA. METHODS: This retrospective analysis compared LASIK outcomes with the femtosecond laser to those with the Carriazo-Barraquer (CB) microkeratome (Moria, Inc.) and the Hansatome microkeratome (Bausch & Lomb, Inc.). The 3 groups were matched for enrollment criteria and were operated on under similar conditions by the same surgeon. RESULTS: There were 106 eyes in the IntraLase group, 126 eyes in the CB group, and 143 eyes in the Hansatome group. One day postoperatively, the uncorrected visual acuity (UCVA) results in the 3 groups were similar; at 3 months, the UCVA and the best spectacle-corrected visual acuity results were not significantly different. A manifest spheroequivalent of +/-0.50 diopter (D) was achieved in 91% of eyes in the IntraLase group, 73% of eyes in the CB group, and 74% of eyes in the Hansatome group (P<.01). IntraLase flaps were significantly thinner (P<.01) and varied less in thickness (P<.01) than flaps created with the other devices. The mean flap thickness was 114 microm +/- 14 (SD) with the IntraLase programmed for a 130 microm depth, 153 +/- 26 microm with the CB using a 130 microm plate, and 156 +/- 29 microm with the Hansatome using a 180 microm plate. Loose epithelium was encountered in 9.6% of eyes in the CB group and 7.7% of eyes in the Hansatome group but in no eye in the IntraLase group (P =.001). Surgically induced astigmatism in sphere corrections was significantly less with the IntraLase than with the other devices (P<.01). CONCLUSIONS: The IntraLase demonstrated more predictable flap thickness, better astigmatic neutrality, and decreased epithelial injury than 2 popular mechanical microkeratomes.