Retardation of Myopia by Multifocal Soft Contact Lens and Orthokeratology: A 1-Year Randomized Clinical Trial.

OBJECTIVES: This randomized, single-blind, clinical trial compared the effectiveness of multifocal soft contact lenses (MFSCLs), orthokeratology contact lenses (Ortho-kCLs), and single vision spectacles (SVSs) for myopia control. METHODS: Sixty-six eligible Chinese subjects, aged 7 to 15 years old with cycloplegic refraction measurements between -1.00 and -8.00 diopters (D), astigmatism not more than 1.00 D, and no history of myopia control treatment, were randomly assigned to wear MFSCLs, Ortho-kCLs, or SVSs for 1 year. For all three groups, baseline measurements of cycloplegic refraction, axial length (AL), and corneal endothelial cell density (CECD) were made. At the 6- and 12-month follow-up visits, changes in cycloplegic refraction, AL, and CECD were measured in the MFSCL and SVS groups. For the Ortho-kCL group, only changes in the AL were measured at 6 and 12 months, and CECD was measured at the 12-month follow-up visit. RESULTS: After 1 year of lens wear, myopia progression of the SVS group, -0.938±0.117 D, was greater than that of the MFSCLs group, -0.591±0.106 D (P=0.032). Thus, MFSCLs reduced the rate of myopia progression by 37.0% compared with the SVSs. The AL elongations after 1 year were 0.30±0.03 mm for MFSCLs (P=0.027 vs SVSs), 0.31±0.04 mm for Ortho-kCLs (P=0.049 vs SVSs), and 0.41±0.04 mm for SVSs. Compared with the SVS group, the reduction in AL elongation was 26.8% and 24.4% in the MFSCL and Ortho-kCL groups, respectively. There were no significant differences in CECD among the three groups (P>0.05). CONCLUSIONS: Compared with SVSs, wearing MFSCLs and Ortho-kCLs significantly delayed myopia progression. MFSCLs and Ortho-kCLs are safe and promising methods of myopia control (chictr.org number, ChiCTR2100048452).

Mapping research trends of chronic ocular graft-versus-host disease from 2009 to 2020: a bibliometric analysis.

PURPOSE: To evaluate the global scientific output of research on ocular chronic Graft versus host disease (cGVHD) and explore the current status and trends in this field over the past decade by bibliometric analysis. METHODS: The bibliometric search was performed in the Web of Science Core Collection (WoSCC) database. VOSviewer v.1.6.16 was used to map the knowledge domain. The annual number of publications and citations, distribution of countries and organizations, productivity of authors and journals, international collaborations, cited references, and keywords in the field of ocular cGVHD were visualized. RESULTS: In total, 398 peer-reviewed publications from 2009 to 2020 on ocular cGVHD were retrieved. The United States among all countries had the highest number of publications and citations, and Keio University was the most effective institution. Dana, R ranks the highest regarding the number of publications and citations on ocular cGVHD. Cornea and Biology of Blood and Marrow Transplantation were the most-cited journals in ocular cGVHD studies from ophthalmology and hematology, respectively. The top-cited references were primarily centered on dry eye. The keywords constituted three clusters: (1) consensus criteria and epidemiology of ocular cGVHD, (2) preclinical medical research of ocular cGVHD, and (3) treatment. CONCLUSION: Based on the data retrieved from WoSCC, a comparative analysis of the quantity and quality of papers on ocular cGVHD was conducted through bibliometric methods. This may contribute to better understanding of the status of ocular cGVHD study. The three major research topics shed new light on the ocular cGVHD study as well as meaningful materials for scholars to identify potential collaborators and promising partner institutions.

High performance OCTA enabled by combining features of shape, intensity, and complex decorrelation.

Motion contrast optical coherence tomography angiography (OCTA) entails a precise identification of dynamic flow signals from the static background, but an intermediate region with voxels exhibiting a mixed distribution of dynamic and static scatterers is almost inevitable in practice, which degrades the vascular contrast and connectivity. In this work, the static-dynamic intermediate region was pre-defined according to the asymptotic relation between inverse signal-to-noise ratio (iSNR) and decorrelation, which was theoretically derived for signals with different flow rates based on a multi-variate time series (MVTS) model. Then the ambiguous voxels in the intermediate region were further differentiated using a shape mask with adaptive threshold. Finally, an improved OCTA classifier was built by combining shape, iSNR, and decorrelation features, termed as SID-OCTA, and the performance of the proposed SID-OCTA was validated experimentally through mouse retinal imaging.

The relationship between major intrinsic protein genes and cataract.

BACKGROUND: Genetic factors play an essential role in the development of cataracts, and the major intrinsic protein (MIP) gene is a type of causative genes. Our study aims to discuss the current research progress of MIP genes responsible for cataractogenesis in DNA and protein levels, which is essential in achieving a response to the molecular deficiencies and pathophysiologic features of cataract. METHODS: We developed a search strategy using a combination of the words "Cataract", "Mutation", "MIP gene", and "AQP0" to identify all articles from PubMed, Web of Science, Scopus, and Google Scholar up to December 2019. To find more articles and to ensure that databases were thoroughly searched, the reference lists of selected items were also reviewed. RESULTS: A total of 29 MIP gene mutations causing congenital cataract were obtained by searching these databases and analyzing the results of genetic mutation pathogenicity prediction software tools; most of them caused amino acid codon changes in the H4, H5, H6, C-TIDs, and loop C in the structure of the MIP protein. However, there was no clear causality between lens morphology, phenotypes, and genotypes. The genotype TC in polymorphism c.-4T > C and haplotype CCG of rs2269348, c.-4T > C, and rs74641138 in MIP may attach an additional genetic risk factor for age-related cataract. CONCLUSION: These single-base mutations and single nucleotide polymorphisms might be importantly involved in the pathogenesis of congenital cataract and age-related cataract, respectively. This review provides a significant reference for clinical trials and theoretical studies.

Repeatability of ocular surface vessel density measurements with optical coherence tomography angiography.

BACKGROUND: To determine the repeatability of measurements of ocular surface vessel density in normal and diseased eyes using optical coherence tomography angiography (OCTA). METHODS: Ten normal eyes, 10 pinguecula eyes, and 10 pterygium eyes of 30 volunteers were subjected to OCTA (AngioVue Imaging System, Optovue, Inc.). For scanning, we used the corneal adapter module. Each eye was scanned three times in the nasal and temporal directions, separately. AngioVue software was used to generate the ocular surface vessel density. Ocular surface vessel density was defined as the proportion of vessel area with blood flow to the total measurement area (3 × 3 mm2). Intersession repeatability of the measurement was summarized as the coefficient of variation (CV), and intraclass correlation coefficients (ICC) were calculated by variance component models. RESULTS: The CVs were less than 5% in all subjects, and the ICCs exceeded 0.9; thus, all measurements showed good repeatability. The nasal vessels densities differed significantly between healthy eyes and eyes with pterygium (P < 0.05); however, there was no significant difference between healthy eyes and eyes with pinguecula (P = 0.466). CONCLUSIONS: These results suggest that measurement of ocular surface vessel density by OCTA in normal eyes and eyes with pterygium and pinguecula is repeatable. This preliminary research describes a quantitative and visual method for assessing vessel density of the ocular surface with a high level of consistency.

Factors influencing axial elongation in myopic children using overnight orthokeratology.

Several factors influence axial length in children with myopia treated using overnight orthokeratology. To identify these factors, this retrospective study collected axial length and corneal aberration data on 78 eyes before and 1-year after orthokeratology. Patients were divided according to axial elongation (cut-off, 0.25 mm/year). Baseline characteristics included age, sex, spherical equivalent refraction, pupil diameter, axial length, and orthokeratology lens type. Corneal shape effects were compared through tangential difference maps. Group differences in higher-order aberrations of a 4 mm zone were compared at baseline and 1-year following therapy. Binary logistic regression analysis was conducted to identify the variables determined for axial elongation. Significant differences between both groups included the initial age of wearing orthokeratology lenses, type of orthokeratology lens, size of central flattening area, corneal total surface C12 (1-year), corneal total surface C8 (1-year), corneal total surface spherical aberration (SA) (1-year root mean square [RMS] values), change in total corneal surface C12, and change in front and total corneal surface SA (RMS values). The age when wearing an orthokeratology lens was the most important factor influencing axial length in children with orthokeratology-treated myopia, followed by lens type and change in the C12 of the total corneal surface.

Ultrasound biomicroscopy of anterior segment accommodative changes with posterior chamber phakic intraocular lens in high myopia.

PURPOSE: To investigate changes in anterior chamber depth (ACD) and the distance between the Visian implantable Collamer lens (ICL) and the crystalline lens during pharmacologic accommodation in high myopia. DESIGN: Prospective, comparative case series. PARTICIPANTS: Thirty-three phakic eyes of 18 high myopic patients (range, -8.63 to -23.86 diopters) with a mean age of 29 years (range, 20-44 years) were examined at least 1 year after ICL implantation. METHODS: Ultrasound biomicroscopy was used to measure distance changes between the corneal endothelium, the ICL, and the crystalline lens after inducing pharmacologic accommodation with topical pilocarpine in 1 eye. The contralateral eye served as the control. MAIN OUTCOME MEASURES: Mean changes of ACD measured from the posterior corneal surface to the crystalline lens (ACD-L), from the posterior corneal surface to the anterior surface of the ICL (ACD-ICL), and the distance between the ICL and the crystalline lens (ICL-L) at the central and peripheral regions of the eye. RESULTS: For each eye, the ICL was in contact with the iris, but it was never in contact with the crystalline lens. At baseline, the mean distance between the ICL and the crystalline lens was 0.609 ± 0.165 mm at the central horizontal meridian, 0.588 ± 0.157 mm at the central vertical meridian, 0.281 ± 0.106 mm at the peripheral temporal sulcus, and 0.290 ± 0.098 mm at the peripheral nasal sulcus. After instillation of pilocarpine, a significant decrease in ICL-L was accompanied by a significant reduction in ACD-L and an increase in ACD-ICL (P<0.01). There were no significant changes in the control eyes (P>0.05). The central ICL-L reduction in the study group was significantly larger than that in the control group (P<0.01), but the peripheral ICL-L changes in the study group were not significantly different from those in the controls (P>0.05). CONCLUSIONS: During pharmacologic accommodation, the ICL and the crystalline lens came closer as the ICL was pushed backward by the iris as a result of pupillary constriction. Simultaneously, the anterior surface of the crystalline lens became more convex and moved forward. Reduction of the distances at peripheral sulci was not as obvious as at the center. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Anterior segment biometry during accommodation imaged with ultralong scan depth optical coherence tomography.

PURPOSE: To measure by ultralong scan depth optical coherence tomography (UL-OCT) dimensional changes in the anterior segment of human eyes during accommodation. DESIGN: Evaluation of diagnostic test or technology. PARTICIPANTS: Forty-one right eyes of healthy subjects with a mean age of 34 years (range, 22-41 years) and a mean refraction of -2.5 ± 2.6 diopters were imaged in 2 repeated measurements at minimal and maximal accommodations. METHODS: A specially adapted and designed UL-OCT instrument was used to image from the front surface of the cornea to the back surface of the crystalline lens. Custom software corrected the optical distortion of the images and yielded the biometric measurements. The coefficient of repeatability and the intraclass correlation coefficient were calculated to evaluate the repeatability and reliability. MAIN OUTCOME MEASURES: Anterior segment parameters and associated repeatability and reliability upon accommodation. The dimensional results included central corneal thickness (CCT), anterior chamber depth and width (ACD, ACW), pupil diameter (PD), lens thickness (LT), anterior segment length (ASL = ACD + LT), lens central position (LCP = ACD + 1/2LT), and horizontal radii of the lens anterior and posterior surface curvatures (LAC, LPC). RESULTS: Repeated measurements of each variable within each accommodative state did not differ significantly (P>0.05). The coefficients of repeatability (CORs) and intraclass correlation coefficients for CCT, ACW, ACD, LT, LCP, and ASL were excellent (1.2%- 3.59% and 0.998-0.877, respectively). They were higher for PD (18.90%-21.63% and 0.880-0.874, respectively) and moderate for LAC and LPC (34.86%-42.72% and 0.669-0.251, respectively) in the 2 accommodative states. Compared with minimal accommodation, PD, ACD, LAC, LPC, and LCP decreased and LT and ASL increased significantly at maximal accommodation (P<0.05), whereas CCT and ACW did not change (P>0.05). CONCLUSIONS: The UL-OCT measured changes in anterior segment dimensions during accommodation with good repeatability and reliability. During accommodation, the back surface of the lens became steeper as the lens moved forward. FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any of the materials discussed in this article.

Daytime variations of tear osmolarity and tear meniscus volume.

OBJECTIVES: The aim of this study was to determine the pattern of variations in tear osmolarity and tear meniscus volume in patients with dry eyes and in healthy control subjects over an 8-hr daytime period. METHODS: Ten normal subjects (5 men and 5 women with a mean age of 27±7 years) and 10 dry eye patients (4 men and 6 women with a mean age of 36±12 years) who had been diagnosed on the basis of having an ocular surface discomfort index >12 and a tear breakup time of <10 sec or Schirmer test score of <5 mm were included. The tear meniscus volumes of the participants were measured using ultrahigh resolution optical coherence tomography (OCT), and tear osmolarity was measured using the TearLab Osmolarity System. Both measurements protocols were conducted on the right eye of each participant every 2 hrs beginning at 8:30 AM and ending at 4:30 PM. The OCT imaging was performed first and was followed by osmolarity testing. RESULTS: The mean tear osmolarity of the dry eye patients was 304.0±10.8 mOsm/L, and the mean tear osmolarity of the normal subjects was 298.0±14.2 mOsm/L (P>0.05). Over the course of 8 hrs, the average measured osmolarities of the dry eye group varied by approximately 21.9±13.5 mOsm/L (range, 6-43 mOsm/L), and the average measured tear osmolarities of the normal group varied by approximately 21.0±9.2 mOsm/L (range, 8-35 mOsm/L). At 2:30 PM, the average volume of the tear menisci in the dry eye group was significantly lower than that of the subjects in the normal group (P<0.05). No correlations between the tear meniscus volumes and tear osmolarities of either group were observed. CONCLUSIONS: Variations in the tear osmolarities of individual dry eye patients and healthy normal control subjects were documented over the course of 8 daytime hours. No relationships between tear osmolarities and tear meniscus volumes were observed.

Red light irradiation as an intervention for myopia.

Myopia is one of the main causes of visual impairment worldwide. Preventing myopia and providing myopia-related interventions are of paramount importance. Based on a thorough review of the available literature, we conclude that red light irradiation can produce hyperopia, resulting in myopia prevention and control. Further, we suggest that red light irradiation may be a powerful tool for myopia prevention and control in the future. At the same time, red light has a protective effect on the cornea and retina at the cellular level, suggesting that red light irradiation may be a safe and effective modality for delaying myopia. Therefore, this form of irradiation is expected to play an important role in the prevention and control of myopia. However, more studies are needed to enhance the current state of knowledge and inform medical guidelines more comprehensively.

Machine learning for predicting the treatment effect of orthokeratology in children.

Purpose: Myopia treatment using orthokeratology (ortho-k) slows myopia progression. However, it is not equally effective in all patients. We aimed to predict the treatment effect of ortho-k using a machine-learning-assisted (ML) prediction model. Methods: Of the 119 patients who started ortho-k treatment between January 1, 2019, and January 1, 2022, 91 met the inclusion criteria and were included in the model. Ocular parameters and clinical characteristics were collected. A logistic regression model with least absolute shrinkage and selection operator regression was used to select factors associated with the treatment effect. Results: Age, baseline axial length, pupil diameter, lens wearing time, time spent outdoors, time spent on near work, white-to-white distance, anterior corneal flat keratometry, and posterior corneal astigmatism were selected in the model (aera under curve: 0.949). The decision curve analysis showed beneficial effects. The C-statistic of the predictive model was 0.821 (95% CI: 0.815, 0.827). Conclusion: Ocular parameters and clinical characteristics were used to predict the treatment effect of ortho-k. This ML-assisted model may assist ophthalmologists in making clinical decisions for patients, improving myopia control, and predicting the clinical effect of ortho-k treatment via a retrospective non-intervention trial.

Synergistic effects of defocus-incorporated multiple segments and atropine in slowing the progression of myopia.

Myopia is a leading cause of visual impairment in young people worldwide. It sometimes increases the risk of blindness and reduces life quality. Previous reports have revealed the treatment effects of defocus-incorporated multiple segments (DIMS) and topical atropine (ATP) on myopia control. However, no study has evaluated these two interventions together. In this retrospective study, we aimed to determine whether the combination of DIMS lenses and 0.01% ATP can slow the progression of myopia compared with DIMS lenses or single vision (SV) lenses alone. We included 107 children with myopia who were treated with DIMS and 0.01% ATP combination (DIMS + ATP group), DIMS monotherapy (DIMS group), or a control group (SV group). We compared treatment effects among three groups in axial length and myopia progression. After a 1-year follow-up, the DIMS + ATP group showed a smaller change in axial length and myopia progression than the DIMS and SV groups (P < 0.05). Hence, combination treatment with DIMS and 0.01% ATP might be a better choice for children with myopia.

Optical Coherence Tomography Angiography in Pinguecula and Pterygium.

PURPOSE: To investigate the density of conjunctival blood vessels in normal eyes and in eyes with pinguecula or pterygium. METHODS: In this cross-sectional study, the conjunctival blood vessel density of 15 normal eyes, 15 pinguecula eyes, and 15 pterygium eyes of 43 healthy adults was assessed using optical coherence tomography angiography with an anterior segment lens adapter. The nasal surface of each eye (3 × 3 mm) was scanned 3 times to a depth of 800 µm. Conjunctival vessel density was defined as the percent of the scanned volume occupied by vessels in which blood flow was measured. RESULTS: The high reliability of data measurement was supported by good coefficients of repeatability (<10%) of the image quality score and high intraclass correlation coefficients (>0.9). The vessel density in normal conjunctivas, 52.2 ± 4.1%, was similar to that in pinguecula conjunctivas, 50.5 ± 4.7% (P = 0.3006). However, the vessel density in conjunctivas with pterygium, 63.6 ± 3.7%, was greater than that in either normal (P < 0.0001) or pinguecula (P < 0.0001) conjunctivas. CONCLUSIONS: Using optical coherence tomography angiography with an anterior segment lens adapter, the ocular surface blood vessel density was imaged and assessed with good repeatability and reliability. The blood vessel density of conjunctivas with pterygium was significantly greater than that in either normal or pinguecula conjunctivas. This suggests that, in contrast to pinguecula development, pterygium development includes angiogenesis and neovascularization.

[Observation on changes of anterior chamber and chamber angle structures after posterior chamber phakic intraocular lens implantation by ultrasound biomicroscopy].

OBJECTIVE: To study the changes of anterior chamber and chamber angle structures after implantable contact lens (ICL) implantation in high myopia by using ultrasound biomicroscopy (UBM). METHODS: A prospective series case study was conducted on 15 high myopia patients (30 eyes) treated with ICL implant. These patients were followed for one year postoperatively. Intraocular pressure (IOP) was measured by Goldmann applanation tonometer after surgery. All eyes were examined by UBM one year after the surgery. Central anterior chamber depth (ACD), trabecular-iris angle (TIA), the distance between the posterior surface of ICL and the lens and the distance between peripheral surface of ICL and the lens were measured. Nonparametric test was used to compare TIA. One-way ANOVA was used to assess the distance between peripheral surface of ICL and the lens. Repeated Measure ANOVA and Bonferroni test was performed to compare the IOP level before and after surgery. Paired t-test was used to compare ACD. RESULTS: Intraocular pressure changed from (13.75 +/- 2.27) mm Hg (1 mm Hg = 0.133 kPa) preoperatively to (14.27 +/- 1.70), (14.70 +/- 2.07), (14.07 +/- 2.24), (14.00 +/- 2.69) and (13.97 +/- 2.95) mm Hg at 1 week, 1, 3, 6 and 12 months after the surgery, respectively. There was a statistically significant increase of the IOP one month after the surgery, which was normalized completely at 3 months after surgery. The distances between central posterior surface of the cornea to the ICL and the lens were (2.24 +/- 0.21) and (2.97 +/- 0.11) mm, respectively. There was significant difference between these two data (t = 20.63, P < 0.01). TIA was measured in 12:00, 3:00, 6:00 and 9:00. There were no statistically differences between them. TIA was greater than 30 degree in 55.8% of cases. The distance between the central anterior surface of the ICL to the lens (central section) was (0.63 +/- 0.16) mm. No contact was found between the ICL and the crystalline lens. CONCLUSIONS: Posterior chamber phakic intraocular lens implantation for the surgical correction of high myopia is a safe procedure as evaluated with immediate visual and refractive results. We found that the iridocorneal angle and the anterior chamber depth are decreased after the surgery. There is no contact between the crystalline lens and ICL. The ICL contacts with the posterior iris surface.

Analysis of amino acids in human tears by hydrophilic interaction liquid chromatography and quadrupole orbitrap mass spectrometry.

Amino acids in human tears play certain physiological roles and their determination is challenging due to complicated chemical properties. This study described a fast and sensitive method for the simultaneous determination of 15 amino acids (AAs) in tears by hydrophilic interaction liquid chromatography and quadrupole orbitrap mass spectrometry (HILIC-Q-Orbitrap-MS). Amino acids in tears were extracted by methanol, and then cleaned up with a solid phase extraction (SPE) cartridge. Chromatographic separation was performed on a 1.7 µm BEH Amide column within 8 min. Tear samples spiked with free AAs were tested in terms of linearity, sensitivity, repeatability, and recovery. Two stable isotope-labeled amino acids were used as internal standards to improve the method performance. Recoveries for all analytes ranged from 89 to 107%. Intra-day and inter-day precision, expressed as relative standard deviations, were all below 10%, and the method detection limits ranged from 0.02 µmol L-1 to 0.11 µmol L-1. The developed method with high throughput and high analyte specificity shows good promise for consistent analysis of free amino acids in tears.

Anterior Segment Biometry with Phenylephrine and Tropicamide during Accommodation Imaged with Ultralong Scan Depth Optical Coherence Tomography.

PURPOSE: To investigate the influence of phenylephrine and tropicamide on anterior segment biometry with ultralong scan depth optical coherence tomography (UL-OCT) during accommodation. METHODS: In this study, 20 left eyes of healthy volunteers with a mean ± standard deviation age of 31.05 ± 5.84 years and a mean refraction of -1.16 ± 1.11 diopters (range 0∼-3.0 D) were imaged using UL-OCT after instillation of artificial tears, phenylephrine, and tropicamide in three follow-up trials, respectively. At each follow-up trial, two repeated measurements were performed at states of relax and 5D accommodative stimulation. The dimensional parameters included central corneal thickness (CCT), anterior chamber depth (ACD), pupil diameter (PD), lens thickness (LT), and horizontal radii of the lens anterior and posterior surface curvatures (LAC and LPC). RESULTS: Tropicamide led to larger pupil, deeper ACD, thinner LT, and flatter crystalline lens surface (P < 0.05). Phenylephrine induced an increase in PD (P < 0.05), while no significant changes were seen in ACD, LT, LAC, and LPC (P > 0.05). CCT did not change after both phenylephrine and tropicamide instillation in this study (P > 0.05). Tropicamide induced the loss of accommodation and phenylephrine achieved pupil dilation without affecting the accommodation. PD, ACD decreased, LT increased significantly and the anterior and posterior surface of the lens in a 6.294 mm of diameter optical zone became steeper during accommodation after administration of phenylephrine (P < 0.05). CONCLUSION: The anterior segment physiology changed after tropicamide instillation. Besides, tropicamide induced the loss of accommodation and phenylephrine preserved the accommodation with a larger pupil. And, the anterior and posterior surface of lens in a 6.294 mm of diameter optical zone became steeper during the accommodation.

The use of in-strip digestion for fast proteomic analysis on tear fluid from dry eye patients.

Tear is an accessible fluid for exploring biomarkers of dry eye disease. This study describes a fast proteomic method by LC-Q-orbitrap-MS analysis with in-strip digestion and investigates the tear proteome of dry eye patients. Schirmer's strips were used for collection of tear fluid from patients. These strips were cut into pieces and directly digested with trypsin before mass spectrometry analysis. The data showed that more than 50 proteins were found in tear fluid from dry eye patients. Gene Ontology (GO) annotation showed that most of proteins were transfer/carrier proteins, hydrolyses, enzyme modulators and signaling molecules. Targeted proteomics strategy revealed that 18 proteins were differentially expressed in dry eye patients. Furthermore, it was showed that the common post-translational modification in tear proteins is deamidation of Asn.

Comparison of high order aberration after conventional and customized ablation in myopic LASIK in different eyes of the same patient.

PURPOSE: To verify whether there exists any difference in higher order aberrations after undergoing myopic LASIK (laser in situ keratomileusis) with conventional ablation and customized ablation in different eyes of the same patient. METHODS: This was a prospective randomized study of 54 myopic eyes (27 patients) that underwent LASIK using the Nidek EC-5000 excimer laser system (Nidek, Gamagori, Japan). Topography-guided customized aspheric treatment zone (CATz) was used in the first eye of the patient (study group) and the other eye of the same patient was operated on with conventional ablation (control group). Higher order aberrations [root-mean-square (RMS) in the 5-mm zone] of both groups were observed with the Nidek OPD-Scan aberrometer before and 3 months after LASIK. Preoperative mean refractive error was similar between two eyes of the same patient (t=-0.577, P>0.05). RESULTS: Preoperatively, higher order aberrations (RMS in the 5-mm zone) in the CATz ablation and conventional groups were (0.3600+/-0.0341) microm and (0.2680+/-0.1421) microm, respectively. This difference was not statistically significant (t=1.292, P>0.05). Three months after LASIK, higher order aberrations (RMS in 5-mm zone) in the CATz ablation and conventional groups were (0.3627+/-0.1510) microm and (0.3991+/-0.1582) microm, respectively. No statistically significant difference was noted between pre- and postoperative higher order aberrations in the CATz group (t=-0.047, P>0.05). However, a statistically significant increase in higher order aberrations was observed after conventional ablation (t=-5.261, P<0.05). A statistically significant difference was noted in the increase of higher order aberrations after LASIK between groups (t=-2.050, P=0.045). CONCLUSION: LASIK with conventional ablation and topography-guided CATz ablation resulted in the same BSCVA (best spectacle-corrected visual acuity) 3 month after LASIK. Higher order aberrations were increased, but the increase of higher order aberrations after customized ablation treatment was less than that after conventional ablation.