Microbiological Profile and Clinical Characteristics of Bacterial Keratitis with Poor Visual Outcome

Purpose@#To compare clinical characteristics between the poor visual outcome (PVO) and good visual outcome (GVO) groups in culture-proven bacterial keratitis. @*Methods@#A total of 230 cases (44 and 186 eyes in the PVO and GVO groups, respectively) of culture-proven bacterial keratitis, treated between January 2007 and December 2020, were reviewed retrospectively. The PVO group included cases with the final best-corrected visual acuity (BCVA) of less than 0.1 and no improvement compared to the initial BCVA. The remaining cases were included in the GVO group. The microbiological profiles, epidemiology, predisposing factors, and clinical characteristics were compared between the PVO and GVO groups, and the risk factors for PVO were analyzed. @*Results@#Staphylococcus spp. and Pseudomonas spp. were common isolates in both the PVO and GVO groups, with no significant differences in the distribution of isolates. There were no significant differences between the groups in terms of sex, seasonal distribution, corneal trauma, and prior topical steroid use, but contact lens wear was significantly less in the PVO group. Significant risk factors for PVO were age ≥60 years (Z = 4.22, two-proportion Z-test), central corneal lesions (Z = 3.80), epithelial defect size ≥5 mm2 (Z = 3.74), prior ocular surgery (Z = 3.63), hypopyon (Z = 3.42), previous ocular surface disease (Z = 3.32), and diabetes (Z = 3.12). @*Conclusions@#In patients with bacterial keratitis, PVO was associated with older age, severe initial corneal findings, previous ocular disease history, and diabetes, but not with the causative pathogen itself.

Comparative Clinical Analysis of Polymicrobial and Monomicrobial Bacterial Keratitis

Purpose@#We comparatively analyzed the microbiological profiles, predisposing factors, clinical aspects, and treatment outcomes of patients with polymicrobial and monomicrobial bacterial keratitis. @*Methods@#A total of 194 cases of culture-proven bacterial keratitis treated between January 2007 and December 2016 were reviewed. Microbiological profiles, the epidemiology, predisposing factors, clinical characteristics, and treatment outcomes were compared between the polymicrobial group (polymicrobial bacterial keratitis [PBK]; 29 eyes, 62 isolates) and monomicrobial (monomicrobial bacterial keratitis [MBK]; 165 eyes, 165 isolates) group. @*Results@#The most common isolates were Enterobacter (24%) in the PBK group and Staphylococcus (22%) in the MBK group. There were no significant differences between the two groups in previous ocular surface disease, previous ocular surgery, prior topical steroid use, epithelial defect size, and hypopyon. Age ≥60 years (PBK vs. MBK, 31% vs. 51%, p = 0.048), symptom duration (4.7 days vs. 8.0 days, p = 0.009), and contact lens use (34% vs. 18%, p = 0.036) were significantly different between the two groups. Regarding treatment outcomes, epithelial healing time ≥10 days, the final best-corrected visual acuity (BCVA), a need for surgical intervention, and the rate of poor clinical outcome were not significantly different between the two groups. Significant risk factors for a poor clinical outcome in all patients were an initial BCVA <0.1 (Z = 6.33, two-proportion Z-test), an epithelial defect size ≥5 mm2 (Z = 4.56), and previous ocular surface disease (Z = 4.36). @*Conclusions@#Polymicrobial bacterial keratitis, compared to monomicrobial bacterial keratitis, was more significantly associated with younger age, contact lens use, and shorter symptom duration.

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

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

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

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

Clinical Analysis of Candida Species Keratitis: Predisposing Factors, Clinical Characteristics, and Treatment Outcomes

Purpose@#To investigate the epidemiology, predisposing factors, clinical characteristics, and treatment results of Candida species keratitis. @*Methods@#Eighteen eyes of 18 patients who were diagnosed with Candida species keratitis (C. albicans [CA], 9 eyes; non-CA [NCA], 9 eyes) via corneal culture and hospitalized at Yeungnam University Hospital were included. The epidemiology, predisposing factors, initial clinical characteristics, and treatment outcomes were analyzed retrospectively. Treatment success was defined as the successful healing of corneal lesions after medical intervention. @*Results@#The mean age was 67.5 ± 15.4 years and polymicrobial infection was observed in seven eyes (39%). The mean duration of symptoms was 23.9 days. The common predisposing factors were previous ocular surface disease (8 eyes, 44%), corneal trauma (8 eyes, 44%), and previous topical steroid use (7 eyes, 39%). Common initial clinical characteristics were round infiltration (13 eyes, 72%), hypopyon (8 eyes, 44%), and an initial best corrected visual acuity (BCVA) of less than 0.1 (13 eyes, 72%).In terms of treatment outcomes, we recorded a mean corneal epithelial healing time of 23.5 ± 18.9 days, a final BCVA <0.1 in 12 eyes (75%), and treatment success in 6 eyes (35%). Surgical treatments were performed in 11 eyes (61%), five of which experienced evisceration or enucleation. There were no significant differences in clinical characteristics or treatment outcomes between the CA and NCA groups. In the treatment failure group, previous topical steroid use (64% vs. 0%, p = 0.04) was more common and symptom durations were relatively longer than in the treatment success group (31.3 vs. 13.5 days, p = 0.08). @*Conclusions@#Our results showed that Candida keratitis is associated with old age, previous ocular disease, and surgical treatment. Compared with the group in which successful outcomes were achieved, the treatment failure group was associated with previous topical steroid use and longer symptom duration.

Clinical Analysis of Bacterial Keratitis According to Culture Positivity

PURPOSE: The purpose of this study was to evaluate the clinical aspects of inpatients with bacterial keratitis according to culture positivity. METHODS: This was a retrospective review of 98 cases of inpatients with bacterial keratitis who were treated between January 2011 and December 2016 in Yeungnam University Hospital. Epidemiology, predisposing factors, clinical characteristics, and treatment outcomes were compared between culture positive (CP, 39 eyes) and culture negative (CN, 59 eyes) groups. Risk factors for poor clinical outcome were evaluated in the total cohort and analyzed using multivariate logistic regression. RESULTS: Pseudomonas spp. (31%) and Staphylococcus spp. (24%) were common in the CP group. There were no significant differences in previous ocular surface disease, contact lens wear, or hypopyon between the two groups. Epithelial defect size ≥5 mm² (51%:31%, p = 0.04) and initial visual acuity <0.1 (Snellen) (51%:31%, p = 0.04) were significantly higher in the CP group than in the CN group. Epithelial healing time ≥14 days (18%:5%, p = 0.08) and poor clinical outcome (28%:20%, p = 0.37) were more common in the CP group than in the CN group. Risk factors for poor clinical outcome were previous ocular surface disease (odds ratio [OR] = 11.29, 95% confidence interval [CI] = 2.01–63.41, p = 0.006) and previous ocular surgery (OR = 6.98, 95% CI = 1.51–32.20, p = 0.01). CONCLUSIONS: The CP group showed relatively worse initial clinical characteristics than the CN group. Treatment outcomes were slightly worse in the CP group than in the CN group; however, this difference was not statistically significant. Previous ocular surface disease and previous ocular surgery were associated with poor clinical outcome.

Clinical Analysis of Staphylococcus Keratitis According to Coagulase Positivity

PURPOSE: To analyze clinical aspects in a cohort of patients with Staphylococcus keratitis according to coagulase positivity (coagulase negative Staphylococcus [CNS], coagulase positive Staphylococcus [CPS]). METHODS: Epidemiology, predisposing factors, clinical characteristics, treatment outcomes, and antibiotic susceptibility were comparatively analyzed in 138 cases of culture-proven Staphylococcus keratitis (94 eyes with CNS and 44 eyes with CPS) over 20 years (1998–2017) at Yeungnam University Hospital. Poor clinical outcomes were defined as a final corrected visual acuity <0.1, a decreased visual acuity after treatment, complications, or surgical treatment. Risk factors for poor clinical outcomes were evaluated in the total cohort and analyzed using multivariate logistic regression. RESULTS: The most common predisposing factors were corneal trauma in the CNS group (47.9%) and previous ocular surface disease in the CPS group (31.8%). No significant differences were observed in mean age, sex, previous ocular surface disease, epithelial defect size, and hypopyon between the two groups. Methicillin susceptibility (39.4% vs. 72.7%, p < 0.001) was significantly lower in the CNS group, and poor clinical outcomes (28.0% vs. 43.9%, p = 0.076) were more common in the CPS group. The significant risk factors for poor clinical outcomes were initial best-corrected visual acuity <0.1, epithelial defect size ≥ 5 mm², symptom duration ≥10 days, and hypopyon. CONCLUSIONS: No significant differences were observed in epidemiological factors and initial clinical characteristics between the two study groups, but predisposing factors and methicillin susceptibility differed between the two groups. Treatment outcomes were relatively worse in the CPS group than in the CNS group, but the difference was not statistically significant. Poor clinical outcomes were more associated with long symptom duration and poor initial clinical characteristics than with coagulase positivity.

A Case of Isolated Conjunctival Lymphangioma Mimicking a Recurrent Conjunctival Cyst

PURPOSE: To report a case of isolated conjunctival lymphangioma mimicking a recurrent conjunctival cyst. CASE SUMMARY: A 39-year-old male with a conjunctival cyst in the right eye lasted for 1 month visited our hospital. He had previously undergone aspiration of the cyst at another hospital 1 week before visiting our hospital. However, the cyst recurred, and he was referred to our hospital. On slit lamp biomicroscopy, yellow-colored turbid fluid and a hemorrhage were observed in the conjunctival cyst, but no specific finding was found in the fundus photography. The patient was initially treated with topical antibiotics and steroids. Three weeks later, absorption of the hemorrhage was noted, but there was no change in the size of the cyst. Therefore, surgical removal and histological examination of the cyst were performed. The histological examination revealed that the lesion was positive for CD 31 and D2-40, and the cyst was diagnosed as a cystic conjunctival lymphangioma. Thereafter, brain magnetic resonance imaging was performed to screen for orbital lymphangioma and systemic disease that could accompany a conjunctival lymphangioma. However, no specific findings were observed. There was no recurrence of the conjunctival cyst at 1 year and 6 months after surgical removal, and no other ophthalmic or systemic complication was observed. CONCLUSIONS: An isolated conjunctival lymphangioma is a rare lesion. In the diagnosis of lymphangioma, systemic examination is recommended for the identification of comorbid diseases, such as orbital lymphangioma.

Clinical Analysis of Staphylococcus aureus Keratitis according to Methicillin-resistance

PURPOSE: This study analyzed clinical characteristics of Staphylococcus aureus keratitis according to methicillin-resistance. METHODS: The authors performed a retrospective chart review of 46 isolates in 46 eyes with Staphylococcus aureus keratitis that were followed up for more than 2 months between January 1998 and December 2014. Comparative analyses of the epidemiology, predisposing factors, initial clinical manifestations, antibiotics susceptibility and clinical outcome between methicillin-resistant Staphylococcus aureus (MRSA) keratitis and methicillin-sensitive Staphylococcus aureus (MSSA) keratitis were performed. Risk factors of poor visual outcome were analyzed using logistic regression analysis. RESULTS: Among 46 eyes, MRSA was present in 15 eyes (33%) and MSSA in 31 eyes (67%). Male (61%) and older than 60 year-old group (48%) were common. Ocular surface disease/ocular surgery history and trauma were more common as a predisposing factor. Vancomycin was 100% sensitive to both the MRSA and MSSA groups. Antibiotics susceptibility to MRSA was significantly low in the oxacillin (0%), gentamicin (13.3%) and trimethoprim/sulfamethoxazole (53.3%) groups. Sensitivity to fluoroquinolone was 81.3% (MRSA 64.3% vs. MSSA 94.4%; p = 0.064). There were no differences in early corneal findings between the groups. The ratio of BCVA 0.5 or more was 24.4% initially and increased to 44.4% after treatment among all eyes (p = 0.046). Risk factors for poor visual outcomes included a BCVA less than 0.1 at initial evaluation (p = 0.033). CONCLUSIONS: Among eyes with Staphylococcus aureus keratitis, 33% were MRSA. The ratio of BCVA 0.5 or more increased after treatment among all eyes. There were no differences between MRSA and MSSA eyes in terms of epidemiology, predisposing factors, initial clinical manifestations or clinical outcome, except for antibiotic susceptibility. For positive patient outcomes, a treatment approach considering methicillin-resistance as well as various factors affecting clinical course is recommended.

Reliability of a New Non-invasive Tear Film Break-up Time Measurement Using a Keratograph

PURPOSE: To evaluate the repeatability of non-invasive tear film break-up time and identify its relationships with dry eye parameters. METHODS: A total of 100 participants (50 with dry eye, and 50 in the control group) were enrolled prospectively. Non-invasive keratograph first (NIKf-BUT) and average (NIKav-BUT) break-up times were evaluated 2 times using Keratograph 4 (Oculus, Wetzler, Germany), and then tear film break-up time with fluorescein (FBUT) was measured. The correlation analyses were performed between non-invasive parameters (NIKf-BUT and NIKav-BUT) and FBUT. Intra-observer agreements of NIKf-BUT and NIKav-BUT were assessed using intraclass correlation coefficients (ICC). The receiver operating characteristic (ROC) curve technique was used to evaluate the non-invasive method in the diagnosis of dry eye. RESULTS: The correlation analyses revealed positive correlation between NIKav-BUT and FBUT in both groups (dry eye; r = 0.66, p < 0.001 and control group; r = 0.77, p < 0.001). The ICCs of NIKf-BUT and NIKav-BUT were 0.72 and 0.94 in the dry eye, respectively, and 0.70 and 0.91 in the control group. NIKav-BUT was not different from FBUT in either group. The areas under the ROC curves of NIKf-BUT and NIKav-BUT were 0.917 and 0.980, respectively. CONCLUSIONS: The high ICCs verified the repeatability of NIKf-BUT and NIKav-BUT. NIKav-BUT showed no difference from FBUT and positive correlation with FBUT. NIK-BUT showed high diagnostic power and can be considered a new parameter to evaluate dry eye syndrome.

Gram-Negative Bacterial Keratitis: A 15-Year Review of Clinical Aspects

PURPOSE: In this study we investigated pathogenic organisms, antibiotic susceptibility, and clinical characteristics of patients with Gram-negative bacterial keratitis and elucidated risk factors for poor visual outcomes. METHODS: The authors performed a retrospective chart review of 161 eyes (169 isolates) with Gram-negative bacterial keratitis between January 1998 and December 2012 at Yeungnam University Hospital. The study was divided into 5 periods for analysis of the bacteriological profiles and in vitro antibiotic sensitivity. The epidemiological and clinical characteristics were compared according to 3 groups (Pseudomonas species, Enterobacter species, and Serratia marcescens). Additionally, logistic regression analysis was performed to determine the risk factors. RESULTS: The prevalence of Gram-negative organisms increased from 34.7 to 73.2% between the 1st and 5th periods (p < 0.001). Pseudomonas spp. was the most commonly isolated organism (55 eyes, 32.5%) over the total period, followed by Enterobacter spp. (41 eyes, 24.3%) and Serratia marcescens (33 eyes, 19.5%). The effective antibiotics against Gram-negative bacterial pathogens isolated from culture were cefepime (94.5%), levofloxacin (93.4%), ciprofloxacin (93.0%), and amikacin (92.3%). The incidence was higher in the elderly over 60 years of age and in early adulthood patients in their 20s and 30s. The frequent predisposing factors were contact lens wearing and corneal trauma. S. marcescens had the shortest corneal epithelium healing time (p = 0.012) and the most favorable visual outcome after treatment (p = 0.004) compared with the other species. Risk factors for poor visual outcomes included a best corrected visual acuity less than 0.1 at initial evaluation (p < 0.001) and central corneal lesion (p = 0.027). CONCLUSIONS: Gram-negative bacterial keratitis tended to increase and Pseudomonas spp. was the most common isolate. The clinical prognosis was most favorable in S. marcescens. Early diagnosis of Gram-negative bacterial keratitis and appropriate antibiotic selection including cefepime, quinolone, or amikacin are recommended.

Clinical and Microbiological Analysis of Gram-Positive Bacterial Keratitis, a 15-Year Review

PURPOSE: To investigate the shifting trends of pathogenic organisms, antibiotic resistance, and clinical characteristics of patients with Gram-positive bacterial keratitis and to elucidate the prognostic factors. METHODS: We performed a retrospective chart review of 152 isolates in 146 eyes with Gram-positive bacterial keratitis between January 1998 and December 2012. The study was divided into 5 periods for analysis of the bacteriological profiles and in vitro antibiotic resistance. The epidemiological and clinical characteristics were compared according to bacterial isolates. Logistic regression analysis was performed to determine the risk factors. RESULTS: Gram-positive bacterial keratitis tended to decrease and significant change in the distribution of isolates was not observed. Commonly isolated organisms were S. epidermidis (48.7%), S. aureus (25.0%), and S. pneumoniae (7.2%) in order of frequency. The resistance to fluoroquinolone tended to increase (p = 0.104) and resistance to gentamicin was significantly decreased (p = 0.01). S. epidermidis had the shortest corneal epithelium healing time (p = 0.035) and the most favorable visual outcome after treatment (p = 0.035) compared with the other species. Risk factors for poor visual outcomes included a best corrected visual acuity less than 0.1 at initial evaluation and an epithelial healing time greater than 10 days. CONCLUSIONS: Gram-positive bacterial keratitis tended to decrease and S. epidermidis was the most common isolate. The clinical prognosis was most favorable in S. epidermidis. The BCVA less than 0.1 at initial evaluation was an important risk factor for poor visual outcome and surgical treatment in Gram-positive bacterial keratitis.

Analysis of Inpatients with Contact Lens Related Bacterial Keratitis: Causative Microorganisms, Clinical Aspects, and Prognostic Factors

PURPOSE: To investigate causative microorganisms, clinical characteristics, and prognostic factors for inpatients with contact lens related bacterial keratitis. METHODS: Seventy-three eyes of inpatients with contact lens related bacterial keratitis and hospitalized at Yeungnam University Hospital between January 1998 and December 2011 were reviewed retrospectively. Their bacteriological profiles and clinical characteristics were evaluated. RESULTS: Females in their 20s (35/73 eyes, 47.9%) were the most common gender and age group. Thirty eyes (30/45 eyes, 66.7%) used daily-wear soft contact lenses. The most common predisposing factor was sleeping while wearing contact lenses (30 eyes, 41.1%). Positive culture rate was 53.4%. The ratio of gram-positive and -negative bacteria was 8.3%: 91.6%. The most commonly-isolated microorganisms were Pseudomonas spp. (39.6%), followed by Serratia spp. (29.2%). The characteristics of the corneal lesions were: a central lesion in 49 eyes (67.1%), a lesion less than 5 mm2 in size in 54 eyes (74.0%), and hypopyon in 8 eyes (11.0%). The mean log MAR BCVA improved from 0.93 +/- 0.88 on the initial visit to 0.25 +/- 0.48 on the final visit. Twelve eyes (16.4%) had a BCVA of 0.3 or less after remission medical treatment. A BCVA less than 0.1 on the initial visit was a significant risk factor for poor visual outcome (p = 0.005) after remission medical treatment. CONCLUSIONS: BCVA less than 0.1 on the initial visit, epithelial defect sized over 5 mm2, epithelial healing time over 10 days, and central corneal lesion were associated with poor visual outcome after remission medical treatment in contact lens related bacterial keratitis.

Effects of Temporary Amniotic Membrane Patch after Surgical Excision of Primary Pterygium

PURPOSE: To investigate the clinical results, recurrence rates, and recurrence-related risk factors of temporary amniotic membrane patch (TAMP) after excision of primary pterygium. METHODS: Recurrence grade was evaluated for 73 eyes with a mean follow-up of 15.5 months (range 9 to 56 months). Surgical results were classified into surgical success (G0/G1), conjunctival recurrence (G2), and corneal recurrence (G3). Recurrence rates were analyzed based on gender, age, Tan's preoperative grading system, horizontal and vertical length of the preoperative pterygium, the corneal involvement size of the preoperative pterygium, planned or unplanned removal of amniotic membrane, and epithelial healing time. Using Kaplan-Meier survival analysis, the cumulative proportion of integrated G0/G1 was evaluated. RESULTS: In the postoperative grading, 58 (79.5%) and 9 (12.3%) eyes were graded as clinically recurrence-free G0 and G1, respectively; 4 (5.5%) and 2 (2.7%) eyes were graded as clinically recurrence-occurred G2 and G3, respectively. The cumulative proportion of integrated recurrence-free G0/G1 at 24 months after surgery was 0.83 +/- 0.08. T3 of Tan's preoperative grading system was identified as the only risk factor for recurrence above G1 through multivariate logistic regression analysis (p = 0.02). CONCLUSIONS: The recurrence rate of the present TAMP study showed better results in comparison with 9.1 to 56.1% of recurrence rates in other studies. The TAMP has advantages of surgical procedure with ease, low complications, and low recurrence rates. Therefore, after surgical excision of primary pterygium, the authors concluded the TAMP is highly recommended for good clinical outcomes and low recurrence rates.

Comparison of Permanent Amniotic Membrane Transplantation and Temporary Amniotic Membrane Patch after Primary Pterygium Excision

PURPOSE: To compare the clinical results, recurrence rates, and recurrence-related risk factors of permanent amniotic membrane transplantation (PAMT, group 1) and temporary amniotic membrane patch (TAMP, group 2) after excision of primary pterygium. METHODS: Recurrence grades were evaluated for 66 eyes (T1, T2, and T3; 0, 32, and 34 eyes, respectively) in group 1 and 73 eyes (T1, T2, and T3; 2, 42, and 29 eyes, respectively) in group 2. Surgical results were classified into surgical success (G0 or G1), conjunctival recurrence (G2), and corneal recurrence (G3). Recurrence rates were analyzed based on gender, age, Tan's preoperative grading system, horizontal and vertical length of the preoperative pterygium, the corneal involvement size of the preoperative pterygium, and epithelial healing time. RESULTS: In the postoperative grading, 3 eyes (4.5%) and 1 eye (1.5%) in group 1, and 4 eyes (5.5%) and 2 eyes (2.7%) in group 2 were graded as clinically recurrence-occurred G2 and G3, respectively. There was no statistically significant difference in recurrence-occurred G2 and G3 cases between the two groups (p = 0.62). No risk factors of clinically significant G2 and G3 recurrence were identified in either group by Cox proportional hazards survival regression analysis. CONCLUSIONS: The results of the present study suggest that PAMT tends to lower the recurrence rate compared to TAMP because the PAMT group had more T3 eyes than the TAMP group, although the two groups showed no statistically significant difference in clinically significant recurrence after pterygium excision.

Influences of Cylindrical Correction Amount of PRK on Accuracy of Geometric Corneal Center-Adjusted Ablation Centration

PURPOSE: To evaluate the effect of the amount of cylindrical correction on the accuracy of geometric corneal center-adjusted ablation centration selected by the surgeon in advanced surface ablation-photorefractive keratectomy (ASA-PRK). METHODS: Ninety-five myopic eyes of 62 patients who underwent ASA-PRK were divided into three groups based on the amount of myopic cylindrical correction: Group 1 or =-0.50 D and or =-1.00 D, 28 eyes. The distances and distribution of the ablation centers from the entrance pupil center were analyzed by corneal topography at one month after ASA-PRK. Risk factors for decentration (>0.3 mm) were determined from patient-related factors such as gender, age, laterality, central corneal thickness, and order of procedure and surgery-related factors such as amount of spherical correction, ablation depth, vertical scale bar percentage, and learning effect of surgeon. RESULTS: Mean decentration was 0.26 +/- 0.15 mm (0.04 to 0.83 mm). There was no statistically significant difference in the amount of decentration among the three groups (p = 0.879). Superior-nasal displacement (53.7%) of the ablation center most frequently occurred after ASA-PRK. The amount of decentration among the three groups was not dependent on either patient-related or surgery-related factors. CONCLUSIONS: ASA-PRK using the surgeon-selected ablation center with adjustment toward the geometric corneal center was found to be highly accurate in ablation centration and did not influence the amount of ablation decentration regardless of the amount of myopic cylindrical correction.

Analysis of Inpatients with Bacterial Keratitis Over a 12-Year Period: Pathogenic Organisms and Antibiotic Resistance

PURPOSE: To investigate the distribution of bacterial keratitis isolates and the shifting trends of in vitro antibiotic susceptibility of the isolates for inpatients with bacterial keratitis. METHODS: Three hundred ninety-two bacterial isolates with 366 positive culture cases from consecutive corneal scrapes of 988 clinically diagnosed bacterial keratitis inpatients hospitalized at Yeungnam University Hospital between January 1998 and December 2009 were retrospectively reviewed. The bacteriological profiles and in vitro resistance were evaluated in the first and second six-year periods. RESULTS: The percentage of positive cultures was 37.0% (366/988). The commonly isolated Gram-positive and Gram-negative organisms were S. epidermidis (98; 25.0%) and P. aeruginosa (41; 10.5%), respectively. The ratio of Gram-positive to Gram-negative isolates was 1.24:1. The Gram-positive isolates significantly decreased compared to the Gram-negative isolates in the last six-year period (45.3% versus 54.7%, respectively) relative to those in the first six-year period (66.1% versus 33.9%, respectively). S. epidermidis and S. aureus decreased, and E. cloacae, S. marcescens, and S. maltophilia increased in the last six-year period. The resistance of fluoroquinolone to the Gram-positive isolates, though not statistically significant, tended to increase to 34.1% from 21.5% (p=0.061), and the methicillin-resistant S. aureus tended to increase to 54.2% from 30.0% (p=0.055). CONCLUSIONS: S. epidermidis and P. aeruginosa were the most common bacterial keratitis isolates in Gram-positive and Gram-negative isolates. The Gram-positive isolates tended to decrease, though the Gram-negative organisms tended to increase in the last six-year period compared to the first six-year period. Empirical antibiotic selection should be based on local susceptibility patterns and distribution of bacterial isolates.

Analysis on Elderly Inpatients with Infectious Keratitis: Causative Organisms, Clinical Aspects, and Risk Factors

PURPOSE: To investigate the difference of the epidemiological, microbiological, and clinical characteristics and risk factors of inpatients with infectious keratitis between an elderly group (group I > or = 60 years) and a younger group (group II < 60 years). METHODS: A retrospective chart review of 255 eyes (male/female: 158/97 eyes, I/II: 116/139 eyes) with infectious keratitis hospitalized at Yeungnam University Hospital between January 2004 and December 2008 was performed. RESULTS: The proportion of bacterial/fungal/herpes viral keratitis was 42/31/27% in group I and 74/8/17% in group II. The proportion of fungal keratitis in relation to bacterial keratitis was higher in group I, as compared to group II (p < 0.001). The ratio of Gram-positive/negative bacteria was 43/30% in group I and 48/46% in group II. The proportion of Gram-positive bacteria in relation to Gram-negative bacteria was higher in group I, as compared to group II (p = 0.025). The most commonly isolated microorganisms were Staphylococcus epidermidis (I/II: 9/10 eyes) among Gram-positive bacteria, Enterobacter species (I: 6 eyes) and Pseudomonas aeruginosa (II: 9 eyes) among Gram-negative bacteria, and Candida species (I: 6 eyes, II: 2 eyes) among fungi. Clinical aspects and treatment outcomes, such as previous ocular surgery (I/II: 23/9%), hypertension (26/7%), diabetes mellitus (17/7%), presentation at our clinic after 1 week (43/16%), initial visual acuity less than 0.1 (54/32%), hypopyon (28/15%), epithelial healing time (16/10 days), corneal perforation (18/5%), operative treatment (23/7%), and final visual acuity less than 0.1 (36/14%) were statistically significantly poorer in group I, as compared to group II. Risk factors for unimproved visual outcomes included fungal keratitis in group I and previous ocular surgery and ocular surface disease in group II. CONCLUSIONS: Considering that clinical aspects and treatment outcomes are poor in elderly inpatients with infectious keratitis, special efforts are necessary for a more accurate differential diagnosis and appropriate early treatment to achieve successful treatment outcomes.

Effects of Amount of Myopic Correction on Long-term Changes in Higher-order Wavefront Aberrations in ASA-PRK

PURPOSE: To evaluate the effects of the amount of myopic correction on long-term changes in higher-order wavefront aberrations (HOAs) in advanced surface ablation-photorefractive keratectomy (ASA-PRK). METHODS: The 193 eyes of 101 patients who underwent ASA-PRK were divided into two groups according to the amount of myopic correction by the median value (Group 1 -4.37D, 96 eyes, mean -5.77 +/- 1.00D). Wavefront aberrometry was performed to measure total HOA, coma, trefoil, and spherical aberration preoperatively and at 1, 3, 6, 12, and 24 months after ASA-PRK. Statistical analysis was performed to compare changes in all HOAs between the two groups. RESULTS: Each magnitude of total HOA, coma, and spherical aberration except trefoil significantly increased at 1, 3, 6, 12, and 24 months postoperatively in each group (p -4.37D). Increases in ASA-PRK-induced HOAs primarily originated from short-term changes in the postoperative one-month period and did not return to the preoperative level during the postoperative two-year period.

A Case of Amantadine-Induced Corneal Edema

PURPOSE: To report a rare case of corneal edema caused by amantadine. CASE SUMMARY: A 35-year-old man was diagnosed with hypoxic brain damage caused by ventricular fibrillation. The patient showed Parkinsonism and was started on treatment with amantadine. Thirty-seven months after the commencement of amantadine treatment, the patient suffered a corneal ulcer in his right eye, which healed with opacity and thinning after medical treatment. After healing, slit-lamp examination revealed a bilateral, epithelial and stromal edema without obvious guttae and keratic precipitates. The corneal edema did not improve with topical treatment of 5% NaCl and 0.02% fluorometholone in both eyes. Three months after leaving the hospital, the patient's corrected visual acuity decreased to 0.2 (-2.0 Dsph -0.5 Dcyl Ax 90) in the right eye and 0.4 (-0.75 Dsph -2.0 Dcyl Ax 90) in the left eye. Amantadine medication was discontinued after discussion with the patient's neurologist. At the 1-month follow-up, corneal examination revealed resolution of the epithelial and stromal edema in both eyes. Corrected visual acuity was improved to 0.5 (-1.5 Dsph) in the right eye and 0.7 (-1.0 Dsph -1.0 Dcyl Ax 90) in the left eye. CONCLUSIONS: In cases of corneal edema without an obvious causative disease, the patient's systemic medication list must be reviewed and amantadine should be considered as a possible cause.