Comparison of the Outcome of Silicone Ahmed Glaucoma Valve Implantation with a Surface Area between 96 and 184 mm2 in Adult Eyes

PURPOSE: To compare the success rates, complications, and visual outcomes between silicone Ahmed glaucoma valve (AGV) implantation with 96 mm2 (FP8) or 184 mm2 (FP7) surface areas. METHODS: This study is a retrospective review of the records from 132 adult patients (134 eyes) that underwent silicone AGV implant surgery. Among them, the outcomes of 24 eyes from 24 patients with refractory glaucoma who underwent FP8 AGV implantation were compared with 76 eyes from 76 patients who underwent FP7 AGV implantation. Preoperative and postoperative data, including intraocular pressure (IOP), visual acuity, number of medications, and complications were compared between the 2 groups. RESULTS: There were no significant differences in baseline characteristics between the 2 groups (p > 0.05). The postoperative visual acuity of the patients in the FP8 group was better than that of the patients in the FP7 group in some early postoperative periods (p 0.05). Postoperative IOP was not significantly different between the 2 groups (p > 0.05) except for IOP on postoperative day 1 (11.42 mmHg for the FP7 group and 7.42 mmHg for the FP8 group; p = 0.031). There was no statistical difference in success rates, final IOP, number of medications, or complication rates between the 2 groups (p > 0.05). CONCLUSIONS: The FP7 and FP8 AGV implants showed no difference in terms of vision preservation, IOP reduction, and number of glaucoma medications required.

Surgical Treatment of Overhanging Bleb Using Indocyanin Green Dye

PURPOSE: To report a case of overhanging bleb excision using Indocyanin green (ICG) dye. CASE SUMMARY: A 71-year-old man visited our clinic complaining of a white corneal foreign body in his left eye. The patient underwent mitomycin-assisted trabeculectomy surgery 8 years prior. Slit lamp examination revealed a large overhanging bleb. Because of its large size, surgical excision using ICG dye was performed. After excision surgery, the IOP was well controlled and no anterior chamber inflammation was observed. Two months later, the IOP was still stable at 11 mm Hg and no recurrence of the overhanging bleb was found. CONCLUSIONS: ICG dye is useful in delineating between a functioning bleb and a non-functioning overhanging bleb. ICG dye-assisted bleb excision is a useful method for decreasing complications such as aqueous humor leakage and damage of the original bleb.

Comparison of 180degrees and 360degrees Selective Laser Trabeculoplasty

PURPOSE: To compare the effect and safety of two regimens of Selective Laser Trabeculoplasty (SLT), SLT on 180degrees of trabecular meshwork and SLT with 100 laser spots on 360degrees of trabecular meshwork in patients with primary open-angle glaucoma and ocular hypertension. METHODS: In a retrospective clinical study, the authors compared the pressure-lowering effects of SLT in two groups of patients; group 1 (83 patients) received SLT on 180degrees, group 2 (30 patients) on 360degrees of trabecular meshwork. The clinical outcome indicators included intraocular pressure (IOP) at one day, one week, one month, two months, three months and six months after SLT, and the anterior chamber reaction at post-laser one day. RESULTS: There was no statistically significant difference in the IOP reduction between these two regimens after six months. The anterior chamber reactions in the two groups were significantly different (group 1; 0.61 +/- 0.64, group 2; 1.25 +/- 0.83, p = 0.001). The success rate of group 2 (43.3%) was not different from that of group 1 (31.3%; p = 0.23). CONCLUSIONS: SLT on 180degrees of trabecular meshwork had a similar effect compared to that of SLT on 360degrees of trabecular meshwork in terms of IOP reduction. The authors of the present study suggest that 180degrees SLT is the safest procedure with regard to success rate and complications.

Quantitative Analysis of Optic Disc Color

PURPOSE: To evaluate the reproducibility of ImageJ software in analyzing the color of the optic disc. METHODS: One hundred twelve normal participants (56 males and 56 females) were enrolled in this study. The image of the optic disc was taken using Kowa digital disc photo-graphy, and the gray scales of the nasal rim (NR), brightest cupping center (BCC) and largest inferior retinal vein (IRV) were calculated using histogram in ImageJ. Three different observers calculated the gray scales three separate times. Reproducibility was assessed using the interclass correlation coefficient (ICC). RESULTS: The mean age of the participants was 50.6 years old (range, 11 to 82 years). The mean gray scales of the nasal rim were 91.81, 94.91, and 93.24; those of the brightest cupping center were 174.84, 179.94, and 177.76; and those of the largest inferior retinal vein were 61.85, 53.48, and 56.73 for observers 1, 2, and 3, respectively. Inter-observer reproducibility for NR, BCC and IRV was considered good based upon ICC values of 0.944, 0.860, and 0.789 for observers 1, 2, and 3, respectively. Significant age-related differences between the values of the brightest cupping center were noted, and the gray scale score was decreased in the older participants (p < 0.001). CONCLUSIONS: The gray scale of the brightest cupping center diminished with age. ImageJ can be a useful objective tool with high reproducibility in the analysis of optic disc color.

Comparison of Outcome of Trabeculectomy With Mitomycin C and Ahmed Valve Implantation for Uveitic Glaucoma

PURPOSE: To assess and compare the clinical outcomes of primary trabeculectomy with mitomycin C and Ahmed valve implantation for secondary open-angle glaucoma following uveitis. METHODS: This study was conducted retrospectively on 30 eyes of 25 patients with open-angle glaucoma secondary to uveitis that had undergone trabeculectomy with mitomycin C and 33 eyes of 24 patients that had undergone Ahmed valve implantation. The clinical outcome indicators used in this study were intraocular pressure (IOP), number of anti-glaucoma agents, surgical success rate and occurrence of complications. RESULTS: Mean IOP and surgical success rate in patients who had undergone trabeculectomy with mitomycin C after a 12 month postoperative period were 14.0+/-8.2 mmHg and 76.7%, respectively, while those of patients with Ahmed valve implantation were 13.2+/-7.7 mmHg and 81.8%. The data did not show clinical significance. There was greater risk of surgical failure in patients at a younger age and/or with diabetes mellitus in cases of having gone through trabeculectomy with mitomycin C. CONCLUSIONS: Both trabeculectomy with mitomycon C and Ahmed valve implantation can be considered as primary surgical treatments for patients with open-angle glaucoma secondary to uveitis. However, trabeculectomy with mitomycin C should only be applied to a limited extent in patients that are young and/or have diabetes mellitus.

Concentration of Vascular Endothelial Growth Factor After Intracameral Bevacizumab Injection in Eyes With Neovascular Glaucoma

PURPOSE: To study the concentration of vascular endothelial growth factor (VEGF) in the aqueous humor before and after intracameral injection of bevacizumab in eyes with neovascular glaucoma, and to detect the duration of an anti-VEGF effect of bevacizumab in the anterior chamber. METHODS: In this prospective interventional case series, 1.25 mg of bevacizumab was injected into the anterior chamber of five eyes in five neovascular glaucoma patients. Aqueous humor samples were obtained just before intracameral injection of bevacizumab and two weeks after injection. The concentrations of VEGF in the aqueous humor were measured using ELISA. To investigate corneal endothelial damage after intrecameral bevacizumab injection, specular microscopy was performed before injection and two weeks after injection. Slit lamp photo and iris fluorescent angiography was performed to determine the regression of iris neovascularization. RESULTS: After injection, substantial regression of neovascularization or fluorescein leakage was seen in all treated eyes. The VEGF concentrations in the aqueous humor in eyes with NVG were 1181.8+/-1248.3 pg/mL before intracameral injection of bevacizumab. Two weeks after injection, the VEGF concentrations decreased to 33.2+/-12.2 pg/mL (p=0.04, Wilcoxon signed rank test). There were no significant changes in IOP or corneal endothelial cells. CONCLUSIONS: Intracameral bevacizumab injection can remarkably reduce iris neovascularization in neovascular glaucoma patients. VEGF levels were significantly decreased two weeks after injection and corneal toxicity was not observed during short term follow-up.

Comparison of Safety and Efficacy Between Silicone and Polypropylene Ahmed Glaucoma Valves

PURPOSE: To compare the safety and efficacy of polypropylene and silicone Ahmed glaucoma valves (AGVs). METHODS: The medical records of 62 consecutive refractory glaucoma patients who had undergone AGV implantion from March 2003 to December 2005 were reviewed retrospectively. Among the 62 patients, 32 patients underwent polypropylene AGV implantation (group P) and the other 30 patients underwent silicone AGV implantation (group S). Postoperative IOP, the complication rate, and the success rate were compared between the two groups. RESULTS: The life-table success rates for the group P were 81.3% at 6 months and 71.2% at 12 months, and the success rates for the group S were 89.9% at 6 months and 78.6% at 12 months, showing no significant difference between the two groups. Complications, including non-tube-related complications, were observed more frequently in the group S, but there was no significant difference between the two groups. CONCLUSIONS: The silicone AGV can reduce IOP effectively but may be associated with non-tube-related complications.

Bilateral Spontaneous Anterior Lens Dislocation in a Retinitis Pigmentosa Patient

PURPOSE: To report a case of bilateral spontaneous anterior lens dislocation associated with retinitis pigmentosa (RP). METHODS: A 45-year-old male with RP presented with elevated intraocular pressure (IOP) in the right eye and was treated with laser iridotomy (LI). After LI, complete crystalline lens dislocation into the anterior chamber occurred. Surgical intervention, including anterior vitrectomy, intracapsular cataract extraction (ICCE), and IOL scleral fixation was performed. Two years later, the same episode occurred in his left eye and a similar treatment was done. RESULTS: Surgery was successful in both eyes. CONCLUSIONS: This is the first report of bilateral spontaneous anterior lens dislocation in a RP patient.

The Relationship between Optical Coherence Tomography and Scanning Laser Polarimetry Measurements in Glaucoma

PURPOSE: To investigate the relationship between optical coherence tomography (OCT) and scanning laser polarimetry (SLP) in measuring peripapillary retinal nerve fiber layer (RNFL) thickness in glaucomatous eyes. METHODS: Fifty glaucomatous eyes were evaluated in this study. Evaluations were analyzed two ways. First, parameters of the Stratus OCT (average thickness, superior/ inferior average) and GDx VCC (TSNIT average, nerve fiber indicator (NFI), superior/ inferior average) were correlated using the Pearson's correlation coefficient (r). Secondly, comparison (r) of these parameters was completed using the mean deviation (MD) of visual field defect. RESULTS: The following parameters were found to be significantly correlated (P<0.005). TSNIT average/average thickness (r=0.673), NFI/average thickness (r=-0.742), superior average (r=0.841), and inferior average (r=0.736). In the correlation analysis using the severity of visual field defect, all these parameters had statistically meaningful correlations (P<0.005). CONCLUSIONS: GDx VCC and Stratus OCT are highly correlated in glaucomatous eyes. Therefore, peripapillary RNFL thickness measured by Stratus OCT and GDx VCC may be equally helpful in the diagnosis of glaucoma.

Changes in Axial Length Following Trabeculectomy and Ahmed Glaucoma Valve Implantation

PURPOSE: This study examines the changes in axial length after trabeculectomy and Ahmed glaucoma valve implantation surgery. METHODS: In the forty three eyes of the 42 patients who had the uncontrolled glaucoma, 22 eyes of 21 patients having trabeculectomy and 21 eyes of 21 patients having Ahmed glaucoma valve implantation from October 2004 to September 2005 at Kim's Eye Hospital were analyzed prospectively. These patients had IOP and axial length measurements preoperatively, at 1 week, 1 month, and 3 months after surgery and refractive power measurements preoperatively, at 3 months after surgery. Axial length was measured by IOL Master(R). RESULTS: There was a statistically significant reduction in IOP after 3 months of 26.6+/-11.2 mmHg overall, 22.4+/-8.4 mmHg following trabeculectomy, and 30.9+/-12.3 mmHg after Ahmed glaucoma valve implatation (p<0.001). There was a statistically significant reduction in axial length after 3 months of -0.24+/-0.10 mm overall, -0.21+/-0.1 mm after trabeculectomy and -0.28+/-0.1 mm after Ahmed glaucoma valve implantation. CONCLUSIONS: There was a statistically significant decrease in axial length after both trabeculectomy and Ahmed glaucoma valve implantation. We must consider the influence of axial length change on refraction in planning combined glaucoma and cataract surgery or future IOL implantation.

Diagnostic Outcomes of Patients Suspicious for Glaucoma Referred from The Company Health Screening

PURPOSE: To evaluate the diagnostic outcomes of patients suspicious for glaucoma referred from the company health screening. METHODS: In this prospective study, 147 (87 male, 60 female) patients for glaucoma suspicious referred from the company health screening were enrolled. They underwent slit-lamp examination, Goldmann applanation tonometry, gonioscopy, optic disc examination, visual field examination and peripapillary retinal nerve fiber layer (RNFL) thickness measurement using optical coherence tomography (StratusOCT) and scanning laser polarimetry (GDx VCC). We analyzed their diagnostic outcomes. RESULTS: The mean age of patients was 43.8 9.6 years. Reasons for glaucoma suspicion and the number of referred patients were 111 (75.5%) high cup/disc ratio, 23 (15.6%) high intraocular pressure and 13 (8.8%) both of these. The diagnostic outcome was as follows: glaucoma, 26 (17.7%); glaucoma suspect, 4 (2.7%); ocular hypertension (OHT), 14 (9.5%); no glaucoma and no ocular hypertension, 89 (60.5%); and normal, 18 (12.2%). CONCLUSIONS: Glaucoma, glaucoma suspect and ocular hypertension were confirmed in 27.2% of patients suspicious for glaucoma referred from the company health screening. Thus, the company health screening appears to be relatively sensitive to detecting glaucoma patients.

Neovascular Glaucoma: Diode Laser Trans-Scleral Cyclophotocoaculation Versus Ahmed Glaucoma Valve Implant

PURPOSE: To retrospectively study the clinical outcomes of diode laser trans-scleral cyclophotocoagulation and Ahmed glaucoma valve implant in eyes with neovascular glaucoma. METHODS: We reviewed the medical records of patients who had undergone diode laser trans-scleral cyclophotocoagulation (group 1) and Ahmed glaucoma valve implant (group 2) with a follow-up period of 6 months or longer. The treatments were carried out to control high intraocular pressure (IOP) and ocular pain in the patients with visual acuity less than hand motions. RESULTS: Group 2 had a significantly lower IOP during the first postoperative month. The cumulative probability of success was higher in group 2 than group 1 throughout the follow-up period. The postoperative complications in most cases were transient and improved with conservative management in both groups. However, 3 cases in group 1 required evisceration secondary to phthisis. Subjective relief of ocular pain was higher in group 2. CONCLUSIONS: The Ahmed glaucoma valve implant group showed a higher success rate and fewer serious complications than the diode laser trans-scleral cyclophotocoagulation group in patients with high IOP and ocular pain with poor visual acuity. Diode laser trans-scleral cyclophotocoagulation may be considered in patients with poor general health.

Clinical Factors of Glaucomatous Change in Patients with Posner-Schlossman Syndrome

PURPOSE: To determine the factors that affect glaucomatous change and the clinical course of patients with Posner-Schlossman syndrome. METHODS: A retrospective analysis of 52 eyes of 51 patients who had been diagnosed with Posner-Schossman syndrome between January 1995 and June 2003 was performed. We analysed the factors by the age of onset, the duration of disease, the number of attacks, the highest intraocular pressure, the cup/disc ratio of affected eye and unaffected fellow eye during attacks, and visual field change. RESULTS: Twelve (23.1%) of 52 eyes revealed significant glaucomatous change. The number of attacks showed statistically significant difference between the two groups who had developed glaucoma and who had not (P=0.021). But the age of onset, the duration of disease, and the highest intraocular pressure during attack did not show statistically significant difference (P>0.1). CONCLUSIONS: From this study, we observed that the only factor influencing glaucomatous change in patients with Posner-Schlossman syndrome was the number of attacks. So in case of recurrent attacks, close observation and aggressive treatment is mandatory.

Ahmed Valve Implantation Using Scleral Tunneling

PURPOSE: To assess the usefulness of Ahmed valve implantation using scleral tunneling. METHODS: Thirty-four eyes of 34 patients with refractory glaucoma who had not responded to medical treatment nor previous glaucoma surgery was given Ahmed valve implantation using scleral tunneling and were enrolled in the study with a minimum follow-up of six months. RESULTS: The mean follow-up period was 7.7 +/- 2.8 months (6~24 months). The mean preoperative IOP was 47.6 +/- 6.9 (25~70) mmHg and the mean postoperative IOP at six months was 18.7 +/- 9.8 (4~31) mmHg. The postoperative success rate was 73.5% and 73.3% at six and eighteen months, respectively, and was not affected by sex, preoperative diagnosis, or preoperative IOP. The postoperative complications were hyphema (4 eyes), choroidal detachment (3 eyes), and immediate hypotony (3 eyes). CONCLUSIONS: Ahmed valve implantation using scleral tunneling is useful, especially when patch graft is not available. The success rate was comparable with other traditional methods such as patch graft and scleral flap.

Long-term Intraocular Pressure Change in Attacked and Fellow eyes with Acute Angle-closure Glaucoma after Laser Iridotomy

PURPOSE: To study long-term change of intraocular pressure (IOP) in attacked and fellow eyes after laser iridotomy (LI) in the patients with acute angle-closure glaucoma (AACG). METHODS: All eyes of 72 patients were studied for more than 6-month follow-up (range: 6-67 months). LI was performed in both eyes. Subsequent long-term IOP change, and additional medical or surgical management were analyzed retrospectively. We defined re-elevation as, (1) IOP greater than 21mmHg or, (2) progression of glaucomatous optic disc change or visual field defect despite initial reduction of IOP after LI. RESULTS: The mean IOP of attacked eyes dropped from 46.6 +/- 16.5 to 13.8 +/- 6.9 mmHg after LI. Among the attacked eyes, 32 (44.4%) required further medical therapy due to re-elevation of IOP, of which 4 (5.6%) eventually underwent operation. Among the fellow eyes, 16 (22.2%) underwent further medical therapy, although none required surgery. CONCLUSIONS: We recommend close, long-term follow-up for patients with AACG, because there is high risk of re-elevation of IOP, despite well-controlled immediate IOP after LI in both attacked and fellow eyes.

Influence of Central Corneal Thickness on Diagnosis of Glaucoma

PURPOSE: To determine the effect of central corneal thickness (CCT) on the measurement of intraocular pressure (IOP) and diagnosis of glaucoma on the resultant reclassification of patients as having primary open-angle glaucoma (POAG), normal tension glaucoma (NTG), or ocular hypertension (OHT). METHODS: Intraocular pressure (Goldmann applanation tonometry) and visual field test (Humphrey 24-2) were measured in 22 eyes of 23 patients with OHT, 20 eyes of 20 patients with POAG, 31 eyes of 31 patients with NTG, 27 eyes of 27 control subjects. CCT was measured and used to obtain a corrected value for the IOP and to reclassify the type of glaucoma. RESULTS: There was no significant difference in CCT between controls and patients with POAG, but the CCT in the group with NTG was significantly lower than that in the control group (p=0.012), and the CCT in the group with OHT was significantly higher than in controls (p=0.002). Correcting IOP for corneal thickness, 22.58% of patients with NTG could be reclassified as having POAG, and 56.52% of the patients with OHT as normal. CONCLUSIONS: Underestimation of the IOP in patients with POAG who have thin cornea may lead to a misdiagnosis of NTG, while overestimation of the IOP in normal subjects who have thick cornea may lead to a misdiagnosis of OHT. We suggest that CCT must be considered in diagnosis of glaucoma.

Mitomycin C Trabeculectomy for Refractory Glaucoma: A Comparison between 0.25 and 0.5mg/ml of Mitomycin C

To determine the optimum concentration of mitomycin C(MMC) in patients with refractory glaucoma undergoing trabeculectomy, we retrospectively examined 31 eyes of 22 patients with refractory glaucoma who underwent trabeculectomy with 0.25mg/ml MMC for 5 minutes. They were case matched with a group of 36 eyes of 28 patients who had undergone trabeculectomy with 0.5mg/ml MMC for 5 minutes by using age, gender, type of refractory glaucoma, preoperative intraocular pressure(IOP), and preoperative medications as variables. MMC was applied between the sclera and Tenon's capsule during trabeculectomy, and scleral flap was closed with tight releasable sutures. No statistically significant differences were found in mean IOP between the two groups at the one, three, six, and nine months postoperative periods. The mean follow-up was 9.3 months in the 0.25mg group and 9.8 months in the 0.5 mg group(p=0.70). At the last postoperative visit, 81%(25 eyes) in the 0.25mg group and 86%(31 eyes) in the 0.5mg group had an IOP less than 21mmHg with or without glaucoma medication(p=0.79). At the last postoperative visit, there were no statistically significant differences in mean IOP(17.2 +/- 8.6mmHg and 17.2 +/- 7.3mmHg, respectively, p=0.99), mean number of medications(0.6 +/- 0.9 and 0.5 +/- 0.7, respectively, p=0.77), and change in visual acuity(3 eyes and 6 eyes lost more than 2 lines of vision, respectively, p=0.75) between the two groups. The incidence of complications were similar between the two groups. Our data suggests similar efficacy and safety in trabeculectomy with 0.25 and 0.5mg/ml MMC for 5 minutes.

Two Cases of True and Pseudo-internuclear Ophthalmoplegia with Bilateral Exodeviation

Internuclear ophthalmoplegia(INO) is characterized by the adduction deficit on lateral gaze associated with dissociated nystagmus of an abducting eye and caused by the lesion in the medial longitudinal fasciculus(MLF). It occurs unilaterally or bilaterally in infarction of brain stem and multiple sclerosis. Ocular myasthenia is a localized form of myasthenia involving extraocular, levator palpebrae perioris, and/or orbicularis oculi muscles. It is frequently confused with a variety of ocular mortility disorders including INO. We experienced 2 patients who had bilateral wall-eyes and diplopia. One was a true bilateral INO due to hypertensive brain stem infarction(Wall-eyed bilateral INO) and the other was a myasthenic bilateral pseudo-INO. Diagnosis was made by Tensilon test, repetitive nerve stimulation test of orbicularis oculi muscles, and serum antibody assay in latter case.

Surgical Treatment of Scleral Ulceration as a Complication of Pterygium Excision

Mitomycin C is now being used not only as an adjunct in the surgical treatment of pterygia but also in glaucoma surgery. However, several serious complications that are possibly related to mitomycin C treatment have been reported. We report on a series of 8 patients(10 eyes) who experienced scleral ulcer after pterygium excision. The period from operation to onset of scleral ulcer was between 5 months and 20 years. Complications included corneoscleral perf oration(1 eye), scleral ulceration(9 eyes), corneal ulceration(2 eyes), complicated cataract(5 eyes) and uveitis(4 eyes). We used autogenous temporalis fascia to reinforce the weakened lesion of 10 eyes with scleral or corneoscleral ulceration. Three eyes underwent extracapsular cataract extraction and posterior chamber intraocular lens implantation after stable grafting. Grafts remained stable in 9 eyes over a mean follow-up of 10.8 +/- 10.4 months(3 to 37 months). One graft melted but regrafting salvaged the eye. Six of 10 eyes improved vision. All patients resolved their subjective symptoms after temporalis fascia grafting. We found autogenous temporalis fascia grafting is efficacious in both treating and preventing ocular perforation due to progressively destructive scleral ulceration.