Validity of Tono-pachymetry for Measuring Corrected Intraocular Pressure in Non-surgical and Post-photorefractive Keratectomy Eyes

PURPOSE: To assess the validity of central corneal thickness (CCT) and corrected intraocular pressure (IOP) values obtained by tono-pachymetry in non-surgical and post-photorefractive keratectomy (PRK) eyes. METHODS: For the study, 108 young healthy participants and 108 patients who had PRK were enrolled. Measurements were randomly performed by tono-pachymetry, ultrasonic (US) pachymetry, and Goldmann applanation tonometry (GAT). CCT measurement by tono-pachymetry was compared to that of US pachymetry. The corrected IOP value obtained by tono-pachymetry was compared to that obtained by US pachymetry and GAT. The corrected IOP from US pachymetry and GAT was calculated using the identical compensation formula built into the tono-pachymetry. Bland-Altman plot and paired t-test were conducted to evaluate the between-method agreements. RESULTS: The mean CCT measurement using tono-pachymetry was significantly greater by 7.3 µm in non-surgical eyes (p < 0.001) and 17.8 µm in post-PRK eyes (p < 0.001) compared with US pachymetry. Differences were significant in both Bland-Altman plotand paired t-test. The mean difference of corrected IOP values obtained by tono-pachymetry and calculated from measurements by US pachymetry and GAT was 0.33 ± 0.87 mmHg in non-surgical eyes and 0.57 ± 1.08 mmHg in post-PRK eyes. The differences in the Bland-Altman plot were not significant. CONCLUSIONS: The CCT measurement determined using tono-pachymetrywas significantly thicker than that of US pachymetry. The difference in CCT was greater in post-PRK eyes than in non-surgical eyes. However, the corrected IOP value obtained by tono-pachymetry showed reasonable agreement with that calculated from US pachymetry and GAT measurements.

Nestin Expression in the Adult Mouse Retina with Pharmaceutically Induced Retinal Degeneration

The present study investigated the temporal pattern and cellular localization of nestin in the adult mouse retina with pharmaceutically induced retinal degeneration using N-methyl-N-nitrosourea (MNU). After a single intraperitoneal injection of MNU in 8-week-old C57BL/6 mice, the animals were sacrificed at 1, 3, 5, 7, and 21 days (n = 6, in each stage). The eyes were examined by means of immunohistochemical tests using nestin, ionized calcium-binding adaptor molecule (Iba-1), CD11b, F4/80, and glial fibrillary acidic protein (GFAP). Western blot analysis and manual cell counting were performed for quantification. Nestin expression was increased after MNU administration. Nestin+/Iba-1+ cells were migrated into outer nuclear layer (ONL) and peaked at day 3 post injection (PI). Nestin+/CD11b+ cells were also mainly identified in ONL at day 3 PI and peaked at day 5. Nestin+/F4/80+ cells were shown in the subretinal space and peaked at day 3 PI. Nestin+/GFAP+ cells were distinctly increased at day 1 PI and peaked at day 5 PI. The up-regulation of nestin expression after MNU administration in adult mouse retinal microglia, and monocyte/macrophage suggests that when retinal degeneration progresses, these cells may revert to a more developmentally immature state. Müller cells also showed reactive gliosis and differentiational changes.

Changes in Electroretinogram Parameters after Panretinal Photocoagulation in Diabetic Retinopathy

OBJECTIVE: This study was performed to evaluate the effect of panretinal photocoagulation (PRP) on parameters of electroretinograms (ERG). METHODS: Retrospective study was performed on 58 eyes of 29 patients with proliferative diabetic retinopathy (PDR) who underwent PRP. ERG was performed in each patient before and after PRP, and each ERG parameters were compared between the pre- and post-PRP state. Also, the results of ERG performed after PRP were compared between two groups: one group showing obvious new vessels regression and the other group showing poor regression after PRP. RESULTS: Marked reduction in amplitude and delay in implicit time were observed in all patients (P0.05). CONCLUSION: PRP in diabetic retinopathy patients may affect not only the outer retina but also the cells within the inner nuclear layer, causing changes in ERG parameters. However, ERG was not a good indicator for representing the amount of new vessel regression in PDR.

Postural Effect on Intraocular Pressure in Gas-Filled Eyes after Vitrectomy

PURPOSE: To assess the influence of body position on intraocular pressure (IOP) in patients who underwent vitrectomy and intraocular gas tamponade. METHODS: Patients who did not undergo any surgery were defined as Group 1. The remaining patients were divided into 3 groups according to the surgery performed (Group 2; cataract surgery, Group 3; vitrectomy and cataract surgery, Group 4; vitrectomy with intraocular gas tamponade and cataract surgery). IOP was measured by a non-contact tonometer, Goldmann applanation tonometer, and Tono-Pen in the sitting, supine, and prone positions. RESULTS: The difference of IOP measured in the sitting position among the 4 groups was not significant. IOP was significantly elevated by 2.04 mm Hg on average when the posture was changed from sitting to supine or prone in all 4 groups. The IOP discrepancy between supine and sitting positions was significantly greater in group 4 by 3.61 mm Hg than the other groups (p = 0.003, ANOVA test). The IOP difference between the prone and sitting position was also significantly higher in group 4 by 3.82 mm Hg than the other groups (p = 0.001, ANOVA test). CONCLUSIONS: The patients with vitrectomized gas tamponade eyes had a mean IOP increase of 3.82 mm Hg when the position was changed from sitting to prone. When performing vitrectomy and intraocular gas tamponade on patients in the prone position, an IOP elevation should be monitored thoroughly.

Ocular Myasthenia Gravis in Conjunction with Thyroid-Associated Ophthalmopathy: A Case Report

PURPOSE: To report a case of ocular myasthenia gravis in conjunction with thyroid-associated ophthalmopathy in a patient who showed incomitant strabismus and blepharoptosis as well as to discuss the clinical features and tests that may help distinguish these 2 diseases. CASE SUMMARY: A 46-year-old man without any previous history of systemic and ophthalmic disease presented with binocular diplopia that occured a month earlier. The patient had no other systemic symptoms except a 7 kg weight loss within the last month. The patient was referred to the department of internal medicine and brain magnetic resonance imaging was performed to ascertain the cause of suspected left superior oblique muscle palsy. The patient was diagnosed with Graves' disease and underwent medical treatment. One month later, the patient presented with consistent diplopia and exophthalmos and showed a swelling of eyelid and ptosis in the right eye. Intravenous high-dose steroid therapy was administered to the patient. After the treatment, symptoms of diplopia and lid swelling were improved, however ptosis persisted. Ocular myasthenia gravis was suspected and various tests were conducted. Anti-acetylcholine receptor antibodies were detected in large amounts and ptosis was improved dramatically by an administration of an anticholinesterase agent. The patient was diagnosed with ocular myasthenia gravis in conjunction with thyroid-associated ophthalmopathy. CONCLUSIONS: Ocular myasthenia gravis should be suspected in patients with thyroid-associated ophthalmopathy who have signs or symptoms of ptosis.

Postoperative Visual Field Outcomes in Patients Showing Visual Field Defects due to Pituitary Adenoma

PURPOSE: To evaluate visual field (VF) changes in patients with pituitary adenoma after surgical treatment. METHODS: The present study retrospectively evaluated 96 eyes of 48 patients with pituitary adenoma who received surgical tumor removal between July 2001 and February 2010. Preoperative and postoperative clinical data including age, tumor volume, logMAR BCVA, surgical technique (transsphenoidal surgery and transcranial surgery), static perimetry scores (mean deviation [MD], pattern standard deviation [PSD], and visual field defect [VFD] scores) were reviewed. RESULTS: The MD (15.79%, p = 0.001) and PSD (3.98%, p = 0.003) improved postoperatively (mean postoperative follow-up period 1.85 months). Transsphenoidal surgery for tumor removal showed significant MD (26.99%, p = 0.000) and PSD (12.92%, p = 0.003) improvements. A multivariate regression analysis of the transsphenoidal surgery patient group revealed that the preoperative MD was related to the postoperative MD (Pearson = 0.762, p = 0.000), but negatively correlated to the amount of postoperative improvement in MD score (Pearson = -0.231, p = 0.046). Transcranial surgery did not significantly improve the MD (p = 0.419), PSD (p = 0.562), VFD score (p = 0.135), or logMAR BCVA (p = 0.708). CONCLUSIONS: Visual filed defects in patients with pituitary adenoma improved after neurosurgical treatment. Better postoperative visual field outcomes were achieved in patients who had smaller preoperative visual field defects. Transsphenoidal surgery significantly improved the visual field defects and visual acuity in patients with non-functioning pituitary adenoma, compared to the transcranial surgery patients.

Two Cases of Non-Surgical Removal of Intravascular Foreign Bodies

One of the complication during or after subclavian vein cannulation is intravascular catheter or wire embolization. Although some studies have reported safety of retaining foreign body embolization, and even death. The intravascular foreign body can be removed surgically or non-surgically. With improvement in instrument technology and technique, percutaneous retrieval of intravascular foreign bodies has become a relatively common procedure. Commonly used methods to remove intravascular foreign bodies are loop snare and basket technique. Sometimes biopy forcep can be used. We have experienced 2 cases of non-surgical removal of intravascular foreign bodies. One of the foreign bodies was 7cm wire fragment in right atrium(RA), the other was a 50cm guide wire. We used the standard loop snare technique for removal of 7cm wire fragment in RA and stone removal basket and 3.0mm ACS PTCA balloon to remove the 50cm short guide wire.