Medical hypothesis, discovery & innovation in optometry

Background: Uveitis is associated with several systemic disorders. It may be the initial presentation or manifestation of a systemic disease. It is the most common ocular complication and is sometimes the earliest manifestation of spondyloarthropathies. This study aimed to review the current literature on spondyloarthropathies and associated uveitis.
Methods: A narrative review was performed using various combinations of the keywords spondyloarthropathies, seronegative spondylarthritis-related uveitis, and human leukocyte antigen-associated uveitis using PubMed/MEDLINE and Google Scholar from January 1, 2000, to September 30, 2022. We describe the disease mechanisms, genetics, and classification of spondyloarthropathies, the clinical patterns of their related ocular diseases, and the current modalities for the management of their ocular or systemic manifestations.
Results: Seronegative spondyloarthropathies are a group of rheumatic disorders including ankylosing spondylitis, reactive arthritis, psoriatic arthritis, inflammatory bowel disease-related spondyloarthropathy, juvenile-onset spondyloarthritis, and undifferentiated spondyloarthritis. These are characterized by enthesitis in the absence of serum rheumatoid factor and have a strong association with human leukocyte antigen B27. The clinical courses and features of spondyloarthropathies are remarkably diverse. Ocular inflammation is common in spondyloarthropathies, often precedes the onset or diagnosis of systemic disease, and responds well to topical therapy. Timely diagnosis of systemic diseases may improve quality of life and help avoid ocular and skeletal complications. Recurrence of ocular inflammation is frequent; on occasion, it may be associated with etanercept administration.
Conclusions: Eye care professionals should be able to recognize spondyloarthropathies, manage ocular disease, and collaborate with related specialties for modification of systemic treatment if associated with ocular complications. Timely referral and early management could attenuate or prevent ocular or systemic morbidities associated with spondyloarthropathies.

Background: Novel ocular imaging modalities have greatly impacted the diagnosis and management of different types of ocular neoplasia. In this narrative review, we summarize the practical features of popular and novel imaging modalities for ocular tumors.
Methods: Four databases, including PubMed/MEDLINE, Web of Science, Scopus, and Google Scholar, were searched from January 1, 2000 to August 31, 2022. Articles reporting different imaging modalities for diagnosing or monitoring treatment responses of ocular tumors were extracted using various combinations of the following keywords: ocular neoplasia, positron emission tomography or PET, single-photon emission computed tomography or SPECT, optical coherence tomography or OCT, OCT angiography or OCTA, computed tomography or CT, ultrasonography or US, ultrasound biomicroscopy or UBM, and magnetic resonance imaging or MRI.
Results: Various ocular imaging modalities had different accuracies as adjunctive tools for detecting or managing ocular tumors. Anterior ultra-high-resolution optical coherence tomography (OCT) could be used to evaluate images with < 5-µm resolution. OCT angiography provided deeper insight into retinal vascular changes associated with the malignant transformation of choroidal melanoma. OCT in children altered the diagnosis of suspicious retinoblastoma in 3% of the cases and treatment plan in 11% of the cases. While positron-emission tomography (PET)/computed tomography (CT) allowed the detection of metastatic lesions of choroidal melanoma by full-body scanning, single-photon emission CT was more sensitive compared to PET in detecting choroidal melanoma. Ultrasound biomicroscopy, with an accuracy exceeding 92.5%, could detect retinal calcification in lesions measuring 2–3 mm. Magnetic resonance imaging (MRI) had better contrast compared to ultrasound biomicroscopy and higher sensitivity compared to CT in detecting post-laminar optic nerve invasion. However, MRI had a lower spatial resolution compared to OCT. Further development of imaging modalities and their application in drug development would improve the treatment of ocular tumors.
Conclusions: Although diagnosing ocular tumors depend on clinical characteristics, innovations in ocular imaging have enabled early diagnosis and timely, appropriate management of ocular neoplasia, which are conducive to favorable visual outcomes and increased life expectancy. Further systematic reviews and meta-analyses of primary studies focusing on a specific imaging modality in ocular neoplasia could precisely determine the diagnostic accuracy of each imaging modality to better guide eye practitioners with efficient diagnostic or therapeutic approaches for these sight- or life-threatening entities. Imaging modalities may play a major role in drug development in the future.

Background:  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.

Background: Uncorrected refractive error is the most common cause of vision impairment and the second leading cause of blindness worldwide. Its prevalence differs among and within countries. This study was aimed at exploring the pattern and prevalence of refractive error among school children in the Wangsa Maju Township, Kuala Lumpur, Malaysia.
Methods: A stratified, multistage, cluster random sampling in a geographically defined area was employed, and 245 school children, aged 8–12 years, from two primary schools in Wangsa Maju Township, Kuala Lumpur, were recruited. The cross-sectional study employed interviewing, measuring uncorrected distance visual acuity (UCDVA) using the Snellen chart, cycloplegic refraction under a streak retinoscope refined subjectively, and a detailed slit-lamp examination to assess the anterior and posterior segments. Myopia, hyperopia, and astigmatism were defined as spherical equivalent (SE) greater than or equal to - 0.50, SE greater than or equal to + 2.00, and cylindrical greater than or equal to 0.75 D, respectively. Reduced UCDVA was defined as an unaided visual acuity < 6/9.
Results: The mean (standard deviation) age of the participants was 10.42 (1.22) years. The overall prevalence of refractive error was 47.8%. Of 245 screened school children, including 42 (35.9%) boys and 75 (64.1%) girls, 117 had refractive error, with a prevalence of refractive error of 17.1% and 30.6% in boys and girls, respectively. Myopia was the most common type (30.2%), followed by astigmatism (16.3%) and hyperopia (1.2%). The prevalence of reduced UCDVA was 36.3% among the screened school children, attributable to refractive error with a significantly high positive correlation (r = +.721; P < 0.01). Among those with refractive errors, sex differences in the magnitude of refractive errors were not statistically significant in the three types of refractive errors (all P > 0.05).
Conclusions: The prevalence of refractive error among primary school children in Wangsa Maju Township, Kuala Lumpur, Malaysia was 47.8%; girls outnumbered boys, but the magnitude of refractive errors showed no sex differences. The prevalence of reduced UCDVA was 36.3%, attributable to refractive error. Irrespective of sex, myopia had the highest prevalence compared to other refractive errors, and its prevalence increased with age. Future population-based studies are required to address the limitations concerning environmental risk factors for refractive error and the impact of ethnic or familial backgrounds on their prevalence in a similar but larger population using the same protocol.

Background: 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.

Background: Pars plana vitrectomy (PPV) with silicone oil (SO) injection for rhegmatogenous retinal detachment (RRD) repair may adversely affect electroretinographic responses. This study was aimed at assessing retinal function using electrodiagnostic testing after successful PPV with SO tamponade in the eyes with macula-off RRD.
Methods: In this interventional comparative study, eligible participants were recruited prospectively over 1 year. We included the eyes that underwent a single successful three-port PPV with SO tamponade for the primary repair of macula-off RRD. Full-field electroretinogram (ffERG) and multifocal electroretinogram (mfERG) were recorded 1 day before and 3 days after SO removal. The amplitude and implicit time of the a- and b-waves for ffERG and P1 and N1 waves for mfERG were evaluated. The unaffected fellow eyes of the patients were selected as controls.
Results: We included the ten eyes of ten patients (seven men and three women) with a mean (standard deviation) age of 58.8 (6.2) years. The mean (SD) interval between the diagnoses of macula-off RRD and PPV was 11.7 (3.6) days. The mean (SD) duration of SO tamponade was 147.8 (34.9) days. Using ffERG, significantly lower a- and b-wave amplitudes were found in the eyes before and after SO removal or compared to the unaffected fellow eyes (all P < 0.05). Using the mfERG, treated eyes had significantly lower P1 amplitudes in the central R1+R2+R3 rings and in the R4 and-R5 peripheral rings of the macular area in the eyes before and after SO removal or compared to the unaffected fellow eyes (all P < 0.05). The wave implicit time in ffERG and mfERG did not differ significantly in the eyes before and after SO removal or compared to the unaffected fellow eyes (all P > 0.05).
Conclusions: The electrical retinal response density in ERG waveforms increased following SO removal, indicating amelioration of the electrical activity of the retina and macula. These results indicate that the adverse effects of SO tamponade on electroretinography responses may be reversible with removal. In addition, ffERG and mfERG can be used to monitor retinal function in the eyes with macula-off RRD and SO tamponade. Further clinical trials are required to verify the preliminary findings of this study.