Kyoung In Jung

Cataract Surgery in Eyes With Nanophthalmos and Relative Anterior Microphthalmos

PURPOSE To compare the refractive outcome and postoperative complications of cataract surgery among nanophthalmos and relative anterior microphthalmos and the normal control eyes. DESIGN Retrospective case-control series. METHODS Seventeen eyes with nanophthalmos, 29 eyes with relative anterior microphthalmos, and 54 normal control eyes were enrolled in this study. The subjects were divided into 3 diagnostic subgroups according to the following: nanophthalmos with an axial length <20.5 mm and without morphologic malformation; relative anterior microphthalmos with a corneal diameter (CD) ≤ 11 mm, an anterior chamber depth (ACD) ≤ 2.2 mm, and an axial length (AL) ≥ 20.5 mm; and normal control group eyes defined as an AL ≥ 20.5 mm with a CD >11 mm or an ACD >2.2 mm. The implanted intraocular lens (IOL) power was used to calculate the predicted postoperative refraction error according to 4 IOL power formulas: SRK II, SRK/T, Hoffer Q, and Holladay 1. With each formula, the mean numeric error and mean absolute error were calculated. At postoperative 2 months, the endothelial cell count and the complications were analyzed. RESULTS As measured by mean numeric error or mean absolute error, there was a significant difference among the 3 groups based on SRK II, SRK/T, and Hoffer Q, with less predictability in the nanophthalmic eyes. In eyes with nanophthalmos, the Holladay 1 produced the best refractive results as measured by mean numeric error (P < .001). A higher occurrence rate of posterior capsule rupture (11.7%) was shown in the nanophthalmic eyes. The difference among the 3 groups for the postoperative endothelial cell loss was not significant (P = .421). CONCLUSIONS The refractive predictability and postoperative outcome was poorer in the eyes with nanophthalmos compared to the eyes with relative anterior microphthalmos or normal control.

Changes in the lamina and prelamina after intraocular pressure reduction in patients with primary open-angle glaucoma and acute primary angle-closure.

PURPOSE To compare changes in the prelamina and lamina of patients with POAG and acute primary angle-closure (APAC) after IOP reduction. METHODS We analyzed 20 patients with POAG who were scheduled to undergo glaucoma surgery and 17 patients with APAC scheduled for laser peripheral iridoplasty. Horizontal B-scans of the optic nerve head were obtained using Heidelberg Spectralis optical coherence tomography. The prelaminar position (PLP), laminar position (LP), and prelaminar thickness (PLT) were measured. Scans were obtained before and at 1 month after the intervention. Regression analysis was used to evaluate factors related to the changes in PLP, LP, and PLT. RESULTS Mean IOP reduction after the intervention was 21.69 ± 4.26 mm Hg in the POAG group and 23.06 ± 4.54 mm Hg in the APAC group (P = 0.746). After IOP reduction, the mean changes in the PLP were 21.92 ± 13.16 μm in the POAG group and 47.84 ± 28.05 μm in the APAC group (comparison between two groups, P < 0.001). After IOP reduction, the mean changes in the LP were 19.17 ± 7.25 μm in the POAG group and 32.70 ± 23.23 μm in the APAC group (comparison between two groups, P < 0.001). After IOP reduction, the APAC group exhibited a significantly greater increase in PLT than the POAG group (comparison between two groups, P < 0.001). Cumulative IOP insult, IOP percent reduction, duration of IOP elevation, and diagnosis of APAC were significantly related to the changes in the prelamina and lamina in regression analysis. CONCLUSIONS IOP reduction leads to different responses of the prelamina and lamina between POAG and APAC patients. Anterior movement of the prelamina and lamina and thickening of the prelamina were more pronounced in the optic nerve head of APAC patients.

Comparative study of macular ganglion cell-inner plexiform layer and peripapillary retinal nerve fiber layer measurement: structure-function analysis.

PURPOSE We explored and compared the relationships between the visual field (VF) sensitivities assessed by standard automated perimetry (SAP), and the ganglion cell-inner plexiform layer (GCIPL) and peripapillary retinal nerve fiber layer (pRNFL) thicknesses as measured by Cirrus high-definition optical coherence tomography (HD-OCT) in glaucomatous eyes. METHODS We enrolled 213 eyes of 213 patients with glaucoma. The thicknesses of the average/sectoral GCIPL and pRNFL were measured by Cirrus HD-OCT. The mean sensitivity (MS) of 24-2 SAP was recorded on decibel and 1/L scales. The topographic relationships between structure and function were investigated. RESULTS Statistically significant correlations between the corresponding VF sensitivity and the macular GCIPL thickness were found in all GCIPL sectors. Among six GCIPL sectors, the strongest association was observed between superonasal center MS and inferotemporal GCIPL thickness. In comparative analysis, the association between the central cluster MS and average GCIPL thickness was significantly stronger than that of temporal pRNFL thickness using the decibel scale (P < 0.001). The association between regional VF sensitivities, and the inferior hemifield and inferior GCIPL thicknesses were significantly stronger than those of the corresponding pRNFL thickness using the decibel scale (P = 0.001 and 0.007). CONCLUSIONS The average and sectoral GCIPL thicknesses determined by Cirrus HD-OCT were associated significantly with global and regional VF sensitivity in patients with glaucoma. The macular GCIPL thickness values may provide more valuable information than temporal pRNFL thickness values for understanding the structure-function relationships of the macular region.

Factors affecting plastic lamina cribrosa displacement in glaucoma patients.

PURPOSE To investigate factors associated with irreversible components of anterior lamina cribrosa (LC) depth in glaucoma patients. METHODS A total of 141 glaucoma patients and 51 healthy control subjects were enrolled. The optic nerve head (ONH) was imaged using the enhanced depth imaging (EDI) modes of Spectralis optical coherence tomography (OCT). The depth of the LC was measured at the midhorizontal, superior, and inferior midperipheral regions of the ONH of each eye. Analyzed factors associated LC depth included age, axial length, intraocular pressure (IOP), disc size, central corneal thickness, average retinal nerve fiber layer (RNFL) thickness, and mean deviation (MD). RESULTS In glaucoma patients, the LC was more deeply located compared with the control group at the midhorizontal and superior and inferior midperipheral B-scans (All P < 0.001). Age, initial IOP, and treated IOP was correlated with mean LC depth (All P < 0.001), and those correlations remained after adjusting for MD and RNFL thickness (All P < 0.001). In multivariate analysis, younger age, high untreated IOP, and thinner RNFL thickness was significantly associated with a deeper LC (P = 0.015, <0.001, and 0.042). There was an interaction between age and MD as predictors for LC depth (P = 0.007). CONCLUSIONS The anterior LC surface is more deeply located in glaucoma patients compared with healthy controls. In glaucoma patients, age, initial IOP, and RNFL thickness were influential factors related to LC depth. These factors should be considered in clinical application of plastic LC displacement in glaucoma patients.

Neuroprotective Effects of Cilostazol on Retinal Ganglion Cell damage in Diabetic Rats

Neurodegeneration is an important component of diabetic retinopathy, with increasing evidence that retinal ganglion cell (RGC) death occurs early in diabetes. We investigated the effects of cilostazol, which has been widely used to manage diabetic complications, on retinal ganglion cell death in the diabetic retina. Four-week-old Otsuka Long-Evans Tokushima fatty (OLETF) rats and Long-Evans Tokushima Otsuka (LETO) rats as matched nondiabetic controls were treated with daily oral cilostazol at 30 mg/kg or 0.9% saline solution. In OLETF rats at the age of 40 weeks, glial fibrillary acidic protein (GFAP) immunofluorescence staining was upregulated in vertical sections, and showed a more ramified pattern in whole-mount retinas compared with that in LETO rats. Vascular endothelial growth factor (VEGF) expression was limited to the ganglion cell layer in LETO rats, but extended into the outer plexiform layer in OLETF rats. Immunofluorescence staining and Western blotting demonstrated that cilostazol treatment reduced GFAP and VEGF expression in the retinas of OLETF rats. Terminal deoxynucleotidyl transferase-mediated terminal deoxynucleotidyl transferase–mediated digoxigenin-deoxyuridine nick-end labeling (TUNEL) staining revealed an increase in the RGC layer in OLETF compared with LETO rats (P < 0.05), and cilostazol treatment reduced the number of TUNEL-positive cells in OLETF rats (P < 0.05). Relieving retinal ischemia by systemic cilostazol treatment had a noticeable protective effect on RGCs in diabetic rats. Cilostazol treatment may be useful for the management of diabetic retinal vascular dysfunction and neuronal degeneration.

Foreign Body Reaction in Glaucoma Drainage Implant Surgery

PURPOSE To investigate the histopathology of the foreign body reaction (FBR) and the effect of aqueous humor on it in glaucoma drainage implant surgery. METHODS A glaucoma drainage device was implanted into 20 New Zealand white rabbits. We monitored the histopathology of blebs at microscopic levels from 3 days to 8 weeks postoperatively. Hematoxylin and eosin staining, Massons trichrome staining, anti-actin and α-smooth muscle immunofluorescence staining, and antiproliferating cell nuclear antigen immunohistochemistry were performed. To observe effects of aqueous humor on FBR, we designed two implant models. One group received a plate with a tube placed in the anterior chamber (experimental group), whereas the other received the plate cut from the tube (control group). RESULTS Foreign body giant cells were found along the inner border of blebs, and the innermost layer of blebs demonstrated a densely packed collagenous stratum in both groups. The number of foreign body giant cells was suppressed in the experimental group compared with the control group (P < 0.001). Fibroblast division was more active in the experimental group than that in the control group. Massons trichrome staining demonstrated that the innermost avascular collagenous layer was much thicker in the experimental group than that in the control group (P = 0.021). The extent of α-SMA staining was greater in the experimental group than that in the control group. CONCLUSIONS In the aqueous humor environment, wound healing around a glaucoma drainage implant revealed a unique FBR with the relatively small number of foreign body giant cells and reinforced fibrotic encapsulation.

Effects of an Anti-transforming Growth Factor-β Agent (Pirfenidone) on Strabismus Surgery in Rabbits

Purpose: To evaluate the usefulness of an anti-transforming growth factor-β (TGF-β) agent, pirfenidone (PFD) on postoperative inflammation and fibrosis following strabismus surgery in rabbits. Methods: Both eyes of 16 New Zealand white rabbits underwent reinsertion of the superior rectus muscle (SRM). After reinsertion of the SRM, PFD-loaded liposomes (0.5 mg/ml) were injected into the right eye (PFD group) and normal saline-loaded liposomes was injected into the left eye (control group), subconjunctivally (0.4 ml). To assess the postoperative inflammatory changes and fibrosis of the SRM, immunofluorescence staining with anti-CD11b antibody was performed at 3 days postoperatively, and Masson’s trichrome staining was performed at 4 weeks postoperatively. To evaluate the toxicity of PFD on muscle fibers, the integrity of the muscle fibers was examined by transmission electron microscopy (TEM) at 3 days and 4 weeks postoperatively. Results: CD11b protein expression was significantly reduced in the PFD group compared with the control group at 3 days postoperatively (p = 0.012). Masson trichrome staining, which stains collagen, was diminished in the PFD group at 4 weeks postoperatively. TEM revealed disorganized muscle fibers and vacuoles in both groups, but this was less prominent in the PFD group. Conclusions: Intraoperative injection of PFD may be effective as an adjunctive treatment to decrease inflammation and fibrosis resulting from strabismus surgery.

Comparison of Prelaminar Thickness between Primary Open Angle Glaucoma and Normal Tension Glaucoma Patients

Main Objective The thinning of prelaminar tissue and prelamina cupping is known to occur by ischemia, as we see in anterior ischemic optic neuropathy. Since normal tension glaucoma (NTG) is thought to be more related to vascular factor than in primary open-angle glaucoma (POAG), we hypothesized that prelamina thinning may occur prominently in NTG patients. This study investigated the difference in prelaminar tissue thickness between patients with POAG and NTG and verified the factors related to prelaminar thinning. Methods Complete ophthalmic examination including standard automatic perimetry was performed in all patients. The prelaminar tissue thickness was measured in all patients by performing enhanced depth imaging with a Heidelberg Spectralis Optical Coherence Tomography. The retinal nerve fiber layer and optic nerve head parameters were obtained using the Heidelberg Retina Tomography II and Cirrus Optical Coherence Tomography. Various ocular factors and their relationships with prelaminar thickness were analyzed. Results The mean prelaminar tissue thickness was significantly thinner in patients with POAG than in those with NTG. The difference in the prelaminar thickness between patients with POAG and those with NTG was greater in the early field defect group than in the moderate and severe field groups. In multivariate analysis, the mean prelaminar thickness was related to the intraocular pressure, mean deviation, cup-disc ratio, and cup volume. Conclusions The prelaminar tissue was thinner in patients with POAG than in patients with NTG, and intraocular pressure had a strong influence on the prelaminar thickness in both POAG and NTG. This may indicate that mechanical compression is the main pathogenic factor in both POAG and NTG.

Serial changes in the bleb wall after glaucoma drainage implant surgery: Characteristics during the hypertensive phase

To investigate serial changes in the bleb wall using anterior segment optical coherence tomography (AS‐OCT) in patients who had undergone Ahmed glaucoma valve (AGV) implantation.

α2-Adrenergic modulation of the glutamate receptor and transporter function in a chronic ocular hypertension model

Excitotoxicity, glutamate-induced toxic effects to retinal ganglion cells (RGCs), is one of several mechanisms of RGC loss suggested in glaucoma. In this study, we focused on the role of glutamate transporter of glial cells as well as N-methyl-d-aspartate (NMDA) receptor with regard to glutamate toxicity in glaucoma. We also investigated whether α2-adrenoceptor activation could modulate glutamate transporters and NMDA receptors in a chronic ocular hypertension model. Brimonidine 0.15% was administered topically to the eyes of experimental glaucoma and control animals twice daily. After 8 weeks of intraocular pressure (IOP) elevation, staining with terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) revealed an increase in the ganglion cell layer, and the number of TUNEL-positive cells was reduced by brimonidine treatment (P<0.05). Animals with experimentally induced glaucoma exhibited an increase in retinal stress marker glial fibrillary acidic protein (GFAP) immunoreactivity; brimonidine treatment reduced GFAP. Excitatory amino acid transporter 1(EAAT1) expression remained stable throughout the period of chronic ocular hypertension. α2-Adrenergic treatment upregulated EAAT1 protein levels (P<0.05). NMDA receptor (GluN1) expression was stimulated by chronic elevation of IOP, and GluN1-positive cells in ganglion cell layer were co-localized with TUNEL staining. Brimonidine administration suppressed GluN1 levels (P<0.05). These results indicate that brimonidine decreased RGC apoptosis, upregulating EAAT1 and downregulating NMDA receptors. We suggest that topical brimonidine treatment may decrease the glutamate excitotoxicity through modulation of glutamate transporter and NMDA receptor in glaucoma.