Changes of Ocular Dimensions as a Marker of Disease Progression in a Murine Model of Pigmentary Glaucoma.

PURPOSE: The elevation of intraocular pressure (IOP), a major risk factor in glaucoma, is an important parameter tracked in experimental models of this disease. However, IOP measurement in laboratory rodents is challenging and may not correlate with some key pathological events that occur in the development of glaucoma. The aims of this study were to quantify changes in ocular morphology in DBA/2J mice that develop spontaneous, age-dependent, pigmentary glaucoma and to check the possible correlation of these parameters with IOP. METHOD: Eye morphology was evaluated with MRI in DBA/2J, DBA/2J-Gpnmb+/SjJ, and C57BL/6J female mice ages 3, 6, 9, 12, and 15 months. The animals were anesthetized with isoflurane. A planar receive-only surface coil (inner diameter = 10 mm) was placed over each animal's left eye and the image was acquired with a 7T small animal-dedicated magnetic resonance tomograph and T2-weighted TurboRARE sequence. Ocular dimensions were manually quantitated using OsiriX software. IOP was measured with rebound tonometry. RESULTS: In the control animals, no age-related changes in the ocular morphology were noted. Since 6 months of age, the anterior chamber deepening and elongation of the eyeballs of DBA/2J mice was detectable. We found a significant, positive correlation between IOP and axial length, anterior chamber area, or anterior chamber width in C57BL/6J mice but not in DBA/2J mice. However, after excluding the measurements performed in the oldest DBA/2J mice (i.e. analyzing only the animals ages 3 to 12 months), we demonstrated a significant positive correlation between IOP and anterior chamber width. CONCLUSION: High-resolution magnetic resonance imaging of the eye area in mice enables reproducible and consistent measures of key dimensions of the eyeball. We observed age-dependent alterations in the eye morphology of DBA/2J mice that mostly affected the anterior chamber. We also demonstrated a correlation between some of the ocular dimensions and the IOP of C57Bl/6J mice and DBA/2J mice with moderately advanced glaucomatous pathology.

Comparison of surgical outcomes after phacotrabeculectomy in primary angle-closure glaucoma versus primary open-angle glaucoma.

PURPOSE: To compare postoperative outcomes and assess factors associated with intraocular pressure (IOP) reduction after phacotrabeculectomy in patients with primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG). METHODS: This is a retrospective study of patients who underwent phacotrabeculectomy between 2010 and 2013. Factors including age, gender, visual field (VF), the number of glaucoma medications used, biometric changes, IOP, and surgical success rates were compared between groups. RESULTS: There were 27 PACG and 34 POAG patients. The PACG group had a greater mean IOP reduction after phacotrabeculectomy compared to the POAG group (5.5 ± 7.9 mmHg versus 2.0 ± 4.2 mmHg; p = 0.03). However, the final mean IOP was similar between the two groups (PACG: 12.2 ± 4.8 mmHg, POAG: 12.3 ± 3.1 mmHg; p = 0.92). Phacotrabeculectomy resulted in a mean decrease in axial length (AL) of 0.16 ± 0.15 mm in PACG and 0.16 ± 0.11 mm in POAG (p = 0.96), and an increase in anterior chamber depth (ACD) of 1.41 ± 0.91 mm in PACG, and 0.87 ± 0.86 mm in POAG (p = 0.04). At 2 years follow-up, the cumulative success rate of phacotrabeculectomy was 74% in PACG and 62% in POAG. Multivariate analysis found that early glaucoma stage, greater postoperative increase in ACD, and high preoperative IOP were factors associated with greater IOP reduction. CONCLUSION: Postoperative success rates and mean IOP on the final visit after phacotrabeculectomy were similar between the PACG and POAG groups. Factors associated with IOP reduction were greater postoperative increase in ACD, and high preoperative IOP.

Change in Ocular Dimensions with Age in Patients with Emmetropia

PURPOSE: We evaluated changes in ocular dimensions according to age in patients with emmetropia. METHODS: We examined the refraction, corneal curvature, and biometry in 150 subjects from 5 to 75 years old with spherical equivalent refractions under +/-0.75 diopter (D). Ocular dimensions were measured by A-scan ultrasonography and keratometry. We analysed the distribution and change of ocular dimensions according to age (1: 0~19-year-old group, 2: 20~39-year-old group, 3: 40~59-year-old group, 4: 60~79-year-old group). RESULTS: The values for corneal radius (CR), vitreous chamber depth (VCD) and axial length (AL) were highest in group 2. Lens thickness (LT) increased with increasing age, whereas anterior chamber depth (ACD)decreased with increasing age (P<0.05). CR, VCD, AL (P<0.05) and ACD (P=0.10) seem to have higher values in males, while LT seems to have a higher value in females (P=0.06). CONCLUSIONS: Axial length increases with increasing age in subjects aged 0 to 39 years in emmetropia. In subjects aged 40 years or older, axial length becomes smaller with age. In each age group compensational changes to achieve emmetropia according to AL change are shown in ocular dimensions like CR, VCD, ACD, LT.

Aging and Ocular Dimensions

In order to measure the ocular dimensions with aging, the anterior chamber depth and the lens thickness were measured using contact ultrasonography and anterior chamber photography in normal human eyes. There were 141 women (241 eyes) and 76 men (130 eyes) between the ages of 10 and 70 years. The lens thickness was increased and the anterior chamber depth was decreased with aging in both sexes. The anterior chamber depth showed an accelerated decrease between the 4th and 5th decades in females and the ratio of anterior chamber depth to axial length was smaller in females than in males after the 5th decade. The results suggest that the prevalence of angle closure glaucoma increased in female after middle age.

Ocular dimensions with aging in normal eyes

To quantify the dynamic changes taking place in the anterior segment, we measured the anterior chamber depth (ACD), lens thickness (LT) and their difference between sexes and age groups in normal eyes using contact ultrasonography and anterior chamber photography. There were 141 women (241 eyes) and 76 men (130 eyes) between the ages of 10 and 70 years. In normal eyes, the lens thickness was increased and the anterior chamber depth was decreased with aging in both sexes. The anterior chamber depth showed an accelerated decrease between the 4th and 5th decades in females and the ratio of anterior chamber depth to axial length was smaller in females than in males after the 5th decade. The results suggested that the prevalence of angle closure glaucoma will be increased in females after middle age.