Evaluation of the lamina cribrosa after topical latanoprost therapy in primary open-angle glaucoma or ocular hypertension

PURPOSE

To investigate that the changes of lamina cribrosa (LC) thickness and depth after latanoprost therapy in primary open-angle glaucoma (POAG) and ocular hypertension (OHT) patients.

METHODS

In this single-center prospective cross-sectional study, 35 eyes from 35 patients with POAG or OHT (study group) and 26 age- and gender- matched healthy individuals (control group) were included. All participants were examined by spectral domain optical coherence tomography (SD-OCT) with enhanced depth imaging (EDI) mode for LC thickness and depth measurements at the first visit before latanoprost therapy and at visits after 1 (second visit) and 3 (third visit) months of latanoprost therapy.

RESULTS

The mean LC thickness in both horizontal and vertical scans of the study group were thinner than the control group (p < 0.001, for both). During latanoprost therapy in the study group, the LC thickness values in horizontal scans significantly differed over the three visits, gradually increased (p < 0.05). There was significantly decrease in LC depth in horizontal scans between the first and third visits, and the second and third visits (p = 0.003 and p = 0.008, respectively). The gradual decrease in LC depth in vertical scans was observed at all visits, but the statistically significant difference was between the first and third visits only (p = 0.048).

CONCLUSION

POAG/OHT patients showed more LC thinning compared with healthy individuals. The significant increase in LC thickness and the significant decrease in LC depth were detected after IOP reduction therapy with latanoprost in ocular hypertensive/ glaucomatous eyes.

Comparative Study of Lamina Cribrosa Thickness Between Primary Angle-Closure and Primary Open-Angle Glaucoma

Purpose

To compare lamina cribrosa thickness (LCT) of primary angle-closure glaucoma (PACG) and primary open-angle glaucoma (POAG) using the enhanced depth-imaging mode of the Heidelberg Spectralis spectral-domain optical coherence tomography (EDI-OCT).

Patients and Methods

A comparative cross-sectional study was conducted. We enrolled 34 patients with PACG, 38 with POAG, and 62 controls, testing only one eye of each participant. Lamina cribrosa thickness was determined at the center of the optic nerve head using EDI-OCT. Nine points of LCT were measured, and LCT averages were analyzed.

Results

Mean age, number of glaucoma medications, current intraocular pressure (IOP), cup to disc ratio, and visual field indices, were not significantly different between PACG and POAG eyes. The maximum IOP (SD) was higher in PACG than in POAG, at 32.5 (10.46) vs 25.05 (6.42) mmHg (p = 0.001), and LCTs were significantly different among the PACG, POAG and control groups. Mean (SD) LCTs were 226.99 (31.08), 257.17 (19.46), and 290.75 (28.02) μm, respectively (p < 0.001). Lamina cribrosa thickness was correlated with mean deviation of the visual field (p = 0.001; correlation coefficient, r_s = 0.347), while it was inversely correlated with maximum IOP (p < 0.001; correlation coefficient, r_s = −0.592). Linear regression analysis revealed that LCT was inversely related to age (p = 0.008), female (p = 0.018), and maximum IOP (p = 0.002). LCT was marginally related to visual field MD (p = 0.053).

Conclusion

Glaucomatous eyes had thinner LCT than controls, and maximum IOP was inversely correlated to the LCT. PACG eyes had higher maximum IOP and thinner LCT than POAG ones. In living eye, EDI-OCT emphasizes the pressure-dependent mechanism of glaucoma on lamina cribrosa deformation and the higher IOP-loaded stress which leads to a greater lamina cribrosa strain.

The role of clinical examination of the optic nerve head in glaucoma today

PURPOSE OF REVIEW

The study was undertaken to assess the current importance of clinical examination of the optic nerve head (ONH) in glaucoma management.

RECENT FINDINGS

ONH changes in glaucoma are easily assessed with good specificity on examination, whereas imaging has not been able to identify pallor of the neuroretinal rim (NRR), disc hemorrhages, or vascular signs of acquired cupping. Glaucomatous neuropathy in primary open angle glaucoma (POAG) has extensive databases on imaging machines, however, other glaucomas such as primary angle closure glaucoma (PACG), juvenile open angle glaucoma (JOAG), congenital, and secondary glaucomas have been reported to have a significantly different ONH morphology. Clinical evaluation with knowledge of the underlying cause of glaucoma allows easy diagnosis of any abnormality, whereas the absence of an imaging database in such eyes makes diagnosis difficult on optical coherence tomography (OCT) and so forth. In eyes with congenital anomalies and dysplastic discs, clinical examination and history provide better identification of glaucomatous damage. Staging of glaucoma on ONH examination when perimetry is unreliable provides a means of determining the amount of damage and appropriate reduction of intraocular pressure (IOP).

SUMMARY

Clinical examination of the ONH is very relevant for screening, diagnosis, staging, and management of all glaucomas, and is irreplaceable in detecting nonglaucomatous causes of ONH cupping and visual field defects similar to those in glaucoma.

Associations of Ganglion Cell-Inner Plexiform Layer and Optic Nerve Head Parameters with Visual Field Sensitivity in Advanced Glaucoma

PURPOSE

To evaluate the associations of optical coherence tomography (OCT)-derived macular ganglion cell-inner plexiform layer thickness (mGCIPLT), circumpapillary retinal nerve fiber layer thickness (cpRNFLT), and optic nerve head (ONH) parameters with visual field (VF) sensitivity in advanced glaucoma.

METHODS

In this cross-sectional study, 102 eyes from 102 patients with advanced glaucoma (defined as a 24-2 VF mean deviation (MD) of ≤-12 dB) were included. mGCIPLT, cpRNFLT, and ONH parameters (including the rim area, average cup-to-disc [C:D] ratio, and vertical C:D ratio) were measured using Cirrus high-definition OCT, and 24-2 and 10-2 VF sensitivity tests were performed using standard automated perimetry. Pearson correlations and linear models were used to analyze relationships between OCT-derived parameters and VF parameters.

RESULTS

The mGCIPLT and rim area were significantly positively correlated with the 24-2 VF MD, 24-2 VF pattern standard deviation, 24-2 VF visual field index, and 10-2 VF MD, but cpRNFLT was not significantly correlated with VF parameters. In addition, the average and vertical C:D ratios were significantly negatively correlated with VF parameters. The mGCIPLT and rim area were significantly positively correlated with the 10-2 VF MD (r ranging between 0.542 and 0.621, p < 0.001), while the average and vertical C:D ratios were significantly negatively correlated with the 10-2 VF MD (r = -0.537, p < 0.001, and r = -0.428, p < 0.001, respectively). Each 1-µm change in the average mGCIPLT was associated with an approximately 0.368-dB change in the 24-2 VF MD and 0.677-dB change in the 10-2 VF MD (R2 = 0.268, p < 0.001, and R2 = 0.385, p < 0.001, respectively). The 10-2 VF MD showed a significantly stronger association with inferonasal mGCIPLT than did the 24-2 VF MD in advanced glaucoma (p = 0.007).

CONCLUSIONS

mGCIPLT and ONH parameters were associated with the severity of VF damage and reflected functional damage better than cpRNFLT in advanced glaucoma. Our results suggested that structural measurements of mGCIPLT and ONH parameters and functional measurement of the 10-2 VF may be useful for monitoring progression in advanced glaucoma.