Ocular parameters associated with visual performance of enhanced monofocal intraocular lens.

BACKGROUND: An enhanced monofocal intraocular lenses (IOLs) (Tecnis Eyhance ICB00 and Tecnis Eyhance Toric DIU) has been developed to enhance intermediate vision while avoiding the disadvantages of multifocal IOLs. Although many studies have demonstrated the improvement of intermediate visual acuity with enhanced monofocal IOLs, it is not known specifically for which patients these IOLs should be recommended or avoided. In this study, we aim to find out which ocular parameters affect vision performance and photic phenomenon of ICB00 or DIU at different distances. METHODS: Patients who underwent cataract surgery with ICB00 or DIU, performed by a single surgeon, were included. Before surgery, the patients' age, gender, axial length, anterior chamber depth, spherical aberration Z (4,0), vertical coma, horizontal coma, angle kappa (κ), angle alpha (α), and other ocular parameters were investigated. One month after surgery, uncorrected near visual acuity (UNVA at 40 cm), uncorrected intermediate visual acuity (UIVA at 66 cm), uncorrected distance logMAR visual acuity (UDVA), IOL decentration, and quality of vision (QoV) questionnaires were conducted. RESULTS: A total of 43 patients (58 eyes) were included. The results of the univariate linear regression analyses showed a negative correlation between spherical aberration and logMAR UNVA and UIVA (p = 0.003, ß=-0.51 and p = 0.018, ß=-0.23, respectively) and a positive correlation between angle α and logMAR UIVA (p = 0.036, ß = 0.19). Deeper anterior chamber depth (ACD) was associated with poorer total QoV (p = 0.018, ß = 14.43), particularly in glare, halo, blur, and fluctuation perception. A higher degree of IOL decentration tended to decrease UNVA and UIVA (Pearson correlation coefficient, r = 0.336 and r = 0.221, respectively); however, no significant effect was observed on UDVA (Pearson correlation coefficient, r = 0.042). CONCLUSIONS: In enhanced monofocal IOLs, a higher level of spherical aberration is associated with better performance in UNVA and UIVA, whereas a larger angle α has a negative impact. A deeper ACD negatively affects the QoV.

Relationship between meibomian gland loss in infrared meibography and meibum quality in dry eye patients.

BACKGROUND: In the present study, we evaluated the correlation between meibomian gland dropout and meibum quality in the same central 8 meibomian glands of the eyelid. METHODS: Ninety-nine eyes of 91 patients with dry eye were included in the study. Dropout of the 8 central meibomian glands of the eyelids was graded as 0, 1, 2, or 3, according to the dropout area. The meibum quality was graded as follows: grade 0, no secretion; 1, inspissated/toothpaste consistency; 2, cloudy liquid secretion; and 3, clear liquid secretion. For 68 eyes of 68 patients, correlation analysis between dropout and meibum quality was performed. To precisely analyze the direct correlation between meibomian gland dropout in meibography and meibum quality, we evaluated 31 eyes of 23 patients with focal dropout in meibography. RESULTS: The median (interquartile range) meiboscore was 1.0 (2.0) in the upper eyelids and 0.0 (1.0) in the lower eyelids. The median (interquartile range) meibum quality grade was 3.0 (1.0) in the upper eyelids and 1.0 (1.0) in the lower eyelids. No significant correlation between the meiboscore and meibum quality grade was detected in the upper (p =0.746) or lower (p =0.551) eyelids. Analysis of the direct correlation between meibomian gland dropout in meibography and meibum quality in patients with focal dropout (loss of 1 or 2 adjacent meibomian glands), however, indicated that meibomian glands with dropout secreted little to no meibum. CONCLUSIONS: Overall analysis revealed no relationship between meibomian gland dropout and meibum quality, but more detailed investigation of each meibomian gland alone revealed that meibomian glands with dropout secrete little to no meibum.

Clinical differences between toric intraocular lens (IOL) and monofocal intraocular lens (IOL) implantation when myopia is determined as target refraction.

BACKGROUND: The aim of this study is to analyze and compare the clinical results of toric intraocular lens (IOL) and monofocal IOL implantation when the target refraction value is -3 diopter (D) in cataract patients with corneal astigmatism > 1.5 diopters (D). METHODS: We performed a retrospective chart review for patients with corneal astigmatism > 1.5D who underwent cataract surgery and their target refraction is -3D. 100 eyes (100 patients; monofocal IOL, 60; toric IOL, 40) were enrolled in the current study. Near and distant uncorrected visual acuity (UCVA), corrected VA, spherical equivalent and refractive, corneal astigmatism were evaluated before and after surgery. RESULTS: The near UCVA of the toric IOL group (0.26 ± 0.33) after cataract surgery was significantly better than that of the monofocal IOL group (0.48 ± 0.32) (p = 0.030). The distant UCVA of the toric IOL group (0.38 ± 0.14) was also significantly better than that of the monofocal IOL group (0.55 ± 0.22) (p = 0.026). Best-corrected visual acuity (p = 0.710) and mean spherical equivalent (p = 0.465) did not show significant differences between the toric IOL group and the monofocal IOL group. In the toric IOL group, postoperative refractive astigmatism was - 0.80 ± 0.46D and postoperative corneal astigmatism was - 1.50 ± 0.62D, whereas the corresponding values in the monofocal IOL group were - 1.65 ± 0.77D and - 1.45 ± 0.64D; residual refractive astigmatism was significantly lower with toric IOL implantation compared with monofocal IOL implantation (p = 0.001). There were no postoperative complications. CONCLUSIONS: When myopic refraction such as -3D was determined as the target power in patients with corneal astigmatism, toric IOL implantation led to excellent improvement in both near and distant UCVA.

Development of a novel multifocal lens using a polarization directed flat lens: possible candidate for a multifocal intraocular lens.

BACKGROUND: A polarization-directed flat (PDF) lens acts as a converging lens with a focal length (f) > 0 and a diverging lens with f < 0, depending on the polarization state of the incidental light. To produce a multifocal lens with two focal lengths, a PDF and a converging lens having shorter focal length were combined. In this study, we tested a bifocal PDF to determine its potential as a new multifocal intraocular lens (IOL). METHODS: Constructed a multifocal lens with a PDF lens (f = +/- 100 mm) and a converging lens (f = + 25 mm). In an optical bench test, we measured the defocus curve to test the multifocal function. The multifocal function and optical quality of the lens in various situations were tested. An Early Treatment Diabetic Retinopathy Study (ETDRS) chart as a near target and a building as a distant target were photographed using a digital single-lens reflex (DSLR) camera. Both lenses (multifocal and monofocal) were tested under the same conditions. RESULTS: For the 0 D and - 20 D focal points, the multifocal lens showed sharp images in the optical bench test. In the DSLR test using the multifocal lens, the building appeared slightly blurry compared with the results using the monofocal lens. With the multifocal lens, the ETDRS chart's images became blurry as the ETDRS chart's distance decreased, but became very clear again at a certain position. CONCLUSIONS: We confirmed the multifocal function of the multifocal lens using a PDF lens. This lens can be used as a multifocal IOL in the future.

How does the world appear to patients with multifocal intraocular lenses?: a mobile model eye experiment.

BACKGROUND: To show how the world appear to patients with multifocal intraocular lens (IOL) using a novel mobile model eye. METHODS: The mobile model eye was composed of an artificial cornea, IOL, IOL chamber, and a camera. A monofocal IOL (Tecnis monofocal IOL) and two diffractive multifocal IOL (ReSTOR, Tecnis multifocal IOL) were used in the study. We went outside to take a picture of the scenery. At night, we stood on a road and took pictures to see how the traffic lights and headlights of cars looked. For an indoor analysis, we approached the Early Treatment Diabetic Retinopathy Study (ETDRS) chart to the model eye from a distance of 95 cm to check the multifocal function of the lenses. In the car, we took pictures of the street and a cell phone in turn to check the multifocal function of the lenses. RESULTS: Two multifocal IOLs showed definite multifocal function. Far objects appeared either similarly clear or slightly hazier (depending on the IOL model) than those with the monofocal IOL. In the night vision, there was a mild or severe halo around light sources compared to those with the monofocal IOL. CONCLUSION: We believe that this mobile model eye can be used to evaluate how the real world appear to a patient with a multifocal IOL, to explain multifocal function of the IOLs, and possible complications in the patients, before performing a surgery.

Toric intraocular lens implantation in cataract patients with corneal opacity.

BACKGROUND: To evaluate the effect of toric intraocular lens implantation in cataract patient with corneal opacity and high astigmatism. METHODS: Thirty-one eyes of 31 patients who underwent cataract surgery with toric intraocular lens implantation were included. All patients had corneal opacity with astigmatism. Preoperative total corneal astigmatism was determined considering posterior astigmatism using a rotating Scheimpflug camera (Pentacam®: Oculus, Wetzlar, Germany). At 2 months after toric intraocular lens implantation, we evaluated residual astigmatism, uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA). RESULTS: Postoperative UCVA and BCVA (0.30 ± 0.17, 0.22 ± 0.16LogMAR) were statistically improved compared to preoperative UCVA and BCVA (1.2 ± 0.34, 1.1 ± 0.30LogMAR, respectively) (P < 0.01). Postoperative residual refractive astigmatism (1.2 ± 0.35D) was statistically reduced compared to preoperative refractive astigmatism (2.4 ± 0.65D) (P < 0.05). Preoperative and postoperative total corneal astigmatism values were not statistically different. All eyes achieved postoperative visual acuity as good as or better than preoperative one. The size of corneal opacity covering pupil had significant negative correlation with postoperative UCVA and BCVA (logMAR) (R = 0.91 P < 0.05 and R = 0.92 P < 0.05, respectively). CONCLUSION: Toric intraocular lens implantation can improve UCVA, BCVA, and refractive astigmatism in cataract patient with corneal opacity. The size of corneal opacity covering pupil is the major prognostic factor for postoperative visual improvement. Therefore, toric intraocular lens implantation should be considered for cataract patients who have corneal opacity with high astigmatism.

Easy and effective test to evaluate tear-film stability for self-diagnosis of dry eye syndrome: blinking tolerance time (BTT).

BACKGROUND: The tear film breakup time (tBUT) is a clinical evaluation of evaporative dry eye disease assessed by instilling topical fluorescein into the eyes. In the present study, we introduce a new diagnostic test, blinking tolerance time (BTT), for self-evaluation of tear-film stability. We compared the results with the tBUT and validated the BTT test for self-assessment of tear film instability. METHODS: This was a prospective controlled study involving 212 eyes of 106 participants 20-79 years of age. A total of 114 eyes of 57 dry eye patients and 98 eyes of 49 healthy subjects were included in the study. All patients and subjects were administered the following tests to diagnose dry eye disease: Ocular Surface Disease Index, BTT, tBUT, slit-lamp examination, corneal stain score, and Schirmer I test (without anesthesia). Patients and subjects were instructed not to blink for as long possible after reset blinking. The time interval between the reset blink and the next blink was measured. The mean of 3 tBUT values in both the right and left eyes was defined as tBUTBE. Correlations between the BTT and tBUTBE were also evaluated. To evaluate the diagnostic efficacy of the BTT and tBUT tests, receiver operating characteristic (ROC) curves were generated to obtain a cutoff score, and the sensitivities of the tests against the specificity at all possible thresholds were plotted. RESULTS: Spearman's correlation analysis revealed a significant weakly positive correlation between BTT and tBUTBE (r = 0.447; p = 0.000). The intraclass correlation coefficient (ICC) of the tBUT was 0.679 (95% confidence interval [CI]: 0.575-0.765) and the ICC of the BTT was 0.904 (95% CI: 0.867-0.932). The area under the ROC curve did not significantly differ between the tBUTBE (0.678) and BTT (0.628, p = 0.641). When the cutoff value of the BTT test was set to 8.1 s, the sensitivity was 63.3% and the specificity was 56.1%. CONCLUSION: The BTT test is a simple, inexpensive, and effective method for self-diagnosing dry eye that can also be used in the clinical setting.

Comparative Analysis of Age-Related Changes in Lacrimal Glands and Meibomian Glands of a C57BL/6 Male Mouse Model.

It is not known how biological changes in the lacrimal (LGs) and meibomian (MGs) glands contribute to dry eye disease (DED) in a time-dependent manner. In this study, we investigated time-sequenced changes in the inflammation, oxidative stress, and senescence of stem cells in both glands of an aging-related DED mouse model. Eight-week (8W)-, one-year (1Y)-, and two-year (2Y)-old C57BL/6 male mice were used. MG areas of the upper and lower eyelids were analyzed by transillumination meibography imaging. The number of CD45+, 8-OHdG+, Ki-67+, and BrdU+ cells was compared in both glands. Increased corneal staining and decreased tear secretion were observed in aged mice. The MG dropout area increased with aging, and the age-adjusted MG area in lower lids was negatively correlated with the National Eye Institute (NEI) score. Increased CD4+ interferon (IFN)-γ+ cells in LGs were found in both aged mice. An increase in 8-OHdG+ cells in both glands was evident in 2Y-old mice. Reduced Ki-67+ cells, but no change in CD45+ cells, was observed in the MGs of 1Y-old mice. Increased BrdU+ cells were observed in the LGs of aged mice. This suggests that age-dependent DED in C57BL/6 mice is related to inflammation of the LGs, the development of MG atrophy, and oxidative stress in both glands.

A novel method for quantifying the biomechanical parameters of orbital soft tissue using a corneal dynamic scheimpflug analyser: a retrospective study.

BACKGROUND: To demonstrate that the Corvis ST could be used to quantify the biomechanical parameters of the orbital soft tissues by measuring and comparing whole eye movement (WEM) using the Corvis in normal eyes and in eyes of patients with Graves ophthalmopathy. METHODS: Forty four eyes of 44 ophthalmologically normal subjects and 28 eyes of 28 patients with Graves ophthalmopathy were included in the study. After Corvis test, the examiners recorded WEM by air puff. In the patients with Graves ophthalmopathy, the partial correlation coefficient adjusted for age and gender was calculated to analyze the correlation between exopthalmometry and WEM. Same analysis was repeated for the correlation between and the cross sectional area (%) of the extraocular muscles in the orbit CT and WEM. RESULTS: WEM was 0.314 ± 0.083 mm in the normal subjects and 0.227 ± 0.079 mm in the Graves ophthalmopathy group (p = 0.000). The exophthalmometry was not significantly correlated with WEM after adjusting for age and gender (R = 0.083, p = 0.688). In the 21 Graves ophthalmopathy patients examined by orbit CT, after adjusting for age and gender, WEM significantly decreased as the cross sectional area (%) of the extraocular muscles in the orbit increased (R = - 0.461, p = 0.047). CONCLUSIONS: WEM by Corvis could be used to quantify the biomechanical parameters of the orbital soft tissue. However, it is unclear whether WEM effectively represents the orbital biomechanical parameters, because WEM is only 0.6% of the orbital depth.

Optimal size of pterygium excision for limbal conjunctival autograft using fibrin glue in primary pterygia.

BACKGROUND: In our study we describe a method that optimizes size of excision and autografting for primary pterygia along with the use of intraoperative MMC and fibrin glue. Our objective is to propose a simple, optimizedpterygium surgical technique with excellent aesthetic outcomes and low rates of recurrence and otheradverse events. METHODS: Retrospective chart review of 78 consecutive patients with stage III primary pterygia who underwent an optimal excision technique by three experienced surgeons. The technique consisted of removal of the pterygium head, excision of the pterygium body and Tenon's layer limited in proportion to the length of the head, application of intraoperative mitomycin C to the defect, harvest of superior bulbar limbal conjunctival graft, adherence of graft with fibrin glue. Outcomes included operative time, follow up period, pterygium recurrence, occurrences of incorrectly sized grafts, and other complications. RESULTS: All patients were followed up for more than a year. Of the 78 patients, there were 2 cases of pterygium recurrence (2.6%). There was one case of wound dehiscence secondary to small-sized donor conjunctivaand one case of over-sized donor conjunctiva, neither of which required surgical correction. There were no toxic complications associated with the use of mitomycin C. CONCLUSION: Correlating the excision of the pterygium body and underlying Tenon's layer to the length of the pterygium head, along with the use intraoperative mitomycin C, limbal conjunctival autografting, and fibrin adhesionresulted in excellent outcomes with a low rate of recurrence for primary pterygia.

Meibocyte differentiation and renewal: Insights into novel mechanisms of meibomian gland dysfunction (MGD).

This paper reviews our current understanding of age-related meibomian gland dysfunction (MGD) and the role of the nuclear receptor, peroxisome proliferator-activated receptor gamma (PPARγ), in the regulation of meibomian gland function, meibocyte differentiation and lipid synthesis. The studies suggest that PPARγ is a master regulator of meibocyte differentiation and function, whose expression and nuclear signaling coupled with meibocyte renewal is altered during aging, potentially leading to atrophy of the meibomian gland as seen in clinical MGD. Study of meibomian gland stem cells also suggest that there is a limited number of precursor meibocytes that provide progeny to the acini, that may be susceptible to exhaustion as occurs during aging and other environmental factors. Further study of pathways regulating PPARγ expression and function as well as meibocyte stem cell maintenance may provide clues to establishing cellular and molecular mechanisms underlying MGD and the development of novel therapeutic strategies to treating this disease.

Image-based quantitative analysis of tear film lipid layer thickness for meibomian gland evaluation.

BACKGROUND: Dry eye syndrome is one of the most common ocular diseases, and meibomian gland dysfunction (MGD) is the leading cause of evaporative dry eye syndrome. When the tear film lipid layer becomes thin due to obstructive or hyposecretory meibomian gland dysfunction, the excessive evaporation of the aqueous layer can occur, and this causes evaporative dry eye syndrome. Thus, measuring the lipid layer thickness (LLT) is essential for accurate diagnosis and proper treatment of evaporative dry eye syndrome. METHODS: We used a white LED panel with a slit lamp microscope to obtain videos of the lipid layer interference patterns on the cornea. To quantitatively analyze the LLT from interference colors, we developed a novel algorithm that can automatically perform the following processes on an image frame: determining the radius of the iris, locating the center of the pupil, defining region of interest (ROI), tracking the ROI, compensating for the color of iris and illumination, and producing comprehensive analysis output. A group of dry eye syndrome patients with hyposecretory MGD, dry eye syndrome without MGD, hypersecretory MGD, and healthy volunteers were recruited. Their LLTs were analyzed and statistical information-mean and standard deviation, the relative frequency of LLT at each time point, and graphical LLT visualization-were produced. RESULTS: Using our algorithm, we processed the lipid layer interference pattern and automatically analyzed the LLT distribution of images from patients. The LLT of hyposecretory MGD was thinner (45.2 ± 11.6 nm) than that of dry eye syndrome without MGD (69.0 ± 9.4 nm) and healthy volunteers (68.3 ± 13.7 nm) while the LLT of hypersecretory MGD was thicker (93.5 ± 12.6 nm) than that of dry eye syndrome without MGD. Patients' LLTs were statistically analyzed over time, visualized with 3D surface plots, and displayed using 3D scatter plots of image pixel data for comprehensive assessment. CONCLUSIONS: We developed an image-based algorithm for quantitative measurement as well as statistical analysis of the LLT despite fluctuation and eye movement. This pilot study demonstrates that the quantitative LLT analysis of patients is consistent with the functions of meibomian glands clinically evaluated by an ophthalmologist. This approach is a significant step forward in developing a fully automated instrument for evaluating dry eye syndrome and for providing proper guidance of treatment.

Vascular Regression After Pinguecula Excision and Conjunctival Autograft Using Fibrin Glue.

OBJECTIVES: To determine the change in local vascularization after pinguecula excision and conjunctival autograft secured with fibrin glue at 12 months. METHODS: Thirty-one eyes of 31 patients which underwent excision and conjunctival autografting with fibrin glue were retrospectively reviewed. Anterior segment photography was obtained before and after the surgery. Cosmetic outcome was evaluated by patient self-grading (five-point scale; excellent (5), good (4), acceptable (3), poor (2), and very poor (1)), and medical evaluation of treatment outcome was based on subjective evaluation of vascularization on anterior segment photography (four-point severity scale; 0 [low] to 3 [high]). Clinical outcome and complications are reported at 12 months. RESULTS: Overall cosmetic results were excellent or good in 93.5% (29 of 31) (score 4.68±0.60). Anterior segment photography showed that most cases demonstrated complete removal of pinguecula and regression of surrounding vascularization with mean change in score from 2.13±0.34 preoperatively to 0.09±0.30 postoperatively. CONCLUSIONS: Pinguecula excision and conjunctival autograft using fibrin glue is an effective and safe method to remove pinguecula for cosmetic purposes. The method presented facilitated regression of vascularization.

Comparison of Two Optical Biometers.

PURPOSE: To compare a new optical biometer device, Galilei G6 (Ziemer, Port, Switzerland), with the present optical biometer, Lenstar LS 900 (Haag-Streit, Koeniz, Switzerland), for intraocular lens (IOL) power calculation. METHODS: One hundred forty eyes of 140 cataract patients were evaluated with two optical biometers: the Galilei G6 and the Lenstar. The mean keratometry (K), axial length (AL), anterior chamber depth (ACD), crystalline lens thickness (LT), white-to-white (WTW), and IOL powers using the SRK/T, Holladay 1, Hoffer Q, and Haigis formulas were compared. The intrasession repeatability of the Galilei G6 measurements was assessed in 25 eyes. RESULTS: All ocular parameters measured by the Galilei G6 were highly repeatable (all intraclass correlation coefficients > 0.980). Although K and ACD did not show statistical differences between the two devices (all p > 0.05), the measurements for AL, LT, and WTW were statistically different for the two devices. The K, AL, ACD, LT, and WTW showed good correlations (r = 0.975, 0.998, 0.973, 0.946, and 0.710, respectively; all p < 0.001); however, the agreements of LT and WTW were not good between the two devices. The IOL powers using four formulas did not show statistical differences (all p > 0.05); however, agreements between the IOL powers were not strong. The ranges of 95% limit of agreements were between 1.54 and 1.90D according to the formulas. CONCLUSIONS: The ocular parameters and IOL powers using the Galilei G6 cannot be used interchangeably with those of the Lenstar in clinical practice.

A New Conjunctival Free Flap Design Technique for Pterygium Surgery: Stamp Technique.

PURPOSE: To introduce a new conjunctival free flap design technique for pterygium surgery. PATIENTS AND METHODS: This study was a retrospective medical chart review of 20 patients (21 eyes) who underwent pterygium excision and conjunctival free flap by one surgeon. The following surgical procedures were used in conjunctival free flap design during pterygium surgery. We used the paper wrapper of 10-0 nylon, which will be used for the conjunctival suture, for making an imprint of the recipient defect. The paper was cut to an ellipsoidal shape of 2 to 3 mm larger than the recipient defect with utility scissors. The margin of the recipient defect was marked using a gentian violet pen. The paper was positioned carefully on the recipient defect and pushed down gently with a cotton tip. After removing the paper, the margin of the conjunctival defect was imprinted on the paper in the shape of a "C," The paper was cut according to the inner line of the "C" marking. The paper was placed on the superior conjunctiva. Conjunctival marking was applied according to the outline of paper with a pen. RESULTS: The operation duration ranged from 64 min to 132 min (mean 88 min). The conjunctival free flap was identical to the recipient defect. Complications included recurrence (5%), wound dehiscence (19%), and granulation (5%). CONCLUSIONS: We think that this stamp technique is an efficient method for designing donor conjunctiva that is identical to the defect for free conjunctival transplantation during pterygium surgery.

The Influence of Overnight Orthokeratology on Ocular Surface and Meibomian Glands in Children and Adolescents.

PURPOSE: The aim of this study was to investigate the influence of overnight orthokeratology (OOK) on ocular surface and meibomian glands in children and adolescents. METHODS: Prospective, noncomparative study included the ocular surface disease index (OSDI), tear osmolarity, corneal and conjunctival fluorescein staining, tear film breakup time (TBUT), the Schirmer I test, and meiboscore using noncontact meibography. Immunofluorescence confocal microscopy of interleukin-1ß (IL1ß), interleukin-6 (IL6), epidermal growth factor (EGF), and matrix metalloproteinase (MMP)-9 using impression cytology filter paper was performed. The tests were performed before and at 6, 12, 24, and 36 months after OOK wear. RESULTS: Fifty-eight subjects using OOK were observed. Significant increases in OSDI score (P=0.0009) and corneal and conjunctival staining score (P<0.0001) were observed compared with baseline values at 36 and 24 months, respectively. Ocular surface and meibomian changes were noted in 2 patients (3.5%). One patient exhibited an increase in OSDI score, concurrent with a decrease in TBUT at 36 months and minor loss of the meibomian gland at the distal portion of the lower lid at 24 months. The other patients exhibited the development of papillary hypertrophy and meibomian gland distortion at 24 months. No significant changes were detected in IL1ß, IL6, EGF, or MMP expression after OOK use. CONCLUSION: Based on the findings, OOK was a relatively safe modality. However, given the potential changes in the meibomian gland and tear film stability, special attention must be paid to children with baseline meibomian gland distortions or a history of allergic conditions.

Current status of contact lenses usage in Korea: A population-based cohort study 2021.

PURPOSE: To investigate trends in contact lens usage in a nationally representative sample of the Korean population in 2021. METHODS: For this retrospective study, we analyzed data of 3,601 Korean participants aged 10-59 years, from the Korea National Health and Nutrition Examination Survey (KNHANES 2021 version), who underwent eye examination, of whom 1,136 individuals (274 men and 862 women) were contact lens users. The demographic trend among Korean contact lens wearers was examined using statistical analyses to investigate the changes in their contact lens-wearing experience, duration of lens use, type of lens used, location of purchase, presence of an Eye Care Practitioner(ECP)'s prescription, lens-related ophthalmic complications, and type of lenses worn at the time of complications, according to sex. Multivariable logistic regression analysis was conducted to examine the association of each variable with the rate of complications and use of soft lenses. RESULTS: The average age of the contact lens users was 33.42±0.33 years, with 70.36% (weighted percentage) of users being women who used contact lenses for significantly longer periods than men (p<0.001). Additionally, only wearing of cosmetic lenses was significantly correlated with the occurrence of complications (p = 0.006), and 6.76% of users purchased lenses without a prescription. Multivariate analysis among the contact lens users revealed a significant relationship between the complication rate and female sex (p = 0.002), pre-existing eye disease diagnosed by ECPs (p = 0.0288), and duration of contact lens use (p<0.0001). CONCLUSION: We identified sex differences in contact lens usage trends in Korea. The main changes observed were an increase in middle-aged lens users and a decrease in female users compared to that in the early 2000s. In addition, contact lens complications were significantly associated with sex and pre-existing eye disease. Therefore, those wearing contact lenses for extended periods should exercise caution and consult eye care specialists in the presence of any symptoms.

Retrospective Analysis of a New Intrastromal Dissection Technique Using the Retinal Reflex for Deep Anterior Lamellar Keratoplasty.

PURPOSE: The purpose of this study was to describe a new surgical technique for deep anterior lamellar keratoplasty. METHODS: All pupils in the recipient eyes were dilated preoperatively. Vertical grooving was performed using a crescent blade with a width of 5 mm and a depth of one-third to half corneal thickness on the temporal side of the limbus. Stromal dissection was performed as close as possible to Descemet membrane by observing the gap between the gold line by retinal reflex and the front edge of the crescent blade. Lamellar dissection was performed along the lamellar plane using corneal dissectors. The ophthalmic viscoelastic device was injected into the intrastromal pocket to separate the anterior and posterior stroma and an anterior corneal lamella was excised. A donor cornea was sutured into the recipient bed. RESULTS: In 18 eyes, none of the patients had Descemet membrane rupture during surgery. The mean postoperative residual stromal thickness was 80 ± 31 µm. The mean central corneal thickness after surgery was 660 ± 69 µm. At the last follow-up, the cornea was cleared in all 18 eyes on slit-lamp examination. CONCLUSIONS: We estimated the residual stromal thickness based on the gap between the gold line by the retinal reflex and crescent blade, and intrastromal lamellar dissection was performed using a smooth corneal dissector. Consequently, the surface of stromal dissection was smooth, and the residual stromal thickness was even.

New Korean Guidelines for the Diagnosis and Management of Dry Eye Disease.

New Korean guidelines for the diagnosis and management of dry eye disease were developed based on literature reviews by the Korean Dry Eye Guideline Establishment Committee, a previous dry eye guideline by Korean Corneal Disease Study Group, a survey of Korean Dry Eye Society (KDES) members, and KDES consensus meetings. The new definition of dry eye was also proposed by KDES regular members. The new definition by the regular members of the KDES is as follows: "Dry eye is a disease of the ocular surface characterized by tear film abnormalities and ocular symptoms." The combination of ocular symptoms and an unstable tear film (tear breakup time <7 seconds) was considered as essential components for the diagnosis of dry eye. Schirmer test and ocular surface staining were considered adjunctive diagnostic criteria. The treatment guidelines consisted of a simplified stepwise approach according to aqueous deficiency dominant, evaporation dominant, and altered tear distribution subtypes. New Korean guidelines can be used as a simple, valid, and accessible tool for the diagnosis and management of dry eye disease in clinical practice.

Re-Esterified Triglyceride ω-3 Fatty Acids in Dry Eye Disease With Meibomian Gland Dysfunction: A Randomized Clinical Trial.

Importance: Taking ω-3 supplements has been associated with a reduction in symptoms of dry eye disease (DED) associated with meibomian gland dysfunction (MGD). However, a recent relatively large clinical trial concluded that treating DED with ω-3 consumption was ineffective, potentially warranting additional investigations. Objectives: To investigate the effect of re-esterified triglyceride (rTG) ω-3 fatty acid supplementation on DED associated with MGD. Design, Setting, and Participants: This double-masked, parallel-group, randomized clinical trial was conducted at 7 institutions from September 2020 to January 2023. Patients with DED associated with MGD were included and randomly assigned to the ω-3 group (received 1680 mg of eicosapentaenoic acid and 560 mg of docosahexaenoic acid), whereas those in the grape-seed group received 3000 mg of grape-seed oil daily. Interventions: rTG ω-3 Fatty acid supplementation vs grape-seed oil. Main Outcome Measures: The primary end point was the Ocular Surface Disease Index (OSDI) from baseline to 6 and 12 weeks. The safety parameters were visual acuity and intraocular pressure change. Results: A total of 132 patients (mean [SD] age, 50.6 [13.8] years; 103 female [78.0%]) were included in this study. The mean (SD) baseline OSDI scores of the ω-3 and grape-seed groups were 43.5 (16.5) and 44.1 (16.6), respectively. A total of 58 patients (87.9%) and 57 patients (86.4%) in the ω-3 and grape-seed groups, respectively, completed 12 weeks of follow-up. There were no differences in compliance with the dietary supplement intake between groups (ω-3, 95.8% and grape-seed, 95.4%). The OSDI (SD) change from baseline to 6 and 12 weeks was -20.5 (16.0) and -22.7 (15.7), respectively, in the ω-3 group and -15.1 (20.2) and -18.8 (21.7), respectively, in the grape-seed control group (difference at 6 weeks = -5.4; 95% CI, -12.15 to 1.33; P = .12 and at 12 weeks = -3.9; 95% CI, -10.90 to 3.13; P = .28). There were no changes in safety parameters or adverse events related to taking the dietary supplement in either group. Conclusions and Relevance: This randomized clinical trial did not show a benefit of the rTG form of ω-3 for ameliorating symptoms of DED associated with MGD, although fewer than 60 participants were evaluated in each group. Any secondary outcomes from this study should be considered for hypothesis generation of future evaluations of the effect of the rTG form of ω-3 on DED associated with MGD. Trial Registration: CRIS Identifier: KCT0004927.