Comparing clinical outcomes of Optiwave Refractive Analysis, Lenstar, and surgeon's modified method for intraocular lens power calculation in Asian eyes.

The study aimed to compare the accuracy of intraocular lens (IOL) calculation to predict postoperative refraction by Optiwave Refractive Analysis (ORA), Lenstar LS 900, and the surgeon's Modify method in normal Asian eyes. The IOL power of the Lenstar group was calculated according to Lenstar LS 900, whereas the surgeon's Modify group used topography, axial length (AL) of Lenstar, and Barrett Universal II online formula. Intraoperative aphakic measurements and IOL power calculations were obtained with the ORA system. From the results acquired through Lenstar, Modify, and ORA, the surgeon used his judgment to select the actual IOL power. Postoperative manifest refraction spherical equivalent (MRSE) was obtained 2 months after surgery. The prediction error (PE) was calculated as the difference between the postoperative MRSE and the target refraction proposed by three methods. AL, anterior chamber depth (ACD, measured from corneal endothelium to lens), lens thickness (LT), and ACD + 1/2LT were also included in the survey. In 67 eyes, the average real PE was smaller for the Lenstar (0.06 ± 0.44) and Modify (- 0.05 ± 0.40) than for the ORA group (- 0.25 ± 0.60, p < 0.05). The ORA system demonstrated the best results of IOL power selection in eyes with a normal range of ACD + 0.5 LT (5.2-5.6 mm) in Asian eyes.

Effectiveness of reducing corneal astigmatism after combined high-frequency LDV Z8 femtosecond laser-assisted phacoemulsification and arcuate keratotomy.

Purpose: In this retrospective study, the efficacy of the FEMTO LDV Z8 Femtosecond Laser-Assisted Cataract Surgery (Femto Z8 FLACS) and the Femtosecond laser Arcuate Keratotomy (FSAK) in decreasing the corneal astigmatism was investigated. Methods: During FLACS, FSAK was positioned with the help of the FEMTO LDV Z8 laser at a diameter of 8.5 mm and an 80% depth. Before and 3 months after surgery, the astigmatism of the cornea was measured with the aid of Pentacam. The variables influencing the efficacy of FSAK were assessed using the multiple regression analysis technique. Vector analyses were carried out. To determine the net corneal alterations, the with-the-wound and against-the-wound variations were computed along the FSAKs' meridian. Results: This study investigated 80 eyes from 62 participants. The average keratometric astigmatism value was 0.92 ± 0.44 diopters (D). The average keratometric astigmatism decreased to 0.61 ± 0.45 D 3 months following FSAK compared to preoperative corneal astigmatism (p < 0.05). Additionally, there was a considerable decline in the percentage of eyes with ±0.5 D and ±1.0 D astigmatism, which reduced 3 months after surgery by 58% and 85%, respectively (p < 0.05). Conclusion: The FEMTO LDV Z8 laser can create an effective and precise arcuate keratotomy with an excellent safety profile, rapid recovery, and vision stability.

Comparison of cumulative dispersed energy between conventional phacoemulsification and femtosecond laser-assisted cataract surgery with two different lens fragmentation patterns.

The purpose of the study is to compare the total ultrasound power used between eyes undergoing different lens fragmentation patterns of femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification surgery (CPS). A total of 506 patient eyes underwent preoperative grading of lens opacity using the Lens Opacity Classification System III (LOCSIII). The eyes were divided into two subgroups: subgroup 1 had a LOCSIII grade of 1-3, and subgroup 2 had a LOCSIII grade of 4-6. The eyes underwent FLACS (LenSx) for clear corneal wound, capsulotomy, and lens fragmentation. Either a grid pattern or radial pattern was used for lens fragmentation. The eyes received one of the following three treatments: (1) CPS without femtosecond laser assistant, (2) FLACS with a grid pattern (FGP) lens fragment, or (3) FLACS with a quadrant pattern (FQP) lens fragment. The mean cumulative dispersed energy (CDE) for each subgroup and treatment was evaluated. The mean CDE was lower in the two FLACS groups (1.21±1.91 in FGP and 1.22±1.92 in FQP) than that in the CPG group (2.67±2.84). In subgroup 1, CDE was higher in the CPG group (1.54±1.18) as compared with the FLACS groups (0.16±0.31 in FGP and 0.74±1.17 in FQP; P<0.001). In subgroup 2, CDE was higher in the CPG (6.47±3.46) as compared with the FLACS groups (2.74±2.21 in FGP and 5.34±2.17 in FQP; P<0.001). CDE was lower in the two FLACS groups than that in the CPS group, and CDE was the lowest with FGP in both subgroups 1 and 2.

Surgical outcomes with high and low pulse energy femtosecond laser systems for cataract surgery.

Currently, there is no clear consensus in cataract surgery if low compared to high energy femto-lasers may enable better capsulotomy quality and induce lower inflammatory response. Therefore, the aim of this study was to compare the intra-operative outcomes achieved with high and low pulse energy femtosecond laser systems for cataract surgery. The charts of 200 eyes of 200 patients aged 68.3 ± 10.3 years who had undergone femtosecond laser-assisted cataract surgery using either group 1 high pulse energy: LenSx (Alcon Laboratories) (N = 100) or group 2 low pulse energy: FEMTO LDV Z8 (Ziemer) (N = 100) laser were reviewed retrospectively. Integrity of anterior capsulotomy, classified as (1) complete (free-floating or with minor microadhesions), (2) incomplete and (3) with capsular tears, intraoperative completeness of the clear corneal incisions (CCI, main incision and side port), incidences of intraoperative miosis and incidence of subconjunctival hemorrhage were evaluated and compared between the two groups. The proportion of complete capsulotomies was significantly higher in the group 2 than the group 1 (100% vs 94%; p = 0.03). The incidences of intraoperative miosis (0% vs 19%) and subconjunctival hemorrhage (1% vs 63%) were significantly lower in the group 2 than the group 1 (p < 0.001). Completeness of the main incision was comparable (97% vs 95%; p = 0.721) between the two groups. Although not statistically significant, the completeness of side-port incision was slightly better in the group 2 than the group 1 (91% vs 86%). Low energy laser system performed significantly better in terms of completeness of capsulotomy, intraoperative miosis and sub-conjunctival hemorrhage, compared with high energy laser; the CCI outcomes were comparable.

A Novel Sequential Docking Technique: Use of Femtosecond Arcuate Keratotomy and Femtosecond Assisted Cataract Surgery Using a Pupil Expansion Ring on a Patient with Intraoperative Floppy Iris Syndrome.

PURPOSE: The purpose of this study was to evaluate the efficacy of a novel double-docking technique, incorporating the use of femtosecond laser arcuate keratotomy (FSAK) in correcting low-degree astigmatism and Malyugin ring, in a patient with intraoperative floppy iris syndrome (IFIS). METHODS: A case report of a 72-year-old man with grade 4 cataract, low-degree astigmatism (<2D), and IFIS (pupil size <4 mm, intraoperatively) is presented. The patient underwent cataract surgery using a femtosecond laser to treat low-degree astigmatism because the patient requested for the use of a multifocal  intraocular lens (IOL). The first docking was performed to complete arcuate keratotomy, produce the mainparacentesis incisions, and create clear corneal incisions. Insertion of the Malyugin ring was performed after the first docking, whereas the second one was executed to complete continuous curvilinear capsulotomy and lens fragmentation. The patient's uncorrected visual acuity (UCVA) was measured pre- and post-operatively. The complications were evaluated post-operatively and 3 months later during the follow-up visit. RESULTS: The patient's UCVA for distance improved from 0.3 (6/12 Snellen equivalent) to 0 (6/6 Snellen equivalent) logMAR post-operatively. During the follow-up visit, the patient's uncorrected near visual acuity was at J2. His corneal astigmatism changed from -1.0 Diopter @177° pre-operative to -0.12 D @173° post-operative. No other intraoperative or post-operative complications were observed. CONCLUSION: The double-docking technique, with the use of FSAK, and Malyugin ring produced successful surgical outcomes for the patient. The benefits of this technique allow surgeons to avoid changing the shape of the patient's cornea from the injection of the viscoelastic device into the anterior chamber, which could lower the femtosecond laser's precision and docking location.

A novel minimal fluid technique for effective and safe lens hydrodissection during cataract surgery.

Traditional hydrodissection may cause posterior capsule rupture (PCR) if excessive fluid accumulates. In this study, we describe the successful application of a novel minimal fluid hydrodissection technique in 100 consecutive cataract surgery cases. This technique separates the nucleus from the capsule utilizing low hydrostatic pressure and precise kinetic movement of a small volume (around 0.2 cc) of balanced salt solution. There were no instances of PCR. This technique is suitable for a range of cases, including femtosecond laser-assisted cataract surgery and posterior subcapsular cataract.

Novel method for preventing cyclorotation in Ziemer Femto LDV Z8 femtosecond laser-assisted cataract surgery with Verion image-guided system.

PURPOSE: To investigate the feasibility of a new method involving the use of the Verion image-guided system in preventing cyclorotation during femtosecond laser-assisted cataract surgery (FLACS). PATIENTS: Our preliminary data included details of 24 consecutive patients. All patients underwent cataract surgery at Universal Eye Center, Zhong-Li, Taiwan, between December 2016 and January 2017. METHODS: We developed a technique to use the Verion image-guided system in FLACS and evaluated whether this new technique is compatible with Femto LDV Z8. The Verion image-guided system was used to prevent misalignments. The only additional step in this technique is using a marking tool to place ink on the corneal limbus (at 3 and 9 o'clock positions) guided by the Verion digital marker system. Remaining procedures could be performed using the touchscreen of Femto LDV Z8 to calibrate the horizontal reference axis. RESULTS: This study included 24 patients who underwent cataract surgery. The technique used could effectively neutralize misalignments at an average of 8.08° and 2.66° in clockwise and counterclockwise directions, respectively. CONCLUSION: This technique combines the advantages of iris fingerprinting technology and mobile features of Femto LDV Z8, has fewer transfer steps, improves centration of the eyes, and, most importantly, can prevent misalignments through cyclotorsion or docking procedures. Furthermore, this method can improve the accuracy of arcuate incisions and toric intraocular lens alignment in astigmatism correction.

Comparison of corneal power obtained from VERION image-guided surgery system and four other devices.

PURPOSE: To assess the corneal keratometric values obtained using the VERION image-guided surgery system and other devices. METHODS: This study evaluated the right eyes of 115 cataract patients before intraocular lens (IOL) implantation through consecutive tests using 5 devices: VERION Reference Unit, Placido-based corneal topography (OPD-Scan III), monochromatic light-emitting diodes (LenStar LS900 and AL-Scan), and rotary prism technology (auto kerato-refractometer KR-8800). Analyzed parameters were corneal steep and flat keratometric values (Ks and Kf) and corneal astigmatism and axis. These parameters were evaluated using the one-sample two-tailed t-test and the 95% limits of agreement (95% LOAs) between the devices. RESULTS: The mean corneal cylinder value measurements were -0.97±0.63 D, -0.88±0.60 D, -0.90±0.69 D, -0.90±0.67 D, and -0.83±0.60 D with VERION, LenStar, AL-Scan (2.4 mm), OPD III, and KR-8800, respectively. Only KR-8800 showed a significant difference from VERION in the corneal cylinder value (P<0.05). The mean differences in the Kf and Ks of VERION compared to those of OPD III were 0.18±0.45 D and 0.17±0.38 D (P<0.05), respectively. The 95% LOAs of Bland-Altman analysis for the corneal astigmatism axis of the VERION with LenStar, AL-Scan (2.4 mm), OPD III, and KR-8800 were -26.25° to 58.71°, -20.61° to 47.44°, -25.03° to 58.98°, and -27.85° to 65.17°, respectively. CONCLUSION: None of the VERION parameters were significantly different from those of AL-Scan and LenStar. AL-Scan (2.4 mm zone) was especially similar to VERION. Wide LOAs are potential contributors to axis error in patients with toric IOL implants.

Influences of Flap Shape and Hinge Angle on Opaque Bubble Layer Formation in Femtosecond Laser-Assisted LASIK Surgery.

PURPOSE: To evaluate the effects of different flap shapes and hinge angles on opaque bubble layer (OBL) formation using a femtosecond laser for flap creation in LASIK surgery. METHODS: This retrospective study evaluated 138 eyes of 73 patients who underwent femtosecond laser-assisted LASIK with a 150-kHz IntraLase femtosecond laser (Abbott Medical Optics, Inc., Santa Ana, CA) for myopic astigmatism and compared differences between different flap shapes and hinge angles on OBL formation. The surgical procedures were videotaped, and the patterns and sizes of the OBLs seen during surgery were analyzed. Preoperative and postoperative data including patient demographics, refractive status, keratometry, central corneal thickness, and intraoperative data (flap size and pocket parameters) were recorded. The eyes were divided into four groups based on the corneal flap shape (elliptical versus round) and hinge angle (50° versus 60°). RESULTS: The preoperative demographic data, mean spherical errors, cylindrical power, and central corneal thickness were not significantly different among the groups. Of the 138 eyes, 107 (77%) developed an OBL covering a mean area of 13.8% ± 12.6% in each case. This area was significantly smaller in the elliptical flap with 60° hinge angle group (P < .05). CONCLUSIONS: An oval-shaped flap with a larger hinge angle tended to result in less OBL formation in femtosecond laser-assisted LASIK. [J Refract Surg. 2017;33(3):178-182.].

A comparison of three different corneal marking methods used to determine cyclotorsion in the horizontal meridian.

During toric intraocular lens (IOL) implantation, surgeons must take particular care to ensure that inaccurate preoperative measurement and intraoperative misalignment do not cause unexpected postoperative residual astigmatism. This retrospective, comparative case series study aimed to analyze the rotational deviation, or cyclotorsion, of three corneal marking methods: VERION digital marker (VDM; reference), horizontal slit beam marking (HSBM), and subjective direct visual marking (SDVM) on the table (using a bevel knife tip). Subjects included 81 eyes of 61 patients (mean age: 65.70±13.14 years; range: 32-91 years) undergoing scheduled cataract surgery. A preoperative reference image was taken of each eye. Subsequently, a slit lamp with the light beam turned to the horizontal meridian was used to align the seated patient's head, and two reference marks were placed at the 3- and 9-o'clock positions of the corneal limbus using a 27-gauge needle and marking pen (HSBM). Upon transfer to the surgical table, the VDM was used to display a real-time dial scale on the patient's eye, with the entrance of the temporal clear corneal incision (CCI) at 0° (horizontal meridian). Simultaneously, a bevel knife tip was used to create a marker based on the surgeon's visual determination of the temporal 0° point (SDVM). We used the VDM to quantitatively evaluate the accuracy of axis alignment via deviation from the horizontal reference meridian. Compared with the reference meridian, the SDVM (-3.46°±7.32°, range: -18° to 13°) exhibited greater average relative cyclotorsion versus the HSBM (0.41°±4.92°, range: -10° to 10°). Furthermore, the mean average misalignment was significantly less in the HSBM group versus the SDVM group (t=4.179, P<0.001). The VDM is likely a reliable marking method, similar to the HSBM. In contrast, the SDVM is not entirely reliable. The VDM usage may prevent inaccurate preoperative manual marking during toric IOL implantation.

Blood pressure change during phacoemulsification and femtosecond laser-assisted cataract surgery.

AIM: To evaluate blood pressure (BP) changes during phacoemulsification (PC) and femtosecond laser (FSL)-assisted cataract surgery. METHODS: A retrospective chart review was performed for all patients who received traditional phacoemulsification surgery (PC group) and FSL-assisted cataract surgery (FS group) from July 2013 to December 2014. Totally 206 eyes from 133 patients receiving the two types of procedures were included. Patient characteristics (age, gender, and hypertension history), pre- and post-operative BPs were collected. RESULTS: The pro-operative systolic and diastolic BPs (mm Hg) were 124.89±20.48 vs 126.98±16.85, and 71.88±9.81 vs 73.56±10.03, in PC and FS groups, respectively. While the post-operative systolic and diastolic BPs (mm Hg) were 130.13±22.59 vs 134.77±17.52, and 73.41±11.62 vs 78.89±12.2, in PC and FS groups, respectively. Paired-sample t-tests showed obvious systolic and diastolic BP elevations in FS group after surgery (P=0.001 and 0.007) and no reliability in PC group (P=0.094 and 0.359). A linear regression model revealed systolic and diastolic BP elevations, which were related to longer surgical times for FS group (P=0.008 and 0.021). Age, gender, and hypertension history were not correlated with blood pressure elevation in either group. CONCLUSION: BP increases but at a limited level after FSL-assisted cataract surgery compared to traditional phacoemulsification.

Factors associated with subsequent eye care for children in Taiwan: a population-based historical cohort study.

PURPOSE: To investigate patterns and factors associated with subsequent eye care for Taiwan's children. METHODS: We conducted a population-based historical cohort study of 2464 children aged between 3 and 12 years old from the 2005 National Health Interview Survey (NHIS). Participants' ocular conditions were identified based on 2005 NHIS questionnaire answers given by caregivers. Subsequent eye care data was obtained from 2006 and 2007 National Health Insurance claim data. Eye care related to these children's ocular conditions was defined by physician's diagnosis using the International Classification of Diseases version 9 clinical modification codes. Poisson regression with robust variance estimation was used to determine factors associated with eye care use. RESULTS: Of the 2464 children, 712 (28.9%) had ocular conditions in 2005, and 56.5% and 44.7% of them didn't receive eye care during the subsequent 1- and 2-year periods, respectively. Among those with ocular conditions, the 3-4-year-olds were least likely to receive eye care in the subsequent 1 and 2 years. Children with highly educated fathers were more likely to receive eye care in the subsequent 1-year period. Sex, family income, level of mother's education, residential area and eye care resources were not significant factors for children with ocular conditions receiving subsequent eye care within either 1 or 2 years. CONCLUSIONS: Despite the fact that Taiwan has a National Health Insurance Program, lack of subsequent eye care remains high, even when a child's ocular condition is known by the caregiver. Determinants associated with follow-up eye care must be considered when designing eye care enhancing programs for children.

The association between physical disability and eye care utilization among elderly population in Taiwan: a nationwide cohort study.

Medical utilization by elderly population is influenced by a number of factors, and physical disabilities may play an important role. Despite the fact that extensive studies have been carried evaluating medical utilization by older individuals, little is known regarding the impact of physical disabilities on eye care utilization. Using datasets from the Taiwan National Health Interview Survey and National Health Insurance (NHI) system, a sample of 1726 elderly people was obtained for analysis. Older persons with worse Activity of Daily Living (ADL) disabilities were less likely to have eye care (odds ratio (OR): 0.39, 95% confidence interval (CI): 0.25-0.62), but elderly who had Instrumental Activity of Daily Living (IADL) disabilities alone were not associated with lower odds (OR=0.86, 95% CI=0.61-1.20). In addition to the above, female individuals (OR=1.91, 95% CI=1.44-2.53), those with poorer vision (OR=1.89, 95% CI=1.36-2.62), those having eye discomfort (OR=1.66, 95% CI=1.26-2.18 and OR=2.14, 95% CI=1. 32-3.46 respectively for mild and more than moderate eye discomfort), and those with severe eye disease (OR=1.96, 95% CI=1.23-3.10) were more likely to undergo eye care. In conclusion, physical disability is a strong risk factor for lack of eye care utilization among older Taiwanese. The barriers associated with low eye care utilization among individuals with ADL disabilities should be explored in order to facilitate effective policy implementation among those elderly with disabilities so that they are able to receive appropriate eye care.

Label-free structural characterization of mitomycin C-modulated wound healing after photorefractive keratectomy by the use of multiphoton microscopy.

We applied multiphoton autofluorescence (MAF) and second-harmonic generation (SHG) microscopy to monitor corneal wound healing after photorefractive keratectomy (PRK). Our results show that keratocyte activation can be observed by an increase in its MAF, while SHG imaging of corneal stroma can show the depletion of Bowman's layer after PRK and the reticular collagen deposition in the wound healing stage. Furthermore, quantification of the keratocyte activation and collagen deposition in conjunction with immunohistochemistry and histological images demonstrate the effectiveness of mitomycin C (MMC) in suppressing myofibroblast proliferation and collagen regeneration in the post-PRK wound healing process.

An interval-censored model for predicting myopic regression after laser in situ keratomileusis.

PURPOSE: A time-varying statistical model was proposed to predict the risk of regression toward myopia after laser in situ keratomileusis (LASIK) and to identify significant predictors within a time frame. METHODS: A total of 615 eyes of 311 patients derived from a retrospective cohort who underwent LASIK in 2003 were analyzed. Refraction outcomes were recorded at 1 day, 1 week, and 1, 3, 6, 9, and 12 months or longer after LASIK. A cross-validated design was used, to split data into trained (n = 308) and validated (n = 307) data sets. These data sets were used in an interval-censored model to predict the probability of regression toward myopia and to assess the predictors including demographic features and preoperative and postoperative variables. RESULTS: Myopia regression was observed in 164 (26.7%) of 615 eyes during the follow-up period of 12 months or longer after LASIK. Significant predictors for myopia regression after LASIK included preoperative manifest spherical equivalent (P = <0.0001), mean preoperative central corneal curvature (P = 0.001), size of optic zone (P = 0.0043), undercorrection (P = 0.04), and age (P = 0.0734). The risk of regression toward myopia after LASIK increased rapidly within 1 month, slowed down between 1 and 6 months, and became steady after 6 months, regardless of risk group. The risk of myopia regression up to 6 months after LASIK was 21% in average-risk eyes (based on all eyes). CONCLUSIONS: The proposed interval-censored model was useful not only for predicting the probability of myopia regression after LASIK but also for identifying the evolution of patients within low, moderate, and high-risk groups.

Effect of tear film break-up on higher order aberrations of the anterior cornea in normal, dry, and post-LASIK eyes.

PURPOSE: To evaluate the effects of tear film breakup on higher order aberrations of the anterior cornea in normal, dry, and post-LASIK eyes. METHODS: In a prospective study, 120 eyes (120 subjects) comprised three groups: post-LASIK eyes, dry eyes, and normal eyes. Tear film break-up time (BUT) was measured by fluorescein dye under slit-lamp microscopy. Corneal topographies were measured by videokeratography immediately after the following times: post-blink, 1/2 BUT, BUT, and after normal saline application. VOL-Pro software processed topographies to obtain and analyze higher order aberrations (3rd through 6th orders over 6 mm) of the anterior comeal surface. RESULTS: The measurement time scale was set by the BUT: significantly less for dry eyes (8.3 +/- 3.4 seconds) than post-LASIK eyes (11.3 +/- 5.1 seconds) or normal eyes (10.3 +/- 5.6 seconds). Normal and dry eye subjects showed a pattern of significant increase of aberrations from post-blink through BUT and decrease of aberrations after saline addition in coma, trefoil, and 3rd through 6th order aberrations. Post-LASIK eyes exhibited no significant difference between phases. CONCLUSIONS: Disruption of the tear film increases anterior corneal higher order aberrations in normal eyes and more rapidly in dry eyes. The increase in aberrations caused by conventional LASIK is greater than that of tear film-related effects.