Causes of Punctal Plug Loss in Sjögren’s Syndrome

Purpose@#To evaluate the long-term maintenance rate and associated factors of silicone punctal plugs in patients with Sjögren’s syndrome (SS). @*Materials and Methods@#We retrospectively reviewed the medical records of 163 patients with SS who underwent silicone punctal plug insertion between December 2013 and July 2021 at Severance Hospital. The status of punctal plug insertions was classified into the following three categories by the clinician: maintenance, spontaneous loss, and intended removal. Cox proportional hazards model was used to evaluate the risk factors for spontaneous loss. @*Results@#The mean maintenance period was 12.8±15.3 (median 7.07) months. The rate of spontaneous loss was 58%, and the rate of punctal plug removal by the clinician was 14%. The number of prior plug insertions was a risk factor for spontaneous loss [hazard ratio (HR) 1.055, p=0.035]. The upper eyelid punctum was at a higher risk than the lower one (p=0.042). Small-sized plugs showed a significantly higher risk for spontaneous loss than large-sized ones (HR 1.287, p=0.035). Flow-controller type plugs were more vulnerable to spontaneous loss than complete occluders [Micro FlowTM vs. EagleFlex® (HR 2.707, p=0.008) and Micro FlowTM vs. UltraplugTM (HR 3.402, p=0.005)]. The most common reason for removal was tear overflow (5.6%). @*Conclusion@#In repeated insertion, characteristics of the punctal plug, including the type and size, and location of plug insertion, influenced the spontaneous loss of plugs. The management of punctal plugs, including insertion, maintenance, and removal, requires personalized strategies for versatile situations.

Effect and Safety of Pressure Sensor-equipped Handpiece in Phacoemulsification System

Purpose@#To evaluate the effect of the Active Sentry handpiece of the Centurion Vision System compared to the Centurion Ozil handpiece for phacoemulsification in cataract surgery. @*Methods@#A retrospective study was conducted on 281 patients (449 eyes) who underwent cataract surgery between August 2020 and June 2021. Preoperative measurements, intraoperative parameters, complication rate, and postoperative outcomes were compared between the Active Sentry handpiece and the Centurion Ozil handpiece groups. Additionally, the parameters were compared in different cataract severity groups and multiple predictive factors for the number of active surge mitigation (ASM) actuations were assessed with the Active Sentry handpiece. @*Results@#There were 198 eyes in the Active Sentry group and 251 eyes in the Centurion Ozil group. There were no statistically significant differences between the two groups, as the cumulative dissipated energy in the Active Sentry and Centurion Ozil groups were 8.32 ± 7.74 and 7.87 ± 9.25 μJ, respectively (p = 0.576). Total surgery time, ultrasound usage time, aspiration time, amount of fluid aspirated, postoperative corrected distant visual acuity, and postoperative decrease in corneal endothelial cell density were comparable between the two groups. The significant contributors to the number of ASM actuations were age, preoperative corrected distant visual acuity, axial length, and total ultrasound time. @*Conclusions@#There was no clear advantage of the Active Sentry handpiece compared to the Centurion Ozil handpiece. ASM actuation increases with age, poor visual acuity before surgery, short axial length, and prolonged ultrasound usage time. It is expected that in more severe and high-risk cataract surgery, the Active Sentry handpiece functions more effectively, possibly affecting the safety and prognosis.

Effects of Y-27632, a Rho-associated Kinase Inhibitor, on Human Corneal Endothelial Cells Cultured by Isolating Human Corneal Endothelial Progenitor Cells

Purpose@#Human corneal endothelial progenitor cells (HCEPs), which has been selectively isolated and differentiated into human corneal endothelial cells (HCECs), are crucial for repairing corneal endothelial damage. In this study, we evaluated the roles of a Rho-assisted kinase (ROCK) inhibitor, Y-27632, on the isolation and expansion of HCEPs, and assessed the in vitro effects of different concentrations of Y-27632 on the differentiated HCEPs. @*Methods@#HCEPs were isolated and expanded in a medium with and without 10μM Y-27632, and then differentiated into HCECs in a medium with fetal bovine serum. The characteristics of HCEPs and differentiated HCEPs were confirmed by immunofluorescence staining. The proliferation, viability, morphology, and wound-healing ability of differentiated HCEPs were assessed in the presence of different concentrations of Y-27632. @*Results@#Y-27632 enabled the isolation and expansion of HCEPs from the corneal endothelium. The differentiated HCEPs showed an optimal increase in proliferation and survival in the presence of 10μM Y-27632. As the concentration of Y-27632 increased, differentiated HCEPs became elongated, and actin filaments were redistributed to the periphery of cells. Y-27632 also caused a concentration-dependent enhancement in the wound-healing ability of differentiated HCEPs. @*Conclusions@#Y-27632 enabled the isolation and expansion of HCEPs. It also enhanced the proliferation, viability, and migration of differentiated HCEPs.

Clinical Results of Cataract Surgery Using the ARTIS ® PL E Intraocular Lens

Purpose@#To compare the clinical outcomes of cataract surgery using the ARTIS ® PL E (Cristalens Industrie, Lannion, France) intraocular lens (IOL) and conventional Tecnis ® ZCB00 (Johnson & Johnson Vision, Santa Ana, CA, USA) IOL. @*Methods@#This retrospective study examined patients who underwent in-the-bag implantation of either an ARTIS ® PL E (33 eyes, group A) or Tecnis ® ZCB00 (45 eyes, group B) IOL after phacoemulsification performed by a single surgeon. Best-corrected visual acuity (BCVA), spherical equivalent, and higher-order aberrations (HOA) were measured 1 and 3 months after cataract surgery. @*Results@#Preoperative BCVA did not differ significantly in groups A and B. Postoperative BCVA at 1 and 3 months improved significantly (p < 0.001) in both groups compared to preoperative baseline BCVA. At 1 and 3 months postoperatively, total HOA, spherical aberration, and coma were significantly lower compared to the preoperative baseline HOA (p < 0.05) in both groups. However, there were no significant differences in the trefoil values 1 and 3 months postoperatively compared to the preoperative baseline in both groups. The absolute refractive error 3 months postoperatively was 0.27 ± 0.20 (group A) and 0.28 ± 0.20 (group B), both within ± 0.50 diopters of the targeted goal diopter; there were no significant differences in the accuracy or predictability of the IOL power calculation in both groups (p = 0.390, p = 0.959). The absolute refractive error 1 and 3 months postoperatively did not differ significantly; there were no significant differences in the stability of both IOLs (p = 0.482, p = 0.372). @*Conclusions@#Conventional cataract surgery using the ARTIS ® PL E IOL significantly increased the BCVA, while obtaining comparable clinical results to the verified Tecnis ® ZCB00 IOL in postoperative visual acuity and HOA.

Anterior Ocular Biometrics Using Placido-scanning-slit System, Rotating Scheimpflug Tomography, and Swept-source Optical Coherence Tomography

Purpose@#To compare anterior biometry measurements using placido-scanning-slit topography, rotating Scheimpflug tomography, and swept-source optical coherence tomography. @*Methods@#A retrospective review consisted of 80 eyes of 49 participants who underwent anterior chamber depth (ACD), central corneal thickness (CCT), and keratometry examination on the same day. We used placido-scanning-slit topography (ORBscan II), rotating Scheimpflug tomography (Pentacam HR), and swept-source optical coherence tomography (CASIA SS1000). The intraclass correlation coefficients and Bland-Altman plots were used to evaluate the agreement and differences between measurements. @*Results@#The mean ACD values were 2.88 ± 0.43, 2.82 ± 0.50, and 2.68 ± 0.44 mm; and the mean CCT values were 536.96 ± 31.19, 543.79 ± 31.04, and 561.41 ± 32.60 μm; and the mean keratometry (Km) were 43.81 ± 1.69, 43.81 ± 1.77, and 44.65 ± 1.95 diopters; as measured by CASIA SS-1000, Pentacam HR, and ORBscan II, respectively. Among the three devices, ACD was deepest to shallowest in the order of CASIA SS-1000, Pentacam HR, and ORBscan II (p < 0.05). The CCT was thickest to thinnest in the order of ORBscan II, Pentacam HR, and CASIA SS-1000 (p < 0.05). No significant differences in Km values were examined between CASIA SS-1000 and Pentacam HR, whereas ORBscan II overestimated Km with a statistically significant difference compared to the other two devices. @*Conclusions@#High level of agreement was found between CASIA SS-1000 and Pentacam HR for anterior parameters, including ACD, CCT, and Km, suggesting interchangeability. However, ORBscan II measurements differed considerably with the measurements obtained from the other two devices; therefore, it should not be used interchangeably. However, further studies with repeatability test should be considered in order to elucidate the reliability of each device.

Effect of 0.15% Preservative-free Sodium Hyaluronate on Dry Eye Disease after Femtosecond Laser-assisted Cataract Surgery

Purpose@#The efficacy of using preservative-free 0.15% sodium hyaluronate eyedrops for dry eye disease after femtosecond laser- assisted cataract surgery (FLACS) was evaluated. @*Methods@#This prospective randomized study was conducted on patients with dry eye who were scheduled for FLACS among those with Tear Film & Ocular Surface Society Dry Eye Workshop II Dry Eye Levels 1 and 2. In total, 37 eyes scheduled for FLACS were randomized to the treatment group (n = 19) or control group (n = 18). Corneal and conjunctival fluorescein staining (CFS), tear breakup time (TBUT), Schirmer I test (SIT) value, ocular surface disease index (OSDI), meibomian gland evaluation result, and lipid layer thickness were evaluated for all patients, preoperatively and at 1 and 3 months postoperatively. @*Results@#In the treatment group, the OSDI and CFS scores were significantly lower at 3 months postoperatively than at baseline, but the TBUT and SIT values were significantly increased. In the control group, TBUT was significantly shorter at 3 months postoperatively than at baseline, SIT values were significantly decreased at 1 and 3 months postoperatively compared with the baseline, and meibum quality was significantly aggravated at 1 month postoperatively compared with the baseline. In the treatment group, OSDI improved significantly from baseline at 1 and 3 months. TBUT increased significantly in the treatment group at postoperative 3 months. Meibomian gland quality showed clinically better results in the treatment group than in the control group at postoperative 3 months. There were no significant differences in corneal and CFS, lipid layer thickness, and other dry eye disease parameters between the treatment and control groups. @*Conclusions@#Preservative-free 0.15% sodium hyaluronate eyedrops were effective for improving dry eye symptoms and tear film stability after FLACS.

Clinical Features and Antibiotic Susceptibility of Culture-proven Infectious Keratitis: a Multicenter 10-year Study

Purpose@#To analyze the clinical manifestations of culture-proven infective keratitis patients over a recent 10-year period. @*Methods@#We retrospectively reviewed the medical records of 956 cases of infective keratitis between January 2008 and December 2017 at eight tertiary hospitals. The study was performed to analyze the risk factors, causative microbial organisms, therapeutic outcomes, and prognosis. @*Results@#The most common risk factor of keratitis was trauma (33.2%). Initial visual acuity (V/A) was finger count or less in 449 eyes (47.0%). The common location of keratitis was central, and the size was 4 mm2 or less. Hypopyon was observed in 295 eyes (30.9%). Of the 1,039 cultured isolates, 443 (42.6%) grew Gram-negative bacteria with the most common being Pseudomonas aeruginosa. The most prevalent Gram-positive bacteria was Staphylococcus epidermidis, and fungi was Fusarium species. Surgical treatments were performed in 201 eyes (21.0%), followed by amniotic membrane transplantation (66 eyes) and evisceration (44 eyes). Final V/A was 20/100 or more in 422 eyes (44.1%). Gram-positive organisms were highly susceptible to moxifloxacin and vancomycin, and Gram-negative organisms were highly susceptible to levofloxacin and ceftazidime. An increase in resistance to these antibiotics was detected for Enterococcus and Pseudomonas. @*Conclusions@#In South Korea, infective keratitis occurs frequently in eyes with trauma. Staphylococcus epidermidis, Pseudomonas aeruginosa, and Fusarium species are commonly identified etiologies of microbial keratitis. The appropriate administered medical and surgical treatments of suspected infectious keratitis can lead to visual improvement with particular care taken to minimize infection related to resistant bacteria and fungal microbes as needed. An initial V/A of 0.02 or less, the presence of hypopyon, age of 65 years or more, and a central lesion were associated with poor clinical outcome of bacterial keratitis. Age of 70 years or more was a significant risk factor for poor clinical outcome of fungal keratitis.

Effect of 0.15% Preservative-free Sodium Hyaluronate on Dry Eye Disease after Femtosecond Laser-assisted Cataract Surgery

Purpose@#The efficacy of using preservative-free 0.15% sodium hyaluronate eyedrops for dry eye disease after femtosecond laser- assisted cataract surgery (FLACS) was evaluated. @*Methods@#This prospective randomized study was conducted on patients with dry eye who were scheduled for FLACS among those with Tear Film & Ocular Surface Society Dry Eye Workshop II Dry Eye Levels 1 and 2. In total, 37 eyes scheduled for FLACS were randomized to the treatment group (n = 19) or control group (n = 18). Corneal and conjunctival fluorescein staining (CFS), tear breakup time (TBUT), Schirmer I test (SIT) value, ocular surface disease index (OSDI), meibomian gland evaluation result, and lipid layer thickness were evaluated for all patients, preoperatively and at 1 and 3 months postoperatively. @*Results@#In the treatment group, the OSDI and CFS scores were significantly lower at 3 months postoperatively than at baseline, but the TBUT and SIT values were significantly increased. In the control group, TBUT was significantly shorter at 3 months postoperatively than at baseline, SIT values were significantly decreased at 1 and 3 months postoperatively compared with the baseline, and meibum quality was significantly aggravated at 1 month postoperatively compared with the baseline. In the treatment group, OSDI improved significantly from baseline at 1 and 3 months. TBUT increased significantly in the treatment group at postoperative 3 months. Meibomian gland quality showed clinically better results in the treatment group than in the control group at postoperative 3 months. There were no significant differences in corneal and CFS, lipid layer thickness, and other dry eye disease parameters between the treatment and control groups. @*Conclusions@#Preservative-free 0.15% sodium hyaluronate eyedrops were effective for improving dry eye symptoms and tear film stability after FLACS.

Clinical Features and Antibiotic Susceptibility of Culture-proven Infectious Keratitis: a Multicenter 10-year Study

Purpose@#To analyze the clinical manifestations of culture-proven infective keratitis patients over a recent 10-year period. @*Methods@#We retrospectively reviewed the medical records of 956 cases of infective keratitis between January 2008 and December 2017 at eight tertiary hospitals. The study was performed to analyze the risk factors, causative microbial organisms, therapeutic outcomes, and prognosis. @*Results@#The most common risk factor of keratitis was trauma (33.2%). Initial visual acuity (V/A) was finger count or less in 449 eyes (47.0%). The common location of keratitis was central, and the size was 4 mm2 or less. Hypopyon was observed in 295 eyes (30.9%). Of the 1,039 cultured isolates, 443 (42.6%) grew Gram-negative bacteria with the most common being Pseudomonas aeruginosa. The most prevalent Gram-positive bacteria was Staphylococcus epidermidis, and fungi was Fusarium species. Surgical treatments were performed in 201 eyes (21.0%), followed by amniotic membrane transplantation (66 eyes) and evisceration (44 eyes). Final V/A was 20/100 or more in 422 eyes (44.1%). Gram-positive organisms were highly susceptible to moxifloxacin and vancomycin, and Gram-negative organisms were highly susceptible to levofloxacin and ceftazidime. An increase in resistance to these antibiotics was detected for Enterococcus and Pseudomonas. @*Conclusions@#In South Korea, infective keratitis occurs frequently in eyes with trauma. Staphylococcus epidermidis, Pseudomonas aeruginosa, and Fusarium species are commonly identified etiologies of microbial keratitis. The appropriate administered medical and surgical treatments of suspected infectious keratitis can lead to visual improvement with particular care taken to minimize infection related to resistant bacteria and fungal microbes as needed. An initial V/A of 0.02 or less, the presence of hypopyon, age of 65 years or more, and a central lesion were associated with poor clinical outcome of bacterial keratitis. Age of 70 years or more was a significant risk factor for poor clinical outcome of fungal keratitis.

Accuracy of the Kane Formula for Intraocular Lens Power Calculation in Comparison with Existing Formulas: A Retrospective Review

Purpose@#To evaluate the accuracy of the Kane formula for intraocular lens (IOL) power calculation in comparison with existing formulas by incorporating optional variables into calculation. @*Materials and Methods@#This retrospective review consisted of 78 eyes of patients who had undergone uneventful phacoemulsification with intraocular implantation at Severance Hospital in Seoul, Korea between February 2020 and January 2021. The Kane formula was compared with six of the existing IOL formulas (SRK/T, Hoffer-Q, Haigis, Holladay1, Holladay2, Barrett Universal II) based on the mean absolute error (MAE), median absolute error (MedAE), and the percentages of eyes within prediction errors of ±0.25D, ±0.50D, and ±1.00D. @*Results@#The Barrett Universal II formula demonstrated the lowest MAEs (0.26±0.17D), MedAEs (0.28D), and percentage of eyes within prediction errors of ±0.25D, ± 0.50D, and ±1.00D, although there was no statistically significant difference between Barrett Universal II-SRK/T (p=0.06), and Barrett Universal II-Kane formula (p<0.51). Following the Barrett Universal II formula, the Kane formula demonstrated the second most accurate formula with MAEs (0.30±0.19D) and MedAEs (0.28D). However, no statistical difference was shown between Kane-Barrett Universal II (p=0.51) and Kane-SRK/T (p=0.14). @*Conclusion@#Although slightly better refractory outcome was noted in the Barrett Universal II formula, the performance of the Kane formula in refractive prediction was comparable in IOL power calculation, marking its superiority over many conventional IOL formulas, such as HofferQ, Haigis, Holladay1, and Holladay2.

Immunogenicity of Exosomes from Dendritic Cells Stimulated with Toxoplasma gondii Lysates in Ocularly Immunized Mice

Immunogenicity of dendritic cell-derived exosomes stimulated with Toxoplasma gondii lysates (TLA exo), mixed with cholera toxin as an adjuvant, was investigated in mice immunized via 2 mucosal routes (ocular vs intranasal). BALB/c mice were injected 3 times with TLA exo vaccine at 2 week interval, and the levels of IgG in serum and IgA in tear, saliva, feces, and vaginal wash were measured. To observe the expression of T. gondii-specific B1 gene, mice infected with ME49 T. gondii cysts were immunized with TLA exo or PBS exo (not stimulated with TLA), and their brain tissues were examined. The mice vaccinated via intranasal route elicited significantly higher humoral and mucosal immune responses compared with mice treated with PBS alone. Also, mice immunized via ocular route (by eyedrop) induced significantly higher T. gondii-specific IgG in serum and IgA in tear and feces in comparison with PBS controls. B1 gene expression was significantly lower in TLA exo vaccinated mice than in PBS or PBS exo vaccinated mice. These results demonstrated that ocular immunization of mice with TLA exo vaccine has the potential to stimulate systemic or local antibody responses. This study also highlighted an advantage of an eyedrop vaccine as an alternative for T. gondii intranasal vaccines.

The Use of a Dynamic Scheimpflug Analyzer to Measure Changes of Post-keratoplasty Corneal Biomechanical Properties

Purpose@#To evaluate the biomechanical properties of corneas using a dynamic Scheimpflug analyzer (Corvis ST) after penetrating keratoplasty (PKP) and Descemet’s membrane stripping keratoplasty (DSEK). @*Methods@#The medical records of 11 eyes that had undergone PKP (PKP group) and 11 eyes that had undergone DSEK (DSEK group) from March 2017 to March 2018 and the results were compared with 20 eyes of the control group. All patients’ corneal biomechanical properties, including a deformation amplitude ratio of 2.0 mm (DA ratio 2.0 mm), integrated inverse radius (IntInvRad), stiffness parameter at first applanation (SP-A1), and Ambrosio relational thickness through the horizon meridian (ARTh) were measured and compared with those of the normal control group. In addition, biomechanically corrected intraocular pressure (bIOP) measured by the Corvis ST was compared with intraocular pressure measured by a Tono-Pen Applanation Tonometer (IOP-Tono-Pen). @*Results@#In the PKP group, the biomechanical properties using the Corvis ST showed a significantly lower DA ratio 2.0 mm, SP-A1, ARTh, and IntInvRad, compared with those of the control group. However, in the DSEK group, only ARTh was significantly lower than that of the control group. @*Conclusions@#Corvis ST can be used to measure the change of corneal biomechanical properties after corneal transplantation.

Clinical Efficacy of Microblepharoexfoliation in Meibomian Gland Dysfunction Patients

Purpose@#To assess the clinical efficacy of microblepharoexfolication using BlephEx™ (Scope Ophthalmics, London, UK) in meibomian gland dysfunction (MGD) patients. @*Methods@#We performed a prospective study involving 48 eyes of 24 patients who were diagnosed with MGD. All patients were treated with BlephEx™ for 8-10 minutes, and the ocular surface disease index (OSDI), tear break-up time (TBUT), Schirmer’s I test, corneal staining score, lid margin abnormality, MGD score, and lipid thickness layer using the Lipiview II (TearScience, Morrisville, NC, USA) were assessed before treatment and after one month. @*Results@#Significant changes were observed after microblepharoexfoliation using BlephEx™. The TBUT improved from 2.65 ± 1.16 to 3.77 ± 1.80 after 1 month (p < 0.001) and the OSDI improved from 38.83 ± 17.13 to 18.67 ± 15.01 after 1 month (p < 0.001). Before and after 1 month of treatment, the lid margin abnormalities were 2.98 ± 1.16 and 2.50 ± 1.01 (p < 0.001) and the MGD scores were 21.60 ± 6.95 and 18.02 ± 6.68 (p = 0.001), respectively. @*Conclusions@#BlephEx™ improved the patients’ ocular surface symptoms, MGD score, and TBUT. Using steroid eye drops, there was a synergistic effect in improvement. Therefore, using BlephEx™ may be suggested as a treatment option for MGD patients.

Clinical Reliability of the Topolyzer Vario Instrument for Measurement of Corneal Refractive Power

Purpose@#To evaluate the clinical reliability of the Topolyzer Vario (Wavelight-Alcon, Erlangen, Germany), we compared threedifferent corneal topographers in terms of corneal refractive power. @*Methods@#The medical records of patients who visited Severance Hospital for corneal refractive surgery were retrospectivelyreviewed. Keratometric data of patients who underwent evaluations using the Pentacam HR (Oculus, Wetzlar, Germany),ORBscan II (Bausch & Lomb, Rochester, NY, USA), and Topolyzer Vario instruments on the same day were obtained. Flat keratometry(Kf), steep keratometry (Ks), mean keratometry (Km), astigmatism keratometry (Kastig), Cartesian astigmatism (J0), andoblique astigmatism (J45) values were calculated. The measurement values of the three devices were subjected to Pearson’scorrelation analysis and repeated measures analysis of variance (with Bonferroni correction); a Bland-Altman plot was alsocreated. @*Results@#The keratometric data of 80 eyes were included in the analysis and all of the keratometric measurements obtained bythe three devices showed significant correlations, i.e., good agreement. The Kf and Km measurements of the Pentacam HR wereflatter than those of the ORBscan II, and the Kf, Km, Ks, and J45 measurements were flatter than those of the Topolyzer Vario.However, there was no significant difference in keratometric values between the ORBscan II and Topolyzer Vario. Furthermore,the difference in corneal refractive power between the Pentacam HR and Topolyzer Vario was not clinically significant. @*Conclusions@#When measuring the corneal refractive power of patients without any history of corneal disorder or ocular surgery,the Topolyzer Vario is a clinically reliable device that shows similar performance to the ORBscan II and Pentacam HR.

Clinical Outcomes of Small Incision Lenticule Extraction in Myopia: Study of Vector Parameters and Corneal Aberrations

Evaluation of factors related to Anaesthesia-induced Lens opacity in experimental mice / 한국실험동물학회지

To investigate conditions that cause temporal lens opacity, we tested chemical and physical factors, such as anaesthesia dose, ocular surface dryness, and infrared (IR) light exposure in anaesthetised C57BL/6 N mice. Mice were anaesthetised with a low (80%; tiletamine/zolazepam 32 mg/kg and xylazine 8 mg/kg, intraperitoneal injection) or high (120%; 48 mg/kg and 12 mg/kg) dose of anaesthetic and examined every 5 min from 10 to 30 min after anaesthesia was induced. Lens opacity levels were assessed and graded (1–6) using the standard classification system. Regardless of the anaesthetic dose, lens opacity grade was 1–2 in moisturised eyes with application of 0.5% carboxymethylcellulose, and 5–6 in dry ocular surface conditions. Lens opacity in mice with high-dose anaesthetic in the dry ocular surface condition was not different from that of mice with low-dose anaesthetic. Lens opacity grade 1–2 was noted in eyes in the wet ocular surface condition, regardless of IR light exposure. During IR light exposure in eyes in the dry ocular surface condition, lens opacity (grade 6) in mice with high-dose anaesthetic was not different from that (grade 6) in mice with low-dose anaesthetic. We demonstrated that ocular surface dryness might be a relevant factor for the formation and progression of lens opacity in anesthetized C57BL/6 N mice. Anaesthesia dose and IR light exposure did not strongly influence lens opacity formation. Furthermore, eyes with corneal dryness-induced lens opacity recovered to normal status without additional intervention.

Evaluation of factors related to Anaesthesia-induced Lens opacity in experimental mice / 한국실험동물학회지

To investigate conditions that cause temporal lens opacity, we tested chemical and physical factors, such as anaesthesia dose, ocular surface dryness, and infrared (IR) light exposure in anaesthetised C57BL/6 N mice. Mice were anaesthetised with a low (80%; tiletamine/zolazepam 32 mg/kg and xylazine 8 mg/kg, intraperitoneal injection) or high (120%; 48 mg/kg and 12 mg/kg) dose of anaesthetic and examined every 5 min from 10 to 30 min after anaesthesia was induced. Lens opacity levels were assessed and graded (1–6) using the standard classification system. Regardless of the anaesthetic dose, lens opacity grade was 1–2 in moisturised eyes with application of 0.5% carboxymethylcellulose, and 5–6 in dry ocular surface conditions. Lens opacity in mice with high-dose anaesthetic in the dry ocular surface condition was not different from that of mice with low-dose anaesthetic. Lens opacity grade 1–2 was noted in eyes in the wet ocular surface condition, regardless of IR light exposure. During IR light exposure in eyes in the dry ocular surface condition, lens opacity (grade 6) in mice with high-dose anaesthetic was not different from that (grade 6) in mice with low-dose anaesthetic. We demonstrated that ocular surface dryness might be a relevant factor for the formation and progression of lens opacity in anesthetized C57BL/6 N mice. Anaesthesia dose and IR light exposure did not strongly influence lens opacity formation. Furthermore, eyes with corneal dryness-induced lens opacity recovered to normal status without additional intervention.

Biomechanical Properties of the Cornea Using a Dynamic Scheimpflug Analyzer in Healthy Eyes

PURPOSE: To investigate biomechanical properties of the cornea using a dynamic Scheimpflug analyzer according to age. MATERIALS AND METHODS: In this prospective, cross-sectional, observational study, participants underwent ophthalmic investigations including corneal biomechanical properties, keratometric values, intraocular pressure (IOP), and manifest refraction spherical equivalent (MRSE). We determined the relationship of biomechanical parameters and ocular/systemic variables (participant's age, MRSE, IOP, and mean keratometric values) by piecewise regression analysis, association of biomechanical parameters with variables by Spearman's correlation and stepwise multiple regression analyses, and reference intervals (RI) by the bootstrap method. RESULTS: This study included 217 eyes of 118 participants (20–81 years of age). Piecewise regression analysis between Corvis-central corneal thickness (CCT) and participant's age revealed that the optimal cut-off value of age was 45 years. No clear breakpoints were detected between the corneal biomechanical parameters and MRSE, IOP, and mean keratometric values. Corneal velocity, deformation amplitude, radius, maximal concave power, Corvis-CCT, and Corvis-IOP exhibited correlations with IOP, regardless of age (all ages, 20–44 years, and over 44 years). With smaller deformation amplitude and corneal velocity as well as increased Corvis-IOP and Corvis-CCT, IOP became significantly increased. We provided the results of determination of confidence interval from RI data using bootstrap method in three separate age groups (all ages, 20–44 years, and over 44 years). CONCLUSION: We demonstrated multiple corneal biomechanical parameters according to age, and reported that the corneal biomechanical parameters are influenced by IOP.

Clinical Outcomes after Use of Fibrin Glue Using a Modified Mini-flap Technique for Pterygium Surgery

PURPOSE: To analyze the long-term clinical outcomes after use of fibrin glue using a modified mini-flap technique for pterygium surgery. METHODS: This study is a retrospective, clinical outcome study of 148 subjects that underwent the modified mini-flap technique with fibrin glue from January 2014 to August 2015. We analyzed the recurrence rate and surgical time of modified mini-flap surgery with fibrin glue. We also analyzed associating factors between the recurrence group and non-recurrence group who underwent the same surgery technique. RESULTS: Mean age was 60.2 ± 1.1 (ranging from 29 to 86) years, and mean surgical time was 11.8 ± 5.8 (ranging from 5 to 36) minutes. The recurrence rate of pterygium patients who underwent the fibrin glue using a modified mini-flap technique was 4.0% (6/148), and the re-operation rate was 0.6% (1/148). From the comparison of associating factors between recurred and non-recurred groups, the recurred group was younger, had more severe disease, and had a higher rate of bilaterality than the non-recurred group (p < 0.05). CONCLUSIONS: The new approach using fibrin glue with a modified mini-flap technique shows a low recurrence rate compared to the other type of pterygium surgery. The use of fibrin glue shortened operation time and decreased patient discomfort due to fewer remnant sutures. Fibrin glue use in a modified mini-flap technique can be considered as a feasible surgical option for pterygium patients.

Tectonic Lamellar Keratoplasty Using Cryopreserved Cornea in a Large Descemetocele

We describe herein a case of an impending corneal perforation with a large descemetocele in a patient with previous penetrating keratoplasty (PKP) that subsequently was treated with an emergent lamellar keratoplasty using frozen preserved cornea. A 76-year-old male patient, who had a PKP, presented with a completely whitish and edematous graft accompanied by large epithelial defects. Although antibiotics and antiviral agents were tried for three days, the corneal stroma abruptly melted, except for the Descemet's membrane and endothelium. Cryopreserved corneal tissue that was kept at -80degrees C was thawed and sutured on top of the remaining Descemet's membrane and endothelium. Pathological and microbiological tests were conducted using the remaining donor and recipient corneal tissues. After tectonic corneal transplantation on top of a large descemetocele, a healthy graft and relatively clear interfaces between graft-host junctions were maintained without serious adverse reactions throughout 6 month follow-up period. Microbiological evaluations of donor tissue at the time of thawing and tissue preparation were done, and the results were all negative. Tissue that was taken intraoperatively from the recipient cornea also showed negative microbiological results. In conclusion, tectonic lamellar keratoplasty, using cryopreserved corneal tissue, only onto the remaining Descemet's membrane and endothelium in an emergent condition, was a safe and effective treatment.