Posterior segment complications of Ahmed valve implantation.

BACKGROUND: To assess the time, incidence, and outcome of posterior segment complications of Ahmed valve implantation (AVI). METHODS: 248 eyes that underwent AVI were reviewed retrospectively. Visual acuity, preoperative characteristics, and postoperative posterior segment complications were assessed. RESULTS: The incidence of posterior segment complications of AVI was 31.4% (78/248). The mean follow-up period was 97.4 ± 53.5 months. The mean time to occur posterior segment complication was 1.5 months. The most common posterior segment complication was choroidal detachment (17.7%) and others included ocular decompression retinopathy (3.2%), hypotonic maculopathy (2.8%), vitreous hemorrhage (2.0%), retinal detachment (1.2%), endophthalmitis (1.2%), suprachoroidal hemorrhage (1.2%), epiretinal membrane (0.8%), cystoid macular edema (0.8%), and proliferative vitreoretinopathy (0.4%). Older age, hypertension, and postoperative hypotony had an increased risk of posterior segment complications of AVI. CONCLUSIONS: The overall incidence of posterior segment complications of AVI was 31.4%. Older age, hypertension, and postoperative hypotony were significantly associated with posterior segment complications of AVI.

Torsional and flattening effect on corneal astigmatism after cataract surgery: a retrospective analysis.

BACKGROUND: To evaluate the torsional and flattening effect of steep meridian incisions and influence of posterior corneal astigmatism (PCA) on total corneal astigmatism (TCA) after cataract surgery. METHODS: One hundred thirty-two eyes underwent cataract surgery with steep meridian 2.2 mm microcoaxial and 2.85 mm conventional clear corneal incisions. Eyes were divided into with-the-rule (WTR) astigmatism and against-the-rule (ATR) astigmatism groups depending on the steeper meridian and measured with autokeratorefractor and Pentacam® before surgery, at 1 day, 1 week, 1 and 2 months postoperatively. Polar vector analysis was used to evaluate torsional effect of steep meridian incisions. RESULTS: A decrease in astigmatic polar value (AKP) (+0) was observed in both keratometric and total astigmatism (TA) after 1 and 2 months, although the decrease was only statistically significant in TA (p < 0.05). The AKP(+45) was more significant in the conventional group than the microcoaxial group at 2 months postoperatively (p < 0.05, respectively). There was a significant correlation between corneal thickness of the superior quadrant and PCA in the WTR group (p = 0.028). In eyes with anterior corneal astigmatism smaller than 0.55D of WTR astigmatism and PCA greater than 0.35D of WTR astigmatism showed greater shifting of steep axis and also increment of refractive cylinder powers. CONCLUSIONS: In eyes with superior corneal thickness greater than 714.5 µm and PCA greater than 0.35D of WTR astigmatism, steep meridian incision may cause a significant torsional effect and off-steep meridian change, contributing to an increment of postoperative residual manifest astigmatism after cataract surgery.

VITREORETINAL COMPLICATIONS AFTER PENETRATING KERATOPLASTY.

PURPOSE: To evaluate the time, incidence, and visual outcome of vitreoretinal complications after penetrating keratoplasty (PK). METHODS: A retrospective chart review of 1,594 eyes that underwent PK was conducted. Preoperative characteristics, visual significance, and postoperative vitreoretinal complications were analyzed. RESULTS: The incidence of vitreoretinal complications after PK was 3.3% (52/1,594). The mean follow-up period was 38.5 ± 29.8 months. The mean time for vitreoretinal complications to occur was 4.8 months. The most common vitreoretinal complication was vitreous hemorrhage (0.75%), and others included choroidal detachment (0.7%), endophthalmitis (0.6%), and retinal detachment (0.5%). Majority of vitreous hemorrhage, endophthalmitis, and choroidal detachment occurred within 1 month postoperatively, but most cases of cystoid macular edema and epiretinal membrane occurred after 3 months. At follow-up after PK, the mean corrected distance visual acuity was worse among eyes that experienced vitreoretinal complications compared with eyes that did not (P = 0.013). CONCLUSION: Vitreoretinal complications after PK occurred in a significant percentage, resulting in persistent reduction of corrected distance visual acuity. Given this, it is of particular importance to control intraoperative and postoperative intraocular pressure, infection, and inflammation which will contribute to decrease in the incidence of vitreoretinal complications after PK.

Effect of low-level light therapy in patients with dry eye: a prospective, randomized, observer-masked trial.

To evaluate the efficacy of low-level light therapy (LLLT) with near-infrared light-emitting diodes (LED-LLLT) for the treatment of dry eye. 40 patients were randomly assigned with a 1:1 allocation ratio to receive LED-LLLT (LLLT group, n = 20) or placebo treatment (placebo group, n = 20). Patients in the LLLT group received LLLT twice a week for 3 weeks, for a total of 6 treatment sessions. The primary endpoint was the changes in the fluorescein corneal staining (FCS) score. The secondary endpoints were the changes in the ocular surface disease index (OSDI) score, lissamine green conjunctival staining (LGCS) scores, tear film break-up time (TBUT), Schirmer test, and the meibomian gland dysfunction (MGD) index. These were evaluated before treatment and 4 weeks after start of treatment. The mean difference of score change in primary endpoint revealed significant improvement in the LLLT group, compared to the placebo. Among secondary endpoints, LGCS, Schirmer's test, upper meibography scores showed significant improvements, while TBUT, lid debris, lid swelling, lid telangiectasia, meibomian gland secretion and expressibility scores had slight improvement without significant differences. No serious adverse events were observed. The use of LED-LLLT for the treatment of dry eye and MGD appears to be safe and beneficial.

Explainable Machine Learning Model for Glaucoma Diagnosis and Its Interpretation.

The aim is to develop a machine learning prediction model for the diagnosis of glaucoma and an explanation system for a specific prediction. Clinical data of the patients based on a visual field test, a retinal nerve fiber layer optical coherence tomography (RNFL OCT) test, a general examination including an intraocular pressure (IOP) measurement, and fundus photography were provided for the feature selection process. Five selected features (variables) were used to develop a machine learning prediction model. The support vector machine, C5.0, random forest, and XGboost algorithms were tested for the prediction model. The performance of the prediction models was tested with 10-fold cross-validation. Statistical charts, such as gauge, radar, and Shapley Additive Explanations (SHAP), were used to explain the prediction case. All four models achieved similarly high diagnostic performance, with accuracy values ranging from 0.903 to 0.947. The XGboost model is the best model with an accuracy of 0.947, sensitivity of 0.941, specificity of 0.950, and AUC of 0.945. Three statistical charts were established to explain the prediction based on the characteristics of the XGboost model. Higher diagnostic performance was achieved with the XGboost model. These three statistical charts can help us understand why the machine learning model produces a specific prediction result. This may be the first attempt to apply "explainable artificial intelligence" to eye disease diagnosis.

Comparative study on the effect of hyperthermic massage and mechanical squeezing in the patients with mild and severe meibomian gland dysfunction: An interventional case series.

BACKGROUND: Meibomian glands exist beneath the palpebral conjunctiva; thus, it is invisible to the naked eye without infrared imaging. This study used meibography to group patients with meibomian gland dysfunction (MGD) and assessed the effects of hyperthermic massage and mechanical squeezing in both groups. MATERIALS AND METHODS: Patients with MGD were divided into two groups, according to the degree of meibomian gland loss: group 1, in which the sum of eyelid scores ranged from 0 to 4 (mild to moderate gland loss) and group 2, in which the sum of eyelid scores ranged from 5 to 6 (severe gland loss). Hyperthermic massage and mechanical squeezing were given to both groups once a week for 4 weeks, and only non-preservative artificial tears were allowed. Ocular surface disease index (OSDI), Schirmer's test, meibography score, tear break-up time (TBUT), ocular surface staining, expressible meibomian gland, and quality before and after treatment were compared. RESULTS: Of the 49 patients who completed the 4 weeks of treatment and the evaluation at week 5, 29 were assigned to group 1 and 20 were assigned to group 2. Meibography scores, OSDI, TBUT, and expressibility of meibum had significant differences before and after treatments in both groups. However, there was no significant difference between the changes in clinical signs between group 1 and 2 after treatment. Without grouping, all patients showed significant decreases in meibography score, OSDI, cornea staining score, and increases in TBUT and expressibility of meibum after treatment. CONCLUSIONS: Considering the results of the current study, hyperthermic massage and mechanical squeezing may be effective in patients with meibomian gland loss, regardless of the degree of severity.

Outcome of phacoemulsification in patients with open-angle glaucoma after selective laser trabeculoplasty.

PURPOSE: To investigate the outcome of phacoemulsification in selective laser trabeculoplasty (SLT)-treated eyes. METHODS: This retrospective study included patients who had open angle glaucoma (OAG) with previous SLT who underwent phacoemulsification. We evaluated intraocular pressure (IOP), length of glaucoma control without treatment, and antiglaucoma medication or surgery. SLT-treated eyes that did not receive phacoemulsification were retrospectively chosen as a control. We investigated factors related to outcome of phacoemulsification by multivariate analysis. RESULTS: 42 eyes with previous SLT that underwent phacoemulsification and 40 controls were retrospectively evaluated. Phacoemulsification was performed 52 ± 15 months after SLT. After a mean follow-up of 74 ± 21 months, mean IOP was significantly decreased in the phaco group by 2.2 ± 2.7 mmHg (p < 0.001). In the SLT group, mean IOP was decreased by 0.8 ± 2.8 mmHg (p < 0.001). 9 eyes (16.7%) in the phaco group and 11 eyes (19.0%) of the SLT group needed topical treatment, and no eye needed glaucoma surgery in both groups. The factor related to success was higher baseline IOP (p = 0.002). CONCLUSION: Prior SLT didn't negatively influence phacoemulsification in patients with OAG. Phacoemulsification lowered IOP effectively and safely in OAG patients who were treated with SLT.

Choroidal vascular index in patients with open angle glaucoma and preperimetric glaucoma.

PURPOSE: To evaluate choroidal structural changes in glaucoma using choroidal vascularity index (CVI) compared to healthy subjects. METHODS: This retrospective study included 56 patients with open angle glaucoma (OAG), 50 patients with preperimetric glaucoma (PPG) and 50 age-matched healthy eyes. Choroidal images were binarized into luminal area (LA) and stromal area. CVI was defined as the ratio of LA to total circumscribed choroid area (TCA). Mean choroidal thickness (CT) and mean CVI between glaucoma patients and healthy subjects were compared. RESULTS: OAG and PPG eyes showed smaller LA (0.45 ± 0.13 ㎟ vs. 0.47 ± 0.11 ㎟, p = 0.04). In multivariate regression analysis, CVI of both OAG (64.34±0.19%, p = 0.001) and PPG (65.37±0.15%, p = 0.001) were significantly lower than healthy eyes (68.81±0.14%). CONCLUSION: Eyes with glaucoma demonstrated reduced CVI compared with healthy eyes. CVI may be a potential noninvasive tool for studying vascular dysfunction in glaucoma.

Comparison of peripapillary and macular choroidal thickness and ganglion cell complex thickness in glaucomatous and healthy eyes.

AIM: To assess choroidal thickness (CT) and its association with ganglion cell-inner plexiform layer thickness (GCIPLT) and retinal nerve fiber layer thickness (RNFLT) in open angle glaucoma (OAG) comparing with preperimetric glaucoma (PPG) and normal eyes. METHODS: Totally 55 eyes of OAG, 40 eyes of PPG, and 40 eyes of age-matched normal eyes were studied. Peripapillary CT (PCT), macular CT (MCT), RNFLT, and GCIPLT were evaluated. Relationship between the CT with RNFLT and GCIPLT were studied. The correlation between CT and confounding variables as gender, age, intraocular pressure, and visual field mean deviation were analyzed. RESULTS: Mean PCT were 113.6±39.1 µm in OAG, 116.3±42.7 µm in PPG, and 148.9±41.7 µm in normal eyes. PCT and MCT was thinner in OAG compared to healthy eyes. There was a significant correlation for PCT and mean RNFLT in 1, 2, 6, and 7 clock hours of OAG eyes. The difference in PCT remained after adjusting for axial length, age, and disc area (P=0.003). No significant correlation was shown between MCT and mean GCIPLT in all eyes. CONCLUSION: PCT is thinner in OAG and PPG compared with healthy eyes. The correlation of RNFLT and PCT found in OAG and PPG is not revealed in normal eyes.

A Randomized Multicenter Study Comparing 0.1%, 0.15%, and 0.3% Sodium Hyaluronate with 0.05% Cyclosporine in the Treatment of Dry Eye.

PURPOSE: To investigate the efficacy of 0.1%, 0.15%, and 0.3% sodium hyaluronate (SH) artificial tears compared with 0.05% cyclosporine (CS) ophthalmic solution for the treatment of dry eye. METHODS: One hundred seventy-six patients were recruited and randomized to receive of 0.1%, 0.15%, and 0.3% SH and 0.05% CS. There was a primary end point which is the changes in the fluorescein corneal staining (FCS) score to determine noninferiority of 0.1%, 0.15%, and 0.3% SH. Secondary objective end points were lissamine green conjunctival staining (LGCS) scores, Schirmer test, and tear film break-up time (TBUT). Secondary subjective end point was ocular surface disease index (OSDI) score. These were evaluated before treatment and 6 and 12 weeks after start of treatment. RESULTS: In the primary analysis, the mean change from baseline in FCS scores verified noninferiority of 0.1% and 0.15% SH to 0.05% CS and also indicated significant improvement of all groups (P < 0.05). Values for TBUT, LGCS scores, and OSDI scores showed significant improvements in all groups (P < 0.05), although no significant intergroup difference was shown. However, Schirmer test scores in the 0.15% SH group showed a significant tendency for better improvement at week 12 compared with the other groups (P < 0.05). No serious adverse events were observed. CONCLUSIONS: Administration of 0.1%, 0.15%, and 0.3% SH was effective in improving both the objective signs and subjective symptoms of dry eye. Those findings, in addition to the well-tolerated profile of 0.1%, 0.15%, and 0.3% SH, show that it is effective therapeutic method for dry eye.

Observation of Influence of Cataract Surgery on the Ocular Surface.

INTRODUCTION: To evaluate meibomian gland function, changes of lacrimal tears and ocular surface parameters and tear inflammatory mediators following cataract surgery. METHODS: 48 eyes of 34 patients who underwent uncomplicated phacoemulsification were involved and divided into 2 groups with those who had preexisting dry-eye before cataract surgery and those who did not. Ocular symptom score, Schirmer I test, tear film break-up time (TBUT), corneal sensitivity threshold, corneal staining, inflammatory cytokine activities, lid margin abnormalities, meibum expressibility, meibum quality and meibomian gland imaging were evaluated preoperatively, at 1 day, 1 and 2 months postoperatively. RESULTS: Ocular symptom scores were worse at 1 and 2 months postoperatively but, TBUT, corneal staining score and corneal sensitivity threshold showed gradual improvements at 1 month and 2 months postoperatively (p<0.05, respectively). Interestingly there were statistically significant improvements in TBUT, corneal staining score and corneal sensitivity threshold at 1 month postoperatively when topical eye drops were used compared to the period without topical therapy which is the months 2 postoperatively. There were statistically significant decreases in IL-1ß, IL-6, IL-8, MCP-1, TNF-α and IFN-γ concentrations at 1 and 2 months postoperatively. Lid margin abnormalities, meibum quality and expressibility scores increased significantly (p < 0.05, respectively) at postoperative period. Compared with the no dry eye group, dry eye group revealed significantly higher ocular symptom scores, lower TBUT, higher lid margin abnormalities, meibum quality and expressibility scores after cataract surgery. There were significant correlations between IL-6 and parameters of dry eye, and between MGD parameters and ocular symptom scores. CONCLUSIONS: Our study revealed that meibomian gland function is influenced after cataract surgery accompanying structural changes and these were correlated with increased ocular symptom scores. Therefore, it could elucidate the development of dry eye related to cataract surgery.

The Relationship between Visual Impairment and Health-Related Quality of Life in Korean Adults: The Korea National Health and Nutrition Examination Survey (2008-2012).

INTRODUCTION: To evaluate health-related quality of life (HRQoL) in Korean adults with visual impairment(VI) using various measures based on a nationally distributed sample. METHODS: Using the Korea National Health and Nutrition Examination Survey (KNHANES, 2008-2012) data, we compared EuroQol five-dimensional questionnaire (EQ-5D) and EQ-visual analogue scale (VAS) scores after adjusting for socio-demographic and psychosocial factors as well as for comorbidities with VI. Logistic regressions were used to elucidate determinants for the lowest quintile HRQoL scales according to VI severity. Uncorrected visual acuity (VA) which implies vision of ordinary life was measured using an international standard vision chart based on Snellen scale. RESULTS: 28,825 participants (sum of weights; 37,562,376) were included in the analysis. The mean EQ-5D and EQ-VAS scores were significantly lower in the VI groups than in the normal vision (defined as VA 20/20-20/25) group based on the better or worse seeing eye (P<.0001 and P<.0001, respectively). Participants with moderate (VA 20/80-20/160) and severe VI (VA ≤20/200) had higher scores of multivariate-adjusted odd ratios (aORs) for the lowest quintile than did the normal vision group which was particularly evident in the results from EQ-5D, whereas the results of the mild VI (VA 20/32-20/63) group did not identify significant differences from the normal vision group independent of classification according to the better or the worse seeing eye. Conversely, EQ-VAS revealed significantly higher score of multivariate-aORs for the lowest quintile in participants with mild VI either for the better or worse seeing eye. CONCLUSIONS: The severity of VI was definitely associated with impaired HRQoL compared with the normal vision population. The analyses presented here elicited even mild VI could potentially deteriorate the health-related quality of life (or subjective perception of health quality) and therefore, therapeutic approaches should also focus on the subjective perception and better management of health condition.

Acute endophthalmitis after intravitreal injection and preventive effect of preoperative topical antibiotics.

PURPOSE: To evaluate the incidence, causative organism, clinical features, and visual outcome of acute endophthalmitis following intravitreal injection and to report the clinical outcome of patients receiving preinjection antibiotics for the prevention of endophthalmitis. METHODS: For all intravitreal triamcinolone acetonide, bevacizumab, ranibizumab, and C3F8 gas injections performed in our outpatient clinic between June 2008 and November 2012, the number of injections, indications, types of administered drugs, and methods of injection were investigated. A retrospective chart review was performed comparing patients with self-administration of antibiotic eye drops for 3 days before injection (n=8649 injections), and patients those who received no pretreatment with antibiotics (n=8683 injections). Cases of suspected endophthalmitis after intravitreal injection during this period were identified and reviewed retrospectively. RESULTS: The total number of intravitreal injections was 17,332. The incidence of acute endophthalmitis for all intravitreal injections was 0.000% (0/849) for triamcinolone acetonide, 0.022% (2/9,125) for bevacizumab, 0.000% (0/7,061) for ranibizumab, and 0.337% (1/297) for C3F8 gas injections. The overall rate of intravitreal injection-related endophthalmitis with the use of topical antibiotics given 3 days before injection was no less statistically significant compared with that of no antibiotics. Staphylococcus species was confirmed in the bacterial culture of one eye with acute endophthalmitis. After early vitrectomy and intravitreal antibiotic injection, one eye maintained vision, but the other eye developed phthisis. CONCLUSIONS: All 3 endophthalmitis patients had not taken prophylactic preinjection topical antibiotics, but the difference in the rates of endophthalmitis between those who received a multiday course of preinjection antibiotics and those who did not was not statistically significant. The rate of endophthalmitis after intravitreal injection using aseptic techniques in the clinical practice setting is similar with or without the use of preinjection antibiotics. Preinjection antibiotic use confers no additional benefit in the treatment of endophthalmitis compared to without preinjection antibiotics.