Trends in Corneal Transplantation Revealed by KONOS and Health Insurance Review and Assessment Service Annual Reports

Purpose@#To analyze trends in corneal transplantation surgery and determine the number of domestic and imported corneal grafts used in South Korea.Method: The total number of keratoplasties and number of each individual surgical procedure conducted in 2010 and 2020 were identified using Health Insurance Review and Assessment Service data. The number of keratoplasties using domestic corneas in 2010 and 2020 was determined from the annual report of the Korean Network for Organ Sharing (KONOS). The number of keratoplasties using imported corneas was calculated by subtracting the number of keratoplasties using domestic corneas from the total number of keratoplasties. @*Results@#In 2010, 802 keratoplasties were performed in Korea, of which 299 (37.3%) used imported corneas; 715 (89.2%) were penetrating keratoplasties and 87 (10.8%) were anterior lamellar keratoplasties. In 2020, 911 keratoplasties were done in Korea and 564 (61.9%) used imported corneas; 541 (59.4%) were penetrating keratoplasties, 60 (6.6%) were anterior lamellar keratoplasties, and 310 (34.0%) were endothelial keratoplasties. From 2010 to 2020, the number of penetrating keratoplasties in Korea decreased, while the numbers of endothelial keratoplasties and keratoplasties using imported corneas increased. @*Conclusions@#There was a 30% decrease in the number of penetrating keratoplasties from 2010 to 2020, and a 30% increase in the numbers of endothelial keratoplasties and keratoplasties using imported corneas. The proportions of endothelial keratoplasties and imported corneas have increased steadily in Korea over the last 10 years.

Novel Method Measuring Conjunctival Microvascular Blood Flow Velocity by Zoom-lens, Ultra-high-speed Camera Attached Slit-lamp Biomicroscope

Purpose@#To introduce an intuitive method for measuring conjunctival microvascular blood flow velocity by imaging bulbar conjunctival microvessels using a slit-lamp biomicroscope equipped with a zoom lens and an ultra-high-speed camera. @*Methods@#After obtaining consent from 10 patients (1 male, 9 females) who visited Yeouido St. Mary’s Hospital from August 21, 2020, to June 12, 2021, the patients were examined under a slit lamp microscope equipped with an ultra-high-speed camera and zoom lens. The blood flow in the conjunctival microvessels was photographed. The captured images were analyzed with ImageJ software to measure the blood flow velocity in the conjunctival microvessels, and we investigated whether the blood flow velocity correlated with the vessel diameter and age. @*Results@#The median age of the subjects was 49.0 years. The mean conjunctival blood flow velocity in 53 microvessels was 0.786 ± 0.468 mm/s. The median conjunctival microvascular diameter was 7.06 μm (interquartile range 5.84 to 9.23 μm). The conjunctival microvascular diameter and blood flow velocity were not significantly correlated (Spearman’s p = 0.177), and the subjects’ age and conjunctival microvascular blood flow velocity were also not correlated (Spearman’s p = 0.669). @*Conclusions@#In this study, the blood flow velocity in the bulbar conjunctival microvessels could be measured easily by means of image analysis using a slit-lamp microscope equipped with an ultra-high-speed camera with a zoom lens.

Short-term Outcomes and Prognostic Factors of Cataract-combined Surgery with iStent versus iStent Inject

Purpose@#To analyze the therapeutic effects, prognostic factors, and complications that occurred after iStent® or iStent inject® implantation in South Korean glaucoma patients. @*Methods@#We retrospectively analyzed 42 eyes of South Korean glaucoma patients, who were followed-up for more than 6 months after iStent® or iStent inject® implantation alone or combined with cataract surgery. Surgical success was defined as an intraocular pressure (IOP) ≤21 mmHg and an IOP reduction ≥20% from preoperative IOP levels. @*Results@#The cumulative success rate at 6 months after surgery was 45.3 ± 8.1% for iStent inject® alone (group A), 28.6 ± 13.1% for iStent® alone (group B), 81.2 ± 6.8% for iStent inject® combined with cataract surgery (group A-1), and 27.3 ± 21.8% for iStent® combined with cataract surgery (group B-1). Group A-1 showed a higher success rate than group B-1 (p = 0.007); the difference in success rates between groups A and B was not statistically significant (p = 0.579). When the success prognostic factors were analyzed by Cox regression analysis, the results showed that a higher preoperative IOP was associated with a higher surgical success rate (hazard ratio 0.80, p = 0.02). @*Conclusions@#In our patient group, iStent inject® was more effective than iStent® in combination with cataract surgery. The higher the preoperative IOP, the higher the surgical success rate; the results were significant.

Repeat Descemet Membrane Endothelial Keratoplasty after Descemet Membrane Endothelial Keratoplasty Graft Failure

Purpose@#To report a case of secondary Descemet membrane endothelial keratoplasty (DMEK) for graft failure after primary DMEK.Case summary: A 47-year-old female underwent primary DMEK in her left eye with a diagnosis of Fuchs’ endothelial dystrophy. At 6 weeks later, corneal stromal edema with epithelial and subepithelial bullae was first observed. From that point on, the condition of the cornea and the visual acuity continued to degrade. After 7 months, a second DMEK procedure (i.e., a repeat DMEK) for graft failure was performed successfully without any complications. Since the second procedure, the cornea has been clear, and the best-corrected visual acuity has remained at 0.6 for 8 months. @*Conclusions@#To manage graft failure after primary DMEK, we performed a second DMEK procedure. The removal of the previous graft was easy, and there were no complications. Thus, repeat DMEK may be a feasible procedure.

Descemet Membrane Endothelial Keratoplasty after Penetrating Keratoplasty Graft Failure

Purpose@#To report a case of a successful secondary Descemet membrane endothelial keratoplasty in failed penetrating keratoplasty. Case summary: A 46-year-old male with keratoconus in both of his eyes underwent penetrating keratoplasty in his right eye 30 years ago and in his left eye 14 years ago. From one and a half year ago, the patient’s visual acuity decreased in his left eye due to graft failure. For treatment, secondary Descemet membrane endothelial keratoplasty was performed. Partial detachment of Descemet membrane was observed at 13 days after the operation, and an additional air injection was performed. At 8 months after the operation, the patient’s uncorrected visual acuity improved to 0.5 and the cornea maintained its clearance without rejection. @*Conclusions@#Secondary Descemet membrane endothelial keratoplasty was successfully performed in a patient with failed penetrating keratoplasty.

Short-term Outcomes and Prognostic Factors of Cataract-combined Surgery with iStent versus iStent Inject

Purpose@#To analyze the therapeutic effects, prognostic factors, and complications that occurred after iStent® or iStent inject® implantation in South Korean glaucoma patients. @*Methods@#We retrospectively analyzed 42 eyes of South Korean glaucoma patients, who were followed-up for more than 6 months after iStent® or iStent inject® implantation alone or combined with cataract surgery. Surgical success was defined as an intraocular pressure (IOP) ≤21 mmHg and an IOP reduction ≥20% from preoperative IOP levels. @*Results@#The cumulative success rate at 6 months after surgery was 45.3 ± 8.1% for iStent inject® alone (group A), 28.6 ± 13.1% for iStent® alone (group B), 81.2 ± 6.8% for iStent inject® combined with cataract surgery (group A-1), and 27.3 ± 21.8% for iStent® combined with cataract surgery (group B-1). Group A-1 showed a higher success rate than group B-1 (p = 0.007); the difference in success rates between groups A and B was not statistically significant (p = 0.579). When the success prognostic factors were analyzed by Cox regression analysis, the results showed that a higher preoperative IOP was associated with a higher surgical success rate (hazard ratio 0.80, p = 0.02). @*Conclusions@#In our patient group, iStent inject® was more effective than iStent® in combination with cataract surgery. The higher the preoperative IOP, the higher the surgical success rate; the results were significant.

Repeat Descemet Membrane Endothelial Keratoplasty after Descemet Membrane Endothelial Keratoplasty Graft Failure

Purpose@#To report a case of secondary Descemet membrane endothelial keratoplasty (DMEK) for graft failure after primary DMEK.Case summary: A 47-year-old female underwent primary DMEK in her left eye with a diagnosis of Fuchs’ endothelial dystrophy. At 6 weeks later, corneal stromal edema with epithelial and subepithelial bullae was first observed. From that point on, the condition of the cornea and the visual acuity continued to degrade. After 7 months, a second DMEK procedure (i.e., a repeat DMEK) for graft failure was performed successfully without any complications. Since the second procedure, the cornea has been clear, and the best-corrected visual acuity has remained at 0.6 for 8 months. @*Conclusions@#To manage graft failure after primary DMEK, we performed a second DMEK procedure. The removal of the previous graft was easy, and there were no complications. Thus, repeat DMEK may be a feasible procedure.

Descemet Membrane Endothelial Keratoplasty after Penetrating Keratoplasty Graft Failure

Purpose@#To report a case of a successful secondary Descemet membrane endothelial keratoplasty in failed penetrating keratoplasty. Case summary: A 46-year-old male with keratoconus in both of his eyes underwent penetrating keratoplasty in his right eye 30 years ago and in his left eye 14 years ago. From one and a half year ago, the patient’s visual acuity decreased in his left eye due to graft failure. For treatment, secondary Descemet membrane endothelial keratoplasty was performed. Partial detachment of Descemet membrane was observed at 13 days after the operation, and an additional air injection was performed. At 8 months after the operation, the patient’s uncorrected visual acuity improved to 0.5 and the cornea maintained its clearance without rejection. @*Conclusions@#Secondary Descemet membrane endothelial keratoplasty was successfully performed in a patient with failed penetrating keratoplasty.

Ocular Surface Staining Score and Salivary Gland Scintigraphy in Patients with Primary Sjögren’s Syndrome

Purpose@#To analyze the correlation between the ocular surface staining score and indices of salivary gland scintigraphy in patientswith primary Sjögren's syndrome and dry eye symptoms, and to evaluate the diagnostic value of these indices. @*Methods@#The patients were 51 adults with primary Sjögren's syndrome or non-Sjögren's syndrome plus dry eye symptoms, whowere referred to our ophthalmology clinic for evaluation of the degree of dry eye at the Department of Rheumatology, from July2017 to April 2019. The Mann-Whitney U test and student’s t-test were used for analyzing the ocular surface staining score andquantitative indices of salivary gland scintigraphy, respectively, in the primary Sjögren's syndrome and non-Sjögren's syndromepatients. Spearman correlation was used to analyze the correlations of ocular surface staining score with salivary scintigraphyindices. @*Results@#The ocular surface staining score (p= 0.021), parotid gland excretion fraction (p= 0.022), and submandibular gland excretionfraction (pp= 0.045) were significantly different between the primary Sjögren's syndrome and non-Sjögren's syndromepatients. The submandibular gland uptake ratio (r = -0.369, p= 0.008) and submandibular excretion fraction (r = -0.359, p=0.010) were significantly negatively correlated with ocular surface staining scores. @*Conclusions@#The ocular surface staining score was identified as the gold standard for evaluating the degree of dry eye in primarySjögren's syndrome patients. If salivary gland dysfunction is identified by salivary gland scintigraphy, ocular surface stainingshould be performed to confirm the presence of ocular surface lesions, regardless of the presence of dry eye symptoms.

Descemet Membrane Endothelial Keratoplasty to Treat Graft Failure after Descemet Stripping Endothelial Keratoplasty

Purpose@#We report a case of secondary Descemet membrane endothelial keratoplasty (DMEK) to treat graft failure after Descemet stripping endothelial keratoplasty (DSEK).Case summary: A 66-year-old female underwent DSEK of her right eye to treat pseudophakic bullous keratopathy that developed after cataract surgery and intraocular lens exchange. After 5 years, she complained of decreased vision; graft failure was observed. Secondary DMEK was performed; no additional air injection was needed. The corrected visual acuity was 0.2, 3 months after surgery, and the cornea became clear. @*Conclusions@#Visual recovery can be achieved by performing secondary DMEK after primary DSEK graft failure.

Descemet Membrane Endothelial Keratoplasty to Treat Graft Failure after Descemet Stripping Endothelial Keratoplasty

Purpose@#We report a case of secondary Descemet membrane endothelial keratoplasty (DMEK) to treat graft failure after Descemet stripping endothelial keratoplasty (DSEK).Case summary: A 66-year-old female underwent DSEK of her right eye to treat pseudophakic bullous keratopathy that developed after cataract surgery and intraocular lens exchange. After 5 years, she complained of decreased vision; graft failure was observed. Secondary DMEK was performed; no additional air injection was needed. The corrected visual acuity was 0.2, 3 months after surgery, and the cornea became clear. @*Conclusions@#Visual recovery can be achieved by performing secondary DMEK after primary DSEK graft failure.

A New Amniotic Membrane for Placement during Pterygium Surgery

PURPOSE: We introduce a new amniotic membrane (AM) for placement during pterygium surgery. CASE SUMMARY: After excision of the pterygium, we measured the size of the defect with reference to the side opposite the defective area and prepared an AM with margins 1.5–2.0 mm greater than the defect size. The AM was first sutured vertically, with reference to the opposite side of the defect. Then we sutured the upper and lower horizontal axes, and positioned the eye, from the front, slightly away from the direction of the opposite side of the defect. The AM was cut by reference to its boundary at the limbus, and three fixation sutures were placed. CONCLUSIONS: Appropriate AM sizing is important in terms of AM transplantation; the AM is non-elastic and easily torn. Our technique transplants a correctly sized AM and anchors it firmly.

Two Cases of Pre-descemet Corneal Dystrophy Associated with X-linked Ichthyosis: A Case Report by Genetic Analysis

PURPOSE: To report the first case of steroid sulfatase (STS) gene deletion, confirmed by multiplex ligation-dependent probe amplification (MLPA) analysis in identical twins with pre-Descemet corneal dystrophy associated with X-linked ichthyosis. CASE SUMMARY: 19-year old identical twin brothers with itching senses and hereditary thick scaly skin of the extremity and trunk visited our dermatologic clinic. Upon visiting, an ophthalmologic consultation with anterior segment examination showed diffuse punctate corneal opacities in the pre-Descemet layer. On MLPA analysis of the identical twin brothers, a definitive diagnosis of X-linked ichthyosis was made by identifying STS gene deletion. CONCLUSIONS: Identification of the deletion and mutation of the involved gene using gene analysis can provide insight to diagnosis and clinical characteristics of X-linked ichthyosis.

Comparison of Higher Order Aberrations and Astigmatism after On-Axis Small Incision Cataract Surgery

PURPOSE: To assess the changes of corneal astigmatism and higher order aberrations (HOAs) of the anterior and posterior corneal surface after cataract surgery with on-axis clear corneal incision in eyes with-the-rule (WTR) astigmatism and against-the-rule (ATR) astigmatism. METHODS: This study included 50 patients who underwent phacoemulsification and IOL insertion through a 2.8-mm on-axis clear corneal incision. The eyes were divided into two groups: (1) 26 eyes with WTR astigmatism with a superior incision and (2) 24 eyes with ATR astigmatism with a temporal incision. During the follow-up period, visual acuity was measured, and the surgically induced astigmatism (SIA) and HOAs of the anterior and posterior corneal surface were measured with Pentacam(R) (Occlus, Wetzlar, Germany) preoperatively and 1 week, 1 month, and 2 months postoperatively. RESULTS: There were no significant differences in UCVA and BCVA between the two groups. HOAs increased in both groups 1 week after surgery, but no significant differences were found between the groups (p > 0.05). Surgically induced astigmatism was larger in the WTR group than in the ATR group (p < 0.05). At postoperative 2 months, there were significant differences in HOAs between the two groups, and there were statistically significant differences in HOAs, oblique trefoil at front side, and in HOAs, horizontal coma at rear side (p < 0.05). CONCLUSIONS: In conclusion, superior incision in eyes with WTR astigmatism resulted in higher SIA compared to temporal incision in eyes with ATR astigmatism. Moreover, HOAs was significantly decreased in eyes with WTR astigmatism with superior incision. Thus, superior incision could be more effective in reducing corneal astigmatism in eyes with WTR astigmatism.

Comparison of Intraocular Straylight in Patients with Clear and Photochromic Intraocular Lenses

PURPOSE: To compare visual acuity and intraocular straylight after implantation of clear and photochromic intraocular lenses (IOLs) in a mesopic lighting condition. METHODS: Clear IOLs were implanted in 95 eyes of 72 patients (clear IOL group), and photochromic IOLs were implanted in 22 eyes of 16 patients (photochromic IOL group). Best-corrected visual acuity (BCVA) was measured indoors before surgery and 1 month after surgery. Straylight values were measured indoors before surgery and 1 and 2 months after surgery using the C-quant straylight meter (Oculus GmbH, Wetzlar, Germany). RESULTS: There were no significant differences between the 2 groups in BCVA at 1 month postoperatively (p = 0.587). Mean straylight values of clear and photochromic IOL groups were 2.76 +/- 1.89 log (s) and 2.88 +/- 2.04 log (s) preoperatively, 1.39 +/- 0.84 log (s) and 1.32 +/- 0.26 log (s) at 1 month postoperatively, and 1.43 +/- 0.92 log (s) and 1.45 +/- 0.50 log (s) at 2 months postoperatively. There were no significant differences between the 2 groups in indoor straylight values (p = 0.778, 0.709, 0.929, before surgery, 1 and 2 months after surgery respectively). Repeated-measure analysis of straylight values also showed no significant difference between the 2 groups (p > 0.05). CONCLUSIONS: There were no significant differences in BCVA and straylight values between clear and photochromic IOL groups under a mesopic light condition. Therefore, photochromic IOL could be suitable choice for cataract patients who spend significant time under mesopic conditions.

Effect of Glistening-Free Intraocular Lens on Intraocular Straylight

PURPOSE: To compare intraocular straylight between glistening-free and conventional intraocular lenses in pseudophakic eyes. METHODS: Straylight values were measured prospectively in 21 eyes with glistening-free pseudophakic lenses (group A, model enVista(TM), Bausch & Lomb, Inc., USA) and 79 eyes with conventional hydrophilic pseudophakic lenses (group B, model Akreos MI-60, Bausch & Lomb, Inc., USA). Best corrected visual acuity (BCVA) and straylight were measured preoperatively and 1 month and 2 months postoperatively using C-quant straylight meter (Oculus GmbH, Wetzlar, Germany). RESULTS: There were no statistically significant differences of BCVA preoperatively or 2 months postoperatively between the 2 groups (p > 0.05). BCVA and straylight significantly improved after the operation (p 0.05). CONCLUSIONS: In terms of straylight, glistening-free intraocular lenses were not beneficial. Although straylight was not statistically significant, other correlations between glistening and visual function should be investigated.

Ranibizumab Injection for Corneal Neovascularization Refractory to Bevacizumab Treatment

Vascular endothelial growth factor inhibitor is an emerging therapeutic modality for various ocular diseases with neovascularization (NV). However, for corneal NV, controversy remains regarding whether bevacizumab or ranibizumab is superior. A 32-year-old female diagnosed with herpetic keratoconjunctivitis with refractory corneal NV despite two previous subconjunctival and intrastromal bevacizumab injections, received two subconjunctival and intrastromal ranibizumab injections. Six months postoperatively, there was significant regression of the neovascular area and vessel caliber. Here, the authors report a case of improvement in corneal NV with subconjunctival and intrastromal ranibizumab injections, which was previously refractory to bevacizumab injection. The findings may suggest a new prospect in treating corneal NV.

A Case of Corneal Ulcer Caused by Leclercia Adecarboxylata

PURPOSE: To report a case of corneal ulcer caused by Leclercia adecarboxylata in an immunocompetent patient. CASE SUMMARY: A previously healthy 43-year-old female presented with right ocular pain and was referred to our clinic under the impression of corneal abrasion and secondary infection. The patient was treated at a local clinic for 3 days using artificial tears, therapeutic contact lens, topical antibiotics, and anti-inflammatory eye drops but showed no improvement. Gram staining, bacterial and fungal cultures and antibiotic sensitivity test were performed from a corneal scrape. The cultures revealed growth of Leclercia adecarboxylata. The patient was treated with moxifloxacin and ofloxacin eye drops. After 2 weeks of treatment, the infection resolved without remaining scars. CONCLUSIONS: Reportedly, Leclercia adecarboxylata affects humans only as an opportunistic pathogen or part of polymicrobial infections. However, in the present case, Leclercia adecarboxylata was isolated as a single pathogen in an immunocompetent patient which is the first clinical report of this microorganism found in an ocular sample. Therefore, if antibiotic-susceptible gram-negative bacilli are found in opthalmologic samples, the above bacteria should be considerd in the diagnosis.

Comparison of Clinical Outcomes Between Torsional Phacoemulsification of Infiniti(R) and Longitudinal Phacoemulification of Stellaris(R) Through 2.2 mm Microincision

PURPOSE: To compare clinical outcomes of a 2.2 mm microcoaxial cataract surgery, using torsional mode and longitudinal mode. METHODS: In this comparative study, patients with bilateral cataract were assigned to get microcoaxial cataract surgery by torsional mode of infiniti in one eye and longitudinal mode of Stellaris(R) in the other eye. Primary outcome measures were US time (UST), cumulative dissipated energy (CDE), mean amount of balanced salt solution (BSS) used and surgical complications. Patients were seen 1, 7, 30, and 60 days after surgery. Postoperative outcome measures were the final best corrected visual acuity (BCVA), central corneal thickness (CCT), endothelial cell count and surgically induced astigmatism (SIA). RESULTS: The study evaluated 68 eyes of 34 patients (nuclear opalescence (NO)2: 40 eyes, and NO3: 28 eyes). CDE was significantly lower in torsional mode (3.52 +/- 2.93) than in longitudinal mode (6.20 +/- 3.32) (p = 0.001). Torsional mode (60.88 +/- 21.18 ml) had more BSS use than longitudinal mode (34.58 +/- 13.54 ml) (p 0.05). CONCLUSIONS: The torsional mode may provide lower level of phacoemulsification energy than the longitudinal mode and Torsional mode is considered effective and safe phacoemulsification. However the surgical outcomes were not significantly different in 2.2 mm microcoaxial cataract surgery of moderate cataract. So surgeon can choose any phaco machine based on experience and preference.

Influence of Phacoemulsification on Progression of Glaucoma and Analysis of Related Factors in Glaucoma Patients

PURPOSE: To evaluate the factors affecting glaucoma progression after cataract surgery with phacoemulsification. METHODS: The medical charts of 109 eyes of 68 patients with glaucoma who had phacoemulsification were retrospectively reviewed. The course of glaucoma was followed up for at least 2 years. Age, sex, diabetes, hypertension, preoperative mean deviation, phacoemulsification time, cataract type, refractive error, preoperative and postoperative visual acuity, preoperative and postoperative intraocular pressure, axial length, and central corneal thickness between the progression group and the non-progression group were compared. RESULTS: Among 109 eyes with glaucoma, 19 (17.4%) eyes were classified into the glaucoma progression group. In the multivariate analysis, age (p = 0.026), preoperative mean deviation (p < 0.001), and phacoemulsification time (p < 0.001) were statistically associated with glaucoma progression. CONCLUSIONS: For patients with glaucoma, phacoemulsification may result in its progression. Special attention should be given to patients with the above risk factors.