Ji Hye Park

Head Elevation and Intraocular Pressure in Glaucoma.

Purpose To investigate the effect of different methods of head elevation on intraocular pressure (IOP) in patients with open-angle glaucoma (OAG). Methods Seventy-one patients of OAG were included in this prospective observational study. We measured IOP in the sitting position and in the supine positions with head flat and 30-degree up using two different methods: (1) bed head elevation (BHE) and (2) using multiple pillows (MP). We measured IOP using Tonopen AVIA in both eyes 10 minutes after assuming each position in a randomized sequence. By comparing the mean deviation (MD) of visual field between both eyes of a patient, we classified the eyes into either the better-MD eye or worse-MD eye. Results Compared with that measured in the supine position with head flat, the mean IOP was significantly lower when measured in the supine position with the head 30 degrees up by BHE, with an average drop of 2.0 mmHg (p < 0.001), whereas the mean IOP did not differ significantly when measured in the supine position with head 30 degrees up using MP (p = 0.081). Twenty-five (35.2%) patients showed IOP elevation when the head was kept up by MP. Compared between the better-MD and worse-MD eye, the IOPs did not differ in all positions. The mean IOP of the better-MD eye was lower in the 30-degree head-up (−1.9 mmHg, BHE; −0.8 mmHg, MP) positions compared with that in the flat-lying position, whereas the mean IOP of the worse-MD eye did not differ between the lying flat position and the head-up position with MP. Conclusions Different head-elevating methods had different influences on IOPs of glaucoma patients in the supine position. Although raising the bed head by 30 degrees significantly lowers IOP compared to the supine position, resting on multiple pillows does not appear to offer the same IOP reduction in glaucoma patients.

Effect of Lovastatin on Wound-Healing Modulation After Glaucoma Filtration Surgery in a Rabbit Model

PURPOSE To investigate the efficacy of lovastatin as an antifibrotic agent after glaucoma filtration surgery (GFS) in a rabbit model. METHODS Thirty New Zealand white rabbits underwent GFS on the right eye. The rabbits were randomly assigned to one of three groups: (1) the mitomycin-C (MMC) group, which received 0.2 mg/mL MMC-soaked Weck-Cel under the conjunctival flap; (2) the control group, which received postoperative subconjunctival injections with 0.1 mL balanced salt solution (BSS); and (3) the lovastatin group, which received postoperative subconjunctival injection with 0.1 mL lovastatin (10 μM). Intraocular pressure (IOP), bleb survival, and bleb morphology were examined until blebs showed evidence of failure. Three rabbits in each group were killed on postoperative day (POD) 5, and analyzed for histology and immunohistochemistry. RESULTS Lovastatin significantly improved bleb survival compared with that in the control group (P = 0.002); however, no significant difference in bleb survival was observed between the MMC and lovastatin groups (P = 0.097). The lovastatin group showed significantly larger and higher blebs than did the control group. Further, the IOPs of the lovastatin and MMC groups were significantly lower than that of the control group (8.0 ± 1.4 mm Hg, 7.9 ± 3.2 mm Hg, and 11.1 ± 2.9 mm Hg, respectively; P = 0.016) on POD 5. Histologic analyses revealed decreased inflammatory response and reduced fibrosis in the lovastatin group than in the control group. CONCLUSIONS Postoperative injection of lovastatin improved bleb survival in the rabbit model of GFS. Therefore, lovastatin may have potential as a novel wound-modulating agent after GFS.

Localized Retinal Nerve Fiber Layer Defects in Red-free Photographs Versus en Face Structural Optical Coherence Tomography Images

Purpose: The purpose of this article is to compare the locations of localized retinal nerve fiber layer (RNFL) defects in red-free fundus photographs and optical coherence tomography (OCT) en face images. Methods: We performed a retrospective, comparative study on 46 eyes from 46 glaucoma patients with localized RNFL defects observed in red-free fundus photographs. En face structural images were obtained in the superficial and whole retinal layers using OCT and were overlaid on the corresponding red-free fundus photographs. The proximal/distal angular locations and angular width of each RNFL defect in red-free photos (red-free defects) and in en face structural images (en face defects) were compared. Results: In the superficial retinal layer, there were no significant differences between red-free and en face defects on the proximal/distal angular location and angular width. In the whole retinal layer, the degree of the distal angular location of the en face defects was significantly larger than that of the red-free defects (71.85±18.26 vs. 70.87±17.90 degrees, P=0.003). The correlations of clinical variables with the differences in angular parameters between red-free and en face defects were not significant in the superficial retinal layer. The average RNFL thickness was negatively correlated with the difference in the distal angular location in the whole retinal layer (Pearson correlation coefficient=−0.401, P=0.006). Conclusions: Localized RNFL defects detected in OCT en face structural images of the superficial retinal layer showed high topographic correlation with defects detected in red-free photographs. OCT en face structural images in the superficial layer may be an alternative to red-free fundus photography for the identification of localized RNFL defects in glaucomatous eyes.

Effect of Lateral Decubitus Body Posture on Anterior Chamber Angle in Healthy Subjects: An Anterior Segment Optical Coherence Tomography Study

Purpose: To investigate the effect of the lateral decubitus (LD) position on the anterior chamber (AC) angle in healthy subjects. Materials and Methods: Twenty-three healthy young subjects were included in this prospective observational study. We measured AC angle parameters in the sitting and the left LD positions using anterior segment optical coherence tomography (Visante OCT): trabecular-iris angle (TIA), angle opening distance (AOD500), trabecular-iris space area (TISA500), anterior chamber width, lens vault, and anterior chamber depth. The Wilcoxon signed-rank test was used to compare the parameters between different body positions. Interobserver reproducibility of AC angle measurements was assessed by intraclass correlation coefficients. Results: Postural alterations from sitting to the left LD position significantly reduced the AC angle on the temporal side in right eyes (TIA: 39.53±2.38 to 38.31±3.47 degrees; AOD500: 0.72±0.13 to 0.65±0.08; TISA500: 0.25±0.06 to 0.22±0.04; all P<0.05), whereas no significant changes were noted on the nasal side. Contrastingly, a significant decrease in the AC angle on the nasal side was noted for left eyes (TIA: 39.49±2.24 to 38.17±2.76 degrees; AOD500: 0.68±0.09 to 0.64±0.10; TISA500: 0.23±0.04 to 0.21±0.03; all P<0.05). Anterior chamber width and anterior chamber depth were unaffected by postural alterations, but lens vault significantly was reduced following a shift to the left LD position. Conclusions: The AC angle parameters on the nondependent side of the eye in the LD position were significantly reduced compared with those in the sitting position. Therefore, postural shift from sitting to the LD position may induce alterations in the AC angle.

Visual Field Defects in Young Patients With Open-angle Glaucoma: Comparison Between High-tension and Normal-tension Glaucoma

Purpose: To investigate the clinical features of young Korean patients with open-angle glaucoma (OAG), and to compare visual field (VF) defects between patients with normal-tension glaucoma (NTG) and those with high-tension glaucoma (HTG). Materials and Methods: Patients with OAG younger than 40 years of age were divided into NTG and HTG groups based on untreated intraocular pressure (IOP) level. The patients were matched according to the mean deviation of standard automated perimetry. VFs were divided into 2 pairs of corresponding areas across the horizontal meridian, and the depths of VF defects were compared. Tilt ratio and torsion degree of their optic discs were also compared between the 2 groups. Results: Thirty-four pairs of NTG and HTG eyes were matched. Although untreated IOP showed intergroup differences, there was no difference in age, refractive error, tilt ratio, torsion degree, and depth of VF defects between the 2 groups. However, NTG eyes showed deeper VF defects in the superior paracentral area than in the inferior paracentral area (−8.29±9.33 vs. −4.45±6.03 dB, P=0.038), whereas the HTG eyes showed symmetric VF defects. Moreover, the superior paracentral area showed deeper VF defects compared with the superior arcuate area in the NTG group (P=0.002). Conclusions: Young patients with NTG showed asymmetric VF defects in the paracentral area, whereas those with HTG did not show such asymmetric defects. This suggests that the level of IOP may affect the pattern of VF defects in young patients with OAG. However, these findings may not be generalizable to other populations.

Risk Factors Associated with Glaucomatous Progression in Pseudoexfoliation Patients

Purpose: To investigate risk factors associated with glaucomatous progression in pseudoexfoliation glaucoma (PXG) patients. Patients and Methods: A retrospective observational study with a total of 48 PXG patients and age, sex, and visual field (VF) test mean deviation–matched 48 primary open-angle glaucoma (POAG) patients recruited from 3 university-based hospitals. Glaucomatous progression was defined by 2 criteria, either optic disc/retinal nerve fiber layer photographic assessment or serial VF data. Univariate and multivariate Cox proportional hazard models were used to detect associations between risk factors and progression in each subgroup and shared frailty model were used in total participants. Results: In total participants, PXG diagnosis [hazard ratio (HR), 7.245; P=0.050], a higher baseline intraocular pressure (IOP) (HR, 1.221; P=0.025) and a greater number of glaucoma medications (HR, 3.537; P=0.016) were significant factors for glaucoma progression. In the PXG group, a higher baseline IOP (HR, 1.131; P<0.001), a lower IOP reduction (HR, 0.966; P=0.027), a greater number of glaucoma medications (HR, 2.413; P=0.004), and worse baseline VF mean deviation (HR, 0.875; P=0.004) were significant factors, whereas the number of glaucoma medications (HR, 3.493; P=0.019) and disc hemorrhage (HR, 3.953; P=0.043) showed association in the POAG group. Conclusions: Factors associated with progression differed between PXG and POAG groups. Higher baseline IOP and requirement for a greater number of glaucoma medications were related with PXG progression.

Long-term Surgical Outcomes of 180-Degree Suture Trabeculotomy in Korean Patients With Primary Congenital Glaucoma.

Purpose:To investigate the surgical outcomes of 180-degree suture trabeculotomy in Korean patients with primary congenital glaucoma (PCG). Patients and Methods:This retrospective study included 21 eyes of 17 children with PCG who underwent 180-degree suture trabeculotomy as a first surgical procedure. Surgical success was defined as (1) an intraocular pressure (IOP)<22 mm Hg with or without medication; (2) no additional intraocular surgery; and (3) no evidence of progressive optic disc cupping. The main outcome measure was the success rate of 180-degree suture trabeculotomy. Secondary outcome measures were IOP, number of glaucoma medications, and occurrence of complications. Results:Of the 21 eyes included, 18 (85.7%) were classified as having achieved success at the final visit (mean last follow-up or failure time, 54.91±45.68 mo). Median age at surgery was 11.97 months with mean IOP 29.8±9.6 mm Hg, on average of 1.52 medications. The mean IOP at the final visit was 16.9±5.6 mm Hg on an average of 0.38 medications. The surgical success rate of 180-degree suture trabeculotomy at 1, 3, and 5 years was 95.0%, 87.7%, and 78.9%, respectively (Kaplan-Meier analysis). Three eyes underwent second operations and the mean time to failure was 29.39±19.75 months. Hyphema was observed in 10 eyes, but it cleared up within 7.6 days. Conclusion:The 180-degree suture trabeculotomy performed for PCG had a significant IOP-lowering effect and caused no remarkable complications.

Effect of cataract surgery on intraocular pressure in supine and lateral decubitus body postures

Purpose: To investigate the effect of phacoemulsification on intraocular pressure (IOP) in different recumbent body postures including supine and lateral decubitus (LD) positions. Materials and Methods: This prospective, observational study included patients who had no glaucoma and who had planned to undergo phacoemulsification and intraocular lens implantation in one eye. Before and 1 month after cataract surgery, IOP was measured in both eyes using the Tono-Pen AVIA. We measured IOP in the sitting, supine, and LD (with the operated eye placed on the lower side) positions. IOP was measured 10 min after assuming each position in a randomized sequence. The Wilcoxon signed-rank test was used to compare the IOP changes before and 1 month after phacoemulsification in all postures. Results: Twenty-nine patients participated in this study. Postoperative IOP was lower than the preoperative IOP when measured by Goldmann applanation tonometry in the sitting position (13.8 ± 1.9 mmHg vs. 12.6 ± 2.1 mmHg, P = 0.007). The postoperative IOP was lower than the preoperative IOP for the supine and LD positions. The average IOP reduction of the operated eye was 0.6 mmHg, 1.7 mmHg, and 3.0 mmHg in the sitting, supine, and LD positions, respectively (sitting vs. supine, P = 0.048; sitting vs. LD, P = 0.001; supine vs. LD, P = 0.028). In the nonoperated eye, IOP did not change significantly after surgery (all P > 0.05). Conclusions: Cataract surgery lowered IOP in the sitting position as well as in the supine and LD positions. Such postoperative IOP reductions were greater in the recumbent positions than in the sitting position.