Peripheral Anterior Synechiae and Ultrasound Biomicroscopic Parameters in Angle-Closure Glaucoma Suspects

PURPOSE: To investigate the correlation between peripheral anterior synechia (PAS) and the quantitative anterior chamber angle parameters measured by ultrasound microscopy (UBM) in angle-closure glaucoma suspect (ACGS) eyes. METHODS: Eyes were defined ACGS as having occludable angles and intraocular pressure less than 21 mm Hg without glaucomatous optic nerve head. The gonioscopic criteria for ACGS were the trabecular meshwork invisible in 3 or more quadrants of the entire angle and the angular width less than 20 degrees by Shaffer classification. Twenty-seven eyes of 20 patients underwent anterior chamber angle and ciliary body imaging with UBM. Angle opening distance (AOD500), angle recess area (ARA), trabecular-ciliary process distance (TCPD) and trabecular-iris angle (TIA) were measured from the UBM images at each quadrant. RESULTS: The AOD500, ARA, and TIA were not significantly different between the eyes with PAS (9 eyes) and without PAS (18 eyes) at each quadrant. However, the TCPD was significantly shorter in the superior quadrant when compared with the eyes without PAS (mean: 405.3+/-70.9 micrometer vs 536.4+/-140.5 micrometer) (p<0.05). CONCLUSIONS: The results suggest that the shorter distance from trabecular meshwork to ciliary body or the anterior placement of ciliary process may play a role in the development of PAS in ACGS eyes.

Distribution and Characteristics of Peripheral Anterior Synechiae in Primary Angle-Closure Glaucoma

PURPOSE: To evaluate the characteristics of peripheral anterior synechiae (PAS) in primary angle-closure glaucoma (PACG). METHODS: We reviewed the charts of 155 patients (244 eyes) with PACG. We divided these patients into one of four clinical subtypes: acute angle-closure glaucoma (ACG), chronic ACG, angle-closure hypertension, and ACG suspect. The prevalence, extent, and location of PAS were evaluated according to PACG subtypes. Correlation analysis was used to evaluate relationships between the highest IOP level without treatment and the extent of PAS. RESULT: The average degree of angle-closure with PAS was 14.6+/-9.1 in eyes that were classified as ACG suspect, 83.8+/-48.3 in angle-closure hypertension, 140.5+/-31.3 in acute ACG, and 180.3+/-31.9 in chronic ACG (ANOVA test, P<0.05). PAS was most frequently found in the superior part of the eye, especially from 12 to 1 o'clock. The incidence of broad PAS (PAS over 30 degrees in width) was highest in superior part, but the medium and narrow PAS (PAS limited to within 30 degrees in width) was distributed throughout all 12 sectors relatively equally. Prior to a laser iridotomy (LI) and other medical treatments, a positive correlation was found between the highest IOP (intraocular pressure) levels and the extent of PAS in chronic ACG (r=0.423, P<0.0001). However, statistically significant relationships were not found between the highest IOP levels before treatment and the extent of PAS in any of the other clinical subtypes. CONCLUSIONS: Our results suggest that acute and chronic ACG patients are most likely to have a greater extent of PAS than patients in the angle-closure hypertension or ACG suspect subtypes. PAS may be narrower in earlier stages and broader in later stages. PAS was also found most frequently in the superior part of the eye. The extent of synechial closure of the angle may play a role in raising IOP levels in later stages of the disease rather than early on.

Assessment of the Anterior Segment Using Slit-Lamp Biomicroscope and Gonioscope

PURPOSE: To evaluate the accuracy of the Smith method, van Herick technique, and Shaffer grading system, using a slit-lamp biomicroscope and gonioscope that measure anterior chamber depth (ACD), peripheral chamber depth (PCD), and angle width. METHODS: The anterior chamber of 94 eyes of 53 subjects was evaluated by slit-lamp examination with a gonioscope. An A-scan was carried out on all of the subjects, but ultrasound biomicroscope (UBM) was performed on only 42 of 94 eyes. Slit-lamp biomicroscope-assisted measurements, such as ACD, PCD, and angle width, were compared with those by A-scan and UBM. RESULTS: The correlations among ACD measurements, obtained by the Smith method, and those obtained using A-scan (r=0.673, p<0.001) and UBM (r=0.824, p<0.001) were statistically significant. The mean PCD, measured by van Herick technique, was 14.01+/-15.04 %, and its correlation with that of UBM was statistically significant (r=0.706, p<0.001). In addition, the correlation between the mean angle width, measured by Shaffer grading system and by UBM, was also statistically significant (r=0.853, p<0.001). CONCLUSIONS: Assessments of the anterior segment, using a slit-lamp biomicrosope and a gonioscope, are comparable to those of A-scan and UBM measurements and are, therefore, useful for evaluation of the anterior chamber.

Analysis of Clinical Types and Retinal Nerve Fiber Layer According to Optic Disc Appearances

PURPOSE: To evaluate the clinical characteristic of retinal nerve fiber layer (RNFL) and The clinical types of glaucoma according to optic disc appearances. METHODS: Sixty eyes in 60 patients with glaucoma were evaluated retrospectively. Complete ophthalmologic examination, optical coherent tomography (OCT), automated perimetry, stereoscopic optic disc photography and RNFL photography were performed. We classified optic disc pattern into focal, myopic, generalized enlargement, senile sclerotic, and normal appearance types. RESULTS: In 60 eyes with glaucoma, 15 eyes were adult-onset primary open-angle glaucoma (Adult-onset POAG), 22 eyes were normal-tension glaucoma (NTG), 10 eyes were juvenile-onset open-angle glaucoma (JPOAG), and 13 eyes were secondary glaucoma. JPOAG patients were significantly more detected in association with myopic optic disc type (P<0.05). OCT- measured temporal RNFL thickness in focal optic disc pattern were significantly lower than that in myopic optic disc pattern (P<0.05). Age was significantly correlated with temporal RNFL thickness in our study subjects (P<0.036, r=-0.272). CONCLUSIONS: Our study revealed that JPOAG patients may have a relationship with myopic optic disc type. OCT-measured RNFL thickness of glaucoma patients particularly in the temporal quadrant may be related to age.

Comparison of Corneal Thickness Measurements with Noncontact Specular Microscope and Ultrasonic Pachymeter

PURPOSE: To evaluate the corneal thickness values before and after refractive keratoplasty with the Topcon SP-2000 noncontact specular microscope(Topcon American Corp.) and the common standard ultrasonic pachymeter. METHODS: Corneal thickness was measured in 40 eyes of 20 patients, 5 times each before and after keratoplasty, with the Topcon SP-2000P and an ultrasonic pachymeter (DGH 1000, DGH Technology Inc.). The main outcome measures were accuracy and reproducibility as assessed with coefficient of variation (CV) of corneal thickness measurements. RESULTS: The reproducibility of corneal thickness measurements was better with the ultrasonic pachymeter (CV 0.36%) than with the Topcon SP-2000 (CV 1.23%). Mean corneal thickness measured by the Topcon SP-2000P before and after keratoplasty was significantly less than the mean values obtained with the ultrasonic pachymeter (14.4 micro meter; P<.0001, 5.6 micro meter; P<.01; respectively). Compared with theoretical ablated corneal thickness, ablated corneal thickness measured with the Topcon SP-2000P was significantly less (P<.01) than values obtained with the ultrasonic pachymeter (P=0.07) CONCLUSIONS: The noncontact Topcon specular microscope provides measurements of corneal thickness that are significantly less than those of the ultrasonic pachymeter, both before and after keratoplasty. These results indicate that these 2 techniques are not clinically comparable, thereby precluding interchangeable use of their data in planning or assessing keratoplasty.

Accuracy of Corneal Thickness Measurement with Ultrasound Pachymeter in Thin Corneas

PURPOSE: Accurate assessment of corneal thickness is important in order to prevent iatrogenic corneal ectasia after laser in situ keratomileusis (LASIK). More accurate measurement is needed in LASIK enhancement because the cornea becomes thin after previous refractive surgery. We evaluated the reliability of corneal thickness measurement with ultrasound pachymeter (USP) in the thin corneas. METHODS: The corneal thickness was measured in the 22 eyes of 11 rabbits. The corneal flap was made with an Automated Corneal Shaper microkeratome (Bausch and Lomb, USA) with 130 micro meter plate and the flap was removed in order to make the cornea thin. Residual stromal bed (RSB) thickness was measured with USP and thickness gauge, and the two measurements were compared. RESULTS: Mean corneal thickness was 404.69 +/- 11.01 micro meter with USP and 133.23 +/- 15.66 micro meter with thickness gauge. RSB thickness measured with thickness gauge was 269.05 +/- 24.19 micro meter and this was not significantly different from the expected RSB thickness, although RSB thickness measured with USP was 388.14 +/- 10.17 micro meter, which was significantly different from the expected RSB thickness (p=0.00). CONCLUSIONS: In the thin corneas, corneal thickness measurement with ultrasound pachymeter is not reliable.

Clinical Types of Glaucoma and Comparison Between Diffuse and Focal Nerve Fiber Layer Defects

PURPOSE: To evaluate and compare the characteristics of patients whose nerve fiber layer (NFL) photographs showing diffuse or focal nerve fiber layer defects. METHODS: Patients with diffuse NFL defect were selected by comparing upper and lower half of a NFL photo, and we included the patients only when one part of it showed NFL defect. Patients with focal NFL defect were selected only when one eye had a wedge-shape NFL defect. RESULTS: There were no significant differences between the two groups in visual field index, nor in the results of glaucoma hemifield test. However, patients with diffuse NFL defect (13 eyes, 13 patients) mostly had primary open-angle glaucoma (POAG) (62%), and patients with focal NFL defect (13 eyes, 13 patients) mostly had normal- tension glaucoma (NTG) (62%) (p=0.048, chi-square test). CONCLUSIONS: We found significant differences in the diagnosis of glaucoma between the diffuse and focal NFL loss groups. Our results suggest that the characteristics of NFL loss in POAG and NTG may be different.

Effect of Combined Argon Laser Peripheral Iridoplasty and Laser Iridotomy in Primary Angle-Closure Glaucoma

PURPOSE: To assess the effect of argon laser peripheral iridoplasty in patients with primary angle-closure glaucoma. METHODS: Eyes of 63 patients with primary angle-closure glaucoma who needed laser therapy were evaluated. We divided the patients randomly into two groups and studied prospectively. Thirty eyes (30 patients) were treated with both laser iridotomy and argon laser peripheral iridoplasty. Thirty-three eyes (33 patients) were treated with only laser iridotomy. Anti-glaucoma drugs were not used after laser therapy, and intraocualr pressure (IOP) over 21 mmHg during follow-up period were considered as failure. RESULTS: No differences were found between the two groups in age, sex, initial IOP, clinical forms of angle closure, degrees of peripheral antirior synechiae, and follow-up period. Patients treated with argon laser peripheral iridoplasty and laser iridotomy had successfully controlled IOPs (<21 mmHg) than those with only laser iridotomy through 8 months after laser therapy (p<0.05, log-rank test). However, there was no difference in the two groups at the final follow-up months (12 months) (p=0.180, log-rank test). CONCLUSIONS: Argon laser pheripheral iridoplasty decreased IOP in the early post-laser period. However, in the long term follow-up, the effect of argon laser pheripheral iridoplasty did not last when compared with laser iridotomy.

Inhibition of Melanoma Cell Lines Using Antisense Sequence Expressing Adenovirus and Cisplatin

PURPOSE: Telomerase is known to play a role of adding repetitive parts to chromosomal ending and to be involved in carcinogenic process through cell immortalization. The purpose of this study is to evaluate that restraining of telomerase activation can have killing effect on cancer cell and enhance susceptibility of cancer cells to anticancer substance. METHODS: The killing effect on melanoma cells was studied by using recombinant adenovirus that makes it possible to inhibit telomerase from getting activated, with such targets as two types of melanoma cell lines. This recombinant adenovirus was used combined with cisplatin, one of the most representative anticancer medicine to evaluate enhancement in susceptibility of cancer cells to anticancer substance. RESULTS: From the result of cytotoxic assay, it is found that melanoma cells have much resistance to cisplatin on the whole. In the case of using Ad-OA of recombinant virus alone, killing effect on melanoma cells was insignificant. On the other hand, when Ad-OA was used in combination with cisplatin, susceptibility of melanoma cell lines to cisplatin was enhanced. CONCLUSIONS: Ad-OA, recombinant adenovirus, could be used as a supplementary medicine in the targeted cancer gene therapy against cancer cell lines resistant to cisplatin.

A Case of Decompression Retinopathy after Glaucoma Surgery

PURPOSE: Acute decompression of the eye in patients with high intraocular pressure (IOP) can lead to development of posterior pole hemorrhages. The courses of this rare syndrome is relatively benign. Herein we report a case of decompression retinopathy that developed diffuse retinal hemorrhages after glaucoma surgery in both eyes. METHODS: A 17-year-old male patient diagnosed with juvenile primary open angle glaucoma (JPOAG) underwent glaucoma surgery on both eyes at five months interval. Visual acuity on presentation was no light perception (NLP) in the right eye and 1.0 in the left eye. On the first postoperative day, IOP was 4 mmHg and diffuse retinal hemorrhages was found in the posterior pole after nonperforating trabecular surgery and triangular reticulated sodium hyaluronidate (SK GEL 3.5) implantation in the right eye. Trabeculectomy with 0.02% mitomycin C soaking (1 minute) was performed in the left eye 5 month after the right eye operation. On the second postoperative day, IOP was 5 mmHg and diffuse retinal hemorrhages was also observed in the posterior pole of the left eye. During the follow-up period (8 weeks), the retinal hemorrhage was absorbed without impairment of visual acuity. RESULTS: Decompression retinopathy developed in the posterior pole of the patient with JPOAG after glaucoma surgery, and the hemorrhages were absorbed over time with no visual impairment.

Analysis of Early Failure after Trabeculectomy

PURPOSE: Among the patients with increased intraocular pressure (IOP) after primary trabeculectomy, we evaluated the factors which might influence the surgical results in early failure cases. METHOD: We retrospectively reviewed the charts of the patients who had undergone primary trabeculectomies. Surgical failures were defined as the eyes with the increased IOPs (> or =21 mmHg), and early failure cases were defined as the elevated IOP within 2 months after surgeries, and as late failures thereafter. The early failure cases were then divided into the recovery group (IOP was decreased by digital massages or releasable suture removals) and non-recovery group. RESULTS: Thirty-eight cases among 78 eyes experienced elevated IOPs during the mean follow-up period of 25.3 months, and 28 cases had experienced early failures. Among the early failure cases, 12 eyes belonged to the recovery group and 16 eyes to the non-recovery group. Sex, age, preoperative IOP, mitomycin C use, systemic diseases, types of glaucoma, triple surgeries, numbers of preoperative medications, and types of scleral flap were similar between the recovery and non-recovery groups. However, the mean failure time was shorter in the recovery group than in the non-recovery group (0.4 vs 1.0 months; p= 0.0017, t-test). CONCLUSIONS: Our results suggest that there is greater probability in recovery of increased IOP with earlier digital pressures or releasable suture removals for the early postoperative increased IOP than with the managements of the later postoperative increased IOP.

Clinical Outcome of LASIK with Different Flap Thickness

PURPOSE: Since a few cases of keratectasia after LASIK were reported, the importance of residual corneal thickness has been emphasized. This study was to analyze adverse effects which may occur in reducing corneal flap thickness to increase residual corneal thickness. METHODS: A total of 237 eyes of 149 patients who had been followed up for 6 months or more after LASIK were evaluated retrospectively. Intended corneal flap thickness was 130 micrometer in 116 eyes(group A), and 160 micrometer in 121 eyes(group B) using an Automated Corneal Shaper(Chiron, USA). Clinical outcomes were compared between two groups. RESULTS: Except for some cases with retinal complication after surgery, 3 eyes lost best-corrected visual acuity by 2 lines or more in group A and 1 eye in group B, which was not statistically significant.(p>0.05) Fourteen eyes lost 1 line or more best-corrected visual acuity by postoperative irregular astigmatism in group A and 10 eyes in group B, which showed no significant difference, either. The incidence of flap-related complications such as wrinkling and free cap did not differ significantly between two groups(p>0.05). CONCLUSIONS: To leave residual cornea of greater thickness using a 130 micrometer thick flap rather than 160 micrometer may be a useful method to avoid postoperative keratectasia, one of the most severe complications.

Bacterial Adherence to Intraocular Lenses

Bacterial adherence to intraocular lenses (IOLs)could be the cause of the endophthalmitis following cataract surgery and IOL implantation. In this study we investigated bacterial adherences to the four different IOLs. Clinical strains of Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa were used.Polymethylmethacrylate (PMMA), silicone, hydrophilic acrylate (Acrysof)and hydrogel IOLs were used in this study.Four types of lenses were suspended for 60 minutes in suspensions of each strain of bacteria and then these lenses were washed with sterile broth to remove the nonadherent bacteria.The adherent bacteria were removed from the lenses, diluted with sterile broth and inoculated onto the blood and chocolate agar plates.The plates were incubated for 24 hours, and the numbers of colony forming units were counted. The lenses with the adherence of S.aureus in order of decreasing magnitude were: Acrysof>silicone>hydrogel>PMMA; the adherence of S.epider-midis, silicone>Acrysof>PMMA>hydrogel;the adherence of P.aeruginosa, Acrysof>silicone>PMMA>hydrogel. The bacterial adherence was significantly lower in the hydrophilic IOL.This result suggests that the risk of postoperative endophthalmitis after cataract extraction and IOL implantation may be reduced with the use of hydrophilic IOL.

Painful,Large Bleb after Glaucoma Filtering Surgery

An overhanging, large bleb after filtering surgery leads to various complications ranging from foreign-body sensation to endophthalmitis. Herein we report two case of large painful blebs in nasal area. Argon laser was initially used for its shrinkage. However, this procedure was not successful, requiring surgical excision of bleb. The tissue was then examined to evaluate the cause of failure with the argon laser treatment. On examination, the bleb showed a pseudocyst, and hyaline degeneration in the inner membrane of the bleb. Shrinkage of the large bleb resulted in resolution of the pain.

Initial Mitomycin C Trabeculectomy in Young Patients

Antimetabolites that inhibit postoperative fibroblast proliferation increases the success of glaucoma filtration surgery. However, the use of mitomycin C in young patients has not been extensively studied. The effectiveness of initialtrabeculectomy with mitomycin C or uncomplicated glaucoma in patients age 40 years or younger was evaluated in a consecutive series of 15 eyes of 10 patients. Thirteen eyes had juvenile primary open-angle glaucoma and 2 eyes had steroid induced glaucoma. Mitomycin C (0.002%) was applied for 2 to 4 minutes during the surgery. The success rate was evaluated with Kaplan-Meier analysis, and it was 78% at postoperative 9 months. Complications included postoperative hyphema(7 eyes), hypotony (2 eyes), and bleb-related endophthalmitis.

Corneal Endothelial Changes after Laser Assisted In Situ Keratomileusis

Laser assisted in situ keratomileusis(LASIK) is a widely used technique for correcting high myopia. Its technical methods and excellent clinical results are well known, but its potential risk on the corneal endothelium are poorly known. We used specular microscope to underwent LASIK for the correction of myopia. The mean preoperative refraction was ?4.5 diopters (range, -10.00 to -23.50 diopters.). The average endothelial cell densities were 2,817+/-205 cells/mm2 (mean +/-SD) preoperatively and 2,789+/-211 cells/mm2 3 months postoperatvely, corresponding to fall of 28 cells/mm2. This fall in endothelial cell density was not statistically significant (P>0.05). But significant correlation between the change in cell density and the residual corneal thickness was found(P>0.05). These results suggest that LASIK is a predictable and safe method for correcting high myopia, but care is recommended when doing deep corneal ablation. Long term follow-up may be needed to confirm its safety.

Peripapillary Atrophy in Asymmetric Glaucoma

Peripapillary atrophy is more frequently seen and larger in glaucomatous eyes than in ocular hypertension or normal eyes. There have been numerous debates whether peripapillary atrophy is caused by elevation of intraocular pressure or it is an anatomic variant which is more vulnerable to glaucomatous damage. In this study, we compared the area of peripapillary atrophy of normal and glaucomatous eye in asymmetric glaucoma. The optic nerve head area was 2.65 +/- 0.54mm2 in glaucomatous eyes and 2.59 +/- 0.47mm2 in control eyes(p=0.53). The peripapillary atrophy area was 1.13 +/- 0.86mm2 in glaucomatous eyes and 0.94 +/- 0.81mm2 in control eyes(p=0.35). There was no significant difference in peripapillary atrophy area or optic nerve head area between glaucomatous eyes and normal eyes. Our results suggest that peripapillary atrophy may not be caused by the intraocular pressure elevation.

Psychosocial Characteristics in Candidates of Photorefractive Keratectomy

We evaluate the psychosocial characteristics and primary reason for electing operation in myopic patients who were candidates for photorefractive keratectomy (PRK). The questionnaire data were collected on PRK patients and compared them with similar group of myopia. Most of the PHK patients were unmarried female in their twenties. The most striking demographic chracteristic of PRK sample was that the high proportion of them was highly educated office worker with high socioeconomic status. They were in possession of extroversive character rather than introversive one. They thought that their visual acuity was very serious, and preferred wearing contact lens for visual correction. The most important reason for undergoing PRK was avoiding inconveniences of contact lens or glasses. The other reasons were improving vision, improving appearance, and hoping to change life style with better vision. They were afraid of unpredictability of visual recovery and occurrence of complications, after operation, The results of this study may help analyze the factors that influence the success of PRK and patient's satisfaction.

The Effect of Excimer Laser PRK Using Single-pass Multizone Technique on High Myopia

Corneal haze and myopic regression are not uncommon complications following photorefractive keratectomy(PRK). To avoid these problems, multipass multizone technique has been introduced. However, it is quite difficult to coincide the center of the each ablation zone during the procedure and needs to take longer operation time. Single-pass multizone software was replaced by Summit technology(USA). The current study evaluates the clinical results of single-pass multizone PRK for high myopia. We performed PRK using single-pass multizone technique on 48 eyes of 44 patients for the treatment of high myopia. Preoperative spherical equivalent refractions ranged from -8.00 diopters((D) to -16.00 D (mean+/-SD, -11.01 +/- 1.84 D). Mean postoperative refraction was +1.12 +/- 1.20 D at one month, -0.42 +/- 1.24 D at six months, and -0.92 +/- 1.09 D at one year. The percentage of patients achieving correction within +/-2.0 D was 79.2% at one month, 85.4% at six months, and 88.2% at one year postoperatively. There was no serious complications after surgery. This study provides evidence that single-pass multizone PRK is a safe, simple and fairly predictable method for high myopic correction. But further studies are needed to confirm the longer-term stability.

The Effect of Excimer Laser PRK Using Single-pass Multizone Technique on High Myopia

Corneal haze and myopic regression are not uncommon complications following photorefractive keratectomy(PRK). To avoid these problems, multipass multizone technique has been introduced. However, it is quite difficult to coincide the center of the each ablation zone during the procedure and needs to take longer operation time. Single-pass multizone software was replaced by Summit technology(USA). The current study evaluates the clinical results of single-pass multizone PRK for high myopia. We performed PRK using single-pass multizone technique on 48 eyes of 44 patients for the treatment of high myopia. Preoperative spherical equivalent refractions ranged from -8.00 diopters((D) to -16.00 D (mean+/-SD, -11.01 +/- 1.84 D). Mean postoperative refraction was +1.12 +/- 1.20 D at one month, -0.42 +/- 1.24 D at six months, and -0.92 +/- 1.09 D at one year. The percentage of patients achieving correction within +/-2.0 D was 79.2% at one month, 85.4% at six months, and 88.2% at one year postoperatively. There was no serious complications after surgery. This study provides evidence that single-pass multizone PRK is a safe, simple and fairly predictable method for high myopic correction. But further studies are needed to confirm the longer-term stability.