Surgical Results of Trabeculectomy and Ahmed Valve Implantation Following a Previous Failed Trabeculectomy in Primary Congenital Glaucoma Patients

PURPOSE: To compare the surgical results of trabeculectomy and Ahmed glaucoma valve implantation after a previous failed trabeculectomy. METHODS: A retrospective comparative case series review was performed on 31 eye surgeries in 20 patients with primary congenital glaucoma who underwent trabeculectomy or Ahmed glaucoma valve implantation after a previous failed trabeculectomy with mitomycin C. RESULTS: The preoperative mean intraocular pressure was 25.5 mmHg in the trabeculectomy group and 26.9 mmHg in the Ahmed glaucoma valve implantation group (p = 0.73). The 48-month postoperative mean intraocular pressure was 19.6 mmHg in the trabeculectomy group and 20.2 mmHg in the Ahmed glaucoma valve implantation group (p = 0.95). The 12-month trabeculectomy success rate was 69%, compared with 64% for Ahmed glaucoma valve implantation, and the 48-month success rates were 42% and 36% for trabeculectomy and valve implantation, respectively. The success rates following the entire follow-up period were not significantly different between the two groups (p > 0.05 by log rank test). Postoperative complications occurred in 25% of the trabeculectomy-operated eyes and 9% of the Ahmed-implanted eyes (p = 0.38). CONCLUSIONS: There was no significant difference in surgical outcome between the trabeculectomy and Ahmed glaucoma valve implantation groups, neither of which had favorable results. However, the trabeculectomy group demonstrated a higher prevalence of adverse complications such as post-operative endophthalmitis.

Choice of One-Piece Intraocular Lens Power and Changes of Anterior Chamber in Sulcus Implantation due to Posterior Capsular Rupture during Cataract Surgery

PURPOSE: To evaluate the appropriate correction of predicted intraocular lens (IOL) power when sulcus implantation due to posterior capsular rupture was performed and to compare the anterior chamber angle of sulcus-implanted eyes with in-the-bag implanted eyes using anterior segment optical coherence tomography (Visante OCT). METHODS: Fifty-two eyes of 52 patients who had IOL implantation in the sulcus due to posterior capsular rupture during cataract surgery were retrospectively reviewed. A 0.5 lower diopter IOL than predicted IOL power using SRK-T formula was chosen. The difference between the predicted refractive error and the spherical equivalence at the 3-month time-point after sulcus implantation were evaluated. Among 52 patients, 16 patients whose fellow eye had an in-the-bag IOL implantation underwent Visante OCT and the anterior angle of affected eyes and normal fellow eyes were compared. RESULTS: The difference between the predicted refractive error using SRK-T formula and the spherical equivalence after sulcus implantation was a myopic shift of 0.597 +/- 0.879 diopter. The mean iridocorneal angles, angle opening distance (AOD), trabecular iris surface area (TISA) at 500 um and 750 um for both nasal and temporal sides in sulcus implantation were all significantly lower than in-the-bag implantation. CONCLUSIONS: A choice of a 0.5 lower diopter power IOL than the power for in-the-bag implantation may be considered because of greater myopic shift than predicted refractive error when sulcus implantation due to posterior rupture is performed. Anterior chamber angle in sulcus IOL implantation was shallower than in-the-bag IOL implantation.

A Case of Decreased Visual Field after Uneventful Cataract Surgery: Nonarteritic Anterior Ischemic Optic Neuropathy

The purpose of this article is to report a case of nonarteritic anterior ischemic optic neuropathy (NAION) after uneventful cataract surgery. A 53-year-old Filipina underwent cataract surgery. She had a small optic disc with cup-to-disc ratio of 0.2 in the left eye and 0.3 in the right eye. On the first postoperative day, the uncorrected visual acuity (UCVA) was 20/20, with an intraocular pressure (IOP) of 20 mmHg in the left eye. At one week after operation, the UCVA was 20/20 and the IOP was 15 mmHg. Three weeks later, she underwent cataract surgery in the right eye. On the first postoperative day, her UCVA was 20/20 in both eyes, but she complained of a visual field decrease in the left eye. A relative afferent pupillary defect (RAPD) was noted and the optic disc was pallid and swollen diffusely. A red-free photo showed defect surrounding the optic disc. A visual field test showed tunnel vision sparing the central vision. In this report, the authors hypothesize an association between cataract extraction and delayed NAION. Since the risk of NAION in the fellow eye is 30-50%, visual acuity, visual field, fundus exam and RAPD should be routinely checked.

Comparison of Measurement of Anterior Segment Parameters Between Scheimpflug Camera and Ultrasound Biomicroscopy

PURPOSE: To evaluate the clinical reliability of Pentacam(R) by comparing anterior chamber parameters measured by Oculus Pentacam system (Oculus Inc., Germany) and Hi-scan ultrasound biomicroscopy (OPTIKON 2000, Rome, Italy) in primary angle closure (PAC) and normal patients. METHODS: A prospective study was performed from June 2006 to January 2007. Fifty-one eyes in 26 primary angle-closure patients and 39 eyes in 20 normal control patients, for a total of 90 eyes of 46 patients were recruited from glaucoma out-patient clinics. The correlation and agreement of both measurements of anterior chamber depth and anterior chamber angle measured by UBM and Pentacam(R) were calculated. Sensitivity and specificity of each tool were also compared and the diagnostic value of angle closure was examined. RESULTS: Anterior chamber depth measured by UBM and Pentacam(R) showed strong correlation in the normal control group (r=0.821) and PAC group (r=0.957). Anterior chamber angle showed moderate correlation in the normal control group (r=0.523) and PAC group (r=0.456) while good agreement was also observed. In diagnosing angle closure, anterior chamber measurements appear similar in UBM and Pentacam(R) using the ROC curve (AUC of UBM, 0.942; AUC of Pentacam(R), 0.931). CONCLUSIONS: Pentacam(R) shows high to moderate correlation of anterior chamber measurements and good agreement compared with UBM. Pentacam(R) shows similar ability in diagnosing angle closure compared with UBM and thus is expected to be a good tool in diagnosing angle closure.

Anterior Chamber Measurements by Pentacam and AS-OCT in Eyes With Normal Open Angles

PURPOSE: To assess the reproducibility and agreement of anterior chamber measurements between the Pentacam (PTC) and the Anterior segment optical coherence tomography (AOCT) in normal healthy eyes with open angle. METHODS: Prospective cross-sectional comparative case series. A total of 162 eyes of 81 healthy volunteers with normal open angle were included in this study. Anterior chamber angle (ACA) and anterior chamber depth (ACD) were measured with PTC and AOCT. Intra-observer variability and inter-methods agreement of both instruments for ACA and ACD were evaluated. RESULTS: Values of temporal and nasal ACA measured by two instruments were similar, and the results of ACD were also not significantly different between modalities (p>0.01). ACA and ACD measurements by PTC and AOCT showed good intra-observer and inter-method agreements (all >0.9). CONCLUSIONS: PTC and AOCT are presumed to be very useful for the anterior chamber angle examination. They may provide good images and quantitative data about the angle structures including ACA and ACD.

Relationship between the Retinal Thickness Analyzer and the GDx VCC Scanning Laser Polarimeter, Stratus OCT Optical Coherence Tomograph, and Heidelberg Retina Tomograph II Confocal Scanning Laser Ophthalmoscopy

PURPOSE: To assess the relationship between the retinal thickness analyzer (RTA) parameters, and those of the GDx VCC scanning laser polarimeter (GDx VCC), Stratus OCT optical coherence tomography (Stratus OCT), and Heidelberg retinal tomograph II confocal scanning laser ophthalmoscopy (HRT II). METHODS: Twenty-nine primary open-angle glaucoma patients were retrospectively included in this study. Measurements were obtained using the RTA, GDx VCC, Stratus OCT, and HRT II. We calculated the correlation coefficients between the parameters of RTA and those of the other studies. RESULTS: Among the optic disc parameters of RTA, the cup volume was best correlated with Stratus OCT (R=0.780, p<0.001) and HRT II (R=0.896, p<0.001). Among the posterior pole retinal thickness parameters, the posterior pole abnormally thin area (PPAT) of the RTA and the inferior average of the GDx VCC were best correlated (R=-0.596, p=0.001). The PPAT of the RTA and the inferior maximum of the Stratus OCT were best correlated (R=-0.489, p=0.006). The perifoveal minimum thickness (PFMT) of the RTA and the cup shape measurement of the HRT II were best correlated (R=-0.565, p=0.004). CONCLUSIONS: Many RTA optic disc parameters were significantly correlated with those of the Stratus OCT and HRT II. The RTA posterior pole retinal thickness parameters were significantly correlated with those of the GDx VCC, Stratus OCT and HRT II. The RTA optic disc and posterior pole retinal thickness parameters may be valuable in the diagnosis of glaucoma.

The Effect of Swimming Goggles on Intraocular Pressure and Blood Flow within the Optic Nerve Head

PURPOSE: Goggles are frequently worn in the sport of swimming and are designed to form a seal around the periorbital tissue orbit. The resultant pressure on the eye may have the potential to affect intraocular pressure and blood flow of the optic nerve head. This study evaluates the influence of wearing swimming goggles on intraocular pressure (IOP) and blood flow of the ocular nerve head (ONH) in normal subjects. MATERIALS AND METHODS: Thirty healthy participants took part in this study. The IOP of each participant was measured using a Goldmann tonometer. Measurements were taken immediately before putting on swimming goggles, at 5, 10, 30, and 60 minutes after putting on swimming goggles, and then immediately after taking off the goggles. Blood flow of the ONH was measured using the Heidelberg retinal flowmeter. RESULTS: The average IOP before, during and after wearing the swimming goggles were 11.88 +/- 2.82mmHg, 14.20 +/- 2.81 mmHg and 11.78 +/- 2.89mmHg, respectively. The IOP increased immediately after putting on the goggles (p 0.05). Blood flow of the ONH was 336.60 +/- 89.07 Arbitrary Units (AU) before and 319.18 +/- 96.02 AU after the goggles were worn (p < 0.05). CONCLUSION: A small but significant IOP elevation was observed immediately after the swimming goggles were put on. This elevated IOP was maintained while the goggles were kept on, and then returned to normal levels as soon as they were taken off. Blood flow of the ONH did not change significantly throughout the experiment. These facts should be considered for safety concerns, especially in advanced glaucoma patients.

Correlation between Optokinetic Nystagmus Response and Visual Acuity

PURPOSE: The purpose of this paper was to determine the correlation between optokinetic nytagmus and grating and Snellen visual acuity charts and the validity of this correlation as an index. METHODS: Diffusion blur was used to cause visual decrease in 24 patients with normal eyes. Vision was measured using 3 different methods. To compare the central and peripheral vision, visiual acuity was measured using a macula occluder. RESULTS: Twenty four patients had an average uncorrected vision of 1.0 and showed regular visual acuity decrease using diffusion blur. Grating visual acuity showed correlation with the Snellen visual acuity but OKN visual acuity showed low correlation (p<0.05, ANOVA with repeated measure trend). OKN visual acuity showed low correlation with grating acuity when central visual acuity was occluded and only peripheral acuity was taken into consideration. CONCLUSIONS: Visual acuity measured using Snellen or grating acuity had little correlation with OKN visual acuity, and visual acuity measured using OKN was unable to indicate visual acuity in a quantitative manner.

Kearns-Sayre Syndrome: 3 Case Reports and Review of Clinical Feature

Kearns-Sayre syndrome, first described by Kearns and Sayre in 1958, is a rare disorder consisting of ptosis, limited movement of both eyes and atypical retinal pigmentary change (salt-pepper like appearance). Most cases have shown an increase in the concentration of mitochondria and ragged-red fiber under Gomori-trichrome staining on muscle biopsy. Occasionally, it is combined with other neurologic and endocrinologic symptoms such as ataxia, dementia, diabetes, and hyperaldosteronism. We recently experienced three cases of male teenaged patients who expressed the clinical features of Kearns-Sayre syndrome.

Anterior Transposition of Inferior Oblique Muscle for Treatment of Unilateral Superior Oblique Muscle Palsy with Inferior Oblique Muscle Overaction

Although many weakening procedures for the inferior oblique muscle have been advocated, there is some controversy as to the most beneficial procedure for weakening overacting inferior oblique muscles. This study was undertaken to determine if unilateral anterior transposition of the inferior oblique muscle alone could be a safe and effective procedure for treating unilateral superior oblique palsy from the perspective of hypertropia, inferior oblique overaction, and abnormal head posture. The records of 33 patients, who underwent anterior transposition of the inferior oblique muscle for unilateral superior oblique palsy at our institution between Jan 1995 and Dec 2002, were retrospectively reviewed. The average preoperative inferior oblique overaction was 2.3 +/-0.64, and the hypertropia in the primary position was 12.3 +/-7.69 prism diopter (PD). Twenty-six patients showed head tilt to the opposite direction preoperatively. After the anterior transposition of the inferior oblique, inferior oblique overaction was diminished in 32 patients (97%). Twenty-six out of 33 patients (79%) had no hypertropia in the primary position at last postoperative assessment. Of the 26 patients with head tilt before surgery, 21 patients (81%) achieved full correction after surgery. Satisfactory results were obtained in most of the patients in our study with the exception of three patients who required additional surgery. No patient demonstrated postoperative hypotropia in the primary position. None of the patients noticed elevation deficiency or lower lid elevation. The anterior transposition of the inferior oblique was found to be safe and effective for treating superior oblique palsy with secondary overaction of the inferior oblique muscle.