Visual Impairment and Blindness in Saudi Arabia's School for the Blind: A Cross-Sectional Study

Macular and peripapillary vascular parameters in the fellow eyes of unilateral primary congenital glaucoma: a comparative study

PURPOSE

To study the fellow eyes of patients with unilateral primary congenital glaucoma (PCG) using optical coherence tomography angiography (OCTA) and compare them to normal age- and refractive error-matched healthy controls.

METHODS

Using OCTA, the foveal avascular zone (FAZ) area, cup:disk ratio, vessel density (VD) of the optic nerve head (ONH) and peripapillary area and the macular VD in superficial (SCP) and deep vascular complexes in both 3 mm and 6 mm scans of both groups were compared. Clinical data included best-corrected visual acuity (BCVA), cycloplegic refraction, intraocular pressure (IOP), anterior and posterior segments examination findings, including ONH cup:disk ratio.

RESULTS

A total of 48 eyes of 48 children (24 eyes in each group) were included. There was no difference in the mean retinal nerve fiber layer thickness, cup:disk ratio, baseline visual acuity, or spherical equivalent between groups (P > 0.05). In the 3 mm macular scan, the VD of the SCP at the fovea was significantly higher in the PCG group compared to controls (P = 0.04). In the ONH scans, there was a significantly reduced inside the disk VD in the PCG group compared to controls (P = 0.03). There was no significant difference in other macular and ONH vascular parameters between groups (P > 0.05).

CONCLUSIONS

In our study cohort, there was no difference in most of the macular and ONH vascular parameters between groups. However, the fellow eyes of PCG patients exhibited higher VD of the SCP at the fovea and reduced inside the disk VD compared with control eyes.

Assessment of the Levels of Knowledge Regarding Cataract and Glaucoma in Saudi Arabia and Measurement of the Ability to Differentiate Between the Two

Objectives

To assess the general public’s level of knowledge on glaucoma and cataract and measure their ability to differentiate between the two.

Materials and methods

This was an analytic, cross-sectional study. We used a self-explanatory questionnaire to obtain information regarding the level of knowledge of glaucoma and cataract and measured the ability of the public to differentiate between the two in Saudi Arabia. The obtained results were manually entered into an Excel sheet and analyzed using the Statistical Package for the Social Sciences (SPSS) software version 26.

Results

The levels of knowledge on glaucoma and cataract and those of education were significantly associated (chi-square: P < 0.001). There was a significant association between having an eye condition and the ability to correctly define glaucoma and cataract (chi-square: P = 0.002). Concerning the definition of glaucoma, 48.4% of the participants who had a previous eye disorder answered correctly, whereas 40.1% of the participants who had no previous eye disorder answered correctly. In addition, 20.9% of the participants with a previous eye disease and 17.6% of the participants without any previous eye disease defined glaucoma incorrectly as cataract. A total of 71.4% of the participants with a previous eye disease, compared with 49.6% of the participants without any previous eye disease, correctly defined cataract. In addition, only 7.3% of the participants with a history of eye disease answered the definition of cataract as that of glaucoma (glaucoma: chi-square, P = 0.002; cataract: chi-square, P < 0.001).

Conclusion

This study is in line with other studies measuring the knowledge of the two diseases, with glaucoma being less known than cataract. While many of the participants were able to define glaucoma and cataract, they had many difficulties identifying how they present and which symptom belonged to cataract and glaucoma. Glaucoma and cataract were confused by a number of participants especially in the case of glaucoma as more defined it as cataract rather than the opposite.

Conformational insights into the C-terminal mutations of human rhodopsin in retinitispigmentosa

Rhodopsin is a light-sensitive transmembrane receptor involved in the visual transduction cascade. Among the several rhodopsin mutations related to retinitis pigmentosa (RP), those affecting the C-terminal VAPA-COOH motif that is implicated in rhodopsin trafficking from the Golgi to the rod outer segment are notably associated with more aggressive RP forms. However, molecular reasons for defective rhodopsin signaling due to VAPA-COOH mutations, which might include steric hindrance, physicochemical features and structural determinants, are yet unknown, thus limiting further drug design approaches. In this work, clinically relevant rhodopsin mutations at the P347 site within the VAPA-COOH motif were investigated by molecular dynamics (MD) simulations and compared to the wild-type (WT) system. In agreement with experimental evidence, conformational fluctuations of the intrinsically disordered C-terminal tail of WT and mutant rhodopsin were found not to affect the overall structure of the transmembrane domain, including binding to the retinal cofactor. The WT VAPA-COOH motif adopts a unique conformation that is not found in pathological mutants, suggesting that structural features could better explain the pathogenicity of P347 rhodopsin mutants than physicochemical or steric determinants. These results were confirmed by MD simulations in both membrane-embedded full-length opsin and membrane-free C-terminal deca-peptides, these latter becoming very useful and small-size model systems for further investigations of rhodopsin C-terminal mutations. Structural details elucidated in this work might facilitate the understanding of the pathological mechanisms of this class of rhodopsin mutants, which will be instrumental to the development of new therapeutic strategies.

Public Awareness of Common Eye Diseases and the Role of Pharmacists in Raising This Awareness in Saudi Arabia: A Cross-Sectional Study

Knowledge of common eye disorders and their prevention and treatment can play an essential role in reducing the visual impairment burden. A cross-sectional, questionnaire-based study was conducted from 15 November 2020 to 15 January 2021 to estimate the knowledge and awareness about common eye problems and their possible risk factors among the general population of the Hail Region, Saudi Arabia. The study also investigated the participants’ sources of information about eye diseases. Participants from various areas of the Hail Region were randomly selected. There were four parts in the questionnaire based upon the general awareness about the common eye diseases, participants’ knowledge and awareness of risk factors associated with eye disorders, awareness of treatment and prevention of various eye disorders, and the participants’ sources of information about ocular diseases. The questionnaire was distributed to the participants by direct contact with them at eye clinics, hospitals, malls, and markets. The number of participants in the survey was 400 people, 53.8% males and 46.3% females. Cataracts were known to 31% of the participants, 43% knew about glaucoma, 66% knew about dry eyes, and 44% knew about diabetic retinopathy. Overall, 46% of the participants knew about eye problems, and the male participants had better knowledge about eye problems than the female ones. The primary sources of information about the common eye diseases were pharmacists (43.3%), family physicians (40.3%), the Internet (37.3%), the community (37.3%), television and radio (9.3%), and books/ brochures (9.5%). In the Hail Region, the general public carries a moderate awareness of preventable vision-threatening ocular disorders. However, the awareness of cataracts and glaucoma was low. The gaps in awareness can be overcome by public health promotion. In offering information about eye conditions to the general public, pharmacists may play a crucial role.