Impact of cornea recovery training and certification on ophthalmology residents

Background

In Asian countries, such as Taiwan, social taboos regarding organ and tissue donation decreases the prevalence of organ and tissue transplants. This also applies to cornea recovery, which is a skill that requires precision and practice to perform well. In Taiwan, to ensure the maintenance of high-quality corneas, a comprehensive training program and certified examination has been implemented. This study aims to investigate the impact of these programs and examinations on cornea recovery.

Methods

Researchers evaluated the efficiency of the training and certified examination process by comparing the corneoscleral rim width, Descemet's membrane folds, endothelial layer stress lines, and endothelial cell density performed by ophthalmology residents in 2018 and 2019.

Results

After training and certification, the Descemet's membrane folds rate decreased from 14.3 % to 2.0 % and endothelial layer stress lines rate decreased from 22.5 % to 5.0 %. The endothelial cell density of donor grafts significantly improved from 2681.9 cells/mm2 to 2869.7 cells/mm2 (p < 0.001).

Conclusions

This study used objective data to evaluate cornea recovery quality after training and certification. The training and certified examination significantly improved the surgical skills of ophthalmology residents and could be applied in other tissue or organ recovery procedures to maintain and improve quality.

Overweight and Obesity as Risk Factors for Recurrent Herpetic Stromal Keratitis during Long-Term Antiviral Prophylaxis

Although past research has shown an association between obesity and herpes simplex virus infection, the relationship between body mass index (BMI) and herpetic stromal keratitis (HSK) recurrence has never been investigated. In this study, we included HSK patients who received oral valacyclovir as prophylactic treatment between January 2016 and January 2021. Recurrence, possible risk factors, and the time to recurrence were recorded during follow-ups. Among the 56 patients included in this study, recurrence was reported in 21 (37.5%) patients. The age at disease onset and mean follow-up time were not significantly different in the recurrence and non-recurrence groups. However, in the Cox regression analysis, BMI ≥ 24 kg/m2 was noted as the variable having significant correlation with recurrence (p = 0.01 in univariate analysis and p = 0.001 in multivariate analysis). In conclusion, overweight and obesity were revealed as risk factors for HSK recurrence in patients receiving long-term antiviral prophylaxis. Further studies are needed to determine the appropriate acyclovir concentrations in the blood or aqueous humour in order to achieve desirable prophylactic effects, especially in the overweight and obese patients.

Long-Term Outcome of Treatment with 2% Topical Ganciclovir Solution in Cytomegalovirus Anterior Uveitis and Corneal Endotheliitis

Purpose

This study aimed to evaluate the therapeutic efficacy and long-term outcomes of treatment with topical 2% ganciclovir solution in immunocompetent patients with aqueous humor polymerase chain reaction (PCR)-proven cytomegalovirus (CMV) anterior uveitis and corneal endotheliitis.

Methods

We retrospectively reviewed the findings for immunocompetent patients diagnosed with CMV uveitis or endotheliitis based on clinical manifestations and polymerase chain reaction (PCR) examination results and treated with topical 2% ganciclovir solution at National Cheng Kung University Hospital. Clinical outcome measurements included evaluations of the response rate, relapses, resolution of anterior chamber inflammation, visual acuity, and intraocular pressure.

Results

The study included 38 eyes of 32 patients. Long-term administration of topical 2% ganciclovir significantly decreased keratic precipitates (p = 0.001), anterior chamber cells (p = 0.001), and reduced intraocular pressure (p < 0.001). Only one eye was unresponsive to topical ganciclovir treatment, and the recurrence decreased to 0.13 relapses per year. The presence of keratic precipitates and higher intraocular pressure at the initial presentation were significantly associated with recurrence (p = 0.036 and p = 0.001, respectively).

Conclusions

Long-term use of topical 2% ganciclovir solution is effective, safe, and applicable when commercialized ganciclovir gel is not available.

A Population-Based Study of Social Demographic Factors, Associated Diseases and Recurrent Corneal Erosion in Taiwan

Purpose

To investigate the association of recurrent corneal erosion (RCE) with sociodemographic factors and associated ocular conditions or systemic diseases.

Methods

This nationwide, population-based, retrospective, matched case-controlled study included 98,895 RCE patients, identified by the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code 371.42, were selected from the Taiwan National Health Insurance Research Database. The age-, sex-, and index date- matched control group included 98,895 non-RCE control group also selected from the Taiwan Longitudinal Health Insurance Database 2000. Sociodemographic factors and associated ocular conditions or systemic diseases were examined using univariate logistic regression analyses, and continuous variables were analyzed using paired t-test. The odds ratio (OR) of developing RCE were compared using adjusted logistic regression analysis.

Results

Patients with ocular conditions including corneal abrasion, ocular allergic conditions, and corneal dystrophy were more likely to have RCE than the control group (adjusted OR = 63.56, 95% CI = 42.06-96.06, p < 0.0001; adjusted OR = 24.27, 95% CI = 20.51-28.72, p < 0.0001; adjusted OR = 17.10, 95% CI = 5.14-59.93, p < 0.0001, respectively). Patients with systemic diseases such as diabetes mellitus, hyperlipidaemia, and atopy trait have significantly higher ORs for RCE development. Patients residing in either Northern Taiwan or a metropolis city had higher odds of developing RCE; however, there were no significant differences in income or occupation on the probability to develop RCE.

Conclusion

RCE is strongly associated with corneal abrasion, ocular allergic conditions, corneal dystrophy, diabetes mellitus, hyperlipidaemia, and atopy trait.

Case Report: Allogenic Simple Limbal Epithelial Transplantation From a Human Leukocyte Antigen-Matched Living Related Donor to Treat Bilateral Corneal Chemical Burns Post Laser-Assisted in situ Keratomileusis

A 35-year-old woman who had undergone laser-assisted in situ keratomileusis in both eyes experienced bilateral total limbal stem cell deficiency (LSCD) due to chemical burns. Due to bilateral severe LSCD, allogenic simple limbal epithelial transplantation (SLET) from a human leukocyte antigen (HLA)-matched living related donor was the first choice of treatment for her left eye. We report the first case of HLA or ABO matching living related allogenic SLET for permanent restoration of the cornea for bilateral LSCD treatment. Our ABO-HLA-matched living related allogenic SLET alleviation of the systemic immunosuppressant to topical corticosteroids alone. It also came the limitations of prolonged systemic immunosuppressant usage in conjunctival-limbal allografts and keratolimbal allograft.

The Sociodemographic and Risk Factors for Fuchs’ Endothelial Dystrophy: A Nationwide, Matched Case–Control Study in Taiwan

This nationwide, population-based, retrospective, matched case–control study included 4334 newly diagnosed Fuchs’ endothelial dystrophy (FED) patients who were identified by the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM), code 371.57, and selected from the Taiwan National Health Insurance Research Database. The age-, sex-, and index-date-matched control group included 4334 non-FED controls selected from the Taiwan Longitudinal Health Insurance Database 2000. Ocular allergic conditions and sociodemographic conditions were examined using univariate logistic regression analyses and paired t-test was used for continuous variables. Adjusted logistic regression was used to compare the odds ratio (OR) of the FED development. Patients with ocular allergic conditions were more likely to have FED than the controls (OR = 25.50, 95% CI = 12.58–51.68, p < 0.0001) even after conditional logistic regression was conducted (adjusted OR = 25.26, 95% CI = 11.24–56.77, p < 0.0001). Regarding the sociodemographic factors, we found that more than half of the FED patients in Taiwan were aged ≥45 years old, there was an equal female-to-male ratio (1.06:1), and patients with a lower income and living in northern Taiwan had higher odds of developing FED. The results strongly support an association between ocular allergic conditions, geographic region, residential status, income, and FED.

Associations between Sjögren Syndrome, Sociodemographic Factors, Comorbid Conditions, and Scleritis in a Taiwanese Population-Based Study

This nationwide, population-based, retrospective, matched case–control study included 111,960 newly diagnosed patients with scleritis who were identified by the International Classification of Diseases, Ninth Revision, Clinical Modification code 379.0, selected from the Taiwan National Health Insurance Research Database. Demographic characteristics, Sjögren syndrome, and comorbid conditions within 1 year before the scleritis diagnosis were examined using univariate logistic regression analyses, and a paired t-test was used for continuous variables. Adjusted logistic regression was used to compare the prognosis odds ratio (OR) of the patients with scleritis with the controls. After adjustment for confounders, patients with Sjögren syndrome were remarkably more likely to have scleritis than the controls (OR = 33.53, 95% confidence interval (CI) = 27.43–40.97, p < 0.001). Other conditions found to have increased odds of scleritis included post ocular pterygium, glaucoma, and scleral surgery (OR  =  4.01, 95% CI  =  3.64–4.43; OR  =  3.16, 95% CI  =  2.24–4.47; OR  =  6.83, 95% CI  =  5.34–8.74, respectively); systemic infections, such as syphilis, tuberculosis, and a human herpes viral infection (OR  =  4.01, 95% CI  =  2.93–5.50; OR  =  2.24, 95% CI  =  1.94–2.58; OR  =  8.54, 95% CI  =  8.07–9.03, respectively); and systemic diseases, such as rheumatoid arthritis, granulomatous vasculitis, systemic lupus erythematosus, ankylosing spondylitis, and gout (OR  =  2.93, 95% CI  =  2.66–3.23; OR  =  7.37, 95% CI  =  3.91–13.88; OR  =  3.18, 95% CI  =  2.63–3.85; OR  =  5.57, 95% CI  =  4.99–6.22; OR  =  2.84, 95% CI  =  2.72–2.96, respectively). The results strongly support an association between Sjögren syndrome, post ocular surgery, systemic infection disease, systemic autoimmune disease, and scleritis.

Sociodemographic Factors and Comorbidities Including Hyperparathyroidism Are Associated With an Increased Risk of Band Keratopathy: A Population-Based Study in Taiwan

PURPOSE

To investigate the association of comorbidities including hyperparathyroidism and sociodemographic factors with band keratopathy.

METHODS

This retrospective, population-based, matched case-control study recruited 2,545 patients suffering from band keratopathy. They were selected from the Taiwan National Health Insurance Research Database, based on the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code 371.43. The control group included 15,270 sex-, age-, and index date-matched non-band keratopathy patients collected from the Taiwan Longitudinal Health Insurance Database 2000. To compare band keratopathy patients with controls, McNemar's test was used for nominal data and paired t- tests were used for continuous variables. Univariate conditional logistic regression analysis and multivariable conditional logistic regression were used to obtain the odds ratio (OR) and adjusted OR of developing band keratopathy.

RESULTS

Patients with hyperparathyroidism were more likely to develop band keratopathy than controls (OR, 43.5; 95% confidence interval [CI], 23.789-79.544; P < 0.001) even after conditional logistic regression (adjusted OR, 11.28; 95% CI, 5.461-23.33; P < 0.001). Other conditions that increased the odds of scleritis development included systemic diseases such as chronic kidney disease (CKD) and diabetes mellitus (DM) and ocular conditions such as iridocyclitis, phthisis bulbi, and ever silicone oil retention. Regarding sociodemographic factors, >40% of patients with band keratopathy were aged ≥65 years old. Moreover, patients living in Eastern Taiwan and fishermen had higher odds of developing band keratopathy.

CONCLUSIONS

Band keratopathy is significantly associated with hyperparathyroidism, CKD, DM, iridocyclitis, phthisis bulbi, and ever silicone oil retention.

Recombinant thrombomodulin domain 1 rescues pathological angiogenesis by inhibition of HIF-1α-VEGF pathway

Pathological angiogenesis (PA) contributes to various ocular diseases, including age-related macular degeneration, diabetic retinopathy, and retinopathy of prematurity, which are major causes of blindness over the world. Current treatments focus on anti-vascular endothelial growth factor (VEGF) therapy, but persistent avascular retina, recurrent intravitreal neovascularization, and general adverse effects are reported. We have previously found that recombinant thrombomodulin domain 1 (rTMD1) can suppress vascular inflammation. However, the function of rTMD1 in VEGF-induced PA remains unknown. In this study, we found that rTMD1 inhibited VEGF-induced angiogenesis in vitro. In an oxygen induced retinopathy (OIR) animal model, rTMD1 treatment significantly decreased retinal neovascularization but spared normal physiological vessel growth. Furthermore, loss of TMD1 significantly promoted PA in OIR. Meanwhile, hypoxia-inducible factor-1α, the transcription factor that upregulates VEGF, was suppressed after rTMD1 treatment. The levels of interleukin-6, and intercellular adhesion molecule-1 were also significantly suppressed. In conclusion, our results indicate that rTMD1 not only has dual effects to suppress PA and inflammation in OIR, but also can be a potential HIF-1α inhibitor for clinical use. These data bring forth the possibility of rTMD1 as a novel therapeutic agent for PA.

Conjunctival Expression of Toll-Like Receptor 3 Plays a Pathogenic Role in the Formation of Ultraviolet Light-Induced Pterygium

Purpose

Toll-like receptor 3 (TLR3), as a damage-associated molecular pattern sensor, can detect self-RNA released from necrotic cells induced by ultraviolet B (UVB) radiation exposure. Pterygium formation is believed to be a tumorigenesis-like process induced by UVB exposure. In this study, we aimed to investigate the expression pattern of TLR3 in pterygium specimens and cultured pterygial epithelial cells (PECs).

Methods

Human pterygium and ipsilateral pterygium-free conjunctiva from the same patients were used in this study. The expression of TLR3 and nuclear factor-kappa B (NF-κB) was investigated in these specimens. PECs were exposed to UVB radiation to determine the effect of UVB on the expression of TLR3 and the activation of NF-κB.

Results

The immunofluorescence study showed stronger TLR3 expression in superficial epithelial cells in the pterygial epithelium in comparison with the normal conjunctival epithelium. The expression of TLR3 decreased in intensity from the superficial epithelium toward the basal cell layer, implying a correlation between UVB exposure and TLR3 expression. Differential TLR3 expression patterns in pterygial and conjunctival tissues were also found in quantitative PCR analyses. PECs after UVB irradiation had higher protein levels of TLR3 and phospho-NF-κB than those of the PECs without irradiation. Immunofluorescence studies showed that UVB irradiation induced the nuclear translocation of NF-κB in the PECs. In PECs with the targeted TLR3 gene silencing, the expression of phospho-NF-κB was not induced by UVB irradiation.

Conclusions

Our results indicate that UVB exposure, TLR3 expression, and NF-κB activation may be a critical sequence that leads to the formation of pterygium.

Association Between Atopic Keratoconjunctivitis and the Risk of Recurrent Corneal Erosion

Purpose: To investigate the risk of recurrent corneal erosion (RCE) in patients with atopic keratoconjunctivitis (AKC).

Methods: This national, retrospective, matched cohort study enrolled 184,166 newly-diagnosed AKC patients, selected from the Taiwan National Health Insurance Research Database and identified by the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code 372.05. The control group comprised 184,166 non-AKC patients matched by age, sex, and potential comorbidities and they were selected from the Taiwan Longitudinal Health Insurance Database, 2000. Information from patients was gathered from 1 January 2004 to 31 December 2011, and both groups were traced from the index date until December 2013. The incidence and risk of RCE (ICD-9-CM code 361.42) was compared between the groups. The adjusted hazard ratio (HR) for RCE was obtained by a Cox proportional hazard regression analysis. The Kaplan–Meier analysis was performed to calculate the cumulative incidence of RCE.

Results: In total, 564 AKC patients and 406 non-AKC controls developed RCE during the follow-up span. The incidence of RCE was 1.45 times higher in AKC patients than in controls (95% confidence interval [CI] = 1.27–1.64; P < 0.0001). After adjusting for potential confounders, including diabetes mellitus, keratoconjunctivitis sicca, corneal transplantation, ocular blunt trauma, corneal dystrophy, and band keratopathy, AKC patients were 1.36 times more likely to develop RCE than controls (adjusted HR, 1.36; 95% CI = 1.19–1.54; p < 0.05).

Conclusions: AKC Patients had an increased risk of developing RCE and should be informed of this risk.

Association between atopic keratoconjunctivitis and the risk of corneal ulcer

AIMS

To investigate the risk of corneal ulcer in patients with atopic keratoconjunctivitis (AKC).

METHODS

The nationwide, population-based, retrospective, matched cohort study included 171 019 newly diagnosed patients with AKC who were identified by the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM), code 372.05, and selected from the Taiwan National Health Insurance Research Database. The age-, sex- and potential comorbidities-matched control group included 171 019 patients with non-AKC selected from the Taiwan Longitudinal Health Insurance Database 2000. Patient information was collected between 1 January 2004 and 31 December 2011, and both groups of patients were tracked from the index date until December 2013. The incidence and risk of corneal ulcer (ICD-9-CM code 370.0 except for 370.07) was compared between the groups. A Cox proportional hazard regression analysis was performed to obtain the adjusted HR for corneal ulcer. The cumulative corneal ulcer incidence rate was calculated with the Kaplan-Meier analysis.

RESULTS

In total, 2018 patients with AKC and 1481 controls developed a corneal ulcer during the follow-up period. The incidence rate of corneal ulcer was 1.42 times (95% CI1.33 to 1.52; p<0.0001) higher in patients with AKC than in controls. After adjusting for potential confounders, including diabetes mellitus, chronic renal disease, topical steroid ophthalmic agent use, lid margin disease, keratoconjunctivitis sicca, ocular blunt trauma and post-corneal transplantation, patients with AKC were 1.26 times more likely to develop a corneal ulcer than controls (adjusted HR, 1.26; 95% CI 1.14 to 1.39; p<0.05).

CONCLUSIONS

Patients with AKC had an increased risk of developing a corneal ulcer and should be advised of this risk.

Risk of Mitral Valve Prolapse in Patients with Keratoconus in Taiwan: A Population-Based Cohort Study

This retrospective, nationwide, matched-cohort study included 4488 new-onset keratoconus (KCN) patients, ≥12 years old, recruited between 2004 and 2011 from the Taiwan National Health Insurance Research Database. The control group included 26,928 non-KCN patients selected from the Taiwan Longitudinal Health Insurance Database 2000. Information for each patient was collected and tracked from the index date until December 2013. The incidence rate of mitral valve prolapse (MVP) was 1.77 times (95% confidence interval (CI) = 1.09–2.88; p = 0.0206) higher in KCN patients ≥40 years old and 1.49 times (95% CI = 1.12–1.98; p = 0.0060) higher in female KCN patients than in controls. After using the Cox proportional hazard regression analysis to adjust for potential confounders, including hypertension, hyperlipidemia, and congestive heart failure, KCN maintained an independent risk factor, MVP being 1.77 times (adjusted hazard ratio (HR) = 1.77, 95% CI = 1.09–2.88) and 1.48 times (adjusted HR = 1.48, 95% CI = 1.11–1.97) more likely to develop in patients ≥40 years old and female patients in the study cohort, respectively. We found that KCN patients ≥40 years of age and female KCN patients have increased risks of MVP. Therefore, it is recommended that KCN patients should be alerted to MVP.

Risk of recurrent corneal erosion in patients with diabetes mellitus in Taiwan: a population-based cohort study

OBJECTIVE

To investigate the risk of recurrent corneal erosion (RCE) in patients with diabetes mellitus (DM).

DESIGN, SETTING AND PARTICIPANTS

This retrospective, nationwide, matched cohort study included 239 854 patients with DM recruited between 2003 and 2005 from the Longitudinal Cohort of Diabetes Patients database. The control group included the same number of age-matched and sex-matched patients without DM selected from the Taiwan Longitudinal Health Insurance Database, 2000. Data for each patient were collected from the index date until December 2013.

MAIN OUTCOMES AND MEASURES

The incidence and risk of RCE were compared between the two groups. Cox proportional hazards regression was used to calculate the HR for RCE after adjustment for potential confounders. The cumulative RCE incidence rate was calculated using Kaplan-Meier analysis.

RESULTS

In total, 1236 patients with DM and 884 controls developed RCE during the follow-up period, resulting in an incidence rate of RCE in patients with DM (5.87/10 000 person-years (PY)) higher than that in the controls (4.23/10 000 PY). After adjustment for potential confounders, including hypertension, hyperlipidaemia, chronic renal disease and keratoconjunctivitis sicca, patients with DM were 1.35 times (95% CI, 1.24 to 1.48) more likely to develop RCE than the total sample cohort.

CONCLUSIONS

DM increases the risk of RCE, which is an interdisciplinary issue. Therefore, close collaboration between endocrinologists and ophthalmologists is important in managing RCE following DM.

Microsporidial stromal keratitis: characterisation of clinical features, ultrastructural study by electron microscopy and efficacy of different surgical modalities

AIMS

To report the clinical manifestations, ultrastructure and evaluate the efficacy of therapeutic lamellar keratectomy (TLK) and penetrating keratoplasty (PK) for microsporidial stromal keratitis (MSK).

METHODS

Fourteen MSK cases between 2009 and 2018 were recruited. Each patient's clinical presentation, light microscopy, histopathology, PCR and electron microscopy (EM) of corneal samples were reviewed.

RESULTS

The patients were 70.0±4.7 years old (average follow-up, 4.5 years). Time from symptoms to presentation was 10.6±13.0 weeks. The corneal manifestations were highly variable. Corneal scrapings revealed Gram stain positivity in 12 cases (85.7%) and modified Ziehl-Neelsen stain positivity in 9 (64.3%). Histopathology revealed spores in all specimens, while sequencing of small subunit rRNA-based PCR products identified Vittaforma corneae in 82% of patients. EM demonstrated various forms of microsporidial sporoplasm in corneal keratocytes. All patients were treated with topical antimicrobial agents or combined with oral antiparasitic medications for >3 weeks. As all patients were refractory to medical therapy, they ultimately underwent surgical intervention (TLK in 7, PK in 6 and 1 received TLK first, followed by PK). Postoperatively, the infection was resolved in 78.6% of the patients. Nevertheless, a high recurrence rate (21.4%) was noted during 3-year follow-up, with only two patients retained a final visual acuity ≥20/100.

CONCLUSION

MSK usually presents with a non-specific corneal infiltration refractory to antimicrobial therapy. The diagnosis relies on light microscopic examinations on corneal scrapings and histopathological analyses. Surgical intervention is warranted by limiting the infection; however, it was associated with an overall poor outcome.

Postoperative Mycobacteroides abscessus subsp. abscessus endophthalmitis: Clinical analysis of 12 clustered adults and a proposed therapeutic algorithm

PURPOSE

Postoperative endophthalmitis caused by nontuberculous mycobacterium is a rare but devastating complication after intraocular surgery. However, optimal treatment strategies remain undetermined in view of its rarity.

METHODS

We investigated the cases of culture-proven postoperative Mycobacteroides abscessus subsp. abscessus endophthalmitis in southern Taiwan, focusing on clinical manifestations and microbiological study, and aimed to describe clinical staging and to propose a therapeutic modality for this disease.

RESULTS

Twelve cases, including two published cases, were treated in two medical centers in southern Taiwan between Aug. 2011 and Dec. 2016, and all ever received cataract surgery at one clinic. Their disease courses could be categorized into four distinct stages, i.e., the initial, quiescent, recurrent, and end stage, and some cases experienced 1-4 cycles of quiescent-recurrent stages. Although all eyes ended up with phthisis or were eviscerated, the affected eyes receiving pars plana vitrectomy (PPV) tended to become quiescent and survived longer than those without PPV (adjusted hazard ratio: 13.9, p < 0.05). Eight isolates of eight patients were available for microbiological study. All isolates were susceptible to amikacin, and inducible clarithromycin resistance was observed in 100% of isolates.

CONCLUSION

Despite the preservation of vision in postoperative M.abscessus endophthalmitis remained a challenge, a stage-based approach is proposed, which may facilitate decision-makings for the future study.

Effect of ethanol pretreatment in Acanthamoeba keratitis: a long-term follow-up study

Purpose

The aim of this study was to evaluate the long-term outcomes of ethanol pretreatment in Acanthamoeba keratitis (AK).

Patients and methods

This single-center, retrospective, interventional study included 22 patients (24 eyes) who developed AK and underwent ethanol pretreatment between 2009 and 2015. Samples for smears, polymerase chain reaction, and culture for evidence of Acanthamoeba were collected. After ethanol pretreatment, the patients were treated with corneal epithelial debridement, topical 0.02% polyhexamethylene biguanide, and 0.1% propamidine isethionate. The primary outcomes were a clinically stable ocular surface, complete recovery from corneal infection, and acceptable corneal haze. The secondary outcome measure was improvement in best-corrected visual acuity. Complications and predictors of the visual outcome were also recorded.

Results

Ethanol pretreatment was successful in 20 (83.3%) of the 24 eyes, and no further optical keratoplasty was required. Four eyes required rescue therapeutic keratoplasty because of rapid progression of AK. Patients in whom ethanol pretreatment was successful achieved good final visual outcomes regardless of sex, age, or causative Acanthamoeba species. Patients with worse initial best-corrected visual acuity and rigid gas permeable lens-related AK had better improvement in vision.

Conclusion

Ethanol as a pretreatment for AK is safe and effective. Combined with corneal epithelial debridement, ethanol pretreatment may preclude the need for optical and therapeutic keratoplasty. This technique is suitable for all stages of AK presenting within 3 weeks of symptom onset and achieves favorable results especially in early AK.

Orbital complications of paranasal sinusitis in Taiwan, 1988 through 2015: Acute ophthalmological manifestations, diagnosis, and management

Purpose

Paranasal sinusitis is widespread and can lead to orbital complications, blindness, and death. However, the correlation between ophthalmological findings and disease staging remains unclear. This study aimed to investigate the staging, acute ophthalmological manifestations, diagnosis, management, and outcomes of orbital complications of paranasal sinusitis during a 27-year period.

Methods

We retrospectively reviewed the medical records of all patients with orbital complications of paranasal sinusitis hospitalized at the National Cheng Kung University Hospital, a medical center in Taiwan during 1988–2015. Sex, age, symptoms, history, ophthalmological findings, laboratory and imaging findings, treatments, and outcomes were analyzed by staging.

Results

Eighty-three patients aged 9 days to 80 years had stage I (preseptal cellulitis, n = 39 patients), II (postseptal orbital cellulitis, n = 8), III (subperiosteal abscess, n = 16), IV (orbital abscess, n = 8), or V (intracranial involvement, n = 12) complications. Peak incidences occurred in patients aged 0–19 and 60–69 years. Chronic sinusitis and diabetes mellitus were common preexisting diseases. Extraocular movement limitation and proptosis predicted postseptal (stage II or more) involvement. The likelihood of elevated intraocular pressure increased with stage. Reduced visual acuity and presence of relative afferent pupillary defect indicated consideration of magnetic resonance imaging to investigate possible intracranial extension. Ipsilateral maxillary (81.7%) and ethmoidal (75.6%) sinuses were the most common sources of infection, and the most frequently implicated pathogens were coagulase-negative Staphylococcus spp. (25.3%) and Staphylococcus aureus (20.5%). All patients received intravenous antimicrobial therapy (multi-drug therapy in 88.0%), and 55.4% underwent surgery, most commonly endoscopic sinus surgery. One (1.2%) diabetic man with stage V complications died of fungal sinusitis with intracranial invasion. Five (6.0%) patients, all stage V, lost vision despite intensive treatment. The average length of hospital stay was 13.8 days (range 2–72 days), and significantly longer stays were associated with stages II–V as compared to stage I.

Conclusions

Orbital infection originating from paranasal sinusitis can cause vision loss and death due to intracranial extension. Acute ophthalmological findings predict staging and prognosis. Cooperative consultation between ophthalmologists, otorhinolaryngologists, and neurologists is essential. Urgent diagnostic studies and aggressive antimicrobial therapy are indicated, and surgery should be considered.

A comparative, retrospective, observational study of the clinical and microbiological profiles of post-penetrating keratoplasty keratitis

Infectious keratitis after penetrating keratoplasty (PK) is a devastating condition that may result in graft failure and poor visual outcome. In this study, we retrospectively reviewed the medical records of patients who underwent PK between 2009 and 2014, and recorded those who developed infectious keratitis. We compared the predisposing factors and organisms isolated to those identified in our previous study, conducted between 1989 and 1994. The incidence of post-PK infectious keratitis decreased from 11.6% (41 out of 354 cases, 1989–1994) to 6.5% (9 out of 138 cases, 2009–2014). Graft epithelial defect and suture-related problems remained the leading two risk factors of infectious keratitis after PK. Gram-positive and Gram-negative bacterial infection decreased from 58.5% and 46.3% to 11.1% and 22.2%, respectively (P = 0.023 and P = 0.271). In contrast, fungus infection increased from 9.8% to 66.7% (P = 0.001); fungi have become the major pathogen for post-PK infectious keratitis. In conclusion, while the incidence of post-PK infectious keratitis has decreased over time, the number and frequency of fungal infections have significantly increased in the recent study period. Clinicians should be aware of the shifting trend in pathogens involved in post-PK infectious keratitis.

Risk of Retinal Vein Occlusion Following End-Stage Renal Disease

The aim of the study was to investigate the risk of retinal vein occlusion (RVO) following end-stage renal disease (ESRD). The study was designed as a retrospective, nationwide, matched cohort study. The subjects were ESRD patients identified by the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM), code 585. The study cohort included 92,774 ESRD patients registered between January 2000 and December 2009 at the Taiwan National Health Insurance Research Database. An age- and sex-matched control group comprised 92,774 patients (case:control = 1:1) selected from the Taiwan Longitudinal Health Insurance Database 2000. Information for each patient was collected from the index date until December 2011. The incidence and risk of RVO were compared between the ESRD and control groups. The adjusted hazard ratio (HR) for RVO after adjustment for potential confounders was obtained by Cox proportional hazard regression analysis. Kaplan-Meier analysis was used to calculate the RVO cumulative incidence rate. The main outcome measure was the incidence of RVO following ESRD. In total, 904 ESRD patients (0.97%) and 410 controls (0.44%) had RVO (P < 0.0001) during the follow-up period, leading to a significantly elevated risk of RVO in the ESRD patients compared with controls (incidence rate ratio = 3.05, 95% confidence interval = 2.72-3.43). After adjustment for potential confounders including diabetes mellitus, hypertension, hyperlipidemia, congestive heart failure, and coronary artery disease, ESRD patients were 3.05 times more likely to develop RVO in the full cohort (adjusted hazard ratio = 3.05, 95% confidence interval = 2.64-3.51). In addition, hypertension patients showed high incidence rate of RVO in the ESRD group compared with controls (incidence rate ratio = 1.71, 95% confidence interval = 1.44-2.03) and maintained significant risk of RVO after adjustment for other confounders in the cohort (adjusted hazard ratio = 1.39, 95% confidence interval = 1.20-1.60). ESRD increases the risk of RVO. For ESRD patients, we recommend education regarding RVO in addition to blood pressure control to prevent subsequent RVO.

Risk of Retinal Artery Occlusion in Patients With End-Stage Renal Disease: A Retrospective Large-Scale Cohort Study

There is globally increasing prevalence and incidence in end-stage renal disease (ESRD). These patients are frequently reported to have retinal abnormalities and both diseases share some systemic risk factors. Hence, it is clinically relevant to determine whether ESRD is a predictor of retinal artery occlusion (RAO).To investigate the risk of RAO in ESRD patients.A retrospective, nationwide, matched cohort study. The study included 93,766 ESRD patients recruited between 2000 and 2009 from the Taiwan National Health Insurance Research Database. The same number control group included age- and sex-matched patients without ESRD selected from the Taiwan Longitudinal Health Insurance Database, 2000. Data for each patient were collected from the index date until December 2011.The incidence and risk of RAO were compared between the 2 groups. The hazard ratio (HR) for RAO after adjustment for potential confounders was calculated using Cox proportional hazards regression. Kaplan-Meier analysis was used to calculate the cumulative RAO incidence rate.In total, 237 ESRD patients and 73 controls exhibited RAO during follow-up; thus, the RAO incidence rate in ESRD patients was 4.49 times (95% confidence interval (CI), 3.45-5.83) that in the control patients. After adjustment for potential confounders, including diabetes mellitus, hypertension, hyperlipidemia, congestive heart failure, and coronary artery disease, ESRD patients were 2.78 times (95% CI, 2.02-3.84) more likely to develop RAO in cohort for the total sample. Among patients with hypertension, the RAO incidence rate was significantly higher in the ESRD group, and hypertension significantly increased RAO risk even after adjustment for other confounders in the cohort.ESRD increases the risk of RAO, particularly in ESRD patients with hypertension. Therefore, clinicians should educate ESRD patients about RAO and ensure appropriate blood pressure control.

Occult Descemet's membrane detachment after phacoemulsification surgery mimicking pseudophakic bullous keratopathy

We herein report two cases of occult Descemet's membrane detachment (DMD) after phacoemulsification surgery, which initially presented as persistent corneal edema and had been considered as pseudophakic bullous keratopathy. The patients were thus scheduled to receive corneal transplantation. For Case 1, DMD was incidentally detected by slit-lamp examination 2 months postoperatively, only when part of the cornea became clearer. For Case 2, anterior segment optical coherence tomography demonstrated extensive DMD, which had lasted 5 months after the operation. DMDs in both patients had been successfully attached after descemetopexy. Occult DMD should be suspected in patients with persistent severe corneal edema after phacoemulsification surgery. Corneal transplantation may be avoided by timely diagnosis and treatment of DMD.

Expression of WW domain-containing oxidoreductase WWOX in pterygium

PURPOSE

Pterygium was traditionally regarded as a degenerative disease, but certain characteristics suggest that pterygium is probably premalignant tissue. The human WWOX gene, encoding the WW domain containing oxidoreductase (WWOX, FOR, or WOX1), is a candidate tumor suppressor gene. In this study, we investigated the WWOX gene and protein expression in pterygium.

METHODS

Pterygium tissues were obtained from patients (n=16, primary=8, recurrent=8) who received surgical excisions. Each tissue sample was further divided into head and body regions. The WWOX gene and protein expression were examined with immunohistochemistry, western blot, and quantitative PCR. For comparison, normal superior temporal bulbar conjunctivas were used as controls.

RESULTS

Compared to the controls, upregulation of WWOX and its Tyr33 phosphorylation was observed in the head region of all pterygium specimens. In the head and body of the pterygium specimens, WWOX expression was significantly higher than in the controls. In addition, WWOX expression was stronger in recurrent pterygia than in primary pterygia.

CONCLUSIONS

Increased WWOX expression, especially in the head region, is probably due to the invasiveness of the pterygium. Our results indicate that WWOX may play a role in pterygium progression and recurrence.

Early diagnosis and successful treatment of Cryptococcus albidus keratitis: a case report and literature review

Cryptococcus albidus keratitis is a rare and difficult diagnosed disease. Here we report a case of C albidus keratitis early diagnosed by dot hybridization assay and successfully treated with intrastromal injection of Amphotericin B (AB).A 45-year-old man presented with left red eye for 2 days. The slit lamp examination exhibited deep corneal infiltrations. Smears and cultures were performed but revealed negative findings. Molecular detection of pathogens was performed by dot hybridization assay, and C albidus keratitis was diagnosed. Despite the identification of C albidus, the clinical condition still worsened due to deep corneal infiltration. After performing intrastromal injection of AB, the corneal infiltration gradually improved.C albidus is a rare cause of diseases in humans and should be considered as a potential pathogen of corneal ulcer. The prognosis of C albidus keratitis will improve if the condition is recognized early and treated properly.

Thrombomodulin promotes corneal epithelial wound healing

Purpose

To determine the role of thrombomodulin (TM) in corneal epithelial wound healing, and to investigate whether recombinant TM epidermal growth factor-like domain plus serine/threonine-rich domain (rTMD23) has therapeutic potential in corneal epithelial wound healing.

Methods

TM localization and expression in the murine cornea were examined by immunofluorescence staining. TM expression after injury was also studied. The effect of rTMD23 on corneal wound healing was evaluated by in vitro and in vivo assays.

Results

TM was expressed in the cornea in normal adult mice. TM expression increased in the early phase of wound healing and decreased after wound recovery. In the in vitro study, platelet-derived growth factor-BB (PDGF-BB) induced TM expression in murine corneal epithelial cells by mediating E26 transformation-specific sequence-1 (Ets-1) via the mammalian target of rapamycin (mTOR) signaling pathway. The administration of rTMD23 increased the rate of corneal epithelial wound healing.

Conclusions

TM expression in corneal epithelium was modulated during the corneal wound healing process, and may be regulated by PDGF-BB. In addition, rTMD23 has therapeutic potential in corneal injury.

Cumulative risk assessment for plasticizer-contaminated food using the hazard index approach

Phthalates strongly and adversely affect reproduction, development and liver function. We did a cumulative risk assessment for simultaneous exposure to nine phthalates using the hazard index (HI) and the levels of nine phthalates in 1200 foodstuff samples. DEHP (di-2-ethylhexyl phthalate) present the highest level (mean: 0.443 mg/kg) in 1200 samples, and the highest average daily dose (ADD) was found in DEHP, ΣDBP(i + n) (the sum of dibutyl phthalate [DBP] isomers [DnBP + DiBP]) posed the highest risk potential of all the phthalates. In seven phthalates, the 95th percentiles of the ADDs for ΣDBP(i + n) in 0-6-yr-old children accounted for 91% (79-107%) of the tolerable daily intake, and the 95th percentiles of the HIs for the anti-androgenic effects of five phthalates in 0-3-yr-old children and 4-6-yr-old girls were >1. We conclude that the health of younger Taiwanese may be adversely affected by overexposure of phthalate-contaminated foods.

Strongyloides stercoralis infection in an intestinal transplant recipient

Strongyloides stercoralis is a helminth in tropical and subtropical areas. It may cause latent infection and progress to Strongyloides hyperinfection syndrome, which is associated with a high mortality rate. Transplant recipients under the treatment of immunosuppressant agents are at risk of severe S. stercoralis infection. According to related literature, most cases of S. stercoralis infection after solid organ transplantation are caused by reactivation of latent infections in the recipients, whereas only a few are acquired from the donors. We report on an intestinal transplant recipient who had S. stercoralis infection diagnosed by a larva of this parasite found in the stool from the ileostomy stoma 1 month after transplantation. The donor was considered the source of the infection because the donor was from an endemic area and had marked eosinophilia, and the recipient had no contact history or clinical manifestations related to the S. stercoralis infection before transplantation. The patient was treated with ivermectin and exhibited no evidence of infection after 7 months.

Acute anterior uveitis and optic neuritis as ocular complications of influenza A infection in an 11-year-old boy

The authors describe an 11-year-old boy developing bilateral acute anterior uveitis, papillitis in one eye, and neuroretinitis in the other eye after an upper respiratory tract infection of influenza A virus, possibly H1N1. Steroid pulse therapy resolved these conditions. The authors recommend alertness for visual blurring and ocular inflammation after influenza A infection.

Pterygium and genetic polymorphisms of the DNA repair enzymes XRCC1, XPA, and XPD

PURPOSE

Pterygium is an ultraviolet (UV) related disease. UV radiation can produce DNA damage, which is repaired by the DNA repair systems. Among the DNA repair systems, the base excision repair (BER) and nucleotide excision repair (NER) systems are the major ones involved in repairing UV-induced DNA damage; X-ray repair cross complementary 1 (XRCC1) and human 8-oxoguanine DNA glycosylase 1 (hOGG1) are two BER genes, and xeroderma pigmentosum group A (XPA) and xeroderma pigmentosum group D (XPD) are two NER genes. Polymorphisms of these genes are associated with the differences in their repair DNA damage capacity, and they modulate the susceptibility to cancer. Because the polymorphism of hOGG1 was reported to be associated with pterygium, it is logical to assume the correlation between XRCC1, XPA, and XPD polymorphisms and pterygium formation.

METHODS

One hundred and twenty-seven pterygium patients and 103 volunteers without pterygium were enrolled in this study. Polymerase chain reaction based analysis was used to resolve the XRCC1 codon 107, 194, 280, and 399; XPA A23G; XPA codon 228; and XPD codon 751 polymorphisms.

RESULTS

There were significant differences in the frequency of genotypes and alleles of XRCC1 codon 194 and 399 polymorphisms between the groups. In codon 194, individuals who carried at least 1 Trp allele had a decreased risk of developing pterygium compared to those who carried the Arg/Arg wild-type genotype (odds ratio [OR]=0.58; 95% CI: 0.34-0.98). In codon 399, individuals who carried at least 1 Gln allele had a threefold increased risk of developing pterygium compared to those who carried the Arg/Arg wild-type genotype (OR=3.06; 95% CI: 1.78-5.26). There were no significant differences in the frequency of the genotypes and alleles of XRCC1 codon 107 and 280, XPA A23G, and XPD codon 751 polymorphisms between the groups. The XPA codon 228 polymorphism was not detected in any of the cases or controls.

CONCLUSION

The XRCC1 codon 194 polymorphism causes a decreased risk of developing pterygium, but the codon 399 polymorphism increases the risk. There is no correlation between pterygium and XRCC1 codon 107 and 280, XPA A23G, and XPD codon 751 polymorphisms.

Major pediatric ocular trauma in Taiwan

PURPOSE

To investigate major pediatric ocular trauma in Taiwan.

METHODS

Retrospective review of medical records of all patients 15 years and younger who were hospitalized with a primary diagnosis of eye injury at National Cheng Kung University Hospital, Taiwan, between June 1988 and May 2006.

RESULTS

There were 156 children (156 eyes) 1.1 to 15.0 years (mean+/-standard deviation, 7.1+/-0.3 years; boy: girl ratio: 2.1:1). Objects most often causing penetrating injury were scissors (13.5%), pencils/pens (12.2%), broken eyeglasses/spectacles (7.7%), and knives (6.4%). Most blunt trauma occurred in traffic accidents (5.8%). Most injuries occurred at home, followed by on the street, at school, and at sports venues. Injuries were classified as open globe (71.2%), adnexal only (18.6%), or closed globe (10.3%), and included corneal laceration (40.4%), lens damage (27.6%), hyphema (25.6%), and eyelid laceration (23.7%). Most surgical procedures were primary repair (88.5%) or removal of a damaged lens (22.4%). Additional surgery was performed in 19.9% of cases. After treatment, 56.4% of eyes had corneal opacity/scar and 7.1% became phthitic; 52.6% had good visual outcome, whereas 23.1% had poor final vision. Compared with visual acuity measured on admission, final visual acuity was improved in 76.1%, unchanged in 19.7%, and worse in 4.3%. Predictors of worse outcome were open-globe injury and larger wound size, posterior segment involvement, and presence of an intraocular foreign body.

CONCLUSIONS

Most of the children hospitalized for major ocular trauma are younger boys with penetrating injuries suffered at home. Most injuries could have been prevented by increased awareness and reduction of risk factors, and the authors urge better public education for improved safety.

Indocyanine green-assisted phacoemulsification in cases of complicated or simple advanced cataracts

BACKGROUND/PURPOSE

During phacoemulsification for advanced cataracts, particularly when complicated by anterior segment abnormalities, capsulorhexis is very difficult and carries a high risk of complications. This study investigated the efficacy and safety of indocyanine green (ICG)-assisted phacoemulsification in complicated or simple advanced cataracts.

METHODS

Thirty-two patients (35 eyes) underwent phacoemulsification for complicated advanced cataracts (group 1) or simple advanced (mature/hypermature) cataracts (group 2). Anterior segment abnormalities (corneal opacity, small pupil, or glaucoma) in group 1 complicated phacoemulsification. In both groups, 0.5% ICG was used for capsulorhexis, and subsequent procedures were performed in the same routine manner.

RESULTS

Group 1 included 15 patients (17 eyes) with a mean age of 60.0 years. Group 2 included 17 patients (18 eyes) with a mean age of 69.4 years (p<0.05). Continuous curvilinear capsulorhexis was completed in all eyes in group 2, but radial tears occurred in four (23.5%) eyes in group 1 (p<0.05). Phacoemulsification was performed uneventfully in all eyes in both groups. Postoperative complications (corneal edema, vitreous prolapse, posterior capsule opacity, elevated intraocular pressure) were seen in five (27.8%) eyes in group 1 and four (23.5%) eyes in group 2 (p>0.05). None of these were attributed to the use of ICG. Visual acuity improved in all eyes in group 2, but in only 11 (64.7%) in group 1 (p<0.01).

CONCLUSION

ICG-assisted phacoemulsification is safe and helpful for complicated or simple advanced cataracts. Differences between the two groups in patient age, intraoperative complications, and visual outcome could be explained by differences in the cause(s) of advanced cataracts.

Vascular endothelial growth factor gene polymorphisms in age-related macular degeneration

PURPOSE

To investigate vascular endothelial growth factor (VEGF) gene polymorphisms in unrelated Taiwan Chinese patients with late age-related macular degeneration (AMD) and controls.

DESIGN

Retrospective case-control study.

METHODS

We enrolled 190 late AMD patients and 180 age-matched and gender-matched controls. Late AMD was classified as either dry (atrophic; grade 4) or wet (neovascular; grade 5) according to the International Age-Related Maculopathy Epidemiologic Study. Genomic deoxyribonucleic acid was prepared from peripheral blood obtained from all subjects. Polymerase chain reactions were used to analyze five candidate single-nucleotide polymorphisms (SNPs) in VEGF gene: +405C/G (rs2010963), -460 T/C (rs833061), +674 C/T (rs1413711), +936C/T (rs3025039), and -2578C/A (rs699947).

RESULTS

Of the 190 late AMD patients, dry AMD was diagnosed in 104 and wet AMD in 86. Among the five candidate SNPs studied, only the +936 C/T was significantly associated with wet AMD (T allele: 30% in wet AMD vs 14% in controls; P = 1.45 x 10(-5); odds ratio, 2.61; 95% confidence interval, 1.68 to 4.07). No single haplotype was significantly associated with either late AMD or controls. Based on genotypes at both VEGF +936 C/T and the complement factor H (CFH) Y402H (rs1061170), the association of VEGF +936 C/T to AMD was significant when analyzed conditional on the presence of the CFH C risk allele and vice versa (P < .0001). The VEGF +936 C/T was in strong linkage disequilibrium with CFH Y402H (D' = 0.99).

CONCLUSIONS

Both VEGF +936 C/T and CFH Y402H polymorphisms are dependently associated with wet AMD in the Taiwan Chinese population.

Pigment epithelium-derived factor gene Met72Thr polymorphism is associated with increased risk of wet age-related macular degeneration

PURPOSE

To investigate the Met72Thr (T/C) polymorphism (rs1136287) of pigment epithelium-derived factor (PEDF) gene exon 3 in unrelated Taiwan Chinese patients with late age-related macular degeneration (AMD) and control subjects without AMD.

DESIGN

Retrospective case-control study.

METHODS

We enrolled 190 unrelated Taiwan Chinese patients with late AMD and 90 age- and gender-matched control subjects. Grading of late AMD was classified based on a standardized set of diagnostic criteria established by the International Age-Related Maculopathy Epidemiologic Study. Late AMD was classified as either atrophic (dry, grade 4) or neovascular (wet, grade 5). Atrophic AMD refers to dry late-stage AMD without neovascularization, and wet AMD refers to neovascular AMD. Genomic deoxyribonucleic acid was prepared from peripheral blood obtained from all AMD patients and control subjects. Polymerase chain reaction analysis was used to analyze this polymorphism.

RESULTS

Of the 190 participants with late AMD, atrophic AMD was diagnosed in 104 patients and wet AMD was diagnosed in 86 patients. The genotype distribution of the Met72Thr (T/C) variant of PEDF was TT (homozygous T), TC (heterozygous), and CC (homozygous C). The T allele was found significantly more frequently in wet AMD patients than in controls (50% vs 31%; P =.0005). The allele frequencies in atrophic AMD (30%) and controls (31%) did not differ significantly (all P = .87). The homozygous T genotype was more prevalent in wet AMD than in controls (26/86 [30%] vs nine/90 [10%]; odds ratio, 3.9; all P = .0015). The homozygous T genotype in atrophic AMD patients (8%) and controls (10%) did not differ significantly (all P = .75).

CONCLUSIONS

Our data suggest that the PEDF Met72Thr T allele may be a risk factor for wet AMD in the Taiwan Chinese population. PEDF may play a role in the pathogenesis of wet AMD.

In vitro benzyl alcohol cytotoxicity: implications for intravitreal use of triamcinolone acetonide

The aim of the study was to investigate the toxicity of benzyl alcohol (BA), the preservative in commercial triamcinolone acetonide (TA) suspensions, on retinal pigment epithelial (RPE) cells. Cultured RPE cells from a human cell line (ARPE-19) and from rabbits were exposed to the balanced salt solution (control) or BA (0.0225, 0.225, 0.9, 3 or 9mg/mL) for 5, 30, 60, or 120min. Morphological changes of RPE cells were evaluated by the trypan blue in situ staining. The proportions of dead cells were quantitatively measured by the trypan blue exclusion assay, and those of functional cells were assessed by a mitochondrial dehydrogenase assay. The mechanism of cytotoxicity was determined by the acridine orange/ethidium bromide staining and DNA laddering technique. Furthermore, ultrastructural changes were observed by transmission electron microscopy. The results showed that RPE cell damage was dose- and time-dependent. BA 0.225mg/mL, the clinically relevant concentration in TA following intravitreal injection, caused ultrastructural damage and impaired human RPE cell function at 2h; but BA 0.0225mg/mL did not. BA 9.0mg/mL, the concentration in commercial TA suspensions, was toxic within 5min on each assay for both human and rabbit RPE cells. The major mechanism of cell death was necrosis. In conclusion, BA in commercial TA suspensions injected intravitreally (0.225-9mg/mL) can damage RPE cells. Our in vitro study on benzyl alcohol cytotoxicity has significant clinical implications for intravitreal use of TA. We suggest that, before a commercial TA solution is used intravitreally, the vehicle should be removed to prevent damaging the RPE layer, particularly during macular hole surgery. Commercial development of a preservative-free TA suspension for intraocular use is urged.

Interleukin gene polymorphisms in age-related macular degeneration

PURPOSE

To investigate polymorphisms in a candidate gene of interleukin (IL) in unrelated Taiwan Chinese patients with late age-related macular degeneration (AMD) and control subjects without AMD.

METHODS

In this retrospective, case-control study, 312 unrelated Taiwan Chinese patients with late AMD and 180 age- and sex-matched control subjects were enrolled. Late AMD was classified as either atrophic (dry) or neovascular (wet) according to the International ARM Epidemiologic Study. Genomic DNA was prepared from peripheral blood obtained from all patients with AMD and control subjects. Polymerase chain reactions were used to analyze 14 single-nucleotide polymorphisms (SNPs) in candidate genes of 5 ILs: IL-1beta(2q14): -511 T/C; IL-6 (7p21): -572 C/G and -596 G/A; IL-8 (4q13-q21): -251 A/T, +781 C/T, +1633 T/C, and +2767 A/T; IL-10 (1q31-q32): -592 A/C, -819 C/T, and -1082 G/A; and IL-18 (11q22.2-q22.3): +105 A/C, -137 C/G, -607 A/C, and -656 T/G.

RESULTS

In the 312 patients with late AMD, dry AMD was diagnosed in 136 and wet AMD in 176. Among the 14 SNPs in the 5 IL genes studied, only the IL-8 +781 C/T SNP was significantly associated with wet AMD (T allele: 46% in wet AMD versus 28% in the control subjects, P = 1.03 x 10(-6), OR = 2.16, 95% CI = 1.58-2.94). The association analysis based on genotypes at both IL-8 +781 C/T and the CFH Y402H demonstrated that the IL-8 +781 C/T to AMD was not significant when analyzed conditional on the presence of the CFH Y402H C risk allele and vice versa. The IL-8 +781 C/T was in low linkage disequilibrium with CFH Y402H (D' = 0.02).

CONCLUSIONS

The data suggest that Taiwan Chinese carriers of the IL-8 +781 T allele, independent of the CFH Y402H polymorphism, are at increased risk of developing wet AMD.

HTRA1 polymorphism in dry and wet age-related macular degeneration

PURPOSE

To investigate HTRA1 polymorphisms in unrelated Taiwan Chinese patients with age-related macular degeneration (AMD) and control subjects without AMD.

METHODS

A total of 95 unrelated Taiwan Chinese patients with AMD and 90 age- and sex-matched control subjects were enrolled in the study. Genomic DNA was prepared from peripheral blood obtained from all patients with AMD and control subjects. Polymerase chain reactions were used to analyze two HTRA1 single-nucleotide polymorphisms (rs11200638 [G/A] and rs10490924 [G/T]).

RESULTS

Of the 95 participants with AMD, dry AMD was diagnosed in 52 patients and wet AMD in 43 patients. Both rs11200638 (G/A) and rs10490924 (G/T) were significantly associated with all AMD (rs11200638: P = 6.7 x 10(-7) for an additive allele-dosage model, OR(het) = 1.97 [0.81, 4.81], OR(hom) = 8.59 [3.28, 22.49], A allele: 73% in all AMD versus 47% in controls; rs10490924: P = 9.2 x 10(-6), OR(het) = 1.86 [0.79, 4.35], OR(hom) = 5.08 [2.21, 11.70], T allele: 73% in all AMD versus 50% in controls). In terms of significance of association, rs11200638 was the most significantly associated variant. Subtype analysis including dry and wet AMD also revealed similar results. Haplotype analysis demonstrated that AT was significantly associated with wet and all AMD (P = 0.011 and 0.004, respectively), whereas GG was significantly associated with the control group when compared with all AMD (P = 0.035).

CONCLUSIONS

The study demonstrated that both single-nucleotide polymorphisms were significantly associated with dry and wet AMD and rs11200638 was the most significantly associated variant in a Taiwan Chinese population.

Pterygium and genetic polymorphism of DNA double strand break repair gene Ku70

PURPOSE

UV irradiation can produce a wide range of DNA damage, which will lead to gene mutation and uncontrolled cell proliferation. Of the many types of DNA damage, DNA double strand breaks (DSBs) are the most serious form, because of the intrinsic difficulty of their repair, inaccurate repair, or a lack of repair of DSBs can lead to mutations and large-scale genomic instability. DSBs are repaired by the DNA double strand break repair system. The DNA double strand break repair system consists of homologous recombination (HR) and nonhomologous end-joining (NHEJ). In humans, NHEJ is the predominant repair system and Ku70 protein plays an initial and important role in the NHEJ system. Genetic polymorphisms in NHEJ genes influence their DNA repair capacity and confer predisposition to UV-induced skin cancer. Because pterygium is an UV-related uncontrolled cell proliferation, it is logical to assume polymorphisms of Ku70 is associated with genetic predisposition to pterygium.

METHODS

One hundred and twenty eight pterygium patients and 114 volunteers without pterygium were enrolled in this study. Polymerase chain reaction based analysis was used to resolve the Ku70 promoter G-57C (rs2267437) and T-991C (rs5751129) polymorphisms.

RESULTS

There were significant differences between pterygium and control groups in the distribution of genotype (p=0.013) and allelic frequency (p=0.005) in the Ku70 promoter T-991C polymorphism. Individuals who carried at least one C allele (T/C and C/C) had a 2.83 fold increased risk of developing pterygium compared to those who carried the T/T wild type genotype (OR=2.83; 95% CI: 1.38-5.82). Moreover, individuals who carried at least one C allele (T/C and C/C) had a higher tendency to develop both sides of pterygium. In the Ku70 promoter C-57G polymorphism, there was no difference between both groups in the distribution of either genotype or allelic frequency.

CONCLUSIONS

The Ku70 promoter T-991C, but not the Ku70 promoter C-57G polymorphism, is correlated with pterygium. The Ku70 promoter T-991C polymorphism might become a potential marker for the prediction of pterygium susceptibility. It also provides a valuable insight into the pathogenesis of pterygium.

Cytotoxicity of triamcinolone acetonide on human retinal pigment epithelial cells

PURPOSE

To investigate the toxic effects of triamcinolone acetonide (TA) suspensions on human retinal pigment epithelial (RPE) cells.

METHODS

Cultured human RPE cells were exposed for up to 2 hours to one of seven solutions: control (balanced salt solution, BSS; Alcon Laboratories, Ft. Worth TX), commercial TA suspension (cTA), cTA from which the vehicle (which contains the preservative benzyl alcohol) had been removed (vehicle-removed TA, -vTA), vehicle of the cTA (V), or a 1:10 dilution (in BSS; Alcon) of cTA, -vTA or V. Solution effects were evaluated by phase-contrast microscopy of cells stained in situ with trypan blue and in vitro by trypan blue exclusion assay. RPE cell function was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The mechanism of TA toxicity was studied by acridine orange-ethidium bromide staining and epifluorescence microscopy, and ultrastructural changes were examined by transmission electron microscopy (TEM).

RESULTS

The effects of vehicle-removed solutions (-vTA and 1:10 -vTA) were similar to those of the control solution. Exposure for 1 hour or longer to a vehicle-containing solution (cTA and V) resulted in similar and significant degrees of cell damage that were dose and time dependent. The major mechanism of cell death was necrosis, and the early ultrastructural change was swelling of organelles in the cytoplasm.

CONCLUSIONS

Preserved commercial TA suspensions damaged human RPE cells, but vehicle-free solutions did not. The authors suggest removing the vehicle as completely as possible from TA solutions before they are administered intravitreally. Furthermore, they recommend that a commercial formulation of preservative-free TA suspension be made available for intraocular use.

Cyclooxygenase 2 expression in pterygium

PURPOSE

Following the recent discovery of an abnormal expression of the p53 gene in the epithelium in pterygium, some researchers felt that pterygium is a tumor rather than a degenerative disease. Ultraviolet (UV) radiation has been reported to be associated with pterygium formation, however the mechanism whereby UV induces uncontrolled proliferation in pterygial cells is unclear. Because cyclooxygenase 2 (COX 2) was reported to exist and play an important role in UV-related cutaneous carcinogenesis, it is logical to suspect that COX 2 existed in pterygium. This study was designed to investigate the expression of COX 2 in pterygium.

METHODS

Immunohistochemical staining using a monoclonal antibody to COX 2 was performed on 90 pterygial specimens, 40 normal conjunctiva, and 5 normal limbus.

RESULTS

In the pterygium group, 75 (83.3%) specimens stained positive for COX 2. The staining was limited to the cytoplasm of the epithelial layer and predominantly over the basal epithelial layer. No substantial staining was visible in the subepithelial fibrovascular layers. All specimens were negative in the normal conjunctiva and limbus group.

CONCLUSIONS

The present study showed COX 2 existed in pterygium. Given the role of COX 2 in cutaneous tumor carcinogenesis, we suggest COX 2 may also play a role in pterygium formation. This study could be used as the basis for future surveys of the causal relationship between COX 2 and pterygium as well as the effect of COX 2 inhibitor in preventing primary or recurrent pterygium.

Erythema multiforme, Stevens-Johnson syndrome, and toxic epidermal necrolysis: acute ocular manifestations, causes, and management

PURPOSE

To study the acute ocular/cutaneous manifestations, causes, and management of the erythema multiforme (EM)/Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) disease spectrum.

METHODS

We retrospectively reviewed the medical records of all EM/SJS/TEN patients hospitalized at National Cheng Kung University Hospital in Taiwan between 1988 and 2004. Demographic data, medical/medication histories, ocular/mucocutaneous manifestations, management, sequelae, and recurrence were analyzed.

RESULTS

A total of 207 patients 2 months to 95 years of age were hospitalized with 213 episodes/attacks of EM/SJS/TEN. Medications were the most common cause of any condition: for SJS, carbamazepine was most common; for EM or TEN, allopurinol was most common. In 128 of the 213 attacks (60.1%; 126 patients), ocular manifestations were documented during hospitalization, occurring more often in those with SJS (81.3%) or TEN (66.7%) compared with those with EM (22.7%; P < 0.01). The most frequent ocular treatments were topical steroids, topical antibiotics, and lubricants. Overall, 24 (18.8%) of 128 acute attacks in 126 patients were followed by ocular sequelae, mostly dry eye. Five (2.4%) of the 207 patients sustained a total of 6 recurrent attacks, in 3 cases because of the same medication.

CONCLUSIONS

Ocular manifestations occur in a high proportion of patients with EM/SJS/TEN. The most frequent causes were carbamazepine and allopurinol. A careful medication history should be obtained from these patients. Ophthalmic consultation, evaluation, and management are mandatory.

Triamcinolone acetonide suspension toxicity to corneal endothelial cells

PURPOSE

To investigate the cytotoxicity of triamcinolone acetonide (TA) suspensions to corneal endothelial cells (CECs).

SETTING

Department of Ophthalmology, Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan.

METHODS

New Zealand white rabbit CECs were exposed for 1 minute to balanced salt solution (BSS); commercial TA suspension (cTA); vehicle-removed TA (-vTA); pure vehicle (V); 1/10 dilutions of cTA, -vTA, or V in BSS; or benzyl alcohol (BA) (cTA preservative) 9 mg/mL. Corneal endothelial cell toxicity was assessed by light microscopy (trypan blue staining) and transmission electron microscopy. The effects of 3-, 10-, or 30-minute exposures to 1/10 cTA, 1/10 -vTA, or V were also investigated.

RESULTS

One-minute exposures to -vTA or 1/10 -vTA did not damage CECs; however, cTA, V, or 1/10 dilutions of cTA or V caused damage and cells exposed to BA showed severe ultrastructural damage/lysis. A 30-minute exposure to 1/10 -vTA did not cause significant cell damage, whereas 3- to 30-minute exposures to 1/10 cTA or V showed significant time-dependent cytotoxicity.

CONCLUSIONS

Commercial TA suspension was cytotoxic to cultured rabbit CECs because of the preservative, BA, in the vehicle. Because 1/10 -vTA appeared to be safe for up to 30 minutes of exposure, use of 1/10 dilutions of vehicle-removed TA is suggested to help surgeons visualize prolapsed vitreous during anterior vitrectomy in complicated cataract surgeries.

Cytotoxicity of Lidocaine or Bupivacaine on Corneal Endothelial Cells in a Rabbit Model

PURPOSE

To investigate the corneal endothelial cytotoxicity of commercial formulations of agents used for intracameral anesthesia in cataract and other ocular surgery.

METHODS

Cultured corneal endothelial cells (CECs) of New Zealand White rabbits were exposed for 1 minute to balanced salt solution (control); Xylocaine (lidocaine) 1% E (with epinephrine), 2% E, 2%, or 4%; or Marcaine (bupivacaine) 0.5% or 0.5% spinal heavy. The degree of cytotoxicity was determined by in vitro staining with trypan blue and light microscopic evaluation of cell morphology. The effect of longer exposure (up to 16 minutes) to lidocaine 1% E was also investigated.

RESULTS

CECs were not significantly damaged by 1-minute exposure to lidocaine 1% E or 2% E; however, significant cytotoxicity was seen after 1-minute exposure to lidocaine 2% or 4% or bupivacaine 0.5% or 0.5% spinal heavy. Exposure to lidocaine 1% E showed a trend toward time-dependent cytotoxicity that reached significance at 16 minutes.

CONCLUSIONS

One-minute exposure to lidocaine 1% E or 2% E appears to be safe for cultured rabbit CECs, although longer exposures could cause time-dependent cytotoxicity, which should be considered in planning cataract or other ocular surgery. Because bupivacaine 0.5% and 0.5% spinal heavy cause cytotoxic effects within the first minute of contact with CECs, they should be used with great caution, if at all, in the anterior chamber of human eyes.

The cleavage plane of corneal epithelial adhesion complex in traumatic recurrent corneal erosion

PURPOSE

To determine the anatomic cleavage plane of the corneal epithelial adhesion complex in eyes with traumatic recurrent corneal erosion (RCE).

METHODS

A loosened sheet of corneal epithelium was obtained from corneal epithelial wounds in eight patients with traumatic RCE, before each patient underwent phototherapeutic keratectomy. Three control groups were employed in the study, including normal corneal epithelial sheets obtained by mechanical separation, normal corneal tissues obtained by partial lamellar keratectomy during pterygial surgery, and corneal tissues from three residual corneoscleral rims of corneas donated for transplantation. Immunofluorescence staining was performed using monoclonal antibodies against integrins beta1 and beta4, laminin 5, and collagen VII to identify abnormalities in specific layers of the adhesion complex.

RESULTS

In both experimental and control specimens, the suprabasal and basal cells stained positive for integrin beta1, and basal cells stained positive for integrin beta4. Similarly, a continuous line along the base of each epithelial sheet and each control specimen stained positive for laminin 5, a major basement membrane component. In contrast, in all controls there was a continuous linear staining pattern along the basement membrane of stain positive for collagen VII, a marker for the presence of fibrils that anchor corneal basement membrane to Bowman's layer, but epithelial sheets from eyes with RCE showed either a discontinuous line stained positive for collagen VII (three out of eight specimens) or no positively stained areas (five out of eight specimens). The results indicated the cleavage plane of RCE was located at collagen VII layer, between basement membrane and Bowman's layer.

CONCLUSIONS

This study identified a defect in collagen fibrils that anchor the corneal epithelium basement membrane to Bowman's layer as the cause of corneal epithelial loss in cases of traumatic RCE. As hemidesmosomes do not seem to be impaired, a treatment specific to restore anchoring fibril function might prove helpful.