Clinical Outcomes of Descemet Membrane Endothelial Keratoplasty Using a Preloaded Imported Graft

Purpose@#Although the popularity of Descemet membrane endothelial keratoplasty (DMEK) is increased, there is still few clinical studies in Korea. In this study, we aimed to report the initial clinical outcomes of DMEK in patients followed up for more than 6 months. @*Methods@#A total of 96 eyes that underwent DMEK by a single surgeon for Fuchs endothelial corneal dystrophy, pseudophakic bullous keratopathy, or other indications were evaluated for best-corrected visual acuity (BCVA), endothelial cell density (ECD), central corneal thickness (CCT), postoperative complications, and graft survival. @*Results@#The postoperative BCVA significantly increased compared to the preoperative BCVA by 59.4% (1.00 ± 0.77 logarithm of the minimum angle of resolution vs. 0.67 ± 0.76 logarithm of the minimum angle of resolution, p < 0.001). The average preoperative ECD was 754 ± 382 cells/mm2, increasing to 1,333 ± 562 cells/mm2 at 3 months (76.8%, p < 0.001), 1,334 ± 632 cells/mm2 at 6 months (76.9%, p < 0.001), 1,121 ± 474 cells/mm2 at 12 months (48.7%, p = 0.024), and 972 ± 458 cells/mm2 at 24 months postoperatively (28.9%, p = 0.445). Compared to 3 months, the ECD declined by 15.9% at 12 months (p = 0.009) and 27.1% at 24 months postoperatively (p = 0.158). The average CCT was 675 ± 113 μm preoperatively, decreasing to 581 ± 102, 574 ± 101, and 594 ± 94 μm at 6, 12, and 24 months after DMEK, respectively (p < 0.001 between all follow-up time points). Allograft rejection was detected in three (3.1%) and 14 eyes (14.6%) underwent retransplantation at an average of 10.1 ± 8.4 months after DMEK. @*Conclusions@#DMEK is promising for maintaining corneal clarity, low postoperative complication rates, and stable graft longevity.

Impact of Lacrimal Gland Extraction on the Contralateral Eye in an Animal Model for Dry Eye Disease

Purpose@#Although there is still no consensus on the best animal model for dry eye disease research, a model based on lacrimal gland extraction (LGE) model is widely used. In this study, we aimed to investigate the histopathological changes taking place on the contralateral eye after unilateral LGE to determine whether it is useful as a control. @*Methods@#Seven-week-old male C57BL/6 mice were divided into naive control, environmental chamber model, and LGE groups. Corneal fluorescein staining was scored to quantify the severity of damage. Morphological changes in the cornea, conjunctiva, and lacrimal gland (LG) were determined by hematoxylin and eosin staining and compared to those on naive control animals. @*Results@#Compared to naive subjects, the unilateral LGE model showed enhanced corneal erosion scores and loss of conjunctival goblet cells, not only on the ipsilateral but also on the contralateral side. These changes in the ocular surface became more pronounced in a time-dependent manner. Furthermore, loss of LG acinar cells and leukocyte infiltration were detected in the contralateral LGs of the LGE model. @*Conclusions@#Considering the changes observed in the ocular surface and LGs, the contralateral side of the LGE model may not offer proper control conditions for the experimental comparison of the effects of dry eye disease in vivo. There may be regulatory feedback or crosstalk system between both eyes activated in response to LGE.

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

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

Medical research as a clinician: hoping for golden era

Despite the successful development of modern medical educational systems within the last century, such systems need improvement in terms of developing better ways to educate medical students as future clinicians while also nurturing them to be good physician scientists. The period from 1964 to 1972 was called the Golden Era of Nobel Laureates in Medicine. Nine laureates, all graduates from American medical schools, came to the United States National Institute of Health (NIH). During the Vietnam War, many medical doctors substituted military service for service in the NIH, became members of the United States National Academy of Sciences, and attained brilliant medical and scientific achievements. There is a crucial lesson to learn from this golden time of the NIH: ambitious young physicians given opportunities to become cutting-edge scientists can make fundamental discoveries. In hopes of encouraging a similar “golden era” for medical research in Korea, I suggest three steps. First, medical schools and the educational system should provide medical students with more opportunities to conduct in-depth medical research in various fields. Second, the Physician Scientist Program should be further expanded to include more medical students and clinical board holders. Better treatments and approaches are essential for gathering both bright candidates and brilliant mentors, who will support each other in making outstanding scientific discoveries. Finally, the flexibility of the medical educational system in terms of medical students and clinical residency needs updating. In conclusion, a national medical educational system that is well balanced can maintain and support both excellent physician scientists and skillful clinicians.

Cataract Surgery Practices in the Republic of Korea: A Survey of the Korean Society of Cataract and Refractive Surgery 2018

PURPOSE: To describe current cataract surgery practice patterns and changing trends among Korean ophthalmologists. METHODS: A survey of members of the Korean Society of Cataract and Refractive Surgery was performed in July 2018. One hundred and two (12.7%) of 801 questionnaires were returned for analysis. The data were analyzed using descriptive statistics and compared with previous surveys. RESULTS: Most of the respondents (75%) had been in practice for 6 or more years and performed an average of 31 cataract surgeries per month. The preferred method for cataract surgery was phacoemulsification (95%); 5% used a femtosecond laser. The use of topical anesthesia markedly increased from 69% (2012) to 80% (2018). The use of optical biometry exceeded that of ultrasound A-scan biometry. A multifocal intraocular lens was used by 76% of the respondents compared with 44% of the respondents in 2012. Topical nonsteroidal anti-inflammatory drugs were used by 70% of the respondents postoperatively. Most (59%) of these anti-inflammatory drugs were prescribed for 4 weeks. CONCLUSIONS: This survey provided a comprehensive update of the present cataract surgery practices in the Republic of Korea. The results emphasized the increasing use of premium intraocular lenses, optical biometry, and topical anesthesia.

Efficacy of Topical Cyclosporine Nanoemulsion 0.05% Compared with Topical Cyclosporine Emulsion 0.05% and Diquafosol 3% in Dry Eye

PURPOSE: To evaluate the efficacy and safety of cyclosporine nanoemulsion 0.05% compared to cyclosporine emulsion 0.05% and diquafosol sodium 3%. METHODS: This was a multicenter, randomized, evaluator-masked, active control, parallel, phase IV study. A total of 227 patients were randomly allocated to instill cyclosporine nanoemulsion 0.05% (CN) twice daily, cyclosporine emulsion 0.05% (CE) twice daily, or diquafosol sodium 3% (DQ) six times daily. Non-inferiority of CN was analyzed by primary endpoint (cornea and conjunctival staining scores at week 12). The secondary endpoints were scores of corneal staining, conjunctival staining, tear break-up time, Schirmer test, and Ocular Surface Disease Index at weeks 4 and 12. RESULTS: Primary endpoints showed statistically significant improvements in all groups. Primary endpoints were −6.60 for the CN group, −5.28 for the CE group, and −6.63 for the DQ group (National Eye Institute scale from 0 to 33), verifying the non-inferiority of CN compared to CE (95% confidence interval, −0.15 to 2.80, Δ>−2.88). In intergroup comparison between CN and CE groups, the CN group had significantly more decreased conjunctival staining score at week 12. Intergroup comparison between CN and DQ groups showed consistent statistically significant improvements in TBUT and Schirmer test in the CN group. In the DQ group, TBUT showed late statistically significant improvement at week 12 and Schirmer test showed relatively short-term statistically significant improvement at week 4. CONCLUSIONS: Cyclosporine nanoemulsion 0.05% was equivalently efficient compared to cyclosporine emulsion 0.05% and diquafosol sodium 3%. In addition, CN showed significant improvements in several parameters for treatment of dry eyes.

Medical research as a clinician: hoping for golden era

Despite the successful development of modern medical educational systems within the last century, such systems need improvement in terms of developing better ways to educate medical students as future clinicians while also nurturing them to be good physician scientists. The period from 1964 to 1972 was called the Golden Era of Nobel Laureates in Medicine. Nine laureates, all graduates from American medical schools, came to the United States National Institute of Health (NIH). During the Vietnam War, many medical doctors substituted military service for service in the NIH, became members of the United States National Academy of Sciences, and attained brilliant medical and scientific achievements. There is a crucial lesson to learn from this golden time of the NIH: ambitious young physicians given opportunities to become cutting-edge scientists can make fundamental discoveries. In hopes of encouraging a similar “golden era” for medical research in Korea, I suggest three steps. First, medical schools and the educational system should provide medical students with more opportunities to conduct in-depth medical research in various fields. Second, the Physician Scientist Program should be further expanded to include more medical students and clinical board holders. Better treatments and approaches are essential for gathering both bright candidates and brilliant mentors, who will support each other in making outstanding scientific discoveries. Finally, the flexibility of the medical educational system in terms of medical students and clinical residency needs updating. In conclusion, a national medical educational system that is well balanced can maintain and support both excellent physician scientists and skillful clinicians.

Comparison of Contact Lens Corrected Quality of Vision and Life of Keratoconus and Myopic Patients

PURPOSE: To compare and analyze changes in vision quality, subjective symptoms, and psycho-social satisfaction in keratoconus and myopic patients following the wearing of contact lenses. METHODS: This study enrolled 25 keratoconus and 25 myopic patients with corrected vision over 0.8 according to the Snellen chart due to treatment with contact lenses. Patients were surveyed prior to the wearing of contact lenses, and again after three months of contact lens usage with a questionnaire about quality of vision and life. The changes in visual function, visual symptoms, and psycho-social well-being before and after contact lens usage were analyzed. RESULTS: The keratoconus patients' overall degree of satisfaction was higher than the overall degree of satisfaction of myopic patients, and the motivation for contact lens usage and purpose of contact lens treatment were different in the two groups. Keratoconus patients experienced greater changes in satisfaction, particularly in satisfaction during night activities, short-distance work, and the reading of fine print. Furthermore, they experienced fewer dry eye symptoms but greater foreign body sensations than patients with myopia following treatment with contact lenses. No statistically significant differences in social role functions existed between the two groups. Keratoconus patients had a lower expectation of visual acuity recovery before treatment with contact lenses (Mann-Whitney U-test, p = 0.049) compared to myopic patients, and more anxiety about vision loss following treatment (Wilcoxon signed-rank test, p = 0.018) compared to their level of anxiety about vision loss before treatment with contact lenses. CONCLUSIONS: Although the same treatment was applied, keratoconus and myopic patients experienced different types of discomfort and areas of improvement in contact lens corrected vision. Therefore, not only corrected vision, but also subsequent improvement and discomfort outcomes should be considered by patients when choosing contact lens treatment. For patients with mild keratoconus, contact lens treatment may be an efficacious first treatment modality.

Patient Awareness of Cataract and Age-related Macular Degeneration among the Korean Elderly: A Population-based Study

PURPOSE: Age-related eye disease is often considered part of natural aging. Lack of awareness of eye conditions can result in missed treatment. We investigated the rates of awareness of cataract and age-related macular degeneration, the most common age-related eye-diseases, and the associated factors among elderly Koreans. METHODS: We identified 7,403 study subjects (≥40 years old) with cataract or age-related macular degeneration based on ophthalmic examination results during the 5th Korean National Health and Nutrition Examination Survey conducted between 2010 and 2012. We assessed whether patients were aware of their eye condition based on a previous diagnosis by a physician. RESULTS: The average awareness rate over the 3-year study period was 23.69% in subjects with cataract and 1.45% in subjects with age-related macular degeneration. Logistic regression analysis showed that patients with cataract were more likely to recognize their condition if they had myopia (odds ratio, 2.08), hyperopia (odds ratio, 1.33), family history of eye disease (odds ratio, 1.44), or a past eye examination (odds ratio, 4.07-29.10). The presence of diabetes mellitus was also a significant predictor of patient awareness of cataract (odds ratio, 1.88). CONCLUSIONS: Poor patient recognition of eye disease among the Korean elderly highlights the seriousness of this potential public health problem in our aging society. Pre-existing eye-related conditions and diabetes were significant predictors of awareness; therefore, patients in frequent contact with their doctors have a greater chance of detecting eye disease.

Comparison of Biometric Measurements and Refractive Results among Low-coherence Reflectometry, Partial Interferometry and Applanation Ultrasonography

PURPOSE: To compare the measurement results and the accuracy of the predicted refractive error after cataract surgery among 3 ocular biometry devices; OA-2000®, IOL Master® and A-scan ultrasound in posterior subscapular cataracts. METHODS: Biometry measurements including axial length, anterior chamber depth and the keratometry of 80 cataractous eyes were measured using ultrasonography, OA-2000® and IOL Master®. To calculate the intraocular lens (IOL) power, the SRK/T formula was used and 3 months after cataract surgery, the refractive outcome was compared to the preoperatively predicted refractive error. RESULTS: The number of eyes measured by the 3 devices (A-scan, IOL Master® and OA-2000®) was 57 (group A) and the number of eyes measured by 2 devices (A-scan and OA-2000®) was 22 (group B). When cataract grading was performed based on the Lens Opacity Classification system III, the severity of posterior subscapular opacity was significantly different between the 2 groups (p = 0.001). Although no difference was observed in the measured biometry values including axial length, anterior chamber depth and keratometry in groups A and B, the predicted refractive error was significantly different in group B; OA-2000® showed a significantly higher accuracy in predicting IOL power than A-scan. CONCLUSIONS: In cataract patients whose posterior subscapular opacity is not severe, the accuracy for predicting refractive error after cataract surgery was not significantly different among the 3 devices included in our study (A-scan, IOL Master® and OA-2000®). However, in patients with severe posterior subscapular opacity, OA-2000®, that provides a Fourier domain light source-calculated predicted refractive error of IOL may be more accurate.

Are Serum Vitamin D Levels Associated With Dry Eye Disease? Results From the Study Group for Environmental Eye Disease / 예방의학회지

OBJECTIVES: Dry eye disease (DED) is an increasingly important public health problem in Korea. Previous studies conducted in Korea have reported inconsistent results regarding the protective effects of vitamin D on DED, and these discrepancies may be related to the relatively simple questionnaire that has been used. Thus, we evaluated the association of serum vitamin D levels with DED using the ocular surface disease index (OSDI). METHODS: The present study evaluated data from participants in the Study Group for Environmental Eye Disease (2014-2015). This group included data from 752 participants, and data from 740 participants (253 men and 487 women) were analyzed in the present study. DED severity was evaluated using the OSDI. RESULTS: Higher serum vitamin D levels were associated with a non-significantly reduced risk of DED in the crude analysis (odds ratio [OR], 0.991; 95% confidence interval [CI], 0.971 to 1.011) and in the adjusted analysis (OR, 0.988; 95% CI, 0.966 to 1.010). In the crude analysis of no/mild DED vs. moderate/severe DED, men exhibited a decreased risk with increasing serum vitamin D levels (OR, 0.999; 95% CI, 0.950 to 1.051), while women exhibited an increased risk (OR, 1.003; 95% CI, 0.979 to 1.027). In these analyses, we found no significant associations. CONCLUSIONS: The findings of the present study support previous reports that serum vitamin D levels are not associated with DED.

Comparison of Ocular Biometry and Refractive Outcomes Using IOL Master 700, IOL Master 500, and Ultrasound

PURPOSE: To compare the new swept-source optical coherence tomography based IOL Master 700 to both the partial coherence interferometry based IOL Master 500 and ultrasound A-scan in terms of the ocular biometry and the prediction of postoperative refractive outcomes. METHODS: A total 67 eyes of 55 patients who received cataract surgery were included in our study. The axial length, anterior chamber depth, and keratometry were measured using IOL Master 700, IOL Master 500, and A-scan. The predictive errors, which are the differences between predictive refraction and post-operative refraction 1 month after surgery, were also compared. RESULTS: Axial length measurements were not successful in 5 eyes measured using IOL Master 700 and in 12 eyes measured using IOL Master 500. The mean absolute postoperative refraction predictive errors were 0.63 ± 0.50 diopters, 0.66 ± 0.51 diopters, and 0.62 ± 0.51 diopters for IOL Master 700, IOL Master 500, and A-scan, respectively, and these values exhibited no statistically significant differences. The mean axial lengths were 24.25 ± 2.41 mm, 24.24 ± 2.40 mm, and 24.22 ± 2.39 mm; the mean anterior chamber depths were 3.09 ± 0.39 mm, 3.17 ± 0.39 mm, and 3.15 ± 0.46 mm; and the mean keratometry values were 44.12 ± 1.82 diopters, 44.57 ± 2.10 diopters, and 43.98 ± 1.84 diopters for the IOL Master 700, IOL Master 500, and A-scan groups, respectively. None of these parameters showed statistically significant differences between the three groups. Regarding pair-wise comparison, there were significant differences between the IOL Master 700 and the other devices. CONCLUSIONS: The ocular biometric measurements measured using IOL Master 700, IOL Master 500, and A-scan showed no significant differences. However, IOL Master 700 demonstrated a superior ability to successfully take biometric measurements compared to IOL Master 500. Therefore, IOL Master 700 is capable of measuring ocular biometry for cataract surgery in clinical practice.

Efficacy of Strip Meniscometry for Dry Eye Syndrome Diagnosis

PURPOSE: To evaluate the efficacy of strip meniscometry test for dye eye syndrome (DES) by measuring the correlation between strip meniscometry and conventional test measurements. METHODS: All subjects were examined using the Schirmer test, tear breakup time (TBUT) and strip meniscometry using SMTube (Echo Electricity Co., Ltd., Fukushima, Japan). Tear meniscus height (TMH), tear meniscus depth (TMD) and tear meniscus area (TMA) were measured using Fourier-domain optical coherence tomography. The DES group (n = 46 eyes) was compared with the normal group (n = 30 eyes) and correlation was assessed using Spearman's correlation coefficient. RESULTS: Strip meniscometry measurement was significantly correlated with Schirmer score (r = 0.6080, p < 0.01), TBUT (r = 0.5980, p < 0.01), TMH (r = 0.6210, p < 0.01), TMD (r = 0.6080, p < 0.01) and TMA (r = 0.6370, p < 0.01). Strip meniscometry was significantly lower in the DES group (4.58 ± 1.94 mm) than the normal group (7.07 ± 2.61 mm, p < 0.05). CONCLUSIONS: Strip meniscometry was significantly correlated with other conventional test measurements for dry eye syndrome. Strip meniscometry is less time consuming and a less invasive method than the Schirmer test. Strip meniscometry could be an efficient tool to evaluate patients with dry eye syndrome in a clinical setting.

The Effect of TNF-α Blocker HL036337 and Its Best Concentration to Inhibit Dry Eye Inflammation

PURPOSE: Dry eye syndrome is commonly thought of as an inflammatory disease, and we have previously presented data showing the effectiveness of topical TNF-α blocker agents for the treatment of this condition. The purpose of this study was to investigate the effectiveness of the TNF-α blocking agent HL036337 compared to cyclosporine A for the treatment of dry eye induced inflammation in order to establish whether HL036337 represents a more effective method for suppressing inflammation. The efficacy of HL036337 and cyclosporine A was determined using an experimental murine dry eye model. METHODS: The TNF-α blocker HL036337 is a modified form of TNF receptor I. Using dry eye induced C57BL/6 mice (n = 45), corneal erosion was measured at day 4 and 7 after topical treatment with cyclosporine A or HL036337. To determine the effective treatment dose, 0.25, 0.5, 1, 2.5, and 5 mg/mL of HL036337 were topically administered twice per day to dry eye induced murine corneas for 1 week. RESULTS: The optimal concentration of the TNF-α blocker HL036337 for treatment of dry eye induced corneal erosion was determined to be 1 mg/mL. Dry eye induced corneal erosion was improved after 1 week with topically applied cyclosporine A and HL036337 at 1 mg/mL. CONCLUSIONS: HL036337 administered topically at 1 mg/mL effectively improved corneal erosion induced by dry eye. This finding may also suggest that inhibition of TNF-α can improve dry eye syndrome.

The Relationship between Subjective Ocular Discomfort and Blepharitis Severity in Dry Eye Patients

PURPOSE: Although a number of clinical parameters are well known to affect dry eye (DE) disease, it is unknown which factor mostly affects the discomfort of DE. Blepharitis is recognized as one of the leading causes of evaporative-type DE disease, but there have been no large-scale study to investigate the effect of blepharitis on DE symptoms. The purpose of this study was to evaluate the factors influencing subjective ocular discomfort in DE patients with blepharitis and to determine which parameter is most highly related to severity of blepharitis. METHODS: This investigation was a cross-sectional, clinical study. The test population consisted of DE patients suffering from moderate blepharitis. Seventy-three subjects aged 22 to 81 years (mean age 56.36) were enrolled, 49 of whom completed the investigation on a total of 49 eyes. A detailed assessment was conducted, including history taking, visual analog scale (VAS) pain scoring, ocular surface disease index (OSDI) questionnaire, blepharitis severity grading (score 0-4), conjunctival, corneal fluorescein staining (score 0-4), and tear break up time (TBUT) assessment. RESULTS: The results revealed significant correlations between subjective symptoms and blepharitis severity. Significant increases in overall VAS score, OSDI score (p = 0.031, p = 0.006) were recorded in DE patients with severe blepharitis. Conjunctival erosion was significantly related to VAS score (p = 0.016). Other parameters were not significantly related with VAS and OSDI scores. Additionally, conjunctival erosion was related with blepharitis severity (p < 0.0001), and corneal erosion was not correlated with blepharitis severity. TBUT also did not show any statistical correlation with blepharitis. CONCLUSIONS: Our results showed that blepharitis severity is the main factor influencing subjective pain and discomfort in DE patients, although blepharitis severity was not related with the known clinical parameters of DE such as corneal erosion and TBUT. This study indicates that targeting treatment for blepharitis can significantly improve quality of life for patients suffering from DE disease.

A Case of Descemet's Membrane Detachment during Lidocaine Injection for Hordeolum Incision and Drainage

PURPOSE: To report a case of Descemet's membrane detachment and corneal edema caused by an iatrogenic corneal perforation created while performing a local anesthetic (lidocaine) injection into the eyelid for a hordeolum incision and a drainage procedure. The detachment resolved after 14% C₃F₈ gas and air injections into the anterior chamber. CASE SUMMARY: An 8-year-old female visited our clinic after the onset of severe pain and decreased visual acuity while receiving a local anesthetic injection into the upper eyelid in preparation for a hordeolum incision and drainage procedure. Corneal optical coherence tomography (OCT) showed Descemet's membrane detachment. Three days after the first visit, the corneal epithelium had entirely healed. However, Descemet's membrane detachment persisted even after three weeks of follow-up. A corneal OCT was repeated after three weeks and showed a partial Descemet's membrane rupture. A more aggressive treatment method was deemed necessary, and gas and air injections into the anterior chamber were performed. After 48 hours, aside from some Descemet's membrane rolling at the site of rupture, overall reattachment of Descemet's membrane was noted. After three months of follow-up, the patient showed a stable corneal state and normalized vision. CONCLUSIONS: Descemet's membrane detachment and rupture resulting from an iatrogenic corneal perforation during an injection of lidocaine to the eyelid led to decreased visual acuity from corneal edema. As a more aggressive treatment method, 14 % C₃F₈ gas and air injections into the anterior chamber were performed and resulted in near complete reattachment of Descemet's membrane's and normalization of the patient's visual acuity.

Comparison of Ocular Biometry Using Low-Coherence Reflectometry with Other Devices for Intraocular Lens Power Calculation

PURPOSE: To compare axial length (AL) and keratometry (K) using optical low-coherence reflectometry (OLCR, Lenstar LS900(R), Haag-Streit, Bern, Switzerland) with current ocular biometry devices and evaluate the accuracy of intraocular lens (IOL) power calculation. METHODS: In this prospective, comparative observational study of eyes with cataracts, AL and K were measured using an OLCR device (Lenstar LS900(R), Haag-Streit), partial coherence interferometry (PCI, IOL Master(R), Carl Zeiss, Jena, Germany), A-scan (Eyecubed) and automated keratometry (KR-7100, Topcon, Tokyo, Japan). IOL power calculation was performed using the Sanders-Retzlaff-Kraff (SRK/T) formula. The IOL prediction error (PE) was calculated by subtracting the predicted IOL power from the postoperative (PO) IOL power (PO 4 weeks, PO 12 weeks). RESULTS: A total of 50 eyes of 39 patients with cataracts (mean age 67.12 +/- 8.51 years) were evaluated in this study. AL and K were not significantly different between the OLCR device and other devices (analysis of variance [ANOVA], p = 0.946, 0.062, respectively). The mean PE in IOL power calculation was -0.22 +/- 0.50D with the OLCR device, 0.08 +/- 0.45D with the PCI device and -0.01 +/- 0.48D with A-scan and automated keratometry (ANOVA, p = 0.006). The highest percentage of eyes with PE smaller than +/- 0.5D was IOL Master(R) followed by Eyecubed and then Lenstar LS900(R). The mean absolute PE was not statistically significant among the 3 devices (ANOVA, p = 0.684). CONCLUSIONS: Ocular biometry measurements were comparable between the OLCR device and the PCI ultrasound device. However, the IOL power prediction showed significant differences among the 3 devices. Therefore, the differences in application of these devices should be considered.

Comparison of Automatic Pupillometer and Pupil Card for Measuring Pupil Size

PURPOSE: To compare the pupil sizes measured using the automatic pupillometer and pupil card. METHODS: We measured pupil sizes using a pupil card (Rosenbaum Card, J.G. Rosenbaum, Cleveland, OH, USA) and automated pupillometer (VIP(TM)-200, Neuroptics Inc., San Clemente, CA, USA) under different luminous intensities in 60 eyes of 60 patients who visited the ophthalmology clinic during August 2013. RESULTS: Under the photopic condition, pupil sizes measured using automated pupillometer were larger than those measured using the pupil card with statistical significance. The 2 techniques were not different under mesopic and scotopic conditions. Under all light conditions, automated pupillometer showed higher inter-rater reliability. Under the scotopic condition, pupil sizes measured using the pupil card were smaller than pupil sizes measured using the pupillometer according to increased pupil size. CONCLUSIONS: When compared with pupil card, automated pupillometer provided accurate and reliable measurement with small inter-rater variation and was easy and simple to use. However, based on comparable measurements of both techniques under mesopic and scotopic conditions, the pupil card can be used as preoperative evaluation when considering the cost of purchase and maintenance.

Analysis of the Cause of Failure in the Correction of Childhood Myopia Using Orthokeratologic Lenses

PURPOSE: To investigate the cause of failure in the correction of childhood myopia using orthokeratologic (Ortho-K) lenses. METHODS: The failure group was 29 patients who stopped wearing the lenses for various reasons, while the success group was 29 patients who bought lenses more than twiceand wore them for two years and more. Statistical analyses were performed to identify significant differences between the groups. RESULTS: Among the failure group, failure to continuously wear the Ortho-K lenses was attributed to undercorrection (19 patients), corneal erosion (2 patients), and sleep disorders (1 patient). Initial spherical diopter and initial spherical equivalent diopter showed statistical diffence between the success group and failure group. Of these two factors, as the initial spherical equivalent diopter increased, the chance of failure to use Ortho-K lens increased. According to a logistic multiple regression analysis, the odds of failure of using Ortho-K lens increased by 1.59 when the initial spherical diopter increased by 1. If the absolute value of the initial spherical diopter was over 6.24, the chance of failure increased by 80%. CONCLUSIONS: The failure of continuously wearing Ortho-K lenses due to undercorrection was found to be the major cause of failure in the correction of childhood myopia. The initial spherical diopter and initial spherical equivalent diopter were significant factors influencing the undercorrection. From these results, we predict that the odds of failure of continuously wearing Ortho-K lenses increases along with increases in the initial spherical diopter. In conclusion, clinicians should be warned concerning the odds of failure due to low initial spherical diopter.

Surface Ablation with 0.02% Mitomycin C for Retreatment after LASIK and LASEK

PURPOSE: To evaluate the efficacy and safety of surface ablation with mitomycin C (MMC) for the retreatment of refractive errors following laser-assisted in-situ keratomileusis (LASIK) and laser-assisted sub-epithelial keratectomy (LASEK). METHODS: In this retrospective clinical study conducted at a single center, we evaluated 23 eyes that received surface ablation with MMC (0.02%, 20 seconds) between 2009 and 2013 for the treatment of residual refractive errors following myopic LASIK and LASEK. All eyes were evaluated for corneal thickness, initial refractive error, time interval to retreatment, amount of retreatment, duration of postoperative topical steroids use as well as uncorrected vision, spherical equivalent and corneal haziness preoperatively and 1, 3, 6 and 12 months postoperatively. RESULTS: Initially corrected myopia in the LASIK group was -6.47 +/- 2.17 D and -5.68 +/- 2.51 D in the LASEK group. Mean time between initial and retreatment by surface ablation was 11.88 +/- 5.59 months for LASIK and 14.07 +/- 10.10 for LASEK. Retreat amount was 1.49 +/- 0.36 D after LASIK and -1.65 +/- 0.41 D after LASEK. At postoperative 12 months, uncorrected visions were -0.061 +/- 0.886 (log MAR) in the LASIK group and -0.004 +/- 0.745 (log MAR) in the LASEK group and spherical equivalents were -0.55 +/- 0.56 D in the LASIK group and 0.36 +/- 0.33 D in the LASEK group. Postoperative hazes developed in 1 of 8 LASIK eyes and 3 of 15 LASEK eyes which resolved with application of topical steroid for 2-3 months postoperatively. CONCLUSIONS: Surface ablation with 0.02% MMC is safe and highly effective for treating myopic regression following LASIK or LASEK. Application of 0.02% MMC for 20 seconds was effective in preventing postoperative haze formation and maintaining stable vision and spherical equivalent at 12 months after retreatment.