Three-Year Follow-Up of Laser In Situ Keratomileusis Treatments for Myopia: Multi-Center Cohort Study in Korean Population.

This multi-center cohort study included 3401 myopic laser in situ keratomileusis (LASIK) procedures conducted in 1756 myopia patients between 2002 and 2005. Pre- and postoperative uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), and manifest refraction spherical equivalent (SE) were recorded. Factors predicting low postoperative efficacy (defined as a postoperative UCVA < 0.5) were identified using univariate and multivariate logistic regression analysis. Compared with 1 month postoperatively, logMAR UCVA at 3 months postoperatively was significantly decreased (p = 0.002) and that at 2 and 3 years was significantly increased (p < 0.001). LogMAR BCVA at 2 years postoperatively was significantly decreased compared with 1 month postoperatively (p = 0.008). Over the 3-year postoperative period, overall refractive predictability within ±1.00 D and ±0.50 D ranged from 69.0% to 86.2% and from 43.3% to 67.8%, respectively. This also decreased from 1 month to 6 months postoperatively (p < 0.005). Multivariate logistic regression analysis using generalized estimating equations, revealed that higher preoperative SE (odds ratio [OR], 2.58 and 7.23; p < 0.001) and lower preoperative BCVA (OR, 2.44; p = 0.003) were predictive of a low postoperative efficacy. In summary, myopic LASIK can be effective and safe with a high refractive predictability in a Korean population, but myopic regression occurs over time. Higher preoperative SE and lower preoperative BCVA are predictive of a low postoperative efficacy.

Novel Findings about Myopia in Patients with Oculodermal Melanocytosis (Nevus of Ota).

Purpose: To test the hypothesis that ocular pigment in patients with oculodermal melanocytosis decreases myopia severity.Methods: Refractive and biometric parameters were measured and compared between pigmented eyes and non-pigmented contralateral eyes in oculodermal melanocytosis patients that underwent surgical ocular pigmentation removal. To assess pigmentation, the pigmentation score was measured in each quadrant of the sclera and added together for a cumulative score. For subgroup analyses, patients were categorized into three groups according to the severity of myopia in the non-pigmented eye.Results: Fifty-five patients (110 eyes) were included. Spherical power and spherical equivalent were significantly less myopic in pigmented eyes relative to contralateral non-pigmented eyes. The spherical powers of non-pigmented eyes were positively correlated with the difference in spherical power between contralateral eyes (r = 0.697, p < .001). The pigmentation scores of pigmented eyes were positively correlated with the ratio of myopia inhibition (r = 0.373, p = .005). In subgroup analyses, pigmented eyes exhibited significantly less myopic spherical powers and spherical equivalents than non-pigmented contralateral eyes in the moderate and high myopia groups. Pigmented eyes exhibited significantly shorter axial length than non-pigmented contralateral eyes in the high myopia group only.Conclusions: In patients with oculodermal melanocytosis, pigmented eyes exhibited less severe myopia relative to non-pigmented contralateral eyes. This suggested that ocular pigmentation inhibited myopic changes, potentially by blocking UV transmission. This study will be helpful in elucidating the mechanisms of myopic progression.

A New Perspective on Dry Eye Classification: Proposal by the Asia Dry Eye Society.

The 2017 consensus report of the Asia Dry Eye Society (ADES) on the definition and diagnosis of dry eyes described dry eye disease as "Dry eye is a multifactorial disease characterized by unstable tear film causing a variety of symptoms and/or visual impairment, potentially accompanied by ocular surface damage." The report emphasized the instability of tear film and the importance of visual dysfunction in association with dry eyes, highlighting the importance of the evaluation of tear film stability. This report also discussed the concept of tear film-oriented therapy, which stemmed from the definition, and which is centered on provision of insufficient components in each tear film layer and ocular surface epithelium. The current ADES report proposes a simple classification of dry eyes based on the concept of tear film-oriented diagnosis and suggests that there are three types of dry eye: aqueous-deficient, decreased wettability, and increased evaporation. It is suggested that these three types respectively coincide with the problems of each layer: aqueous, membrane-associated mucins, and lipid/secretory mucin. Although each component cannot be quantitatively evaluated with the current technology, a practical diagnosis based on the patterns of fluorescein breakup is recommended. The Asia Dry Eye Society classification report suggests that for a practical use of the definition, diagnostic criteria and classification system should be integrated and be simple to use. The classification system proposed by ADES is a straightforward tool and simple to use, only through use of fluorescein, which is available even to non-dry eye specialists, and which is believed to contribute to an effective diagnosis and treatment of dry eyes.

New Perspectives on Dry Eye Definition and Diagnosis: A Consensus Report by the Asia Dry Eye Society.

For the last 20 years, a great amount of evidence has accumulated through epidemiological studies that most of the dry eye disease encountered in daily life, especially in video display terminal (VDT) workers, involves short tear film breakup time (TFBUT) type dry eye, a category characterized by severe symptoms but minimal clinical signs other than short TFBUT. An unstable tear film also affects the visual function, possibly due to the increase of higher order aberrations. Based on the change in the understanding of the types, symptoms, and signs of dry eye disease, the Asia Dry Eye Society agreed to the following definition of dry eye: "Dry eye is a multifactorial disease characterized by unstable tear film causing a variety of symptoms and/or visual impairment, potentially accompanied by ocular surface damage." The definition stresses instability of the tear film as well as the importance of visual impairment, highlighting an essential role for TFBUT assessment. This paper discusses the concept of Tear Film Oriented Therapy (TFOT), which evolved from the definition of dry eye, emphasizing the importance of a stable tear film.

Clinical characteristics of glaucomatous subjects treated with refractive corneal ablation surgery.

PURPOSE: To evaluate the clinical characteristics of newly diagnosed glaucomatous subjects who had a history of refractive corneal ablation surgery (RCAS). METHODS: Sixty-eight glaucomatous subjects who had a history of RCAS and 68 age- and visual field (VF) mean deviation-matched glaucomatous subjects with no history of RCAS were included. Intraocular pressure (IOP), central corneal thickness (CCT), VF, and retinal nerve fiber layer thickness determined by optical coherence tomography were assessed. Parameters were compared between patients with and without a history of RCAS. Between-eye comparisons in the same participant (more advanced vs. less-advanced eye, in terms of glaucoma severity) were performed in the RCAS group. RESULTS: With similar levels of glaucoma severity, those with a history of RCAS showed significantly lower baseline IOP and a thinner CCT than the eyes of individuals without a RCAS history (13.6 vs. 18.7 mmHg, 490.5 vs. 551.7 µm, all p < 0.001). However, the extent of IOP reduction after anti-glaucoma medication did not significantly differ between the two groups (17% vs. 24.3%, p = 0.144). In the between-eye comparisons of individual participants in the RCAS group, the more advanced eyes were more myopic than the less-advanced eyes (-1.84 vs. -0.58 diopter, p = 0.003). CONCLUSIONS: Eyes with a history of RCAS showed a similar level of IOP reduction as eyes without such a history after anti-glaucoma medication. Our finding that the more advanced eyes were more myopic than the less-advanced eyes in the same participant may suggest an association between glaucoma severity and myopic regression.

Clinical outcomes after combined Ahmed glaucoma valve implantation and penetrating keratoplasty or pars plana vitrectomy.

PURPOSE: To evaluate whether a combination of penetrating keratoplasty (PKP) or pars plana vitrectomy (PPV) and Ahmed glaucoma valve (AGV) implantation affords a level of success similar to that of AGV implantation alone. METHODS: Eighteen eyes underwent simultaneous PPV and AGV, 14 eyes with PKP and AGV and 30 eyes with AGV implantation alone were evaluated. Success was defined as attainment of an intraocular pressure (IOP) >5 and <22 mmHg, with or without use of anti-glaucoma medication. Kaplan-Meier survival analysis was performed to compare cumulative survival between the combined surgery groups and the AGV implantation-alone group. Cox proportional hazard regression analysis was conducted to identify factors predictive of success in each of the three groups. RESULTS: Mean (±standard deviation) preoperative IOP was 30.2 ± 10.2 mmHg in the PKP + AGV, 35.2 ± 9.8 mmHg in the PPV + AGV, and 36.2 ± 10.1 mmHg in the AGV implantation-alone group. The cumulative success rate at 18 months was 66.9%, 73.2%, and 70.8% in the three groups, respectively. Neither combined surgery group differed significantly in terms of cumulative success rate compared with the AGV implantation-alone group (p = 0.556, p = 0.487, respectively). The mean number of preoperative anti-glaucoma medications prescribed was significantly associated with success in the PKP + AGV implantation group (hazard ratio, 2.942; p = 0.024). CONCLUSIONS: Either PKP or PPV performed in conjunction with AGV implantation afforded similar success rates compared to patients treated with AGV implantation alone. Therefore, in patients with refractory glaucoma who have underlying corneal or retinal pathology requiring treatment with PKP or PPV, AGV implantation can be performed simultaneously.

Glaucoma progression in eyes with a history of refractive corneal surgery.

PURPOSE: To evaluate the glaucoma progression in patients with a history of refractive corneal surgery (RCS). METHODS: A total of 313 eyes of 313 glaucoma patients (RCS group, 34 eyes; non-RCS group, 279 eyes) with a mean follow-up period of 2.7 years were included. Glaucoma progression was determined either by experts' stereoscopic optic disc/retinal nerve fiber layer (RNFL) photographs or by serial visual field (VF) data. Uni- and multivariate Cox's proportional hazards models were used to determine associations between potential risk factors including a history of RCS and glaucoma progression. RESULTS: Among 313 eyes, 87 (27.8%) eyes showed progression either by optic disc/RNFL photographs or VF assessment during the follow-up period. Ten (29.4%) of eyes in the RCS group and 77 (27.6%) of eyes in the non-RCS group showed glaucoma progression; however, prevalence of progression did not differ between the two groups (P = 0.482). Among all participants, baseline age and VF pattern standard deviation (PSD; hazard ratios of 1.013 and 1.119; P = 0.026 and P < 0.001, respectively) were significant risk factors for progression. In both the RCS and the non-RCS group, only VF PSD was a significant risk factor for progression according to multivariate Cox proportional hazards (1.193, 1.099, P < 0.001, P < 0.001, respectively). CONCLUSIONS: Baseline VF PSD and age substantially affected glaucoma progression in all study participants, although their RCS history was not a significant risk factor for glaucoma progression.

Factors associated with anterior chamber narrowing with age: an optical coherence tomography study.

PURPOSE: The purpose of our study is to evaluate the effect of age on various anterior segment (AS) parameters in healthy eyes using AS optical coherence tomography (OCT), and to examine their relationship to anterior chamber angle (ACA) narrowing with age. METHODS: A total of 388 consecutive Korean subjects aged 30 to 89 years was imaged by AS OCT. Anterior chamber depth (ACD), iris cross-sectional area (IA), iris thickness at 750 and 1500 µ from the scleral spur (IT(750, 1500)), iris curvature (IC), lens vault (LV), and anterior chamber area (AA) were determined using Image J software (version 1.44). The absolute and normalized slopes of these parameters, adjusted for axial length and sex, were determined by linear mixed-effects modeling. Multivariate regression analysis was performed to evaluate factors associated with ACA narrowing, which was defined as the angle-opening distance (AOD(500)) at the temporal angle. RESULTS: ACD and AA had significantly negative slopes (-0.0119 mm/year, -0.0845 mm(2)/year, P < 0.0001, <0.0001) with age, and LV, IC, IT(750), IT(1500), and IA had significantly positive slopes (0.0084 mm/year, 0.0019 mm/year, 0.0006 mm/year, 0.0008 mm/year, 0.0131 mm(2)/year, all P < 0.05). IC, ACD, LV, and AA underwent the greatest changes when analyzed by normalized slopes. IC, LV, age, and axial length were associated significantly with ACA narrowing (all P < 0.0001). CONCLUSIONS: Increments of LV, IC, IT, and IA with age led to a reduction in the dimensions of the AC and to narrowing of the ACA. This may explain why aging is a significant risk factor for primary angle closure glaucoma.

Effect of age on anterior chamber angle configuration in Asians determined by anterior segment optical coherence tomography; clinic-based study.

PURPOSE: To evaluate the distribution of anterior chamber angle (ACA) parameters and to assess association of these parameters with age in Asian subjects. METHODS: Four hundred and thirty-nine consecutive Korean subjects aged from 30 to 89 were enrolled from a university clinic. All participants were scanned using anterior segment optical coherence tomography (AS-OCT, Visante, version 2.0). We measured ACA parameters such as anterior chamber depth (ACD), angle opening distance at 500 and 750µm (AOD(500,750) ), angle recess area at 500 and 750µm (ARA(500,750) ), trabecular iris space area at 500 and 750µm (TISA(500,750) ), and determined age-related changes in these parameters with use of a linear mixed effect model that adjusted for gender, axial length, intraocular pressure, and keratometry data. Slopes of ACA parameters as a function of age were determined. For various AS-OCT parameters, the normalized slope was calculated by dividing the slope by the mean value. RESULTS: All analysed ACA parameters decreased with age in both nasal and temporal quadrants. Axial length and keratometry data were significant covariates for ACA changes. The slopes of ACD were -0.02396mm/year, AOD(500) , ARA(500) , and TISA(500) measured at the temporal angle were -0.00634mm/year, -0.0019mm(2) /year, and -0.00177mm(2) /year, respectively. There was no age-dependent difference in central corneal thickness (p value; 0.4597) Based on the normalized slopes, the AOD showed the steepest slope at both temporal and nasal sectors. CONCLUSION: All ACA parameters assessed by AS-OCT, which accounted for other ocular biometric parameters, showed significant negative slopes with increasing age. These results should be considered when assessing changes in the anterior chamber over time.

Different epithelial cleavage planes produced by various epikeratomes in epithelial laser in situ keratomileusis.

PURPOSE: To determine the anatomic cleavage planes produced by various epikeratomes in epithelial laser in situ keratomileusis (epi-LASIK). SETTING: Department of Ophthalmology, IIsan Paik Hospital, Goyang, Korea. METHODS: Sixteen eyes (8 patients) were included in this study. Three epikeratomes, the Moria Epi-K, Centurion SES, and Amadeus II, were used to collect 4 epithelial flaps from 2 patients in the epi-LASIK procedure. Four epithelial flaps from 2 patients were also obtained by laser-assisted subepithelial keratectomy (LASEK). Immunohistochemical staining using monoclonal antibodies against integrin beta1, integrin beta4, laminin 5, and collagen type VII was performed. RESULTS: Immunohistochemical staining showed expression of integrin beta1 and integrin beta4 in all epithelial flaps. In epi-LASIK, the expression of laminin 5 and collagen type VII had a linear or dotted pattern that differed based on the epikeratome used. In the epithelial flaps obtained using LASEK, the expression of laminin 5 and collagen type VII had a dotted pattern. CONCLUSIONS: Each epikeratome yielded reproducible but different cleavage planes of corneal epithelium. The results suggest that further study is needed to elucidate the wound-healing process after epi-LASIK because different cleavage planes produced by different epikeratomes may influence the process.

Effect of laser in situ keratomileusis on retinal nerve fiber layer thickness measurements by scanning laser polarimetry.

PURPOSE: To determine the effect of laser in situ keratomileusis (LASIK) on retinal nerve fiber layer measurements by scanning laser polarimetry in a large clinical trial. SETTING: Asan Medical Center, University of Ulsan, Department of Ophthalmology, Seoul, Korea. METHODS: Scanning laser polarimetry measurements were performed in 59 eyes of 59 consecutive patients who had LASIK. The mean retardation values of the whole measurement ellipse and of the superior, inferior, temporal, and nasal sectors of the ellipse before and after LASIK were compared statistically. RESULTS: The mean spherical equivalent refractive error was -6.10 diopters (D) +/- 2.34 (SD) (range -1.19 to -15.50 D) preoperatively and -0.31 +/- 0.52 D (range +0.68 to -2.13 D) postoperatively. The mean ablation depth was 94.0 +/- 30.49 microm (range 28.0 to 161.1 microm). The mean postoperative retardation values of all the sectors and of the superior, temporal, inferior, and nasal sectors showed reduced nerve fiber layer thickness (P =.000, P =.000, P =.011, P =.000, and P=.002, respectively). CONCLUSION: Laser in situ keratomileusis affected nerve fiber layer thickness measurements by scanning laser polarimetry. The change in nerve fiber layer thickness was probably due to modification of the corneal architecture. This effect of keratorefractive surgery should be considered when using scanning laser polarimetry as a diagnostic and follow-up tool for glaucoma.