Medical Hypothesis, Discovery & Innovation (MEHDI) Ophthalmology Journal
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Validity of vision screening program conducted by preschool teachers: An interventional study
Get PDFBackground: Clear vision is crucial for effective learning among preschool children. Hence, early detection of vision impairment and prompt treatment are required to improve prognosis. Currently, limited information is available, and no program exists to screen for vision impairment among preschoolers in Bangladesh. This study aimed to validate the KieVision™ Preschool Vision Screening Kit, translated into the Bengali language, to improve vision impairment detection among preschool children.
Methods: In this prospective case–control study, 60 preschool teachers from Chittagong were randomly selected. The study group was trained to conduct vision screening among preschool children using the translated kit, whereas the control group was trained using the Chittagong Eye Infirmary and Training Complex (CEITC) School Teachers’ Training Module. Fifteen preschool children aged 4–6 years were screened by each preschool teacher and again by the optometrist.
Results: Sixty preschool teachers screened 900 children. The results showed a higher validity of vision screening findings by the preschool teachers in the study group (sensitivity, 68.00%; specificity, 92.75%) than in the control group (sensitivity 47.37%, specificity 70.39%). The level of agreement between the preschool teachers and optometrists was high for all tests (first-order agreement coefficient [AC1] ? 0.80 in the study group). The sensitivity and specificity of the visual acuity test for the study group were 59.65% and 94.15%, respectively, while in the control group it was 13.33% and 62.54%, respectively. A similar trend was noted in the general observation component and Hirschberg’s test.
Conclusions: The Bengali Language KieVision™ Preschool Vision Screening Kit can be used effectively by preschool teachers in vision screening programs to improve the identification of vision impairment among preschool children in Bangladesh
Ocular dimensions by three-dimensional magnetic resonance imaging in emmetropic versus myopic school children
Get PDFBackground: Magnetic resonance imaging (MRI) has been used to investigate eye shapes; however, reports involving children are scarce. This study aimed to determine ocular dimensions, and their correlations with refractive error, using three-dimensional MRI in emmetropic versus myopic children.
Methods: Healthy school children aged < 10 years were invited to take part in this cross-sectional study. Refraction and best-corrected distance visual acuity (BCDVA) were determined using cycloplegic refraction and a logarithm of the minimum angle of resolution (logMAR) chart, respectively. All children underwent MRI using a 3-Tesla whole-body scanner. Quantitative eyeball measurements included the longitudinal axial length (LAL), horizontal width (HW), and vertical height (VH) along the cardinal axes. Correlation analysis was used to determine the association between the level of refractive error and the eyeball dimensions.
Results: A total of 70 eyes from 70 children (35 male, 35 female) with a mean (standard deviation [SD]) age of 8.38 (0.49) years were included and analyzed. Mean (SD) refraction (spherical equivalent, SEQ) and BCDVA were -2.55 (1.45) D and -0.01 (0.06) logMAR, respectively. Ocular dimensions were greater in myopes than in emmetropes (all P < 0.05), with no significant differences according to sex. Mean (SD) ocular dimensions were LAL 24.07 (0.91) mm, HW 23.41 (0.82) mm, and VH 23.70 (0.88) mm for myopes, and LAL 22.69 (0.55) mm, HW 22.65 (0.63) mm, and VH 22.94 (0.69) mm for emmetropes. Significant correlations were noted between SEQ and ocular dimensions, with a greater change in LAL (0.46 mm/D, P < 0.001) than in VH (0.27 mm/D, P < 0.001) and HW (0.22 mm/D, P = 0.001).
Conclusions: Myopic eyeballs are larger than those with emmetropia. The eyeball elongates as myopia increases, with the greatest change in LAL, the least in HW, and an intermediate change in VH. These changes manifest in both sexes at a young age and low level of myopia. These data may serve as a reference for monitoring the development of refractive error in young Malaysian children of Chinese origin
Validity of external observation examination by teachers during vision screening for preschool children
Get PDFBackground: A vision-screening program is effective in prevention of vision impairment. The validity of vision screening conducted by nurses, medical assistants, and teachers has been previously reported. However, the validity of preschool teachers in conducting external eye observations in preschool children has not been widely investigated. This study aimed to determine validity of preschool teachers in conducting external eye observation tests, including the observation of behavior and external eye health, in preschool children.
Methods: In this cross-sectional study, preschool teachers from Kemajuan Masyarakat kindergarten in Klang Valley, Malaysia, were randomly allocated to the study (n = 30) or control (n = 30) groups. The study group underwent theory training with an optometrist and practical sessions with preschool children on vision screening, while the control group received only brief verbal instructions on steps to conduct the screening. After the briefing, teachers from both groups conducted vision screening tests at their kindergartens on preschool children aged 4–6 years. The same vision screening procedure was repeated in the same children by optometrists to verify results of the teachers.
Results: A total of 700 preschool children were screened by 60 preschool teachers and optometrists. Teachers from the study and control groups displayed high validity in screening for external ocular health, including sensitivity (66.67% versus 66.67%), specificity (95.21% versus 95.54%), and negative predictive value (99.41% versus 99.69%). The positive predictive value was slightly higher in the study group (19.05%) than in the control group (11.76%).
Conclusions: Preschool teachers competently observed external eye health in preschool children. A training module for vision screening is important, and a revision of the current training module is needed. Empowering preschool teachers could help in the early detection and intervention necessary in needy children. This could reduce the nationwide prevalence of visual impairments
A situational analysis of clinical refraction services in the capital city of the Maldives
Get PDFBackground: Uncorrected refractive error is a leading cause of visual impairment globally. This study aimed to determine the current state of clinical refraction services and barriers to service provision in the capital city of the Maldives.
Methods: This cross-sectional, descriptive-analytical study used a purposive sampling technique. The list of facilities providing refraction services in the city of Malé was compiled through a desk review and finalized after verification by personnel from the Ministry of Health. The availability of human resources and infrastructure was measured using a pre-coded questionnaire that also listed barriers to service provision, followed by on-site observations and subsequent data analysis.
Results: Three clinical ophthalmology departments within hospitals, two ophthalmology hospitals, and nine primary eye care centers were selected for this study. The private sector (n = 12, 85.7%) was the primary provider of refractive error services. All facilities possessed the essential equipment required for refraction. Only optometrists and ophthalmologists conducted refraction. Contact lens assessment and low vision services were not available at any facility. The number of refractions conducted in Malé annually was 145,392. Human resources and management-related factors were the major barriers to the provision of clinical refraction services (n = 21, 44.7%).
Conclusions: Accessibility to refractive error management and low vision services is needed in Malé to meet current population needs. Existing resources, including humans and equipment, require augmentation regarding service provision and enhancement. Knowledge of these barriers could lead to the upscaling of refraction services in Malé, Maldives by health policy makers
Common causes of visual impairment in the elderly
Get PDFBackground: Aging is not a disease; rather, it is a process. As people age, visual impairment (VI) becomes more common. In 2010, the overall prevalence rate of vision impairment in all races was 25.66% in individuals aged equal to or more than 80 years, according to the estimate of the National Eye Institute at the National Institutes of Health. This review aimed to address the common causes of VI in the elderly.
Methods: In this narrative review, an electronic search of the PubMed/MEDLINE database was conducted using “visual impairment” and “elderly” for the period between January 2010 and April 2021, to include randomized clinical trials and observational studies concerning VI in the elderly. The selected time period was chosen to provide an updated review.
Results: The search yielded 2,955 articles published over the period of more than 11 years. The relevant randomized clinical trials or observational studies were included and reviewed. Cataracts, refractive errors, open-angle glaucoma, age-related macular degeneration, and diabetic retinopathy were the most common age-related ocular disorders leading to VI if untreated in the elderly. The loss of visual acuity can adversely affect quality of life in the elderly. Difficulty with activities of daily living related to VI can lead to social isolation, depression, and anxiety. Loss of vision in the elderly is linked to an increased risk of falls, hip fracture, depression, and poor quality of life.
Conclusions: The most common causes of VI in the elderly are cataracts and refractive errors. VI in most ocular diseases is more prevalent in women than in men due to longer lifespan. The overall prevalence of the main causes of VI in the elderly is expected to increase; therefore, health policymakers should consider this when planning for the health-enhancement program of the population
Effect of mitomycin-C on corneal endothelial cell parameters after refractive surface ablation procedures
Get PDFBackground: The effect of mitomycin-C (MMC) on the reduction of endothelial cell count in the cornea remains controversial. We aimed to evaluate the effect of MMC on corneal endothelial cell parameters after refractive surface ablation procedures, including photorefractive keratectomy (PRK) and laser epithelial keratomileusis (LASEK).
Methods: In this interventional, comparative, follow-up study, 342 eyes of 171 patients were followed up for 6 months. Patients undergoing PRK or LASEK were included and were divided into two groups: group one (188 eyes of 94 patients) with an ablation depth of ? 65 µm and who received intraoperative 0.02% MMC for 30 s, and group two (154 eyes of 77 patients) with an ablation depth of < 65 µm and who received balanced salt solution for 30 s. Changes in endothelial cell density (ECD), central corneal thickness (CCT), coefficient of variation (CV), and hexagonality values were compared between the groups at 3 and 6 months after surgery.
Results: The mean ± standard deviaiton (SD) age of the patients was 28.11 ± 6.56 years. The mean ± SD ECD did not change significantly in either group between the baseline and at 3 and 6 months postoperatively. The baseline mean ECD was significantly higher in group one than that in group two (P < 0.001) and remained so at 3 (P = 0.002) and 6 months (P = 0.022) postoperatively. The baseline hexagonality value was lower in group one (P = 0.173), with a gradual decrease during the postoperative follow-up as compared with that in group two (P = 0.016 and 0.001 at 3 and 6 months postoperatively, respectively). Group one had a significantly lower CCT at 3 and 6 months postoperatively (both P < 0.001) and a higher mean CV (3 months: P = 0.028; 6 months: P = 0.328).
Conclusions: A single intraoperative application of MMC for 30 s as prophylaxis for corneal haze development during refractive surface ablation procedures had no significant effect on ECD up to 6 months postoperatively. Future studies with a contralateral-eye design (to neutralize factors specific to the individual patient), a larger sample size, and longer follow-up are necessary to confirm or disprove our observations
Refractive outcomes in infants treated for retinopathy of prematurity
Get PDFBackground: Infants treated for retinopathy of prematurity (ROP) can develop visually significant refractive error. However, the degree of refractive error may differ between laser treatment and intravitreal anti-vascular endothelial growth factor (anti-VEGF) injection. We reviewed studies that investigated refractive error outcomes of treatment in premature infants with ROP.
Methods: In this narrative review, a literature search was carried out in PubMed/MEDLINE from 01/01/2000 to 20/10/2022 without language restrictions, using the following keywords: “anti-VEGF,” “ROP” or “prematurity retinopathy,” and “laser.” We included comparative studies on refractive error outcomes of intravitreal anti-VEGF and laser treatments, a combination of both modalities simultaneously or sequentially, and two anti-VEGF agents.
Results: The initial search yielded 164 records. We reviewed the titles and abstracts of the retrieved papers and the reference list of published systematic reviews and meta-analyses, meta-analyses, or reviews on our topic. Thirty-three records fulfilled our inclusion criteria, which included refractive outcomes in 4350 eyes of 2359 participants treated for ROP. Based on the reported refractive outcomes, we divided the studies into four categories: 1) those that revealed a higher rate of refractive error in the laser-treated eyes than in the anti-VEGF-treated eyes; 2) those that revealed no significant difference in refractive outcomes between the two treatment modalities; 3) those that revealed a higher rate of refractive error in the anti-VEGF-treated eyes or compared refractive outcomes between two anti-VEGF agents; and 4) those that reported refractive outcomes in the eyes that received combined simultaneous or sequential treatment with laser after initial anti-VEGF treatment. We also summarized the refractive outcomes of all included primary studies in each category.
Conclusions: This study showed that the laser-treated eyes experienced more myopic shift. However, the refractive outcomes in premature infants of laser treatment, anti-VEGF treatment, and a combination of both modalities simultaneously or sequentially were often contradictory. This variability resulted from obvious differences in the sample size, different follow-up durations, or inhomogeneous study or treatment designs. Further well-designed prospective trials on refractive outcomes and the trend of changes in the refractive status over long-term follow-ups in the eyes treated with ROP are necessary to identify consensus results concerning real-world refractive outcomes of each treatment modality or simultaneous or sequential combination of both modalities, to suggest a safe and effective treatment option for eye care professionals
A 10-year review of the visual outcomes of early versus late pars plana vitrectomy in eyes with dropped lens fragment or nucleus during phacoemulsification
Get PDFBackground: Pars plana vitrectomy (PPV) is a routine surgical option for the removal of dropped lens fragment or nucleus in the vitreous cavity due to complicated cataract surgery; however, its optimal timing is controversial. Therefore, we aimed to determine the visual outcomes of early versus late PPV in eyes with dropped lens fragment or nucleus due to complicated phacoemulsification cataract surgery.
Methods: This descriptive-analytical retrospective study collected data of patients who underwent early (less than or equal to 1 week) versus late (> 1 week) PPV for the management of dropped lens fragment or nucleus resulting from complicated phacoemulsification cataract surgery over a 10-year period at Imam Khomeini Tertiary Referral Hospital, Ahvaz, Iran. Demographic characteristics, the interval between complicated phacoemulsification and PPV, pre- and postoperative intraocular pressures, best-corrected distance visual acuity (BCDVA), and postoperative complications were extracted from each patient’s record.
Results: Fifty-one eyes of 51 patients with a mean (standard deviation [SD]) age of 64.66 (6.54) years and a male-to-female ratio of 33 (64.7%) to 18 (35.3%) were included over 10 years. The mean (SD) BCDVA before PPV was 1.87 (0.53) logarithm of the minimum angle of resolution (logMAR), which improved significantly to 0.54 (0.46) logMAR at the final postoperative visit (P < 0.001). The mean (SD) BCDVA was significantly better after early PPV than after late PPV (0.41 [0.30] versus 0.62 [0.52] logMAR; P < 0.05). There was no significant difference in the final BCDVAs among the three methods of lens fragment removal (P > 0.05). The rates of post-PPV complications were as follows: 29 (56.9%) eyes with corneal edema, 16 (31.4%) eyes with uveitis, 10 (19.6%) eyes with cystoid macular edema, 8 (15.7%) eyes with rhegmatogenous retinal detachment, and 8 (15.7%) eyes with other complications (optic nerve atrophy, choroidal neovascularization, vitreous hemorrhage, or epiretinal membrane formation). No significant differences were observed in the rates of complications according to the time interval between complicated phacoemulsification and PPV (all P > 0.05). The frequency of corneal edema was significantly higher when removing lens fragments using the trans-limbal method than using the other methods (P < 0.05), yet the rates of other complications were comparable among the three methods of lens fragment removal (all P > 0.05).
Conclusions: Early PPV and removal of a dropped lens fragment or nucleus resulting from complicated phacoemulsification cataract surgery are recommended to achieve better visual outcomes. Future studies with longer follow-up, greater sample sizes, and analysis of other parameters of visual function, such as contrast sensitivity, visual field, color vision, and stereopsis, could provide more conclusive results and help verify our preliminary findings
Absorbable suture for band tightening of scleral buckling in pseudophakic rhegmatogenous retinal detachment: a modified surgical technique and a 6-month follow-up
Get PDFBackground: Rhegmatogenous retinal detachment (RRD) is a separation of the neurosensory retina from the retinal pigment epithelium as a result of liquid vitreous passing through a retinal break. Scleral buckling surgery (SB) is a conventional treatment for RRD. In SB, a silicon explant is used to indent the sclera, reduce vitreous traction, and close the retinal break, and an encircling band is used circumferentially, leading to myopia. This study aimed to evaluate the functional and biometric outcomes after SB with absorbable band-tightening sutures in patients with pseudophakic RRD.
Methods: In this prospective interventional study, we included pseudophakic eyes with RRD treated surgically with SB and a temporary encircling band using a 6-0 absorbable Vicryl suture to tighten the band, instead of conventional permanent suture tightening. Anterior chamber depth (ACD), axial length (AL), intraocular pressure (IOP), spherical equivalent refractive error (SER), and best-corrected distance visual acuity (BCDVA) were measured preoperatively and at 1 day, 2 weeks, 3 months, and 6 months postoperatively.
Results: We included 30 eyes of 30 patients with a mean (standard deviation [SD]) age of 66.1 (10.5) years who underwent SB with an absorbable band-tightening suture for pseudophakic RRD. Significant increases in AL and ACD were observed at 2 weeks after surgery, with a significant decline in values thereafter; however, at the 6-month follow-up, the values were significantly higher than those at baseline (all P < 0.05). Based on the Vicryl tension and its hydrolysis, mean (SD) SER at 2 weeks postoperatively was significantly more myopic than at baseline (-5.8 [1.6] D versus +1.3 [1.8] D). However, the mean (SD) SER decreased significantly throughout the 6-month follow-up (all P < 0.05), and it reached -1.8 (0.9) D, which was comparable with the mean baseline SER (P = 0.140). The participants experienced significant improvement in BCDVA throughout the follow-up period (all P < 0.05).
Conclusions: Using an absorbable suture to tighten the encircling band in patients with pseudophakic RRD can reduce postoperative myopia without adversely affecting the anatomical or functional outcomes. Future comparative studies with larger sample sizes and longer postoperative follow-up are needed to verify these findings
Urban inequality: a hypothetic risk factor for myopia
Get PDFBackground: Myopia is a common refractive error with an expected increase in prevalence. Inequalities in access to ocular health care for sight-threatening or life-threatening ocular diseases have been described. Urbanization is a risk factor for both the incidence and progression of myopia; however, socioeconomic inequalities in urban settings are a new concept in myopia incidence.
Hypothesis: Considering the proven impact of inequalities existing in general and ocular health, urban inequality could be a new risk factor for both the incidence and progression of myopia. Inequalities in urban infrastructure vary between countries; however, there are currently various manifestations of urban inequality, and scholars are concerned about intra-urban inequality as a public health risk. Considering the significant influence of urban inequality on health of children, and because myopia develops and progresses faster during childhood, the effect of urban inequality on myopia must be examined. Although urban inequality could be a putative risk factor for myopia, a causal relationship should be investigated. However, myopia is multifactorial in etiology, originating from the interaction of environmental and genetic factors. Thus, causality between urban inequality and myopia should be investigated through a randomized, controlled trial with strict matching of genetic backgrounds and environmental factors.
Conclusions: Several risk factors for myopia have been proposed, and studies have confirmed causal relationships with most of these factors. Considering the proven impact of urban inequality on both general and ocular health, experimental studies are necessary to confirm the possible causal relationship between urban inequality and myopia. Certainly, there will be substantial challenges in the implementation phase