Utility of retinoscopy to examine peripheral refraction

Purpose: This study explored whether retinoscopy (RET) provides comparable results of relative peripheral refraction (RPR) to open–field autorefractometry (AR) in myopic subjects.Methods: Peripheral refraction was measured in 20 myopic and 20 control adult subjects. Both central and peripheral refraction (20° nasal and temporal eccentricity) were measured using RET and open-field AR. Differences in the median central spherical equivalent (SE), median RPR, and median J45/J180 power vectors between the RET and AR techniques were analyzed. Moreover, Bland – Altman plots were used to assess the agreement between RET and AR methods for RPR measurements in MG. Results: For MG, the median RPR values were positive (hyperopic shift), and no significant differences were observed between the RET and AR techniques with respect to RPR measurement. In addition, we did not observe any significant differences in the RPR values between the nasal and temporal eccentricities for either the RET or AR technique for myopic subjects. There was also a significant correlation and agreement between the RET and AR technique for RPR measurements. With respect to central refraction, the median SE was slightly more positive for the RET than for the AR technique. Inside the CG, we also found significant correlation between the RET and AR technique for RPR measurements, and we observed a myopic shift in peripheral eccentricities. Conclusion: Our results show that retinoscopy may be a useful tool for objective measurements of RPR in myopic subjects and may be used interchangeably with the open-field AR method in everyday clinical practice. (AU)

Enhanced ophthalmic bioavailability and stability of atropine sulfate via sustained release particles using polystyrene sulfonate resin.

Atropine sulfate (ATS) eye drops at low concentrations constitute a limited selection for myopia treatment, with challenges such as low ophthalmic bioavailability and inadequate stability. This study proposes a novel strategy by synthesizing ophthalmic sodium polystyrene sulfonate resin (SPSR) characterized by a spherical shape and uniform size for cationic exchange with ATS. The formulation of ATS@SPSR suspension eye drops incorporates xanthan gum and hydroxypropyl methylcellulose (HPMC) as suspending agents. In vitro studies demonstrated that ATS@SPSR suspension eye drops exhibited sustained release characteristics, and tropic acid, its degradation product, remained undetected for 30 days at 40℃. The ATS levels in the tear fluids and aqueous humor of New Zealand rabbits indicated a significant increase in mean residence time (MRT) and area under the drug concentration-time curve (AUC0-12h) for ATS@SPSR suspension eye drops compared to conventional ATS eye drops. Moreover, safety assessment confirmed the non-irritating nature of ATS@SPSR suspension eye drops in rabbit eyes. In conclusion, the cation-responsive sustained-release ATS@SPSR suspension eye drops enhanced the bioavailability and stability of ATS, offering a promising avenue for myopia treatment.

Progression of macular retinoschisis following intravitreal aflibercept injection for myopic macular neovascularization-a case report and review of literature.

BACKGROUND: Macular retinoschisis (MRS) and myopic macular neovascularization (mMNV) are both potentially blinding complications of high myopia. In this case report, we highlight the progression of MRS after intravitreal anti-vascular endothelial growth factor (anti-VEGF) treatment for mMNV, as well as an extensive review of the literature on this topic. CASE DESCRIPTION: A 49-year-old woman presented with two weeks of recent onset blurring and metamorphopsia in her right eye. She had high myopia in both eyes (right eye - 20/60 with - 16D, left eye - 20/20 with - 13D). Slit-lamp ophthalmoscopy found a normal anterior segment in both eyes. On fundus examination, features of pathological myopia with posterior staphyloma and peripapillary atrophy were observed in both eyes. An active mMNV, as well as intraretinal fluid, minimal perifoveal inner and outer MRS, and focal posterior vitreous traction along the inferotemporal retinal arcade, were detected on optical coherence tomography (OCT) of the right eye. The patient received an intravitreal injection of Aflibercept (2 mg/0.05 ml). RESULTS: OCT scans at two- and four-month follow-up visits revealed regressed mMNV with a taut epiretinal membrane, progressive worsening of outer MRS, and the development of multiple perifoveal retinal detachment inferior to the fovea. Pars plana vitrectomy surgery was performed for the progressive MRS with good anatomical (resolved MRS) and functional outcome (maintained visual acuity at 20/60) at the last one-month post-surgery visit. CONCLUSION: Intravitreal anti-VEGF injections for mMNV can cause vitreoretinal interface changes, exacerbating MRS and causing visual deterioration. Vitrectomy for MRS could be one of several treatment options.

Ten-year observation of corneal densitometry and associated factors following small incision lenticule extraction.

AIM: To investigate the long-term changes of corneal densitometry (CD) and its contributing elements after small incision lenticule extraction (SMILE). METHODS: Totally 31 eyes of 31 patients with mean spherical equivalent of -6.46±1.50 D and mean age 28.23±7.38y were enrolled. Full-scale examinations were conducted on all patients preoperatively and during follow-up. Visual acuity, manifest refraction, axial length, corneal thickness, corneal higher-order aberrations, and CD were evaluated. RESULTS: All surgeries were completed successfully without complications or adverse events. Ten-year safety index was 1.17±0.20 and efficacy 1.04±0.28. CD value of 0-6 mm zones in central layer was statistically significantly lower 10y postoperatively, compared with preoperative values (0-2 mmΔ=-1.62, 2-6 mmΔ=-1.24, P<0.01). There were no correlations between CD values and factors evaluated. CONCLUSION: SMILE is a safe and efficient procedure for myopia on a long-term basis. CD values get lower 10y postoperatively, whose mechanism is to be further discussed.

Changes in posterior corneal elevation after small incision lenticule extraction for different myopic diopters.

AIM: To study the changes and effect factors of posterior corneal surface after small incision lenticule extraction (SMILE) with different myopic diopters. METHODS: Ninety eyes of 90 patients who underwent SMILE were included in this retrospective study. Patients were allocated into three groups based on the preoperative spherical equivalent (SE): low myopia (SE≥-3.00 D), moderate myopia (-3.00 D>SE>-6.00 D) and high myopia (SE≤-6.00 D). Posterior corneal surfaces were measured by a Scheimpflug camera preoperatively and different postoperative times (1wk, 1, 3, 6mo, and 1y). Posterior mean elevation (PME) at 25 predetermined points of 3 concentric circles (2-, 4-, and 6-mm diameter) above the best fit sphere was analyzed. RESULTS: All surgeries were completed uneventfully and no ectasia was found through the observation. The difference of myopia group was significant at the 2-mm ring at 1 and 3mo postoperatively (1mo: P=0.017; 3mo: P=0.018). The effect of time on ΔPME was statistically significant (2-mm ring: P=0.001; 4-mm ring: P<0.001; 6-mm ring: P<0.001). The effect of different corneal locations on ΔPME was significant except 1wk postoperatively (1mo: P=0.000; 3mo: P=0.000; 6mo: P=0.001; 1y: P=0.001). Posterior corneal stability was linearly correlated with SE, central corneal thickness, ablation depth, residual bed thickness, percent ablation depth and percent stromal bed thickness. CONCLUSION: The posterior corneal surface changes dynamically after SMILE. No protrusion is observed on the posterior corneal surface in patients with different degrees of myopia within one year after surgery. SMILE has good stability, accuracy, safety and predictability.

Effectivity and safety of trifocal intraocular lenses and capsular tension rings implantation for cataract patients with axial high myopia.

AIM: To assess effectivity and safety of trifocal intraocular lenses (IOLs) and capsular tension rings in treating cataract patients with axial high myopia. METHODS: A prospective nonrandomized controlled clinical trial was conducted. Totally 98 eyes (74 patients) who underwent femtosecond laser-assisted cataract surgery (FLACS) with trifocal IOLs were enrolled in the study and followed up for 2y after surgery: 46 eyes (33 patients) with capsular tension ring implantation in the long axial lengths (AL) group (260.05). The dysfunctional lens index and total modulation transfer function (MTF) average height were similar between the two groups. The postoperative internal coma aberrations in the axial high myopia eyes were significantly higher than that in the normal AL group (P<0.05). The total satisfaction score in the long AL group (91.32±2.76) was slightly higher than that in the normal AL group (90.36±3.47), but there was no difference (P=0.136). A statistically negative correlation was found between corrected distance visual acuity (CDVA) and dysfunctional lens index (r=-0.382, P=0.009), and between CDVA and the total MTF average height (r=-0.374, P=0.01). But there was no significant correlation between CDVA and total satisfaction score (r=0.059, P=0.696). Postoperative complications mainly presented as posterior capsular opacity (PCO), retinal detachment and cystoid macular edema. There was no difference in the incidence of fundus disease (6.5% vs 3.8%, P=0.663) or PCO (17.4% vs 7.7%, P=0.217) between the two groups at two years. CONCLUSION: The utilization of trifocal IOL and capsular tension ring implantation is beneficial for cataract patients with axial high myopia undergoing FLACS. This approach not only ensures excellent subjective feelings and objective visual quality, but also does not increase the incidence of postoperative complications.

Nonperfusion of the Far Peripheral Retina in Highly Myopic Stickler Syndrome.

Purpose: To describe the clinical course of 3 patients with Stickler syndrome found on fluorescein angiography (FA) to have nonperfusion of the peripheral retina. Methods: Three patients with confirmed Stickler syndrome were examined under anesthesia. Genetic testing and FA were performed. Results: Each patient had characteristic ocular findings of Stickler syndrome, including high myopia with vitreoretinal degeneration. FA was performed on each patient and showed 360 degrees of nonperfusion of the retinal periphery in all eyes, with mild leakage in Case 3. Conclusions: The current series presents evidence of peripheral retinal nonperfusion in 3 consecutive patients with Stickler syndrome. Based on these findings, the authors recommend adopting FA as a standard imaging modality and using laser photocoagulation to treat the areas of retinal nonperfusion for all patients with Stickler syndrome.

Myopic Posterior Persistent Fetal Vasculature: A Rare Presentation.

Persistent fetal vasculature (PFV) is a rare ocular developmental disorder resulting from incomplete apoptosis of the embryonic hyaloid vasculature during the in-utero period. Variability in the development and regression of hyaloid vasculature is responsible for the wide range of clinical presentation of the disorder. PFV may manifest as anterior segment abnormalities (cataract, glaucoma, microphthalmia, elongated ciliary process with central traction, retrolental membrane, and shallow anterior chamber), posterior segment abnormalities (vitreous stalk, preretinal membranes, optic hypoplasia, and retinal folds), or with a combined anteroposterior disease. The most common associated clinical feature is leukocoria with microphthalmia and usually unilateral presentation. Most of the cases have poor visual prognosis and present early in childhood. Association with myopia is a very rare and atypical presentation, especially unilateral cases which may present later in life and have a good visual prognosis. Hereby, we present a case of a 27-year-old young adult male with unilateral atypical myopic posterior PFV with anisometropic amblyopia and good functional vision in the right eye.

Pharmacologically Induced Accommodation Palsy and the Bioelectrical Activity of the Muscular System: A Preliminary Investigation.

The aim of this study was to pharmacologically induce accommodative paralysis and evaluate its effects on the bioelectrical activity of the muscular system. The study included two participant groups: those with myopia and those with normal vision (emmetropes). Electromyographic assessments were performed using the Noraxon Ultium DTS 8-K MR 3 myo Muscle Master Edition system. The muscles analyzed in this study were the temporalis, masseter, sternocleidomastoid, trapezius, abdominal muscles, biceps brachii, and the external oblique muscles of the abdomen. It is important to acknowledge that, based on the current findings, it cannot be definitively stated that the observed effects have clinical significance, and additional studies are encouraged.

Effect of exogenous calcitriol on myopia development and axial length in guinea pigs with form deprivation myopia.

The annual increase in myopia prevalence poses a significant economic and health challenge. Our study investigated the effect of calcitriol role in myopia by inducing the condition in guinea pigs through form deprivation for four weeks. Untargeted metabolomics methods were used to analyze the differences in metabolites in the vitreous body, and the expression of vitamin D receptor (VDR) in the retina was detected. Following form deprivation, the guinea pigs received intraperitoneal injections of calcitriol at different concentrations. We assessed myopia progression using diopter measurements and biometric analysis after four weeks. Results indicated that form deprivation led to a pronounced shift towards myopia, characterized by reduced choroidal and scleral thickness, disorganized collagen fibers, and decreased scleral collagen fiber diameter. Notably, a reduction in calcitriol expression in vitreous body, diminished vitamin D and calcitriol levels in the blood, and decreased VDR protein expression in retinal tissues were observed in myopic guinea pigs. Calcitriol administration effectively slowed myopia progression, preserved choroidal and scleral thickness, and prevented the reduction of scleral collagen fiber diameter. Our findings highlight a significant decrease in calcitriol and VDR expressions in myopic guinea pigs and demonstrate that exogenous calcitriol supplementation can halt myopia development, enhancing choroidal and scleral thickness and scleral collagen fiber diameter.

Efficacy of repeated low-level red-light therapy in the prevention and control of myopia in children.

OBJECTIVE: In this study, we aimed to determine how different factors influence the effectiveness of repeated low-level red-light (RLRL) therapy in preventing and treating myopia in children. METHODS: Between June 2022 and April 2023, 336 children who visited our hospital due to myopia or significant decreases in hyperopia reserve were enrolled. The children were treated twice daily for three minutes with a head-mounted low-level red-light (single wavelength of 650 nm) therapeutic device. Each of the two treatment sessions was separated by at least four hours. The axial lengths and diopters of the children's eyes were compared before and three months after treatment, and the effects of gender, age, and baseline diopter on the efficacy of RLRL therapy were analyzed. RESULTS: Following three months of treatment, the average axial length of the eyes decreased by 0.031 mm. The condition was better for the boys than for girls, but the difference was not statistically significant. As age increased (F = 8.112, P = 0.000) or as the absolute value of baseline myopia degree increased (F = 10.51, P = 0.000), axial lengths of the eyes tended to decrease. The spherical equivalent refraction (SER) of children decreased by an average of 0.012 ± 0.355D. The condition was better for the boys than for girls, but the difference was not statistically significant. SER increased in the direction of hyperopic drift as age increased (F = 2.48, P = 0.031), or as the absolute value of baseline myopia degrees increased (F = 6.835, P = 0.000). There were no obvious side effects following the treatment. CONCLUSION: This study showed that RLRL therapy is a potential efficient, easily operable, and practically feasible method for the prevention and control of myopia.

Corrigendum: Establishment of noncycloplegic methods for screening myopia and pre-myopia in preschool children.

[This corrects the article DOI: 10.3389/fmed.2023.1291387.].

A Case of Strabismus Fixus With Extremely Long Axial Length Results in Improvement of Limitation of Abduction by the Yokoyama Procedure.

Acquired strabismus in high myopia is typically fixed in the positions of adduction and depression, with restrictions in both abduction and elevation. As a treatment for myopic strabismus fixus, the Yokoyama procedure is effective. We report a case of strabismus fixus with a long axial length (34 mm), in which abduction limitation was improved by the Yokoyama procedure with medial rectus recession. A 68-year-old woman was referred for strabismus fixus in her right eye. Her right eye was fixed in the positions of adduction and depression, with restrictions in both abduction and elevation. The axial length of her right eye was extremely long 33.97mm. Magnetic resonance imaging (MRI) showed that the posterior eyeball of her right eye had dislocated out of the superotemporal muscle cone, and she was diagnosed with strabismus fixus with high myopia. She underwent the Yokoyama procedure in her right eye, and medial rectus recession was performed at the same time because abduction limitations remained at the end of the Yokoyama procedure. After surgery, there was a small residual esotropia, but abduction beyond the midline was possible, and the patient's satisfaction was high. A combination of the Yokoyama procedure and medial rectus recession for a patient with myopic strabismus fixus with long axial length resulted in good improvement of ocular misalignment and limitation of abduction.

Assessment of OCT-Based Macular Curvature and Its Relationship with Macular Microvasculature in Children with Anisomyopia.

INTRODUCTION: To evaluate the intraocular differences in optical coherence tomography (OCT)-based macular curvature index (MCI) among children with anisomyopia and to investigate the relationship between MCI and the macular microvasculature. METHODS: Fifty-two schoolchildren with anisometropia > 2.00 D were enrolled and underwent comprehensive examinations including cycloplegic refraction, axial length (AL), and swept source OCT/OCT angiography. OCT-based MCIs were determined from horizontal and vertical B-scans by a customized curve fitting model in MATLAB R2022 at 1-mm-, 3-mm-, and 6-mm-diameter circles at fovea. Characteristics and topographic variation of MCI was analyzed, and the relationships with microvascularity and its associated factors were investigated. RESULTS: MCI achieved high reliability and repeatability. There were overall larger MCIs in the more myopic eyes than the less myopic eyes in 1-mm-, 3-mm-, and 6-mm-diameter circles at fovea (all p < 0.001). For the topographic variation, horizontal MCI was significantly greater than vertical MCI (all p < 0.001), and was the largest in 6-mm circle, followed by 3-mm and 1-mm circles. Stronger correlation of horizontal MCI with myopic severity than vertical MCI was found. Partial Pearson's correlation found MCI was negatively associated with deep capillary plexus (DCP) vessel density (p = 0.016). Eyes with a higher MCI in a 6-mm circle were more likely to have longer AL (p < 0.001), lower DCP vessel density (p = 0.037), and thinner choroidal thickness (ChT) (p = 0.045). CONCLUSION: Larger MCI was found in the more myopic eyes of children with anisomyopia and was significantly associated with smaller DCP density, suggesting that MCI was an important indicator of myopia-related retinal microvascularity change, and it could be a valuable metric for myopia assessment in children.

Association of myopia and astigmatism with postoperative ocular high order aberration after small incision lenticule extraction.

OBJECTIVE: To investigate the correlation between higher-order aberrations (HOA) after small incision lenticule extraction (SMILE) and the severity of myopia and astigmatism, along with the relevant factors. These findings will provide valuable insights for decreasing the occurrence of HOA after SMILE and enhancing visual quality. METHODS: A total of 75 patients (150 eyes) with myopia and astigmatism who underwent SMILE were categorized into four groups based on the severity of myopia and astigmatism: Myopia Group 1 (Group M1, spherical diopter ranged from -1.00 D to -4.00 D), Myopia Group 2 (Group M2, spherical diopter ranged from -4.10 D to -10.00 D), Astigmatism Group 1 (Group A1, cylindrical diopter ranged from 0 D to -1.00 D), and Astigmatism Group 2 (Group A2, cylindrical diopter ranged from -1.10 D to -3.00 D). A comprehensive assessment was performed to examine the association between HOA and various relevant factors, including a detailed analysis of the subgroups. RESULTS: Group M1 had significantly lower levels of total eye coma aberration (CA), corneal total HOA (tHOA), internal tHOA, and vertical CA ( Z 3 - 1 ) after SMILE than Group M2 (P < 0.05). Similarly, Group A1 had significantly lower levels of total eye tHOA, CA, trefoil aberration (TA), corneal tHOA, TA, and vertical TA ( Z 3 - 3 ) after SMILE than Group A2 (P < 0.05). Pearson correlation analysis indicated a statistically significant positive relationship between the severity of myopia/astigmatism and most HOA (P < 0.05). Subgroup evaluations demonstrated a notable increase in postoperative HOA associated with myopia and astigmatism in Groups M2 and A2 compared with the control group. Lenticule thickness, postoperative central corneal thickness (CCT), postoperative uncorrected distance visual acuity (UDVA), and postoperative corneal Km and Cyl were strongly correlated with most HOA. Age, eyes, and postoperative intraocular pressure (IOP) were only associated with specific HOA. CONCLUSION: HOA positively correlated with the severity of myopia and astigmatism after SMILE. However, this relationship was not linear. HOA after SMILE was influenced by various factors, and additional specialized investigations are required to establish its clinical importance.

Polydactyly-Myopia Syndrome: Genetic and Ophthalmologic Perspectives.

Polydactyly-myopia syndrome is a rare genetic condition characterized by the co-occurrence of polydactyly and myopia. Herein, we present the case of a 28-year-old Muslim male, born of consanguineous parents, who presented with complaints of diminished vision since childhood. Ophthalmologic examination revealed severe myopia with characteristic fundus changes indicative of high myopia. Additionally, the patient exhibited polydactyly in all limbs, with a positive family history of both polydactyly and myopia. This case underscores the importance of recognizing and managing rare syndromes to provide appropriate genetic counseling and clinical care. Further research is warranted to elucidate the underlying genetic mechanisms and optimize therapeutic strategies for polydactyly-myopia syndrome. Awareness of this syndrome among healthcare providers is essential to facilitate early diagnosis and intervention for affected individuals and their families.

Clinical and genetic characteristics and natural history of Finnish families with familial exudative vitreoretinopathy due to pathogenic FZD4 variants.

PURPOSE: To report clinical and genetic characteristics of familial exudative vitreoretinopathy (FEVR) in the Finnish population. METHODS: Detailed clinical and genetic data of 35 individuals with heterozygous pathogenic variants in FZD4 were gathered and analysed. RESULTS: Thirty-two individuals with FZD4 c.313A>G variant and three individuals with FZD4 c.40_49del were included in the study. The clinical phenotype was variable even among family members with the same FZD4 variant. Only 34% (N = 12/35) of variant-positive individuals had been clinically diagnosed with FEVR. The median age of the onset of symptoms was 2.3 years, ranging between 0 to 25 years. Median visual acuity was 0.1 logMAR (0.8 Snellen decimal), ranging between light perception and -0.1 logMAR (1.25 Snellen decimal). Most (N = 33/35, 94%) were classified as not visually impaired. Despite unilateral visual loss present in some, they did not meet the criteria of visual impairment according to the WHO classification. Two study patients (N = 2/35, 6%) had severe visual impairment. The most common FEVR stage in study patient's eyes (N = 28/70 eyes, 40%) was FEVR stage 1, that is, avascular periphery or abnormal vascularisation. Most of FZD4-variant-positive study patient's eyes (N = 31/50 eyes, 62%) were myopic. Two individuals presented with persistent hyperplastic primary vitreous expanding the phenotypic spectrum of FEVR. Shared haplotypes extending approximately 0.9 Mb around the recurrent FZD4 c.313A>G variant were identified. CONCLUSION: Most study patients were unaffected or had mild clinical manifestations by FEVR. Myopia seemed to be overly common in FZD4-variant-positive individuals.

Evaluation of Lag of Accommodation with Full-Field Diffusion Optics Technology™ (DOT) Contrast Management Spectacle Lenses in Emmetropic Children.

Purpose: To evaluate the impact on the lag of accommodation (LOA) in emmetropic children after short-term wear of full-field Diffusion Optics TechnologyTM (DOT) spectacle lenses, designed to modulate retinal contrast to control myopia progression. Patients and Methods: This was a single-visit, prospective, randomized, subject-masked study of emmetropes (ametropes ±1.00D or less in each meridian) with no history of myopia control treatment. Unaided logMAR visual acuity was measured, and ocular dominance was determined using the sighting method. In a randomized order, participants wore plano full-field contrast management (DOT) spectacles (no clear central aperture) or control spectacles (standard single vision spectacle lenses). Each participant was given 5 minutes for adaptation to the respective lenses before open field autorefraction measurements were taken at 6 meters and 40 cm. Ten measurements were taken for each eye. Data were evaluated from the right eye and the dominant eye separately. Results: A total of 30 participants (20 females and 10 males) with a mean age of 10.4 ± 2.8 (7 to 17) years completed the study. There was no significant difference in right eye mean LOA with contrast management spectacles 0.57 ± 0.39D versus control spectacles 0.62 ± 0.34D; Wilcoxon test, p = 0.37. For dominant eyes, LOA values were 0.60 ± 0.40D and 0.68 ± 0.33D with contrast management spectacles and control spectacles, respectively (p = 0.14). Additionally, no significant difference was observed in mean LOA between males and females or between age groups (7-11 years vs 12-17 years) for either right or dominant eyes with contrast management or control spectacles (all p > 0.05). Conclusion: Full-field contrast management spectacle lenses had no significant effect on LOA compared to standard single vision spectacle lenses, indicating no differential impact on accommodative response over the short period of lens wear tested.

Complement decay-accelerating factor inhibits inflammation-induced myopia development.

Myopia is regarded as a worldwide epidemic ocular disease, has been proved related to inflammation. CD55, also known as decay-accelerating factor (DAF) can modulate the activation of complement through inhibiting the formation of complement 3 convertase and its dysregulation is involved in various inflammatory diseases. To investigate the association between CD55 and myopia, and to test whether CD55 can inhibit myopia development by suppressing inflammation in the eye, we use three different animal models including monocular form-deprivation myopia, myopia induced by TNF-α administration and allergic conjunctivitis animal model to reveal the CD55 in myopia development. The tears of thirty-eight participants with different spherical equivalents were collected and CD55 in the tears were also analyzed. Complement 3 and complement 5 levels increased while CD55 levels decreased in allergic conjunctivitis and myopic eyes. After anti-inflammatory drugs administration, CD55 expression was increased in monocular form-deprivation myopia model. We also found inflammatory cytokines TGF-ß, IL-6, TNF-α, and IL-1ß may enhance complement 3 and complement 5 activation while CD55 level was suppressed contrary. Moreover, lower CD55 levels were found in the tears of patients with myopia with decreased diopter values. Finally, CD55-Fc administration on the eyelids can inhibit the elongation of axial length and change of refractive error. CD55-Fc application also suppress myopia development subsequent to complement 3 and complement 5 reduction and can lower myopia-specific (MMP-2 and TGF-ß) cytokine expression in TNF-α induced myopia animal model. This suggests that CD55 can inhibit myopia development by suppression of complement activation and eventual down-regulation of inflammation.

Prevalence of Refractive Errors Among Medical Students of Raichur Institute of Medical Sciences, Raichur, Karnataka, India.

Introduction Refractive errors (REs) are on the rise among medical students due to the high academic pressure of long hours of reading and their association with close technology. Uncorrected REs cause impaired vision and blindness with considerable morbidity. Documenting the prevalence of REs among medical students helps with early detection and appropriate remedial measures to prevent eye morbidity. Aim The aim of the study was to find the prevalence of REs among medical students at Raichur Institute of Medical Sciences, a medical institution in Raichur City, Karnataka, India. Methodology This hospital-based cross-sectional study was conducted with a total of 425 medical students. An examination of the eye for REs was carried out using a streak retinoscope. The REs were noted in myopia <-0.5 diopters (D), hypermetropia >+0.5 D, and astigmatism >0.5 cylinder D. The data was statistically subjected. Categorical measurements have been presented as frequency (percentage). The chi-square test was applied to the association between the parameters. A p-value less than 0.05 was considered statistically significant. Results Among the 425 observed participants, 160 (37.6%) subjects had REs. Among the REs in the total population, myopia 78 (18.4%) was the most prevalent, followed by hypermetropia and astigmatism, both with 41 (9.6%) and 41 (9.6%) prevalence, respectively. Gender-wise and age-wise, myopia was highly prevalent in both genders and in all age groups except the 20 years age group. Conclusion The prevalence of REs in our study among medical students is a matter of concern, although it is less compared to other previous studies in different geographical areas of India. Regular checkups, early detection, and immediate treatment are very important to prevent further ocular complications.