Application of Spectral Domain Optical Coherence Tomography to Objectively Evaluate Posterior Capsular Opacity In Vivo

A 3D in vitro model for assessing the influence of intraocular lens: Posterior lens capsule interactions on lens epithelial cell responses

Posterior Capsule Opacification (PCO), the most frequent complication of cataract surgery, is caused by the infiltration and proliferation of lens epithelial cells (LECs) at the interface between the intraocular lens (IOL) and posterior lens capsule (PLC). According to the "no space, no cells, no PCO" theory, high affinity (or adhesion force) between the IOL and PLC would decrease the IOL: PLC interface space, hinder LEC migration, and thus reduce PCO formation. To test this hypothesis, an in vitro hemisphere-shaped simulated PLC (sPLC) was made to mimic the human IOL: PLC physical interactions and to assess their influence on LEC responses. Three commercially available IOLs with different affinities/adhesion forces toward the sPLC, including Acrylic foldable IOL, Silicone IOL, and PMMA IOL, were used in this investigation. Using the system, the physical interactions between IOLs and sPLC were quantified by measuring the adhesion force and interface space using an adhesion force apparatus and Optical Coherence Tomography, respectively. Our data shows that high adhesion force and tight binding between IOL and sPLC contribute to a small interface space (or "no space"). By introducing LECs into the in vitro system, we found that, with small interface space, among all IOLs, acrylic foldable IOLs permitted the least extent of LEC infiltration, proliferation, and differentiation (or "no cells"). Further statistical analyses using clinical data revealed that weak LEC responses are associated with low clinical PCO incidence rates (or "no PCO"). The findings support that the in vitro system could simulate IOL: PLC interplays and predict IOLs' PCO potential in support of the "no space, no cells, no PCO" hypothesis.

An energy efficiency assessment of Yttrium-aluminum-garnet laser in vitro

To study the effect range of the Nd:YAG laser through various levels of cloudy medium for targets with varying grayscale values in vitro. The coated paper cards with grayscale values of 0, 50, 100, and 150 were used as the laser's targets, which were struck straightly with varying energies using three burst modes (single pulse, double pulse, and triple pulse). Six filters (transmittances of 40, 50, 60, 70, 80, and 90) were applied to simulate various levels of cloudy refractive medium. Image J software was used to measure the diameters and regions of the laser spots. The ranges of the Nd:YAG laser spots increased with energy in the same burst mode (P < 0.05). Under the same amount of energy, the ranges of the Nd:YAG laser spot increased with the grayscale value of the targets (P < 0.05). The greater the transmittance of the filters employed, the larger the range of the Nd: YAG laser spots produced. Assuming that the total pulse energy is identical, the effect ranges of multi-pulse burst modes were significantly larger than those of single-pulse burst mode (P < 0.05). The effect range of a Nd:YAG laser grows with increasing energy and the target's grayscale value. A cloudy refractive medium has a negative impact on the effect range of the Nd: YAG laser. The single pulse mode has the narrowest and safest efficiency range.

Analysis of the capsular bend in posterior capsular opacification using anterior segment optical coherence tomography

PURPOSE

To investigate the link between the capsular bend and the morphological types and characteristics of posterior capsular opacification (PCO) using anterior segment optical coherence tomography.

METHODS

Thirty eyes with PCO were examined, and three types of PCO were identified: pearl, fibrosis, and mixed. We assessed anterior capsular overlap, intraocular lens-capsule adhesion, and capsular bending. In addition to measuring the intraocular lens-posterior capsule distance and capsule bending angle (CBA), the PCO parameters (area, density, and score at 6-, 5-, and 3-mm intraocular lens optic regions) were recorded. The associations between capsular bend and PCO type and characteristics were investigated. A control group of 12 eyes without PCO was used to compare the study variables.

RESULTS

With p values greater than 0.001, there was a statistically significant difference in the mean PCO area and score at the 6-, 5-, and 3-mm optic zones in different PCO types, with the pearl type having the highest value, followed by the mixed type, and finally the fibrosis type. The PCO group had a significantly higher mean CBA than the control group (P = 0.001). CBA was positively related to intraocular lens-posterior capsule distance, PCO area, and PCO score at the 6-, 5-, and 3-mm zones (P = 0.001). The receiver operating characteristic curve's cut-off point for CBA was 96.85° when comparing PCO cases to controls. Partial overlap and incomplete adhesion were statistically more common in the PCO eyes than in the control (P = 0.001, 0.003, respectively).

CONCLUSION

PCO types and CBA have a strong relationship with PCO score and intraocular lens-posterior capsule space. In PCO's eyes, CBA has a cut-off value of 96.85°.

Macular retinal and choroidal thickness profile in patients with thyroid-associated orbitopathy compared to healthy individuals: A cross-sectional study

Background and Aims

To evaluate the macular thickness profile and central subfoveal choroidal thickness in patients with thyroid-associated orbitopathy (TAO) compared to healthy subjects.

Methods

We used the convenience sampling method and divided all participants into the patients and control groups. Based on the clinical activity score (CAS) in the first examination, the patient group was divided to two subgroups: the patients with CAS < 3 and the patients with CAS ≥ 3. Complete ophthalmologic examinations and optical coherence tomography imaging were performed for all participants.

Results

The mean ± SD of central choroidal thickness was 277 ± 76.58 microns for the control and 326.07 ± 56.574 micron for the patient group which was statistically significant (p = 0.003). We also found that the parafoveal inner thickness is significantly lower in patients compared to healthy subjects (p = 0.02). A comparison of neuro-structural data between the two subgroups of patients showed a significant difference in central choroidal thickness (p = 0.05).

Conclusion

This study showed that central choroidal thickness in patients with CAS ≥ 3 compared to those with CAS < 3 and also in the patient group compared to healthy individuals have a significantly increasing trend.

Protective Effects of One 2,4-Dihydro-3H-Pyrazol-3-one Derivative against Posterior Capsular Opacification by Regulation of TGF-β2/SMADs and Non-SMAD Signaling, Collagen I, and Fibronectin Proteins

Many elderly individuals frequently experience cataracts that interfere with vision. After cataract surgery, the left lens epithelial cell (LEC) exhibited fibrosis and posterior capsule opacification (PCO). Sometimes, there is a need for a second surgery; nevertheless, people try other methods, such as a good pharmacological agent, to treat PCO to reduce transforming growth factor-β2 (TGF-β2) amounts to avoid secondary surgery. The aim of the present study was to explore the potential anti-PCO activity of five 2,4-dihydro-3H-pyrazol-3-one (DHPO) derivatives in a TGF-β2-induced fibrogenesis SRA01/04 cell model. The 2-phenyl-5-propyl-DHPO (TSE; no. 2: TSE-2) compound showed the best activity of reduced expression levels of TGF-β2 among five derivatives and therefore was chosen to evaluate the anti-PCO activity and molecular mechanisms on the Sma and mad protein (SMAD) signaling pathway (including TGF-β2, SMADs, and the inhibition of nuclear translocation of SMADs), non-SMAD pathway proteins, including p-extracellular, regulated protein kinases (ERK) 1/2, or p-c-Jun N-terminal kinase (JUN) by Western blotting, PCR, or confocal immunofluorescence analyses. Following treatment with 10 μg/mL of the five compounds, the cells displayed great viability by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTT) assay. In this study, the result of lactate dehydrogenase (LDH) activity measurement did not affect the cytotoxicity of the five compounds. In TGF-β2-induced fibrogenesis in SRA01/04 cells, treatment with the TSE compound decreased the TGF-β2/SMAD signaling genes, including reduced mRNA or expression levels of TGF-β2, SMAD3, and SMAD4, leading to inhibition of TGF-β2-induced fibrogenesis. Our confocal immunofluorescence analyses demonstrated that TSE treatment displays a suppressive effect on SMAD2/3 or SMAD4 translocation to the nucleus. Furthermore, TSE treatment exhibits a reduction in the non-SMAD target gene expression levels of p- c-Jun N-terminal kinase (JUN), p- extracellular, regulated protein kinases (ERK)1/2, p- p38 mitogen-activated protein kinase (p38), p-phosphatidylinositol 3-kinase (PI3K), p-mammalian target of rapamycin complex (mTORC), p-Akt (Ser⁴⁷³), and p-Akt (Thr³⁰⁸). The overall effect of TSE is to reduce the expression levels of collagen I and fibrinogen (FN), thus contributing to antifibrotic effects in cell models mimicking PCO. Our findings reveal the benefits of TSE by regulating TGF-β/SMAD signaling and non-SMAD signaling-related gene proteins to display antifibrotic activity in cells for the possibility of preventing PCO after cataract surgery.

The validity and reliability of the Arabic version of the ocular surface disease index (OSDI) questionnaire in a sample of the Gazan population: a study from Palestine

PURPOSE

To develop an Arabic version of OSDI for the Gazan population.

METHODS

A cross-sectional observational study was conducted using a convenience sample technique. The translation procedure included five stages: forward translation, revision of translation, backward translation, refinement of translation, and a final test of the pre-final version. The final sets of questionnaires were constructed using an online JotForm platform. The online platform was chosen to automatically calculate the questionnaire's final overall score. Overall, 260 participants were instructed to fill out the English and the Arab-OSDI version twice to conduct the reliability of the translated version and repeatability evaluation.

RESULTS

The mean age of the participants was 33.45 ± 11.74 years old. Cronbach's alpha for all items was greater than 0.80, except for the "blurred vision" and "deteriorating vision" items (0.77 and 0.74, respectively). The mean overall score difference between the English-OSDI and Arab-OSDI was 0.86 based on the Bland-Altman chart. For repeatability, no significant difference in the overall scores between the two repeats of the Arab-OSDI (p = 0.632). The Arab-OSDI overall score (sessions 1 and 2) has a clinical difference (bias) of 0.21. Using the varimax rotation method, only three factors (ocular symptoms, vision-related function, and environmental triggers) had eigenvalues greater than one in the structure of the Arab-OSDI.

CONCLUSION

The Arab-OSDI is an appropriate, reliable, and repeatable tool for the determination of dry eye symptoms, ocular discomfort, and quality of life in the Gazan population. This version could remove the language barrier in answering OSDI items more easily.

Anterior segment OCT application in quantifying posterior capsule opacification severity with varied intraocular lens designs

AIM

To evaluate the application of anterior segment-optical coherence tomography (AS-OCT) in posterior capsule opacification (PCO) severity assessment and analyse the relationship between PCO severity and intraocular lens (IOL) characters.

METHODS

PCO patients were prospectively recruited. Cross-sectional images of the anterior segment at horizontal and vertical meridians were acquired with AS-OCT. The area of the IOL-PC (posterior capsular) space and PCO severity (area, thickness, and density at 3 mm and 5 mm IOL optic regions) were measured. The relationship between PCO severity and visual acuity, comparisons of PCO severity and IOL-PC space using varied IOL designs were analysed.

RESULTS

One hundred PCO eyes were enrolled. IOL-PC space, PCO thickness and area were positively correlated with axial length. In addition, PCO area and thickness were positively correlated with visual acuity when it was ≤0.52 logMAR. The cut-off level of visual acuity should be 0.52 logMAR. With varied IOL designs, 3-piece C haptic IOL showed a smaller PCO area and thickness than the 1-piece 3 haptic IOL and 1-piece 4 haptic IOL. PCO area and thickness values for an IOL with a diameter ≤11.0 mm was greater than for an IOL with a diameter of 12.5 mm, and the differences were statistically significant. PCO area and thickness increased when IOL haptic angulation increased (from 0 to 12 degrees).

CONCLUSION

In PCO eyes, cut-off level of visual acuity is 0.52 logMAR. With more severe PCO, visual acuity maybe not enough to describe the visual function impairment. PCO severity and IOL-PC space are significantly correlated with axial length and IOL design and material.

Comparison of the Stability of Two Intraocular Lenses in Primary Angle-Closure Glaucoma after Phacoemulsification

Objective. To observe the stability of intraocular lenses (IOLs) in primary angle-closure glaucoma by ultralong scan depth spectral-domain optical coherence tomography (UL-OCT) after phacoemulsification. Methods. A prospective, randomized study. 73 patients (82 eyes) with primary closed-angle glaucoma and age-related cataract were included in the study. 42 eyes were implanted with ZCB00, while 40 eyes were implanted with Softec HD after phacoemulsification. The tilt, decentration, and space between IOL and posterior capsule (IOL-PC space) were analyzed using UL-OCT at 1 week, 1 month, and 3 months after surgery. The intergroup difference was compared with the paired t-test. Result. The difference of decentration and tilt was not statistically significant (both $P>0.05$ ) both in the horizontal and vertical positions at 1 week, 1 month, and 3 months postoperatively. The horizontal IOL-PC space is 0.111 ± 0.091 mm2, 0.044 ± 0.066 mm2, and 0.055 ± 0.055 mm2 in the Softec HD group and 0.458 ± 0.488 mm2, 0.497 ± 0.363 mm2, and 0.492 ± 0.441 mm2 in the ZCB00 group. The vertical IOL-PC space is 0.102 ± 0.061 mm2, 0.037 ± 0.052 mm2, and 0.053 ± 0.079 mm2 in the Softec HD group and 0.692 ± 0.815 mm2, 0.510 ± 0.415 mm2, and 0.691 ± 0.635 mm2 in the ZCB00 group. The difference was statistically significant ( $P<0.05$ ) both in the horizontal and vertical positions except for the first week on the horizon. The Softec HD group is smaller than the ZCB00 group. Conclusion. There is no difference in the stability of the IOL although the IOL-PC space is different. The thickness of IOL may affect the IOL-PC space.