Effect of Prostaglandin Analogues on Central Corneal Thickness:3-Year Follow-up Results

Purpose@#To evaluate the effects of each subgroup of prostaglandin analogues (PGAs) on central corneal thickness (CCT) in patients with normal tension glaucoma (NTG). @*Methods@#We retrospectively reviewed 55 eyes of 55 patients with NTG who were receiving PGA therapy. Patients who were treated with 0.005% latanoprost (16 eyes), 0.0015% tafluprost (16 eyes), or 0.004% travoprost (23 eyes) monotherapy were included. CCT assessments were performed at baseline and 1, 2, and 3 years after initiation of treatment. @*Results@#In the NTG group, the mean CCT showed a decreasing trend, and there was a significant difference in mean CCT at 1, 2, and 3 years compared with baseline (baseline, 538.16 ± 32.14; 1 year, 526.55 ± 37.30 µm [p = 0.00]; 2 years, 521.67 ± 36.79 µm [p = 0.00]; 3 years, 520.43 ± 36.88 µm [p = 0.00]). The reduction of CCT was confirmed by subgroup analysis. In the 0.005% latanoprost group, mean CCT was decreased at 1 year (p = 0.11), 2 years (p = 0.00), and 3 years (p = 0.02). In the 0.0015% ta-fluprost group and the 0.004% travoprost group, mean CCT was also significantly decreased at all years (p = 0.00). No statisti-cal difference was observed between the NTG subgroups (p = 0.06). @*Conclusions@#Topical therapy with PGAs appeared to cause a significant decrease in CCT reduction in patients with NTG. A long-term follow-up study including more participants is needed.

Retinal Nerve Fiber Layer Thickness Measured by Spectral Domain Optical Coherence Tomography in Healthy Koreans

PURPOSE: To determine normal retinal nerve fiber layer (RNFL) thickness by age and to investigate the relationships of the RNFL with clinical variables using spectral domain optical coherence tomography (SD-OCT) in healthy Koreans. METHODS: The peripapillary RNFL thicknesses were measured around the optic disc using consecutive circular B-scans with 3.5 mm diameter and automatically calculated using a SD-OCT. RESULTS: Three hundreds fifty-two eyes of 205 healthy subjects were included in the study and RNFL thickness were measured by SD-OCT. Overall average RNFL thickness was 100.2 ± 10.9 µm, and significantly and negatively correlated with age (r = −0.164, p = 0.002). The overall average RNFL thickness decrease per decade was 0.8 µm (95% confidence interval, −0.3 to −1.3, p = 0.019). Mean RNFL thickness of each quadrant was significantly correlated with axial length except in the superior quadrant. CONCLUSIONS: This study describes the normal RNFL thickness values of Koreans as determined by SD-OCT. Furthermore, age was found to be correlated with normal RNFL thickness, however age-related changes were not uniform across every region.

Association between 7-year Changes in Intraocular Pressure and Systemic Factors in Koreans: A Longitudinal Study

PURPOSE: To investigate the changes in intraocular pressure (IOP) and associated systemic factors over 7 years in a healthy Korean population. METHODS: This longitudinal study included healthy subjects with no history of ocular disease and who had been receiving health examinations seven years apart at the Konkuk University Medical Center, Healthcare Center. The participants completed lifestyle questionnaires and underwent general health examinations (blood pressure, height and weight, and blood biochemical tests) and ocular examinations including noncontact tonometry and fundus photography. Subjects with abnormal fundus photography findings and ocular hypertension were excluded. Changes in IOP and systemic factors over 7 years were analyzed. RESULTS: Of 524 possible subjects, 469 were enrolled (55 subjects were excluded: 50 due to abnormal fundus photography and 5 for missing data). The left eye was analyzed in all patients. In all subjects, initial IOP (mean 14.50 ± 3.14 mmHg) was not significantly different from final IOP (14.72 ± 3.38 mmHg) (paired t-test, p = 0.074). In male patients, the final IOP was significantly higher than the initial IOP (paired t-test, p = 0.035). Lifestyle questionnaire variables were associated with a final IOP that was significantly higher than the initial IOP (smokers, alcohol drinkers and less exercisers, paired t-test; p = 0.014, 0.010 and 0.024, respectively). A linear mixed-effects model analysis showed that the change in IOP was negatively associated with age, but this was not statistically significant. Changes in systolic blood pressure (SBP), body mass index (BMI), total cholesterol (T.Chol) and low density lipoprotein (LDL) were positively correlated with change in IOP. CONCLUSIONS: A linear mixed-model analysis showed IOP decreased with age but this was not statistically significant. Changes in SBP, BMI, T.Chol and LDL were significantly positively correlated with change in IOP.

24-hour Ambulatory Blood Pressure in Normal Tension Glaucoma: Associations with Retinal Vessel Diameter and Visual Field Defect Progression

PURPOSE: To investigate the correlation between 24-hour ambulatory blood pressure (BP) monitoring and peripapillary retinal vessel width and visual field (VF) defect progression in normal tension glaucoma (NTG) patients. METHODS: All patients were classified by 24-hour ambulatory BP monitoring as non-dipper (nocturnal dip < 10%) and dipper (nocturnal dip ≥ 10%) group. Vessel diameter, mean deviation (MD) value by VF test and VF progression from Glaucoma Progression Analysis (GPA) were compared among non-dipper and dipper groups. RESULTS: Retinal arterial diameter was wider in the non-dipper group compared to the dipper group (p = 0.015), while retinal venous diameter had no significant relationship between the two groups (p = 0.131). The MD value at baseline and 2 years after was worse in the non-dipper group than the dipper group, respectively (p = 0.006, p = 0.030). But, there was no significant relationship between nocturnal dip and GPA progression (p = 0.658). CONCLUSIONS: There was a statistically significant correlation between nocturnal dips and retinal arterial diameter and MD values. These results suggest that non-invasive fundus photography can predict hemodynamic features like nocturnal dip.

Comparison of Risk Factors for Initial Central Scotoma versus Initial Peripheral Scotoma in Normal-tension Glaucoma

PURPOSE: To investigate the risk factors for initial central scotoma (ICS) compared with initial peripheral scotoma (IPS) in normal-tension glaucoma (NTG). METHODS: Fifty-six NTG patients (56 eyes) with an ICS and 103 NTG patients (103 eyes) with an IPS were included. Retrospectively, the differences were assessed between the two groups for baseline characteristics, ocular factors, systemic factors, and lifestyle factors. Also, the mean deviation of visual field was compared between the two groups. RESULTS: Patients from both ICS and IPS groups were of similar age, gender, family history of glaucoma, and follow-up periods. Frequency of disc hemorrhage was significantly higher among patients with ICS than in patients with IPS. Moreover, systemic risk factors such as hypotension, migraine, Raynaud's phenomenon, and snoring were more prevalent in the ICS group than in the IPS group. There were no statistical differences in lifestyle risk factors such as smoking or body mass index. Pattern standard deviation was significantly greater in the ICS group than in the IPS group, but the mean deviation was similar between the two groups. CONCLUSIONS: NTG Patients with ICS and IPS have different profiles of risk factors and clinical characteristics. This suggests that the pattern of initial visual field loss may be useful to identify patients at higher risk of central field loss.

Comparison of Retinal Nerve Fiber Layer Thickness between Stratus and Spectralis OCT

PURPOSE: To compare the peripapillary retinal nerve fiber layer (RNFL) thickness of normal patients and those with various glaucoma diseases by time domain (Stratus) and spectral domain (Spectralis) optical coherence tomography (OCT). METHODS: The RNFL thickness as measured by the Stratus and Spectral OCT was compared (paired t-test). The relationship and agreement of RNFL thickness between the two OCT modalities were evaluated by Pearson correlation, Bland-Altman plot, and area under the receiver operating characteristic curve. RESULTS: Two-hundred seventeen eyes of 217 patients, including twenty-four normal eyes, ninety-one glaucoma suspects, seventy-six normal tension glaucoma cases, and twenty-six primary open angle glaucoma cases (POAG) were analyzed. The peripapillary RNFL thicknesses as measured by Stratus OCT were significantly greater than those measured by Spectralis OCT. However, in quadrant comparisons, the temporal RNFL thickness obtained using Stratus OCT were significantly less than those obtained using Spectralis OCT. Correlations between RNFL parameters were strong (Pearson correlation coefficient for mean RNFL thickness = 0.88); a high degree of correlation was found in the POAG group. Bland-Altman plotting demonstrated that agreement in the temporal quadrant was greater than any other quadrant. CONCLUSIONS: Both OCT systems were highly correlated and demonstrated strong agreement. However, absolute measurements of peripapillary RNFL thickness differed between Stratus OCT and Spectralis OCT. Thus, measurements with these instruments should not be considered interchangeable. The temporal quadrant was the only sector where RNFL thickness as measured by Spectralis OCT was greater than by Stratus OCT; this demonstrated greater agreement than other sectors.

Comparison of Cup-to-disc Ratio Using the Superfield Lens and Optical Coherence Tomography

PURPOSE: The author compared the effect of the cup-to-disc ratio using the Volk Superfield lens and optical coherence tomography (OCT) to evaluate its usefulness in glaucoma diagnosis and follow-up. METHODS: One hundred ninety-seven eyes of 100 patients were enrolled: 34 normal, 75 glaucoma suspected, 43 normal tension glaucoma (NTG), 45 primary open angle glaucoma (POAG). Routine ophthalmic examinations, fundus examinations, and cup-to-disc ratio measurement using the Superfield lens after pupil dilatation, visual field test, OCT optic nerve head analysis, and OCT retinal nerve fiber layer analysis were performed. The author compared cup-to-disc ratio using the Superfield lens and OCT in normal, glaucoma suspected, normal tension glaucoma, and primary open angle glaucoma. RESULTS: Using the Superfield lens, the mean cup-to-disc ratio was 0.36+/-0.07 in normal eyes, 0.61+/-0.12 in suspected glaucoma, 0.75+/-0.11 in NTG, 0.70+/-0.17 in POAG. Using OCT, the mean cup-to-disc ratio was 0.58+/-0.13 in normal eyes, 0.69+/-0.12 in suspected glaucoma, 0.80+/-0.10 in NTG, and 0.76+/-0.15 in POAG. In all groups, cup-to-disc ratio using OCT were greater than using the Superfield lens and were statistically significant. CONCLUSIONS: Considering these differences in the clinical assessment of glaucoma, the combined use of the Superfield lens and OCT would be helpful in its diagnosis and follow-up.

Pulsatile Ocular Blood Flow in Healthy Koreans

PURPOSE: To determine the normal reference range of pulsatile ocular blood flow (POBF) values in healthy Korean subjects and to find out the factors that may affect them. METHODS: A total of 280 eyes of 280 normal subjects were included in this study. Best corrected visual acuity (BCVA), intraocular pressure (IOP), axial length, POBF, systemic blood pressure, and pulse rate were measured. The mean, standard deviation, range, and the 5th and 95th percentiles of POBF were calculated, and the influences of various parameters to POBF were determined by multiple regression analyses. RESULTS: The mean POBF value was 766.0+/-221.6 microliter/min in men and 1021.1+/-249.5 microliter/min in women. The 5th and 95th percentiles for POBF values were 486.0 microliter/min and 1140.0 microliter/min in men and 672.0 microliter/min and 1458.0 microliter/min in women. The POBF values were significantly influenced by gender, mean blood pressure, pulse rate, and axial length. CONCLUSIONS: Even though the POBF values were influenced by gender, BP, and axial length, we could define the normal reference range of POBF in healthy Koreans.

Pin Point Anesthesia with 4% Lidocaine in Cataract Surgery

The increase of preoperative intraocular pressure by anesthetic is a troublesome problem in pin point anesthesia. In order to evaluate the efficacy of 4% lidocaine with less volume in pin point anesthesia 60 cataract surgeries were performed with different anesthetic dosage divided into 3 groups and compared preanesthetic with postanesthetic intraocular pressure and pain score(1; mild, 2; moderate, 3; severe). In the group 1(20 eyes), using 0.3ml of lidocaine, intraocular pressure change from preanesthesia to postanesthesia was 11.83+/-3.44mmHg to 12.19+/-3.27mmHg and there was no statistical significance(p=0.1025). In the group 2(20 eyes), using 0.4ml of lidocaine, intraocular pressure change was 11.53+/-3.22mmHg to 12.33+/-2.91mmHg and was statistically significant(p=0.0028). In the group 3(20 eyes), using 0.5ml of lidocaine, intraocular pressure change was 12.07+/-2.34mmHg to 13.41+/-2.51mmHg and was statistically significant(p=0.0000). Pain score in 3 groups were 1.60+/-0.17, 1.55+/-0.14, 1.35+/-0.11 and there was no statistical difference in 3 groups(p=0.5192). With these results, pin point anesthesia using 0.3ml of 4% lidocaine might be another useful local ocular anesthesia for the routine cataract operation.

Bacterial Culture of conjuncitiva and Aqueous Humor in Cotaract Surgery

Endophthalmitis after cataract surgery causes a profound visual loss. In this study, we performed bacterial cultures from conjuncitival swab atthe beginning of operation and of aqueous humor at the end of operation in 213 uncomplicated cataract surgery to examine the kinds of microorganisms being able to induce an endophthalmitis. Among five positive cultures from conjunctival swabs, Staphylococcus aureus was positive in four cases and Pseudomonas aeruginosa was positive in one case. In bacterial culture of aqueous humor, two microorganisms were observed, in which one case was Staphylococcus epidermidis and the other was Proteus vulgaris. However, ther was no case showing bacterial positive concurrently of conjunctiva and aqueous humor. In addition, there was no case of endophthalmitis. With these results, we could find that various microorganisms existed in conjunctival surface and in aqueous humor. However, itseems to be under the control of self-defense mechanis suppressing an endophthalmitis postoperatively in case of intact posterior capsule. Nevertheless, cataract surgeons should be careful to avoid an endophthalmitis with meticulous aseptic technique forundesirable events.

The Effect of Gentamicin on Calcium Transport in Normal Rabbit Lenses According to the Route of Administration

Endophthalmitis is one of the most catastrophic complications in intraocular surgery and penetrating injuries of the eye and intraocular injection of gentamicin is frequently used for its treatment. But the use of gentamicn resulted in sight-limiting complication such as cataract and the increased calcium level in the lens is an important factor of cataractogenesls. In this experiment, Ca++ - achivated ATPase activity, active Ca++ efflux and calcium concentration in the lens were measured at day 1, day 3 and 7 days after injection of gentamicin into the anterior chamber or vitreous to compare the effect on calcium transport in the rabbit lenses according to the route of administration. Ca++ -activated ATPase activity was progressively inhibited, active efflux of Ca++ was significantly decreased and calcium concentration progressively increased. So, it may be speculated that the decreased active efflux of Ca++ from the lens is related to inhibiting Ca++ -activated ATPase activity and this makes the accumulation of calcium in the lens. These effects were more severe in the intravitreal injection than in the intracameral injection group.

The Effect of Gentamicin on Calcium Transport in Normal Rabbit Lenses According to the Route of Administration

Endophthalmitis is one of the most catastrophic complications in intraocular surgery and penetrating injuries of the eye and intraocular injection of gentamicin is frequently used for its treatment. But the use of gentamicn resulted in sight-limiting complication such as cataract and the increased calcium level in the lens is an important factor of cataractogenesls. In this experiment, Ca++ - achivated ATPase activity, active Ca++ efflux and calcium concentration in the lens were measured at day 1, day 3 and 7 days after injection of gentamicin into the anterior chamber or vitreous to compare the effect on calcium transport in the rabbit lenses according to the route of administration. Ca++ -activated ATPase activity was progressively inhibited, active efflux of Ca++ was significantly decreased and calcium concentration progressively increased. So, it may be speculated that the decreased active efflux of Ca++ from the lens is related to inhibiting Ca++ -activated ATPase activity and this makes the accumulation of calcium in the lens. These effects were more severe in the intravitreal injection than in the intracameral injection group.

A Case of Gonococcal Keratoconjunctivitis in Adult

Ocular infection caused by Neisseria gonorrhea produces purulent conjunctivitis, which may lead to ulcerative keratitis and perforation if not promptly treated Most cases occur in neonates and rarely occur in adults. The author experienced a case of gonococcal keratoconjunctivitis which was confirmed by conjunctival exudate smear, culture and biochemical study.

Refractive state in Adult with Normal Visual Acuity

Visual acuity refers to the spatial limit of visual discrimination. It is surely the single most significant measure of functional integrity of the eye. Normal visual acuity can be represented in hyperopia of less than 2 diopters or astigmatism of less than 1 diopter. The purpose of this study was to observe the prevalence, type and degree of of refractive errors in 338 eyes of 40-69 years of age with normal visual acuity(20/20 or more). The results were as follows: 1. In objective manifest refraction, 246 eyes(72.8%) had refractive error such as hyperopia(110 eyes), simple hyperopic astgmatism(61 eyes),compound hyperopic astigmatism(57 eyes) and simple myopic astigmatism(18 eyes). 2. In subjective manifest refraction, 132 eyes(39.1%) had refractive error such as hyperopia(51 eyes), simple hyperopic astigmatism(44 eyes), simple myopic astigmatism(24 eyes) and compound hyperopic astigmatism(13 eyes). 3. As to the type of astigmatism, 71 of 81 astigmatism were "against the rule" and the rest(10 eyes) "with the rule". Degree of astigmatism was less than 1.00 diopter. 4. A verage degree of refractive errors was 0.43 diopter.

Refractive State in Childhood with Normal Visual Acuity

To manifest visual acuity of 20/20 or better, the requirements are good optical imagery, foveal fixation, intact receptor structure and function, and full integrity of the involved neural pathways. Person with hyperopia of 1-10 diopter or astigmatism of 1 diopter may be able to read the line marked 20/20 of Snellen's chart. Non-cycloplegic and cycloplegic subjective manifest refractions were done on 380 normal eyes with visual acuity of 20/20 or more to observe the prevalence, type and degree of the refractive errors. The results were as follows; 1. In non-cycloplegic subjective manifest refraction, 147 eyes(38.7%) had refractive error such as simple hyperopic astigmatism(50.3%), hyperopia(37.4%), simple myopic astigmatism(6.8%) and compound hyperopic astigmatism(5.4%). In cycloplegic subjective manifest refraction, 183 eyes(48.2%) were ametropia such as simple hyperopic astigmatism (49.7%), hyperopia(38.3%), compound hyperopic astigmatism(8.7%) and simple myopic astigmatism(3.2%). 2. As to the type of astigmatisms, "with the rule" astigmatism was 2.5 times more than "against the rule". 3. Average degree of refractive errors were 0.12 diopter in non-cycloplegic refraction and 0.22 diopter in cycloplegic refraction. 4. The degree of hyperopia was less than 1.00 diopter in all cases of noncycloplegic refractions and in most cases(93%) of cycloplegic refractions. 5. Degree of astigmatism were less than 1.00 diopter in the majority(98%).