The Relationship Between Age and the Morphology of the Crystalline Lens, Ciliary Muscle, Trabecular Meshwork, and Schlemm's Canal: An in vivo Swept-Source Optical Coherence Tomography Study

The effect of uneventful cataract surgery on Schlemm's canal and the trabecular meshwork in cases with pseudoexfoliation

PURPOSE

To evaluate the effect of uneventful cataract surgery on Schlemm's canal (SC) and the trabecular meshwork (TM) in cases with pseudoexfoliation (PX).

METHODS

In this prospective study, 37 PX and 37 normal eyes, who underwent cataract surgery, were included. The PX group was further divided into two subgroups: PX syndrome (PXS) and PX glaucoma (PXG). Preoperative complete ophthalmologic examination, anterior segment (AS) imaging using a Scheimpflug camera, and measurements of SC length and area and TM thickness and length using AS optical coherence tomography (AS-OCT) were performed in all cases. All measurements were repeated at the first and third months after surgery.

RESULTS

Preoperative intraocular pressure (IOP), AS parameters, SC, and TM values showed no significant differences between the groups (p > 0.05). After surgery, there was a significant increase in AS parameter values and a significant decrease in IOP values in both the PX and control groups (p < 0.05). The nasal and temporal SC area showed a significant increase in the PX group after surgery (p = 0.007, p = 0.003, respectively). In the subgroup analysis, the only significant change in the nasal and temporal SC area was in the PXS group (p = 0.006, p = 0.003, respectively).

CONCLUSION

Cataract surgery resulted in an increase in the SC area in patients with PXS. This increase may be due to multiple mechanisms including the IOP-lowering effect of cataract removal, change in AS, and removal of intraocular PX material after surgery.

Relationship between the main components of the crystalline lens and the anterior chamber depth after cataract formation

PURPOSE

To assess the relationship between anterior chamber depth (ACD) and lens thickness (LT), as well as its three main components (anterior and posterior cortex and nucleus thickness), in cataractous and non-cataractous eyes, depending on the axial length (AxL).

METHODS

Anterior and posterior cortex and nucleus thickness of the crystalline lens, ACD, and AxL were measured using optical low-coherence reflectometry in cataractous and non-cataractous eyes. They were also classified into hyperopia, emmetropia, myopia, and high myopia, depending on AxL; thus, eight subgroups were created. A minimum sample size of 44 eyes (of 44 patients) for each group was recruited. Linear models were fitted for the whole sample and each AxL subgroup to assess if there were differences in the relationships between the crystalline lens variables and ACD, including age as a covariate.

RESULTS

Three hundred seventy cataract patients (237 females, 133 males) and 250 non-cataract controls (180 females, 70 males), aged 70.5 ± 9.4 and 41.9 ± 15.5 years, respectively, were recruited. The mean AxL, ACD, and LT for the cataractous and non-cataractous eyes were 23.90 ± 2.05, 24.11 ± 2.11, 2.64 ± 0.45, and 2.91 ± 0.49, 4.51 ± 0.38, 3.93 ± 0.44 mm, respectively. The inverse relationship of LT, anterior and posterior cortex, and nucleus thickness with ACD was not significantly (p ≥ 0.26) different between cataractous and non-cataractous eyes. Further subclassification of the sample depending on AxL showed that the inverse relationship between the posterior cortex and ACD was no longer significant (p > 0.05) for any non-cataractous AxL group. LT, anterior and posterior cortex, and nucleus thickness was not significantly (p ≥ 0.43) different between cataractous and non-cataractous eyes for the whole sample, and all AxL groups after adjusting for age.

CONCLUSIONS

The presence of cataracts does not modify the inverse relationship of the LT, anterior and posterior cortex, and nucleus with ACD. And this relationship does not seem to depend importantly on AxL. Besides, the possible differences in LT, anterior and posterior cortex, and nucleus between cataractous and non-cataractous eyes may not be caused by lens opacification, but possibly by the progressive lens growth due to aging.

Morphometric assessment of the ciliary body in patients with Marfan syndrome and ectopia lentis: A quantitative study using ultrasound biomicroscopy: Ciliary body morphology in Marfan syndrome and ectopia lentis

PURPOSE

To explore the biometric characteristics of the ciliary body in patients with Marfan syndrome (MFS) and ectopia lentis (EL).

DESIGN

Cross-sectional study.

METHODS

Seventy-two consecutive MFS patients with EL and 72 non-disease controls were recruited. Ciliary body biometric parameters such as ciliary muscle cross-sectional area at 2000 μm from the scleral spur (CMA2000), ciliary muscle thickness at 1000 μm from the scleral spur (CMT1000), and maximum ciliary body thickness (CBTmax) were measured from multiple directions with ultrasound biomicroscopy (UBM). The relationship between ciliary body parameters and other ocular characteristics was also evaluated.

RESULTS

Average CMA2000, CMT1000, and CBTmax were 0.692 ± 0.015 mm², 0.405 ± 0.010 mm, and 0.855±0.023 mm in MFS eyes, respectively, and were significantly smaller than controls (all p < 0.001). The prevalence of ciliary body thinning was 22.2% in the MFS group versus 0 in controls (p < 0.001); eyes with more severe EL had smaller CMA2000 (p = 0.050), thinner CMT1000 (p = 0.022) and shorter CBTmax (p = 0.015). Patients with microspherophakia (MSP) had even smaller CMA2000 (p = 0.033) and CMT1000 (p = 0.044) than those without MSP. The most common subluxation direction was in the superonasal quadrant (25, 39.7%), which probably correlates with the thinnest CMT1000 in the inferotemporal quadrant (p = 0.005).

CONCLUSIONS

MFS patients with EL had thinner ciliary muscles, shorter ciliary processes, and a higher prevalence of ciliary body thinning, especially those with MSP. Both the extent and direction of subluxation were associated with ciliary body biometry.