Difference In Uncorrected Visual Acuity Research Articles

Comparison of errors in ablation depth calculation after myopic femtosecond laser in situ keratomileusis in patients with different degrees of myopia: a prospective study

BackgroundTo investigate the difference between the predicted preoperative corneal ablation depth and the measured ablation depth for femtosecond laser in situ keratomileusis (FS-LASIK) in patients with different degrees of myopia, and to analyze the source of the difference.MethodsA total of 55 patients (109 eyes) were included in this study. Multiple logistics regression was applied to analyze the sources affecting postoperative refractive outcomes. The difference between the preoperative predicted corneal ablation depth and the 1-day postoperative ablation depth in patients with different degrees of myopia was explored using linear regression. Corneal biomechanical parameters influencing error in ablation depth calculation were examined using multiple linear regression.ResultsOne hundred and nine eyes were divided into low to moderate myopia (55 eyes, myopia of 6 D or less), high myopia (45 eyes, myopia ranging from 6 D to a maximum of 9 D), and very high myopia group (9 eyes, myopia greater than 9 D) based on preoperative refractive error (spherical equivalent). Postoperative visual outcomes were comparable among the three groups of patients, with no significant difference in uncorrected visual acuity (UCVA). We did find notable disparities in spherical equivalent (SE) and central corneal thickness (CCT) in patients with different degrees of myopia at 1 day postoperatively (all p < 0.001). Logistic regression analysis showed that error in ablation depth calculation was an independent risk factor for refractive outcomes one day after surgery (OR = 1.689, 95% CI: 1.366 – 2.089). There was a substantial discrepancy in error in ablation depth calculation at 1 day postoperatively between the three groups. The measured ablation depth of the laser platform was lower than the predicted ablation depth in the low to moderate myopia and very high myopia groups, but the opposite was true in the high myopia group. Pre-operative SE (p < 0.001) and corneal front minimum radius of curvature (Front Rmin) (p = 0.007) obviously influenced the error in ablation depth calculation.ConclusionsError in ablation depth calculation values vary significantly between patients with different degrees of myopia and correlate highly with preoperative SE and Front Rmin. At the same time, the available evidence suggests that error in ablation depth calculation is an influential factor in postoperative refractive status, so it is imperative to control error in ablation depth calculation.

Topography-guided transepithelial corneal collagen cross-linking by sequential ultraviolet A irradiation in different diameters for progressive keratoconus in adults

Objective: To compare the efficacy and safety of a novel customized topography-guided transepithelial corneal collagen cross-linking (TG-CXL) procedure by sequential ultraviolet A irradiation in different diameters and conventional transepithelial corneal collagen cross-linking (TE-CXL) in adult patients with progressive keratoconus. Methods: A prospective cohort study was conducted. Adult patients diagnosed with progressive keratoconus in the Affiliated Xiamen Eye Center of Xiamen University were continuously recruited and randomly assigned to receive the TG-CXL or TE-CXL procedure from March 2020 to March 2021. Patients in the TE-CXL group were irradiated in the central 9-mm zone of the cornea (total energy, 7.2 J/cm2; irradiance, 45 mW/cm2), while patients in the TG-CXL group were first irradiated with the protocol used in the TE-CXL group, and further irradiated in the central 6-mm zone (total energy, 3.6 J/cm2; irradiance, 9 mW/cm2). The subjective symptom of pain and corneal fluorescein sodium staining were scored within postoperative 3 days. Slit lamp examination, measurements of uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), corneal topography, anterior segment optical coherence tomography, in vivo corneal confocal microscopy, corneal endothelial cell count, and non-contact tonometry were performed before surgery and at 3, 6, and 12 months after surgery. Results: A total of 66 patients were enrolled (mean age, 23.0±3.3 years old), with 33 patients (33 eyes) in each group. No statistically significant differences were found in age, gender, and maximum keratometry (Kmax) between the two groups (P>0.05). On day 1 after surgery, the average pain score of the TG-CXL group (2.21±0.45) was significantly higher than that of the TE-CXL group (1.32±0.33) (P<0.05). The pain was rapidly alleviated in both groups on days 2 and 3. On days 1 and 2, the corneal fluorescein sodium staining scores in the TG-CXL group (4.15±0.83 and 2.21±0.60, respectively) were significantly higher than those in the TE-CXL group (1.76±0.56 and 0.85±0.51, respectively, P<0.001), while there was no significant difference between the two groups at day3 (P=0.184). The UCVA and BCVA of the TG-CXL group at 3, 6, and 12 months after surgery were significantly improved when compared with the baseline. At 3, 6, and 12 months, the BCVA (LogMAR) of the TG-CXL group (0.21±0.15, 0.22±0.16, and 0.22±0.16, respectively) were significantly improved when compared with those of the TE-CXL group(0.32±0.15, 0.34±0.15, and 0.36±0.16, respectively, P<0.01). However, there was no significant difference in UCVA between groups at any time point after surgery (P>0.05). The spherical and cylindrical power values of the TG-CXL group were improved when compared with the baseline (P<0.05). However, no significant difference in spherical power values was found between the two groups at any time point after surgery (P>0.05). Meanwhile, there were significant differences in cylindrical power values between the two groups at 6 and 12 months after surgery (P<0.05). The Kmax in the TG-CXL group was improved at all of the time points after surgery when compared with the baseline (P<0.001), while no significant difference in Kmax was found at any time point after surgery in the TE-CXL group when compared with the baseline (P>0.05). At 6 and 12 months after surgery, the Kmax values in the TG-CXL group were significantly lower than the TE-CXL group (P<0.05). No significant differences were found in flat keratomety, steep keratometry, the minimal thickness of the cornea, endothelial cell density, and intraocular pressure between the two groups at any time point after surgery (P>0.05). Within one month after surgery, optical coherence tomography revealed the increased density in the anterior stroma in both groups. In most patients in the TG-CXL group, a demarcation line was visible in the central and para-central corneal stroma, representing a clear and continuous, high-signal arc-shaped linear structure, which was deeper in the central cornea than the para-central cornea. In contrast, a demarcation line, fuzzy and focally discontinuous, was visible only in a few patients in the TE-CXL group, with an almost uniform depth in the central and the para-central cornea. Confocal microscopy demonstrated an apparent mesh-like cross-linked collagen structure in the superficial and intermediate corneal stroma at all time points after surgery in the TG-CXL group, with thickening stromal collagen fibers and an increased number of interconnections. In contrast, the mesh-like structure and number of interconnections in the superficial corneal stroma were significantly reduced at 12 months after surgery in the TE-CXL group, with no cross-linking structure in the intermediate corneal stroma at any time point after surgery. No serious complications such as corneal infection, sterile corneal ulcer, and persistent epithelial defect were observed in both groups during the follow-up of 12 months. Conclusions: The TG-CXL procedure by sequential irradiation in two different diameters with ultraviolet A light was effective and safe in the management of progressive keratoconus in adults, achieving significant refractive improvement. This might be a good technical alternative for refractive corneal cross-linking surgery.

23G Minimally Invasive Vitrectomy Combined with Glaucoma Drainage Valve Implantation and Phacoemulsification Cataract Extraction for Neovascular Glaucoma Secondary to Proliferative Diabetic Retinopathy with Vitreous Hemorrhage.

Objective To evaluate the clinical efficacy of the combined application of 23G minimally invasive vitrectomy, glaucoma drainage valve implantation, and phacoemulsification cataract extraction in the treatment of neovascular glaucoma (NVG) secondary to proliferative diabetic retinopathy (PDR) combined with vitreous hemorrhage (VH). Methods Eighty-three patients (91 eyes) with PDR diagnosed as NVG phase III complicated with VH from June 2018 to May 2020 were selected as the study subjects. The subjects were randomly divided into 3 groups: group A was treated with 23G minimally invasive vitrectomy combined with glaucoma drainage valve implantation; group B was given 23G minimally invasive vitrectomy combined with phacoemulsification cataract extraction; and group C was treated with 23G minimally invasive vitrectomy combined with glaucoma drainage valve implantation and phacoemulsification cataract extraction. The uncorrected visual acuity (UCVA), intraocular pressure (IOP), and iris neovascularization (INV) scores were recorded and compared among the 3 groups before and after operation, and then the postoperative pain relief and complications were observed. Results Through observation, there was no significant difference in the UCVA, IOP, and INV scores in the 3 groups before operation. After the operation, the UCVA, IOP, and INV scores of the 3 groups were significantly lower than those before operation. After operation, the UCVA of the 3 groups increased first and then decreased, and it improved most significantly in the 3rd month after operation and decreased in the 4th month after operation. There were significant differences in UCVA among the 3 groups at each time point after operation. From the 1st day to the 6th month after operation, the IOP of the 3 groups showed an upward trend, and there was no significant difference among the 3 groups in IOP at each time point after operation. At the 1st, 3rd, and 6th months after operation, the INV score of group A and group B was higher than that of group C. There was no significant difference in the INV score between group A and group B. The incidence of complications was not significantly different among the 3 groups. Conclusion 23G minimally invasive vitrectomy, glaucoma drainage valve implantation, and phacoemulsification cataract extraction can effectively improve the UCVA, IOP, and INV scores of NVG secondary to PDR with VH, and the combined application of the 3 methods has better security.

Comparison of the efficacy of lotrafilcon B and comfilcon A silicone hydrogel bandage contact lenses after transepithelial photorefractive keratectomy.

At completion of transepithelial photorefractive keratectomy (t-PRK) surgery, the eye is usually fitted with a bandage contact lens to reduce discomfort and promote epithelial healing. This study aimed to compare the outcomes of eyes fitted with lotrafilcon B versus comfilcon A, silicone hydrogel bandage contact lenses after t-PRK for the correction of low to moderate myopia, with or without astigmatism. In this comparative, prospective study, patients with myopia < -6 D with or without astigmatism (< 1.75 D), who underwent t-PRK between January and June 2018, were randomly allocated to the lotrafilcon B and comfilcon A groups. Preoperative characteristics, including age, sex, eye treated, uncorrected visual acuity (UCVA), best-corrected visual acuity, mesopic pupil size, central corneal thickness, and refractive error were recorded. Postoperatively, pain score, UCVA, and corneal epithelial defect size on days 1, 4, and 7 were compared between the two groups. Twenty-nine eyes were included in each group. Demographic characteristics and preoperative measurements were similar between the two groups. UCVA was significantly improved on day 7 as compared to day 1 in the comfilcon A group (P = 0.03), but remained the same in the lotrafilcon B group (P = 0.70) as on day 1 postoperatively. There was no significant difference in UCVA between the two groups at any follow-up visits (all P > 0.05). The pain score on the first postoperative day was significantly higher in the lotrafilcon B-fitted eyes than in the comfilcon A group (P < 0.001), but was significantly reduced in both groups compared to day 1 (both P < 0.001). The epithelial defect in the comfilcon A group was significantly greater than in the lotrafilcon B group (P < 0.001) at day 1 postoperatively, with significant improvement in both groups (both P < 0.001). Healing responses were better with lotrafilcon B than with comfilcon A bandage contact lenses. The patients had a greater mean pain score with lotrafilcon B than with comfilcon A lenses on the first postoperative day, yet the final outcome was comparable between the two groups. We did not encounter any postoperative complications related to contact lens wear.

Comparison of corneal aberrations and refractive outcomes after small-incision lenticule extraction and femtosecond-assisted laser-assisted in situ keratomileusis.

To retrospectively compare the short-term refractive outcomes and corneal aberrations after small-incision lenticule extraction (SMILE) and femtosecond-assisted laser-assisted in situ keratomileusis (FS-LASIK) combined with smart pulsetechnology (SPT) in patients with compound myopicastigmatism. A total of 91 eyes (91 patients) were included, 43eyes in FS-LASIK group and 48 eyes in the SMILE group. Uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), refractive results and corneal topography were evaluated 1 and 3months postoperatively. Corneal aberrations of anterior corneal surface were calculated from the topography data over 6mm-diameter. There was no significant difference in UCVA, BCVA, and refractive results between the two groups. There were no statistical difference in TIA (target induced astigmatism), SIA (surgery induced astigmatism), DV (difference vector), ME (magnitude of error), AE (angle of error), AE (absolute value) and CI (correction index) between both groups at 1 and 3months. Coma and spherical aberration improved in all the patients in both groups at 1 and 3months postoperatively. The amount of induced spherical aberrations was higher in FS-LASIK group compared to SMILE group. Both FS-LASIK and SMILE achieved similar refractive outcomes in patients with myopia and compound myopic astigmatism. FS-LASIK combined with SPT resulted in higher spherical aberration than SMILE in early postoperative period.

Comparison of early visual quality in patients with moderate myopia using different optical zones in small incision lenticule extraction (SMILE)

BackgroundThe early visual qualities of patients with moderate myopia were evaluated after small incision lenticule extraction (SMILE) using different optical zones.MethodsIn this retrospective case study, 27 cases (51 eyes) were selected, including 10 cases in Group A (19 eyes), 6.6–6.8 mm in the optical zone, 10 cases in Group B (19 eyes), 6.4–6.5 mm in the optical zone, and 7 cases in Group C (13 eyes),6.1–6.3 mm in the optical zone. The following items were examined preoperatively and 1 month postoperatively: uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), spherical, cylinder, central corneal thickness (CCT), corneal mean curvature (CMC), total ocular aberrations (TA), total low order aberrations (tLOAs), defocus, astigmatism and total high order aberrations (tHOAs), spherical, coma, trefoil, modulation transfer function (MTF), MTFcutoff, SR, objective scatter index (OSI), point scatter function at 50 and 10% (PSF50%, PSF10%), and contrast visual acuity of 100, 20, and 9% (VA100%, VA20%, and VA9%). We compared the three groups by Kruskal-Wallis test. Wilcoxon signed ranks test was used for each group before and 1 month after surgeries. P< 0.05 was considered statistically significant.ResultsThere was no significant difference in UCVA, BCVA, CCT, cylinder, and CMC in three groups preoperatively and 1 month postoperatively (P> 0.05). Comparison of the aberrations of the three groups showed statistically significant difference only in TA, tLOA, defocus, astigmatism and SA preoperatively, and trefoil 1 month postoperatively(P< 0.05). The postoperative TA, tLOAs, defocus, astigmatism and trefoil of the three groups were lower than those before surgeries (P< 0.05). The postoperative tHOAs of Group B and C was lower than those before surgeries (P< 0.05). The MTF results showed that before surgeries, there were significant differences in three groups (P< 0.05) in spatial frequencies 5~15 cycles per degree (cpd), and no differences in 20~30 cpd(P> 0.05), while no difference were observed in all spatial frequencies postoperatively (P> 0.05). Comparing the preoperative and postoperative MTF values for each group, the results showed that there was a significant difference in Group C at 5~20 cpd after surgeries(P< 0.05). There was no significant difference in MTFcutoff, SR, OSI, PSF50%, PSF10%, VA100%, VA20%, and VA9% in the three groups preoperatively (P> 0.05). One month after surgeries, higher VA9% values were measured for Group C compared to Group A and B (P < 0.05). There was no significant difference in each group before and after surgeries (P> 0.05).ConclusionSMILE could improve the visual qualities of patients with moderate myopia. Reducing the surgical optical zone will only affect night vision slightly.

The effect of thin lenticule versus thick lenticule (a cut-off value of 55 micrometer) on the outcome of SMILE in low myopia

Objectives: In the current study, the aim was to evaluate the effect difference in lenticule thickness SMILE cases (≤ 55 µm versus &gt; 55 µm) on the visual outcome in a cohort of 61 patients with low myopia (≤3.0 diopters)&#x0D; Methods: The current prospective cohort study included 61 patients undergoing SMILE refractive procedure during the period extending from November the 14th 2019 through June the 14th 2020, a total of 99 eyes. The study was conducted in Ibsar ophthalmology surgery centre "private medical centre" in the wholly Najaf city, mid-Euphrates region of Iraq. The cases enrolled in the study were all operated on by the same ophthalmologist. According to lenticule thickness, eyes were classified into two groups, (≤ 55 µm versus &gt; 55 µm). The main outcome variable was visual acuity postoperative within two short period of time, one week and 3 months.&#x0D; Results: Comparison of visual acuity between patients with lenticule thickness of ≤ 55 µm and patients with lenticule thickness of &gt; 55 µm was shown in table 6. There was no significant difference in UCVA (uncorrected visual acuity) (P = 1.000), significant difference in BCVA (best corrected visual acuity) (better with lenticule thickness of ≤ 55 µm) (P = 0.037), no significant difference in VAAS (visual acuity after surgery) (P = 0.065) and no significant difference in VA3M (visual acuity 3 months after surgery) (P = 0.599).&#x0D; Conclusion: Thin lenticule of less than or equal 55 micrometer to as low as 41 micrometer can be chosen for SMILE with efficacy and safety comparable to that of thicker lenticule provided that the operation is done by well trained and skilled refractive surgeon.

Acupuncture for glaucoma.

Acupuncture for glaucoma.

Clinical study on topography-guided laser ablation combined with accelerated corneal collagen cross-linking for early keratoconus

Objective: To study the safety and efficacy of topography-guided customized excimer laser subepithelial ablation combined with accelerated collagen cross-linking technique in treatment of early keratoconus. Methods: Ninteen patients(20 eyes) (13 males 14 eyes, and 6 females 6 eyes), aged 12 to 44 years (24.7±8.0) were diagnosed as keratoconus by three-dimensional corneal topography and tomography, clinical history and examinations, and classified as KC1~KC3. Based on the classical excimer laser subepithelial keratomileusis (LASEK) method, topography guided laser ablation was performed with an excimer laser system (WaveLight EX500). After laser ablation, the corneal stromal bed was immersed with 0.1% riboflavin for 10 minutes, and then was irradiated by ultraviolet light (Avedro KXL) at 30 mW/cm(2) for 4 minutes. All the patients were followed up for more than 12 months. The uncorrected visual acuity (UCVA), diopter, best corrected visual acuity (BSCVA), corneal topography, central corneal endothelial cell density (ECD), hexagonal cell percentage (HEX), coefficient of variation (CV) and other indicators were observed. For normal distribution variables, Dunnett-t test was used before and after operation, and Wilcoxon test was used for variables with abnormal distribution. And the complications were recorded. Results: There was no loss of BSCVA at 12 months postoperatively, 20% of the eyes had no change of BSCVA, and 15% of the eyes gained 1 line of BSCVA, 15% of the eyes gained 2 lines of BSCVA, 50% of the eyes gained 3 lines and more of BSCVA. There was no significant difference in UCVA, BSCVA, manifest refractive spherical equivalent (MRSE) and the cylinder at 3 months postoperatively (P>0.05). The BSCVA were significantly improved at 6 and 12 months postoperatively compared with those before operation (t=3.095, 3.079, <0.05). Although there was no significant difference in UCVA and MRSE, the cylinder was significantly reduced at 6 and 12 months postoperatively (t=-2.890, -2.435, P<0.05). Apex curvature (Kapex) and mean pupil power (MPP) within 4.5mm of central cornea decreased significantly (Z=-2.903, P<0.01; Z=-2.667, P<0.01). Even though the thinnest corneal thickness decreased from pre-operational (461.9±31.1) μm to post-operational (416.6±27.0) μm (Z=-3.059, P<0.01), the cornea became regular with keratometric asymmetry index of anterior corneal surface decreased (Z=-2.667, P<0.01). The corneal optical quality parameters were improved. There was no significant difference in ECD, HEX and CV at 12 months postoperatively (P>0.05). Twelve months after operation, grade 0, 0.5, 1 and 2 haze were seen on 20%, 55%, 20% and 5% corneas respectively. Conclusions: The topography guided excimer laser ablation combined with accelerated corneal collagen cross linking is safe and effective in treatment of early stage keratoconus. It can significantly improve corneal regularity while preventing keratoconus progression, so as to improve the best corrected visual acuity postoperatively. (Chin J Ophthalmol, 2019, 55: 904-910).

Effect of Mitomycin C on Myopic versus Astigmatic Photorefractive Keratectomy.

Purpose. Long-term mitomycin C (MMC) effects on photorefractive keratectomy (PRK) were compared in simple myopic and astigmatic patients. Methods. In this observational cohort study, subjects were selected based on preoperative and postoperative data collected from medical records; they were divided into simple myopia with/without MMC and myopic astigmatism with/without MMC groups. Haze, uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), subjective refraction, and K-reading were evaluated at 1-, 3-, 6-, and 12-month follow-ups. Results. One hundred fifty-nine eyes of 80 subjects (34 women and 46 men; mean age, 26.81 ± 7.74 years; range, 18–53 years; spherical powers, −0.50 to −8.00 DS; and cylindrical powers, −0.25 to −5.00 DC) were enrolled. One year postoperatively, the simple myopia with/without MMC groups showed no difference in UCVA (P = 0.187), BCVA (P = 0.163), or spherical equivalent (P = 0.163) and a significant difference (P = 0.0495) in K-reading; the haze formation difference was nonsignificant (P = 0.056). Astigmatic groups with/without MMC showed a significant difference in K-reading (P < 0.0001). MMC groups had less haze formation (P < 0.0001). Conclusion. PRK with intraoperative MMC application showed excellent visual outcomes. MMC's effect on astigmatic patients was significantly better with acceptable safety and minimal side effects.

Comparison of the effects among three different corneal refractive surgeries for low and moderate myopia

Objective To compare postoperative uncorrected visual acuity (UCVA) and residual diopters among three different corneal refractive surgeries for low and moderate myopia. Methods This is a retrospective study on non-randomized clinical trial without control group. The following three groups were involved in this trial: LASEK group, 261 patients (521 eyes); microkeratome-assisted flap creation LASIK (MM-LASIK) group, 1513 patients (3024 eyes) and the femtosecond laser-assisted flap creation LASIK (FS-LASIK) group, 1082 patients (2164 eyes). Single factor analysis of variance was used to compare the postoperative UCVA, residual spherical equivalent (S E), root mean aquare of high aberration for pupil diameter of 3mm and 5mm (HOA RMS3 and HOA RMS5) groups. Results After the follow-up of 12 months, the difference in UCVA between MM-LASIK and LASEK group was not statistically significant (P=0.705). The UCVA in MM-LASIK and LASEK group were better than that in FS-LASIK group and the differences were statistically significant (F=17.08, P=0.00). The differences in postoperative residual S E among the three groups were statistically significant (F=4.36, P=0.01). The residual SE in MM-LASIK and FS-LASIK group were lower than that in LASEK group. The descending order of HOA RMS3 was FS-LASIK group, MM-LASIK and LASEK group. There was no statistically significant difference in HOA RMS5 among three groups. Conclusion Three corneal refractive surgeries for correcting low to moderate myopia brought good results. Smaller postoperative residual SE and lower HOA RMS3 are beneficial to the recovery of postoperative UCVA. LASEK and MM-LASIK produced better visual acuity and less corneal aberrations compared to FS-LASIK. The value of HOA RMS3 in LASEK group was the smallest and the postoperative residual SE in LASEK group was the biggest. Key words: LASEK; LASIK; Femtosecond laser; Root mean square, higher order aberration

Riboflavin photoprotection with cross-linking effect in photorefractive ablation of the cornea

Photorefractive ablation is inevitably accompanied by oxidative stress of the cornea and weakening of its biomechanical and photoprotective properties. To validate the expediency of riboflavin use in photorefractive ablation for photoprotection of the cornea and cross-linking. The effects of riboflavin use in photorefractive ablation was first studied in a series of in vitro and in vivo experiments performed on 56 eyes of 28 rabbits, and then on 232 eyes of 142 patients with different degrees of myopia. Biomechanical testing of corneal samples was performed with Zwick/RoellВZ 2.5/TN1S tensile-testing machine. Transepithelial photorefractive keratectomy (TransPRK) and femtosecond laser-assisted in situ keratomileusis (Femto-LASIK) were performed on Wavelight-Allegretto200, MEL-80, and WaveLight-EX500 excimer laser systems and also VisuMax and WaveLight-FS200 femtosecond lasers. For preliminary examinations, an appropriate set of diagnostic tools was used. In vivo experiments have proved that, in the absence of conservative therapy, riboflavin is able to produce both photoprotective and cross-linking effects to the cornea. Corneal syndrome was thus reduced and re-epithelialization after TransPRK accelerated. Biomechanical testing of corneal samples revealed an increase in tolerated load from 12.9±1.4 N to 18.3±1.2 N (p=0.0002) and tensile strength from 8.6±1.7 MPa to 12.4±1.7 MPa (p=0.007). Clinical studies conducted in a group of patients with mild to moderate myopia have also confirmed the photoprotective effect of riboflavin at months 1-12 after TransPRK. There were no significant differences in uncorrected visual acuity (ranged from 0.80±0.16 to 0.85±0.15) and corrected visual acuity at baseline (0.83±0.14). Evaluation of the optical and refractive effect achieved after Femto-LASIK with riboflavin photoprotection in the fellow eye has shown that this technique is not inferior to the traditional one as to its refractive accuracy, but provides better maintenance of biomechanical and photoprotective properties of the cornea. Photorefractive ablation of the cornea with preliminary saturation of the stroma with riboflavin solution ensures its photoprotection and provides an additional cross-linking effect.

Effect of 0.05% Cyclosporine A on the Ocular Surface after Photorefractive Keratectomy

Purpose: To evaluate the effect of 0.05% cyclosporine A on the ocular surface after photorefractive keratectomy (PRK). Methods: This retrospective study included 50 patients who underwent PRK. Patients were divided into two groups: 25 patients in group I were treated with topical 0.05% cyclosporine A with conventional medication, and 25 patients in group II were treated with conventional medication. Visual acuity (VA), tear break-up time (BUT), fluorescein staining score (F-stain), Schirmer I test, and ocular surface disease index (OSDI) were evaluated before surgery and 2 weeks, 1 month, 2 months, and 3 months after surgery. Results: F-stain was significantly lower in group I than in group II at 2 weeks and 1 month (p < 0.05). There was no significant difference in uncorrected VA, BUT, Schirmer I test, or OSDI between the groups. However, group I showed a more effective pattern in dry eye. Conclusions: Combination treatment with 0.05% cyclosporine A was helpful for early ocular surface stability in patients with dry eye after PRK. J Korean Ophthalmol Soc 2016;57(5):710-717

Safety of undiluted intracameral moxifloxacin without postoperative topical antibiotics in cataract surgery

The objective of this study is to evaluate the safety of undiluted 0.5% intracameral moxifloxacin for postoperative endophthalmitis prophylaxis in cataract surgery patients without the use of additional postoperative topical antibiotics. All phacoemulsification cataract surgeries performed by a single surgeon (B.A.) at the John A. Moran Eye Center from June 2012 to May 2015 were reviewed retrospectively. From June 2012 to April 2014, patients were given topical 0.5% moxifloxacin postoperatively. From May 2014 to May 2015, all patients were given moxifloxacin intracamerally with no antibiotics postoperatively. The follow-up period was 1month after surgery. Preoperative visual acuity and postoperative visual acuity, corneal edema, and anterior chamber reaction were recorded and compared between the two groups. 384 cataract surgeries were performed during the study period. None of the 384 eyes in the study developed endophthalmitis. Of those 384 eyes, 222 were included in the study for analysis based on the inclusion and exclusion criteria. 131 were part of the topical antibiotic group and 91 were part of the intracameral group. The differences in uncorrected visual acuity at 1day postoperatively (p=0.595) and best corrected visual acuity at 1month postoperatively (p=0.099) were not statistically significant. Differences in corneal edema (p=0.370) and anterior chamber reaction (p=0.069) at 1day postoperatively and corneal edema (p=0.512) and anterior chamber reaction (p=0.512) at 1month postoperatively were also not statistically significant. Undiluted 0.5% moxifloxacin can be safely injected intracamerally following cataract surgery without additional postoperative antibiotic prophylaxis to prevent endophthalmitis without adverse effects on patient outcomes.

Higher-Order Aberrations and Visual Acuity with Wavefront-Guided and Wavefront-Optimized Ablation in Laser Keratorefractive Surgery

Purpose: To compare higher-order aberrations (HOAs) and visual acuity after wavefront-guided and wavefront-optimized laser keratorefractive surgery. Methods: This retrospective study consisted of consecutive cases of eyes that underwent wavefront-guided (VISX S4 CustomVue®) or wavefront-optimized (WaveLight® EX500) laser assisted in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK). Preoperative and postoperative uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), manifest refraction spherical equivalent (MRSE), and preoperative and 3 month postoperative HOAs were compared. Results: There were no statistical differences in UCVA, BCVA, MRSE, or total HOAs in either the LASIK and PRK groups (all p > 0.05). Induced amount of spherical aberration (SA) was significantly lower in the wavefront-optimized LASIK and PRK than wavefront-guided LASIK and PRK. Conclusions: In laser keratorefractive surgery, wavefront-guided and wavefront-optimized platforms produced equivalent visual outcomes and no differences in total HOAs. However, the wavefront-optimized platform caused less spherical aberration 3 months after operation. J Korean Ophthalmol Soc 2014;55(4):480-485

Refractive Surgery Outcomes Comparison—All Wavefront-guided Versus a Decision Tree for Selecting Wavefront-guided or Wavefront-optimized

The purpose of this article is to compare refractive outcomes based on all wavefront-guided procedures versus a decision tree designed to assist with the selection of wavefront-guided or wavefront-optimized procedures. The setting was the The Laser Center, Greensboro. Twenty subjects were treated with a VISX CustomVue™ wavefront-guided refractive procedure in one eye and a WaveLight Allegretto procedure (wavefront-guided or optimized) in the contralateral eye. A decision tree was used to decide whether a wavefront-guided or wavefront-optimized procedure would be performed with the WaveLight system. The CustomVue eye was chosen at random. Visual acuity and refractive error were recorded pre-operatively and post-operatively. Subjective post-operative data included patient reported eye preference and post-operative glare and halos. The results were that one subject was lost to follow-up, leaving 19 subjects for analysis at three months. Of those subjects with data, 12 received wavefront-optimized treatment while seven subjects received a wavefront-guided treatment with the WaveLight laser. There were no significant differences in uncorrected visual acuity between the VISX and Wavelight groups at the one-day or six-month visits. At three months, 56 % of patients indicated no preference, with the remaining 44 % indicating a preference for the WaveLight-treated eye (p&lt;0.05). The patient reported outcomes showed a similar incidence of post-operative glare and halos reported between the two treatments. Results with the Allegretto Wave Eye-Q laser, using a decision tree to determine whether a wavefront-optimized or a wavefront-guided treatment would be performed, were equivalent to those achieved with the VISX Star S4 wavefront-guided procedure.

Epipolis-Laser In Situ Keratomileusis Discarding Epithelium Versus Laser In Situ Keratomileusis for Myopia and Myopic Astigmatism in Asian Eyes.

To compare long-term safety, efficacy, predictability, and visual outcomes of epipolis-laser in situ keratomileusis (epi-LASIK) discarding epithelium versus LASIK in Asian eyes. This was a prospective, randomized, bilateral case series. This study included 166 eyes of 83 patients with myopia and myopic astigmatism who received epi-LASIK in 1 eye and LASIK in the contralateral eye. Automated separation of the epithelium was performed with epi-K™, and LASIK was performed with M2 microkeratome using 90-μm calibrated heads. Patients were seen post-operatively at 1 and 3 days, 1 week, and on days 1, 3, 7 at 1, 3, 6, and 12 months. Uncorrected visual acuity, best corrected visual acuity, spherical equivalent (SE), contrast sensitivity, total higher-order aberration, corneal sensitivity, and clarity were analyzed. Mean preoperative SE was -4.26 (SD, 1.64) diopters (D) in epi-LASIK and -4.27 (SD, 1.63) D in the LASIK group. Twelve months after surgery, mean SE was 0.04 (SD, 0.40) and 0.11 (SD, 0.30) D, respectively. There was no significant difference in uncorrected visual acuity (P = 0.451), SE (P = 0.157) and contrast sensitivity between groups at the 1-year follow-up (P > 0.05). During 6 months after operation, corneal sensitivity values were significantly lower in the LASIK group (P < 0.05). No eye lost line of best corrected visual acuity in both groups. In epi-LASIK eyes, there was no haze in 97.5% and haze grade 1 in 2.5% at 3 months postoperatively. From 6 months onward, alls corneas were clear. Epi-LASIK was safe, predictable, and effective and may be considered an alternative for LASIK.

Short-term clinical efficacy of flap-free Epi-LASIK and Epi-LASIK for high myopia

Background Compare with the lamellar laser refractive surgery,the laser slip on the surface operation is a better method in the correct of refractive error without the flap-related complications.However,whether to remain corneal epithelial flap and its influence for epithelial healing and visual restoration are still under investigation.Objective The aim of this study was to compare the short-term clinical efficacy of epipolis laser insitu keratomileusis (Epi-LASIK) and flap-free Epi-LASIK for correction of refractive error in high myopia.Methods The paired control design was adopted.Sixty eyes of consecutive 30 patients with high myopia were collected in this study.The written consent form was obtained from each patients prior to operation.Regular EpiLASIK was performed in the right eyes and the flap-free Epi-LASIK was carried out in the left eyes.Patients were followed-up for one month.The postoperative ocular irritation symptoms were scored,and the healing period of corneal epithelium and uncorrected visual acuity were examined at 1,3 and 5 days after operation.The naked visual acuity,diopter,best corrected visual acuity and the grading of haze were recorded and compared between the two groups at one month after operation.Results After surgery,the scores of corneal irritation were 3.13 ±0.43 and 3.30±0.47on the first day,showing insignificant differences between these two groups (t =- 1.54,P＞0.05 ).However,there existed statistically significant difference in the scores of corneal irritation on the third day after operation between the two groups (t =- 17.95,P＜0.01 ).The average time of corneal epithelial healing were (2.58 ±0.49 ) days in the flapfree Epi-LASIK group and ( 3.98 ±0.74) days in Epi-LASIK group with the significant difference between them (t=-11.36,P＜0.01 ).There was no statistical difference in uncorrected visual acuity in the first day (0.59±0.12 vs 0.58±0.11,t=0.39,P＞0.05),the fifth day (0.69±0.08 vs 0.67±0.09,t=0.84,P＞0.05) and 1 month (t =-1.90,P＞0.05 ).No significant difference was seen in the diopter between the two groups in 1 month after surgery (-1.03±0.45 vs -1.07 ±0.38,t =-0.31,P＞0.05 ).The eye numbers of corneal haze for 0 grade were 27 ( 90.00％ ) and over the 0.5 grade were 3 ( 10.00％ ) in flap-free Epi-LASIK group respectively,and those of corneal haze for 0 grade were 26(86.66％ ) and above the 0.5 grade were 4 (13.33％) in Epi-LASIK group respectively,showing a considerably difference between the two groups (x2 =0.0031,P＞0.05).Conclusions Both the flapfree or reserved epithelial Epi-LASIK allow the safe and effective correction of refractive error in high myopia,showing good predictability and stability in short term.Flap-free Epi-LASIK can relieve the corneal irritation symptom and accelerate the healing of corneal epithelium and recovery of visual acuity. Key words: Epipolis laser in-situ keratomileusis; Flap-free epipolis laser in-situ keratomileusis; High myopia

Microcoaxial Torsional Cataract Surgery 1.8 mm Versus 2.2 mm: Functional and Morphological Assessment

To compare functional and morphological outcomes of 1.8-mm versus 2.2-mm microincision coaxial cataract surgery (MCCS). Thirty eyes of 30 patients that underwent MCCS were randomized to two groups: 1.8-mm MCCS (group 1: 15 eyes) and 2.2-mm MCCS (group 2: 15 eyes). There were no significant between-group differences in uncorrected visual acuity, best-corrected visual acuity, keratometric astigmatism, and endothelial cell count. One day postoperatively, a greater increase of corneal thickness at the incision site was observed in group 1 compared to group 2 using anterior segment optical coherence tomography with no significant differences in tunnel morphometric features and confocal microscopy showed more tunnel edema in group 1 versus group 2 that resolved in both groups. Both 1.8- and 2.2-mm torsional MCCS were safe and efficient with easy surgical maneuvers and excellent functional and morphological results; 1.8-mm MCCS induced slightly greater tunnel edema shortly after surgery that resolved in the medium term.

Evaluation of analgesic efficacy of bromfenac sodium ophthalmic solution 0.09% versus ketorolac tromethamine ophthalmic solution 0.5% following LASEK or Epi-LASIK

BackgroundTo evaluate the analgesic efficacy of bromfenac sodium ophthalmic solution 0.09% compared with ketorolac tromethamine ophthalmic solution 0.5% in laser epithelial keratomileusis (LASEK) or epithelial keratomileusis (epi-LASEK), sometimes referred to as epi-LASIK.MethodsEighty eyes (from 40 patients, 18 men and 22 women) undergoing bilateral simultaneous LASEK or epi-LASEK were randomized to receive ketorolac in one eye and bromfenac in the other. Mean age was 33.13 ± 9.34 years. One drop of bromfenac or ketorolac was instilled in each eye 15 minutes and one minute prior to surgery, and two and four hours following surgery. Patients were instructed to instill the medications on-label each day through postoperative day 4. The subjects completed pain and visual blurriness assessments from day of surgery to postoperative day 4. Uncorrected visual acuity was tested on postoperative days 1 and 6.ResultsFor each of the five days, pain scores for bromfenac-treated eyes were significantly less than that for ketorolac-treated eyes (P < 0.01). Of the 40 patients, 32 (80%) said bromfenac provided better postoperative analgesia than ketorolac. There was no statistically significant difference in visual blurriness scores between the two groups (P > 0.1). Uncorrected visual acuity did not vary significantly between the treatment groups (P > 0.1). No serious adverse events were noted.ConclusionBromfenac is subjectively superior to ketorolac in reducing postoperative pain following LASEK or epi-LASEK. The subjects tolerated the drugs well with no serious adverse outcomes and no difference in uncorrected visual acuity.