Difference in patterns of retinal ganglion cell damage between primary open-angle glaucoma and non-arteritic anterior ischaemic optic neuropathy.

PURPOSE: To compare the patterns of retinal ganglion cell damage between primary open-angle glaucoma (POAG) and non-arteritic anterior ischaemic optic neuropathy (NAION). METHODS: In total, 35 eyes with unilateral NAION, and 70 age- and average peripapillary retinal nerve fibre layer (RNFL) thickness-matched eyes with POAG, were enrolled as disease groups; 35 unaffected fellow eyes of the NAION, and 70 age- and refractive error-matched normal subjects for the POAG, were enrolled as their control groups, respectively. The peripapillary RNFL thickness and macular ganglion cell plus inner plexiform layer (GCIPL) thickness were compared between the disease groups and their controls, and between the two disease groups. RESULTS: Mean RNFL thicknesses at the 1 and 2 o'clock (superonasal) positions were thinner in NAION than in POAG (both p < 0.05). Mean RNFL thickness at 7 o'clock (inferotemporal) was thinner in POAG than in NAION (p = 0.001). Although there was no significant difference between NAION and POAG in average GCIPL thickness, all of the sectoral GCIPL thicknesses were thinner in NAION (all p < 0.05), except in the inferior and inferotemporal sectors. The ranges of the clock-hour RNFL with damage greater than the average RNFL thickness reduction, versus fellow eyes and control eyes, were 7 hours in NAION and 4 hours in POAG. CONCLUSIONS: The more damaged clock-hour RNFL regions differed between NAION (1 and 2 o'clock) and POAG (7 o'clock). Most sectoral GCIPL thicknesses were thinner in NAION than in POAG.

Properties of pattern standard deviation in open-angle glaucoma patients with hemi-optic neuropathy and bi-optic neuropathy.

PURPOSE: To evaluate the properties of pattern standard deviation (PSD) according to localization of the glaucomatous optic neuropathy. METHODS: We enrolled 242 eyes of 242 patients with primary open-angle glaucoma, with a best-corrected visual acuity ≥ 20/25, and no media opacity. Patients were examined via dilated fundus photography, spectral-domain optical coherence tomography, and Humphrey visual field examination, and divided into those with hemi-optic neuropathy (superior or inferior) and bi-optic neuropathy (both superior and inferior). We assessed the relationship between mean deviation (MD) and PSD. Using broken stick regression analysis, the tipping point was identified, i.e., the point at which MD became significantly associated with a paradoxical reversal of PSD. RESULTS: In 91 patients with hemi-optic neuropathy, PSD showed a strong correlation with MD (r = -0.973, ß = -0.965, p < 0.001). The difference between MD and PSD ("-MD-PSD") was constant (mean, -0.32 dB; 95% confidence interval, -2.48~1.84 dB) regardless of visual field defect severity. However, in 151 patients with bi-optic neuropathy, a negative correlation was evident between "-MD-PSD" and MD (r2 = 0.907, p < 0.001). Overall, the MD tipping point was -14.0 dB, which was close to approximately 50% damage of the entire visual field (p < 0.001). CONCLUSIONS: Although a false decrease of PSD usually begins at approximately 50% visual field damage, in patients with hemi-optic neuropathy, the PSD shows no paradoxical decrease and shows a linear correlation with MD.

Combined cataract extraction and vitrectomy for macula-sparing retinal detachment: visual outcomes and complications.

PURPOSE: To evaluate the visual outcome of combined phacoemulsification, intraocular lens implantation, and vitrectomy for macula-sparing rhegmatogenous retinal detachment. METHODS: The results of combined vitrectomy with cataract extraction were retrospectively analyzed in patients with preexisting cataracts and new-onset rhegmatogenous retinal detachment. To qualify, patients must also have had macular sparing in a region 6,000 µm in diameter on optical coherence tomography. The anatomical success rate, visual outcomes, and postoperative complications relating to visual acuity were evaluated. RESULTS: In 56 patients followed postoperatively for more than 12 months, the initial and final surgical success rate was 96.4% and 100%, respectively. The mean preoperative logarithm of the minimum angle of resolution visual acuity was 0.05 and decreased to 0.11 postoperatively (p < 0.001). Of the 56 patients, 20 (35.7%) had worse visual acuity postoperatively, compared with preoperatively (0.06 vs. 0.27, p < 0.001); these cases were comprised of six patients with epiretinal membranes, 12 patients with a posterior capsule opacity, and two patients with cystoid macular edema. In the remaining 36 patients, there were no significant differences in visual acuity preoperatively and postoperatively (0.04 vs. 0.03, p = 0.324). CONCLUSIONS: In patients with cataracts who develop macula-sparing rhegmatogenous retinal detachment and whose visual prognosis is excellent assuming the retina can be reattached successfully, combined phacoemulsification, intraocular lens implantation, and vitrectomy might be an effective treatment. However, the visual prognosis is significantly affected by postoperative complications such as an epiretinal membranes, posterior capsule opacity, and cystoid macular edema. Therefore, further studies should examine methods to prevent these postoperative complications.

Expression-associated polymorphisms of CAV1-CAV2 affect intraocular pressure and high-tension glaucoma risk.

PURPOSE: The human CAV1-CAV2 locus has been associated with susceptibility to primary open-angle glaucoma in four studies of Caucasian, Chinese, and Pakistani populations, although not in several other studies of non-Korean populations. In this study with Korean participants, the CAV1-CAV2 locus was investigated for associations with susceptibility to primary open-angle glaucoma accompanied by elevated intraocular pressure (IOP), namely, high-tension glaucoma (HTG), as well as with IOP elevation, which is a strong risk factor for glaucoma. METHODS: Two single nucleotide polymorphisms (SNPs) were genotyped in 1,161 Korean participants including 229 patients with HTG and 932 healthy controls and statistically examined for association with HTG susceptibility and IOP. One SNP was rs4236601 G>A, which had been reported in the original study, and the other SNP was rs17588172 T>G, which was perfectly correlated (r2=1) with another reported SNP rs1052990. Expression quantitative trait loci (eQTL) analysis was performed using GENe Expression VARiation (Genevar) data. RESULTS: Both SNPs were associated with HTG susceptibility, but the rs4236601 association disappeared when adjusted for the rs17588172 genotype and not vice versa. The minor allele G of rs17588172 was associated significantly with 1.5-fold increased susceptibility to HTG (p=0.0069) and marginally with IOP elevation (p=0.043) versus the major allele T. This minor allele was also associated with decreased CAV1 and CAV2 mRNA in skin and adipose according to the Genevar eQTL analysis. CONCLUSIONS: The minor allele G of rs17588172 in the CAV1-CAV2 locus is associated with decreased expression of CAV1 and CAV2 in some tissues, marginally with IOP elevation, and consequently with increased susceptibility to HTG.

Expansive marker analysis replicating the association of glaucoma susceptibility with human chromosome loci 1q43 and 10p12.31.

Three human chromosome loci (1q43, 10p12.31, and 12q21.31) were recently associated with the susceptibility to primary open-angle glaucoma (POAG) in a Japanese population; however, this was not replicated in three subsequent studies using South Indian, Afro-Caribbean, and Chinese populations. To identify genetic markers that are robustly associated across ethnic populations, numerous markers in addition to the six in the three reported loci were examined in this study. A total of 31 single-nucleotide polymorphism (SNP) markers were genotyped for 1115 Korean participants, and many neighboring SNPs were imputed using the Korean HapMap Project genotype data. Each SNP was statistically tested for association with POAG susceptibility by comparisons among 211 POAG patients with 904 unaffected controls. A strong and statistically significant association was found with a previously unreported SNP, rs7098387 (odds ratio, OR=2.0 (1.4-3.0), P=0.00038) at the 10p12.31 locus (where 11 SNPs were typed and 38 imputed) in contrast to the reported rs7081455, which was too poorly correlated with newly associated rs7098387 (r2=0.003, D'=0.40) to show association. Additionally, a modest association was observed with the reported rs693421 (OR=1.4 (1.1-1.7), P=0.0082) and several other SNPs located within and around ZP4 at the 1q43 locus (10 SNPs typed and 14 imputed). However, no association was observed with the reported rs7961953 SNP or any other SNPs at the 12q21.31 locus, upstream of TMTC2 (10 SNPs typed and 29 imputed). Accordingly, POAG susceptibility association was replicated using rs7098387 (C) rather than rs7081455 (T) at the 10p12.31 locus and additionally with rs693421 (T) at the 1q43 locus.

Transient pseudo-Duane syndrome after lateral orbital trauma.

Duane syndrome is a dysinnervation disorder that frequently involves secondary anomalous eye movement, in particular, ocular retraction and the narrowing of the palpebral fissure on the adduction. Pseudo-Duane syndrome is caused by a mechanical restriction that produces clinical findings similar to those of Duane syndrome. Most patients with pseudo-Duane syndrome have restrictive pathologies on the medial side of the globe, such as entrapment of the medial rectus muscle. We report the case of a 44-year-old man with pseudo-Duane syndrome in whom we identified a lateral orbital wall fracture and entrapment of the soft tissue surrounding the lateral rectus muscle by computed tomography. To the best of our knowledge, this etiology of pseudo-Duane syndrome has not been previously reported.

Diurnal variation of retina thickness measured with time domain and spectral domain optical coherence tomography in healthy subjects.

PURPOSE. To investigate diurnal variations in macular thickness and total macular volume using time domain optical coherence tomography (TD-OCT) and spectral domain OCT (SD-OCT) in healthy subjects. METHODS. Data were derived from 52 eyes of 52 healthy subjects. Macular thickness, macular volume was measured by using TD-OCT and SD-OCT at 8 AM and 6 PM. RESULTS. Comparing TD-OCT measurements, retinal thickness was significantly greater in the afternoon than in the morning in 3 of 9 grid subfields: central macular thickness (CMT) (194 vs. 190 µm; P = 0.006), superior inner area (276 vs. 273 µm; P = 0.010), and temporal inner area (261 vs. 258 µm; P = 0.006). In SD-OCT measurements, CMT, pericentral macular thickness, and macular volume did not differ significantly between the morning and the afternoon. Comparing the absolute variation in the parameters measured by the two devices, central macular thickness and temporal inner area thickness differed significantly (P = 0.015, P = 0.029), whereas other area thicknesses and macular volumes did not. Comparing the relative variation of the two devices, CMT and temporal inner area thickness differed significantly (P = 0.014, P = 0.027), whereas other area thicknesses and macular volume showed no significant difference. The moduli of variations for CMT, macular volume, and pericentral macular thickness were significantly lower using SD-OCT than using TD-OCT. CONCLUSIONS. The diurnal variation of the TD-OCT measurements was likely due to the limited repeatability of the device rather than to tissue variation. Diurnal variation was not found using SD-OCT, which has better repeatability.