Clinical Efficacy of Topical Diquafosol Tetrasodium after Laser Epithelial Keratomileusis

PURPOSE: To evaluate the clinical effectiveness of topical diquafosol tetrasodium (DQS) after laser epithelial keratomileusis (LASEK). METHODS: This randomized prospective study included 97 eyes of 49 patients who were scheduled for LASEK. Patients in the DQS group used both 0.3% sodium hyaluronate and 3% DQS for 3 months after surgery while patients in the control group used only 0.3% sodium hyaluronate. Corneal staining score, tear film break-up time (TF-BUT), Schirmer test and ocular surface disease index (OSDI) were evaluated before surgery and 2, 4, 8, 12 and 16 weeks after surgery. RESULTS: There was no significant difference in visual acuity, spherical equivalent and corneal haziness between the 2 groups after surgery. Corneal staining score was significantly lower in the DQS group than in the control group 2 weeks after LASEK (p < 0.01) and increased in the control group after LASEK compared with the preoperative value (2 weeks after LASEK, p < 0.01), but decreased in the DQS group (12 and 16 weeks after LASEK, p < 0.05). TF-BUT was significantly higher in the DQS group than in the control group 2 to 16 weeks after LASEK (p < 0.01) and increased values were observed in the DQS group after LASEK compared with the preoperative value (4 to 16 weeks after LASEK, p < 0.05). The mean OSDI was significantly higher 4 to 16 weeks after LASEK in the control group than in the DQS group (p < 0.01). CONCLUSIONS: Subjective dry eye symptoms and objective markers were worse for 4 weeks after LASEK. The use of 3% DQS for 12 weeks after surgery improved these symptoms and markers with the effect lasting 16 weeks after LASEK.

A Case of Uneventful Cataract Surgery in Idiopathic True Exfoliation Patient

PURPOSE: We present a case of uneventful cataract surgery in an idiopathic true exfoliation patient with areas of capsular delamination based on scanning electron microscope and transmission electron microscope results. CASE SUMMARY: A 77-year-old male presented with gradual deterioration of vision over 1 year in duration. Slit lamp examination revealed bilateral nuclear sclerotic cataracts with ring-shaped fibrous membrane floating within the anterior chamber in the right eye. In addition, the patient was diagnosed with cataract and true exfoliation of the right eye. He underwent uneventful phacoemulsification and posterior chamber intraocular lens implantation by placing capsulorrhexis outside the delaminated capsule margin. At 6 months after cataract surgery, the patient showed favorable visual outcome with uncorrected vision of 20/20 and intraocular pressure of 18 mm Hg in the right eye.

Evaluation of Optical Quality Parameters and Ocular Aberrations in Multifocal Intraocular Lens Implanted Eyes

PURPOSE: We investigated the correlations between optical quality parameters obtained from the double-pass system and ocular aberrations obtained from the ray-tracing aberrometer in multifocal intraocular lens (IOL) implanted eyes. MATERIALS AND METHODS: Twenty eyes from 20 patients were enrolled in this study. Modulation transfer function cutoff frequency, The Strehl ratio, objective scatter index, and objective pseudo-accommodation obtained from the double-pass system were compared with root mean square (RMS) total aberration, RMS higher-order aberration, and spherical aberration obtained from the ray-tracing aberrometer. Additionally, parameters of the double-pass system and ray-tracing aberrometer were compared with manifested refraction values and subjective visual acuity, respectively. RESULTS: There was no statistically significant correlation between optical quality parameters obtained from the double-pass system and ocular aberrations, except between the Strehl ratio and RMS total aberration (r=-0.566, p=0.018). No significant correlations were found between the parameters of both devices, and manifested refraction values or subjective visual acuity. CONCLUSION: Optical quality parameters, especially the Strehl ratio, in multifocal IOL implanted eyes were affected by RMS total aberration. Further studies based on accurate measurements of ocular aberrations and additional optical quality parameters are needed to delineate relationships between optical quality parameters and ocular aberrations in multifocal IOL implanted eyes.

Transient Myopic Shift Due to Increased Latent Accommodation after LASEK

PURPOSE: To investigate accommodation and progress of patients who showed myopia on manifest refraction in the early postoperative period after LASEK. METHODS: Forty-one eyes were included in the present study which had undergone LASEK surgery from February to March 2012. Seven eyes showed myopia over -0.25 D on manifest refraction at 1 month postoperatively, but showed decreased amount of myopia at 2 months postoperatively and were classified as group 1. The other 34 eyes were classified as group 2. The differences between cycloplegic and manifest refraction (CRSE-MRSE) were defined as the amount of latent accommodation and compared between the 2 groups. RESULTS: Amount of latent accommodation was 0.179 +/- 0.426 D in group 1 (7 eyes), 0.265 +/- 0.303 D in group 2 (34 eyes) preoperatively, 1.286 +/- 0.664 D in group 1, 0.368 +/- 0.536 D in group 2 at 1 month postoperatively, and 0.500 +/- 0.520 D in group 1, and 0.489 +/- 0.546 D in group 2 at 2 months postoperatively. The amount of latent accommodation in group 1 was significantly greater than that of group 2 one month postoperatively. As the amount of latent accommodation decreased, the amount of myopic shift decreased gradually over 2 months in group 1 after surgery. CONCLUSIONS: Transient myopic shift due to increased latent accommodation was observed in several patients one month postoperatively and the amount of myopic shift decreased with time without treatment. Thus, surgeons should consider cycloplegic refraction when planning treatment for patients with myopic regression.

Comparison of Optical Quality Between Two Intraocular Lenses Using Double-Pass Based Optical Quality Analysis System

PURPOSE: To compare postoperative optical qualities between two types of 1-piece aspheric intraocular lenses using the double-pass technique. METHODS: Uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), and spherical equivalent were evaluated in the subject groups; the first which included 25 eyes implanted with Tecnis(R) ZCB00 and the second which included 16 eyes implanted with Acrysof(R) IQ SN60WF. In addition, modulation transfer function (MTF) cut-off, Strehl ratio, and objective scattering index (OSI) were measured 6 months after cataract surgery in the 2 subject groups using Optical Quality Analysis System (OQAS, Visiometrics S.L., Terrasa, Barcelona, Spain) which is based on the double-pass technique. RESULTS: There were no significant differences in the spherical equivalent, UCVA, BCVA, and OSI between the 2 groups. However, both the MTF cut-off, and Strehl ratio showed statistically significant differences. The MTF cut-off (28.0 +/- 7.79 vs. 20.4 +/- 9.51 c/deg, p = 0.025) and Strehl ratio (0.14 +/- 0.04 vs. 0.12 +/- 0.05, p = 0.042) were higher in the Tecnis(R) ZCB00-implanted group. CONCLUSIONS: The difference in characteristics of intraocular lenses subtly affects the vision quality as measured by values such as MTF cut-off and Strehl ratio after cataract surgery. OQAS based on the double-pass technique is considered useful in more objective estimates of the real retinal image quality after cataract surgery which is difficult to explain simply by measuring visual acuity.

Relationship between Cataract Maturation and Pain Scale during Cataract Surgery under Topical Anesthesia

PURPOSE: To investigate the relationship between maturity of a cataract and the pattern of pain during cataract surgery under topical anesthesia. METHODS: This study comprised 105 eyes of 75 patients undergoing cataract surgery under topical anesthesia. The pain scale during each procedure was scored from 0 to 10 in numeric pattern and analyzed with the cataract maturation degree. Additionally, pain scores were compared between the first and the second eye in 14 consecutive cataract patients. RESULTS: The average pain score during cataract surgery was 0.86 +/- 0.55, and the average maximal pain experience score during surgery was 3.24 +/- 1.51, which was generally tolerable. Phacoemulsification was marked as the most painful step among cataract surgery procedures (1.93 +/- 1.64), followed by the removal of the surgical draping (1.31 +/- 1.53) and the initial instillation of topical anesthetic (1.29 +/- 1.28). Progression and cataract typing was not related to pain either during overall cataract surgery procedures or when separately analyzed during procedures. There was no significant difference between the pain scores reported in consecutive cataract surgeries. However, in subjective comparison of consecutive surgeries, more patients reported greater pain in the second operation. CONCLUSIONS: The pain score reported during cataract surgery procedures under topical anesthesia was within a generally tolerable range. Cataract progression does not appear to be related to pain during the operation. In consecutive surgeries, pain measured by a numerical scale and subjective pain experience showed different results.

Comparisons of Clinical Results after Implantation of Three Aspheric Intraocular Lenses

PURPOSE: To compare the clinical results after implantation of three one-piece aspheric lenses, Acrysof IQ SN60WF, Tecnis 1-piece ZCB00 and the newly developed IOL HOYA AF-1 NY-60. METHODS: In total 66 eyes, one of three one-piece aspheric lenses, Acrysof IQ SN60WF, TECNIS 1-piece ZCB00 or HOYA AF-1 NY-60 was implanted after cataract extraction. Best corrected visual acuity (BCVA) and uncorrected visual acuity (UCVA) were assessed at postoperative 3 months. Total spherical aberration, high order aberration and modulation transfer function of 5.0 mm pupil size zone were evaluated. RESULTS: There were no significant differences of UCVA, BCVA, the accuracy of postoperative refractive power and modulation transfer function among three groups. High order aberrations of the entire eye and internal optics showed almost no significant differences except some aberration values. CONCLUSIONS: The newly developed intraocular lens, HOYA AF-1 NY-60 showed almost equal clinical results in comparison with Acrysof IQ SN60WF and TECNIS 1-piece ZCB00.

Changes in Optic Nerve Parameter Measurements on Spectral-Domain Optical Coherence Tomography, after Cataract Surgery

PURPOSE: To assess changes in peripapillary retinal nerve fiber layer (RNFL) thickness and optic nerve head parameters after cataract surgery by using spectral-domain optical coherence tomography (OCT). METHODS: Twenty-nine eyes of 26 patients, who underwent cataract surgery, were imaged with spectral-domain OCT before and after surgery to measure peripapillary RNFL thickness and optic nerve head parameters, signal strength (SS), quadrant, 12 clock-hour RNFL thickness, rim area, disc area, cup/disc area ratio, vertical cup/disc ratio, and cup volume. RESULTS: The postoperative RNFL thickness and SS were higher than before surgery (p < 0.05). Regarding optic nerve head parameters, rim area was 0.07 +/- 0.10 mm2 higher than before surgery and disc area, cup/disc area ratio, vertical cup/disc ratio, cup volume were 0.07 +/- 0.15 mm2, 0.04 +/- 0.04, 0.03 +/- 0.05, 0.04 +/- 0.06 mm3, respectively, lower than before surgery (p < 0.05). CONCLUSIONS: Cataracts may decrease peripapillary RNFL thickness measurement and SS on OCT scans and change other optic nerve head parameters. Peripapillary RNFL thickness and optic nerve head parameter measurements should be interpreted with caution in eyes with significant cataracts.

Comparison of Anterior Chamber Parameter and Refractive Change between Three-Piece and Single-Piece Aspheric Intraocular Lenses

PURPOSE: To compare the anterior chamber depth (ACD), anterior chamber volume (ACV), anterior chamber angle (ACA) and refractive change after cataract surgery between 3-piece and 1-piece aspheric intraocular lens (IOL) implantation. METHODS: The present study consisted of 16 patients (25 eyes) having 3-piece aspheric Tecnis(R) ZA9003 IOL and 21 patients (30 eyes) having 1-piece aspheric Tecnis(R) ZCB00 IOL. The ACD, ACV, and ACA were measured using an anterior eye segment analysis system (Pentacam, Oculus, Wetzlar, Germany) preoperatively and postoperatively 1 week and 1 month. Refractive outcomes were evaluated using an autokeratometer. RESULTS: When comparing the 3-piece (Tecnis(R) ZA9003) and 1-piece (Tecnis(R) ZCB00) IOL with the same optic, ACD, ACV, and AVA increased significantly after cataract surgery. The 1-piece IOL showed deeper ACD than the 3-piece IOL at postoperative 1 week and 1 month. Postoperative refraction showed slight myopic shift compared with target diopter, but was stable in both groups. CONCLUSIONS: There was significant increase in ACD, ACV, and ACA after cataract surgery in both IOL-inserted groups. Results showed stable refraction after cataract surgery in both groups. Consideration of the A-constant will be needed because of myopic change with the 1-piece IOL.

Comparison of Anterior Chamber Parameter and Refractive Change between Three-Piece and Single-Piece Aspheric Intraocular Lenses

PURPOSE: To compare the anterior chamber depth (ACD), anterior chamber volume (ACV), anterior chamber angle (ACA) and refractive change after cataract surgery between 3-piece and 1-piece aspheric intraocular lens (IOL) implantation. METHODS: The present study consisted of 16 patients (25 eyes) having 3-piece aspheric Tecnis(R) ZA9003 IOL and 21 patients (30 eyes) having 1-piece aspheric Tecnis(R) ZCB00 IOL. The ACD, ACV, and ACA were measured using an anterior eye segment analysis system (Pentacam, Oculus, Wetzlar, Germany) preoperatively and postoperatively 1 week and 1 month. Refractive outcomes were evaluated using an autokeratometer. RESULTS: When comparing the 3-piece (Tecnis(R) ZA9003) and 1-piece (Tecnis(R) ZCB00) IOL with the same optic, ACD, ACV, and AVA increased significantly after cataract surgery. The 1-piece IOL showed deeper ACD than the 3-piece IOL at postoperative 1 week and 1 month. Postoperative refraction showed slight myopic shift compared with target diopter, but was stable in both groups. CONCLUSIONS: There was significant increase in ACD, ACV, and ACA after cataract surgery in both IOL-inserted groups. Results showed stable refraction after cataract surgery in both groups. Consideration of the A-constant will be needed because of myopic change with the 1-piece IOL.

Comparison of Corneal Measurement Values between Two Types of Topography

PURPOSE: To compare the corneal measurements of Sirius and Pentacam in normal cornea and post-corneal refractive surgery patients. METHODS: Subjects were tested by Pentacam (OCULUS, Wetzlar, Germany), and Sirius (CSO, Firenze, Italy). Measurements included central corneal thickness, thinnest corneal thickness, anterior chamber depth, anterior chamber volume, iridocorneal angle, corneal volume, pupil size, and curvature of cornea. RESULTS: A total of 88 eyes from 44 patients were included in the present study. When comparing Sirius and Pentacam in the normal cornea, corneal thickness (p = 0.693), thinnest corneal thickness (p = 0.386), anterior chamber depth (p = 0.155), anterior chamber volume (p = 0.650), and pupil diameter (p = 0.124) did not differ significantly. Corneal curvature (p < 0.001), corneal volume (p = 0.023), and iridocorneal angle (p < 0.001) were statistically different. When comparing Sirius and Pentacam in post-corneal refractive surgery patients, corneal thickness (p = 0.056) did not differ significantly. There was a statistical difference in corneal curvature (p < 0.001), thinnest corneal thickness (p = 0.019), anterior chamber depth (p < 0.001), anterior chamber volume (p < 0.001), iridocorneal angle (p < 0.001), corneal volume (p < 0.001), and pupil diameter (p < 0.001). CONCLUSIONS: Anterior segment measurements with Pentacam and Sirius showed differences in post-corneal refractive surgery patients.

Changes in Corneal Keratometry Readings after Corneal Collagen Cross-Linking Using Alcohol in Keratoconus Patients

PURPOSE: To evaluate the changes in corneal keratometry (K) readings after corneal collagen cross- linking (CXL) using 20% alcohol in primary keratoconus and keratectasia after refractive surgery. METHODS: Twelve eyes of 10 patients with primary keratoconus and 3 eyes of 3 patients with keratectasia after refractive surgery were included in the present study. Best-corrected visual acuity (BCVA) and mean K, corneal astigmatism by corneal topography, and mean K, corneal astigmatism, and spherical equivalent (SE) by auto refractometer were evaluated at baseline, and 6 months postoperatively. Eight eyes of 7 patients were also evaluated 1 year postoperatively. RESULTS: Mean BCVA improved from log MAR 0.66 +/- 0.50 to log MAR 0.55 +/- 0.58 (p = 0.100) at 6 month after CXL. In corneal topography, mean K significantly decreased from 50.04 +/- 5.88 D to 49.18 +/- 6.15 D (p = 0.019), and corneal astigmatism slightly decreased from 5.33 +/- 4.47 D to 5.29 +/- 4.88 D (p = 0.755) at 6 months after CXL. According to the auto refractometer, mean K significantly decreased from 48.53 +/- 5.94 D to 47.95 +/- 5.79 D (p = 0.038), corneal astigmatism significantly decreased from 3.95 +/- 2.54 D to 3.52 +/- 2.40 D (p = 0.010), and SE significantly decreased from -6.25 +/- 3.45 D to -5.40 +/- 2.91 D (p = 0.037) at 6 months after CXL. Significant mean K and corneal astigmatism decreases in topography were also observed at 1 year after CXL. Complications related to CXL were not observed. CONCLUSIONS: CXL using 20% alcohol appears to be a safe and promising treatment modality with less corneal stromal damage in progressive primary keratoconus and keratectasia after refractive surgery.

Influence of Pupil Size on Visual Acuity after Implantation of the TECNIS 1-Piece Intraocular Lens

PURPOSE: To evaluate the influence of pupil size on uncorrected visual acuity and spherical aberration of the TECNIS 1-piece intraocular lens (IOL). METHODS: In this study 61 eyes were implanted with a TECNIS 1-piece IOL. Pupil size was checked by standard pupil card with cobalt blue light postoperatively. Best corrected visual acuity (BCVA) and uncorrected visual acuity (UCVA) were assessed postoperatively. Total spherical aberration and high-order aberration for mesopic pupil size zone were measured. RESULTS: There were no significant differences of spherical equivalent, age, preoperative astigmatism, BCVA between two groups, but small pupil group revealed better UCVA (p = 0.02) and lower ocular aberration than large pupil group. CONCLUSIONS: After cataract surgery, pupil size greater than 5.0 mm increases total aberration. Thus, visual acuity with small pupil after aspheric TECNIS 1-piece IOL implantation show better clinical result on uncorrected visual acuity.

Comparison of the Refractive Error Measurement Using Different Methods in Wavefront-Guided LASEK

PURPOSE: To predict the accuracy of preoperative refractive error measurement methods in wavefront-guided laser-assisted subepithelial keratectomy (LASEK) surgery and to formulate a nomogram for satisfactory surgical results. METHODS: The medical records of 30 patients (57 eyes) who had undergone wavefront-guided LASEK were reviewed. The ideal surgical ablation amount was defined as the sum of the real surgical ablation amount and the remaining refractive errors. Comparison between the ideal surgical ablation amount and preoperative refractive errors was made using autorefraction, manifest refraction, cycloplegic refraction, postcycloplegic refraction, wavescan, and iTrace aberrometer measurements. RESULTS: The refractive errors measured by the postcycloplegic refraction showed the closest relation with the ideal surgical amount, and the nomogram based on this refraction correlated statistically significantly with the ideal surgical ablation amount. The refractive error using the wavescan also showed more accurate refractive measurements than the autorefractor and iTrace aberrometer. CONCLUSIONS: Accurate manifest refraction immediately before surgery is the most important in determining the ablation amount. Additionally, the refractive errors measured with the wavescan, which is an aberrometer used for wavefront-guided LASEK, showed a minimal amount of errors. After reviewing the results, the nomogram based on these 2 methods can be concluded to possibly contribute to an increase in the accuracy of surgery.