Higher Diopter Research Articles

Vat photopolymerization of multifunctional fresnel lenses for ocular management.

In this study, multifunctional Fresnel lenses were explored as a potential solution for correcting vision in patients with color vision deficiency (CVD) and high myopia. Current studies have primarily focused on color vision correction through the 3D printing of glasses and contact lenses. However, the potential of 3D-printed multifunctional devices, such as Fresnel lenses, goes beyond addressing a single vision correction issue. For this study, computer-aided design (CAD) model of Fresnel lens with high diopter based on constant height configuration was developed. The CAD model was successfully fabricated using vat photopolymerization 3D printer, employing laboratory-prepared transparent HEMA resin. The resin was modified with two Atto dyes (565nm and 488nm), known for their ability to filter out problematic wavelengths (400-500nm and 540-580nm) to address color vision deficiency. The printed lenses were characterized by their chemical, physical, and optical properties using various characterization techniques. The focusing performance was evaluated using focal length measurements, and the results obtained were less than 2mm deviation from the design value, having the potential to assist in higher myopic vision correction. The resulting optical spectra were compared with commercial glasses, revealing close agreement for CVD correction. These results expand the potential applications of multifunctional Fresnel lenses in ophthalmology, demonstrating their effectiveness as vision-correcting lenses and imaging systems.

Intereye Asymmetry as a Predictor of Progression in Patients With Untreated Keratoconus: Findings From a Longitudinal Study.

The purpose of this study was to evaluate interocular predictors of progression in patients with untreated keratoconus. This is a multicenter longitudinal observational study with real-world data collected through the Save Sight Keratoconus Registry. Patients between the period of June 2000 and September 2022 were included in this study. Parameters such as patient age, sex, ocular history, visual acuity, K2, Max-K, and thinnest corneal thickness pachymetry (TCT) were analyzed. There were 4342 untreated eyes from 2171 patients with keratoconus. A total of 333 patients showed progression of either Max-K, TCT, or both, whereas 1838 patients showed stable parameters. Factors associated with a higher incidence of progression in Max-K were younger baseline age (HR 0.96 per year older; 95% CI 0.95-0.98, P < 0.0001) and a higher baseline intereye asymmetry in Max-K (HR 1.02 per higher diopter; 95% CI 1.00-1.04, P = 0.04). A younger baseline age was the only predictor of progression in TCT (HR 0.97 per year older; 95% CI 0.95-0.99, P = 0.001). Age is the most significant predictor of progression for both corneal thinning and progression of Max-K. Interocular asymmetry in Max-K at baseline could be used as part of an algorithm for determining the risk of keratoconus progression. It is recommended that patients with higher interocular asymmetry in Max-K have a closer follow-up of both eyes as they are at a higher risk of progression.

Morphology and microcirculation changes of the optic nerve head between simple high myopia and pathologic myopia

PurposeTo investigate morphological and microcirculation changes of optic nerve head (ONH) in simple high myopia (SHM) and pathologic myopia(PM) to evaluate and identify ONH changes in the development of PM.MethodsA cross-sectional clinical study was used. Medical records from 193 right eyes of 193 patients with high myopia (HM) were included. Using the Topocon swept source optical coherence tomograph (SS-OCT) and fundus camera to detect the parameters, we have assessed the relative position and size of ONH, tilt and rotation of ONH, angle α (Defined as between retinal temporal arterial vascular arcades was measured from the centre of ONH with 250 pixels’ radius), size and type of peripapillary atrophy (PPA), the thickness of peripapillary retinal nerve fiber layer (PRNFL), peripapillary choriodal thickness (PCT) and peripapillary scleral thickness (PST), and peripapillary vessel density (PVD). In addition, subjects were grouped as SHM and PM according to retinopathy, and the above parameters were compared between the two groups.ResultsPatients were divided into the SHM group (138 eyes) and the PM group (55 eyes). Paramters like older age, higher diopter and longer axial length (AL) of the PM were compared to SHM (t=-3.585, -8.808, -11.409, all P<0.05). There were no differences in the smallest diameter and area of ONH, rotation angle and ratio, or PST (all P>0.05). The angle α in PM was smaller than that in SHM (t = 2.728, P<0.01). The disc-fovea distance (DFD), the largest diameter, tilt index and ratio, PPA area and radian in PM were larger than in SHM (t=-3.962, Z=-2.525, t=-2.229, Z=-4.303, Z=-2.834, all P<0.05). The superior and inferior PRNFLs in PM were smaller than in SHM (t = 4.172, 4.263, all P<0.01). The temporoinferior PRNFL was the opposite (t=-2.421, P<0.01). The average PCT in PM (93.82 ± 29.96 μm) was smaller than in SHM (108.75 ± 30.70 μm) (P<0.05). The PVD in each direction of PM was smaller than that in SHM (t = 6.398, 4.196, 4.971, 3.267, 5.029, 5.653, 4.202, 5.146, 2.090, all P<0.05).ConclusionCompared with SHM, the PM patients were older, with higher diopter. Their AL and DFD were longer, the angle α was smaller, the tilt index was more extensive, the PPA area and radian were larger, PCT was generally thinner, and PVD was lower. When the PPA area was bigger than the ONH area, this already indicated the presence of PM. Based on these results, we suggest ophthalmologists and myopia patients pay more attention to ONH’s morphology and microcirculation changes as there is a possibility that microcirculatory changes precede morphologic changes.

Cataract Surgery Results of New Lens Implantation “Synthesis”

Purpose. Analysis of the cataract surgery visual outcomes and advantages of intraocular lens Synthesis SIPY.Material and methods. We have operated 43 eyes with cataract (38 patients) using Synthesis SIPY lens. Non-corrected visual acuity was 0.13 ± 0.08, best corrected visual acuity (BCVA) was 0.36 ± 0.1.Results. Following 7 months, secondary cataract was not detected in any patient, what explain the actuality of square edge optical part on 360° of perimeter. The lens is inserted in cartridge in factory sterile conditions which exclude the contact between lens and environment, reduce the risk of incorrect inserting of the lens in cartridge following pinching by the cartridge flaps and, subsequently, the haptic tearing off. This complex “lens-cartridge” excludes the damage of haptics and optic parts, which can occur in using other IOLs during the removal of the lens from the vial and placing it in the groove of the cartridge. Position of cartridge in injector centralizes the cartridge tunnel for the Accuject Pro injector plunger, thereby reducing the risk of pinching the rubber tip of the IOL haptic plunger during implantation. The diameter of the cartridge tip allows the IOL to be implanted through a 1.6 mm tunnel. The uncorrected visual acuity after surgery was 0.6 ± 0.28. The best corrected visual acuity was 0.78 ± 0.24.Conclusions. The Synthesis SIPY lens has a number of advantages: factory installation of the lens into the cartridge and compatibility of the cartridge with the Accuject Pro injector prevent damage to the IOL; Implantation of the Synthesis SIPY lens is possible through the 1.6 mm corneal tunnel; high diopter ranges from -10.0D to + 40.0D allows for maximum visual results.

Objective Measures of Near Viewing and Light Exposure in Schoolchildren during COVID-19.

SIGNIFICANCEWearable sensors provide the opportunity for continuous objective measurement of the visual environment with high resolution. Our findings show that absolute and temporal properties of near viewing and time outdoors vary between myopic and nonmyopic schoolchildren, which are important considerations when studying refractive error pathogenesis.PURPOSENumerous behavioral factors, including near work, time outdoors, electronic device use, and sleep, have been linked to myopia. The purpose of this study was to assess behaviors using subjective and objective methods in myopic and nonmyopic schoolchildren in the United States.METHODSForty children (aged 14.6 ± 0.4 years) simultaneously wore two sensors for 1 week, a Clouclip for objective measurement of near viewing and light exposure and an Actiwatch for objective measurement of activity and sleep. Parents completed an activity questionnaire for their child. Near-viewing distance, daily duration, short-duration (>1 minute) and long-duration (>30 minutes) near-viewing episodes, light exposure, time outdoors, electronic device use, and sleep duration were analyzed by refractive error group and day of the week.RESULTSObjectively measured daily near-viewing duration was 6.9 ± 0.3 hours. Myopes spent more time in near + intermediate viewing than nonmyopes (P = .008) and had higher diopter hours (P = .03). Short- and long-duration near-viewing episodes were similar between groups (P < .05 for both). Daily light exposure and time outdoors were significantly lower for myopes (P < .05 for both). Electronic device use (12.0 ± 0.7 hours per day) and sleep duration (8.2 ± 0.2 hours per night) were similar between groups (P > .05 for both).CONCLUSIONSObjective and subjective measures confirm that myopic and nonmyopic schoolchildren exhibit different behaviors. Combining wearable sensors with questionnaires provides a comprehensive description of children's visual environment to better understand factors that contribute to myopia.

Evaluation of preoperative dry eye in people undergoing corneal refractive surgery to correct myopia.

To investigate the incidence of preoperative dry eye and related factors in patients undergoing corneal refractive surgery to correct myopia. A total of 141 patients with myopia who underwent corneal refractive surgery were surveyed by questionnaires, tear film break-up time (BUT) test, Schimer I test (SIt), corneal fluorescein staining (FL) test and diagnosed according to the currently recognized domestic diagnostic criteria for dry eye. Correlation analysis of factors such as age, gender, regular wearing of contact lens (CL), diopter (spherical equivalent), corneal thickness, and corneal curvature that may affect the onset of dry eye was carried out to clarify the main influencing factors. There were 64 patients (45.39%) diagnosed with dry eye. The male patients (20.31%) was significantly less than that of non-dry eye subjects (41.56%; χ 2=7.260, P=0.007); the proportion of patients with dry eye wearing CL (81.25%) was significantly higher than that of non-dry eye subjects (51.95%; χ 2=13.234, P<0.001); the median diopter level of dry eye patients was -6.59 (IQR: -8.87, -4.58) D, and the median diopter level of non-dry eye subjects was -5.69 (IQR: -7.15, -4.03) D. The diopter level of dry eye patients was significantly higher (Z=-2.086, P=0.019). However, the age, best corrected visual acuity, and intraocular pressure of dry eye patients were not statistically different from those of non-dry eye subjects (t=-0.257, -0.383 and 0.778, P=0.798, 0.702, and 0.438); the corneal thickness and corneal curvature (K1 and K2) were also not statistically different either (Z=-1.487, -1.036 and -1.707, P=0.137, 0.300, and 0.088). The research further analyzes the three significant factors in the single factor analysis (gender, CL wear, and diopter) in a multi-factor way: CL wear and diopter were the influencing factors of dry eye disease. Among them, CL wear increased the risk of dry eye by 2.934 times compared with no CL wear; for every 1 D increase in diopter, the risk of dry eye increased by 0.761 times. Preoperative dry eye is relatively common in patients who undergo corneal refractive surgery to correct myopia, especially in patients who have a history of CL wear and a high diopter level before surgery. Therefore, it is necessary to carry out preoperative screening and timely treatment of dry eye to obtain the best treatment outcome and postoperative satisfaction.

Analysis of the clinical characteristics and refraction state in premature infants: a 10-year retrospective analysis.

To report the visual outcomes and refractive status in premature infants with and without retinopathy of prematurity (ROP) who were or not treated. The clinical records of all premature infants with or without ROP and with or without treatment between 2007 and 2017 were retrospectively reviewed. Basic demographic data, serial changes in ROP incidence, treatment and outcomes, and the refractive states were analyzed. Correlations among myopia and astigmatism progression, birth weight, gestational age, and treatment methods were also analyzed. A total of 562 screened premature infants (all Chinese, 1124 eyes), were recruited with a 378:184 male-to-female ratio. Birth weight did not directly influence ROP incidence. The overall ROP incidence was 16.55% (93/562 cases). The incidences in boys and girls were 16.14% (33/378 cases) and 17.39% (32/184 cases), respectively, and this difference was not significant. However, all infants with serious ROP (stage IV and V) were male. Myopia combined with astigmatism was common in premature infants with and without ROP (30.99%, 172/555 cases), and myopic refraction (including myopia and myopia combined with astigmatism) was more common in premature infants with ROP (48.84%, 42/86 cases). In the >8.00 diopter group, there were significantly more ROP infants than without ROP. Myopic refraction (including myopia and myopia combined with astigmatism) was most common in infants with ROP after treatment (63.63%, 7/11 cases). The refractive state is different between premature infants and mature infants. Those treated for ROP had a higher chance of developing myopia, astigmatism, and higher diopter.

Corneal hydrops induced by Bell's paralysis in a case of corneal ectasia

An 18-year-old male patient presented with suddenly decreased vision, itching, corneal edema and an inability to close the left eye. He had left Bell’s paralysis for two weeks and used high diopter glasses for five years. The best corrected visual acuity was 0.4 in his right eye and counting fingers in the left eye. Biomicroscopic examination revealed thinning and steepening of the cornea in the right eye and anterior protrusion of the cornea, stromal edema and punctate disruption of the epithelium in the left eye. Topographic image of the right eye was consistent with keratoconus. Six months later, stromal edema gradually regressed and a corneal scar ensued. This case presentation emphasizes that Bell’s palsy may induce disease progression in a patient with preexisting corneal ectasia and results in corneal hydrops.

Orthokeratology for the high myopia and high astigmatism is worth watching

The prevalence of high myopia in teenagers is rising. Due to both genetic factors and environmental factors, most of myopia occurs in early age with rapid progress, and the prevention and control are very difficult. Orthokeratology is considered as one of the most effective ways of controlling myopia for children. It is proved effective through many years of clinical studies not only for low to moderate myopia, but also for high myopia with astigmatism. However, professional knowledge is lacking domestically. This paper introduces the local and overseas research results in recent years, and discusses the necessity and feasibility of high diopter orthokeratology correction, implementation methods and requirements, and safety and effectiveness evaluation standards for reference.

영향인자에 따른 유발 부등상시도의 비교

Purpose: This study was performed to provide indicator of expected aniseikonia by correcting refractive error and to investigate influential factors on aniseikonia. Methods: 20 college students (14 males, 6 females, a mean age of years) were selected as subjects whose refractive error with spherical equivalent were within D, corrected visual acuity were more than 1.0, and aniseikonia values by AWAYA were less than 1%. After correcting refractive error with spectacles in anisometropia induced by wearing contact lens on their dominant eye or non-dominant eye, practical measured values of aniseikonia were compared with theoretical expected values of it by the formula of spectacle magnification. Results: Practical measured values were higher than theoretical expected values in induced aniseikonia over the whole range of diopter of wearing contact lens. And there was higher measured value of aniseikonia in case of higher diopter of wearing contact lens to induce anisometropia and correcting refractive error with spectacles of (+) diopter after wearing contact lens of (-) diopter to induced anisometropia in dominant eye of women. Conclusions: It is considered that dominant eye plays more important role for visual function in induced aniseikonia and factors such as the induced eye of aniseikonia, the diopter of wearing contact lens, and gender have influenced on aniseikonia.

Cataract Surgery Using Piggyback Method in Patient With Nanophthalmos

Purpose: To report a case of cataract surgery using a piggyback method in a patient with pure nanophthalmos with an axial length under 16.00 mm in both eyes. Case summary: The authors performed cataract surgery using a piggyback method inserting two intraocular lenses (IOLs) in a 44-year-old male with nanophthalmos with axial lengths of OD 15.36 mm, and OS 15.59 mm. Primary implantation of two IOLs of +53.0D as calculated by the SRK/T and Holladay formula was performed in the right eye using a piggyback method. In the left eye, two IOLs of +60.0D calculated by the Hoffer Q formula were implanted. Postoperative hyperopic refractive errors occurred in both eyes. The differences between the preoperative target spherical equivalent (SE) and the postoperative one year four month SE were 9.68D in the right eye and 1.63D in the left eye. Conclusions: Due to high diopter IOL requirements in nanophthalmic patients (less than 16.00 mm) during cataract surgery, the refractive errors were well corrected, without complications, by using a piggyback method. In the present case study, the Hoffer Q formula produced better results than did the SRK/T or Holladay formula in reducing the difference in preoperative and postoperative SEs, but more surgical cases and research are required to establish the most appropriate formula for cataract surgery in nanophthalmos.

Analyse of Q value and its related parameters in Chinese myopia population for corneal laser refractive surgery

Objective To investigate the distribution features of Q value of corneal anterior surfaee in Chinese myopia population for refractive surgery, and analyse the relationship between Q value and other related parameters. Methods 120 myopic patients （240 eyes） for laser-assisted in situ keratomileusis （LASIK） were randomly dividied into three groups with the degree of refractive error （40 cases （80 yees） in each group of high diopter, middle diopter and low dioper） . Each subject received investigations as follows： corneal topography （Q value and corneal curvature ）, subject refraction, central corneal thickness, ocular axis and other routine pre-surgery exams. The correlation between Q value and other parameters were analyzed. Results Average Q value was （ -0. 16 ±0. 17） and became Gauss distribution. 206 eyes （ Q 〈 O） was 85. 83%. There were no statistically significant difference in Q value and different eye or different sex. Q value showed linear correlation with diopter of refractive error（ F = 9. 6665, P 〈 0. 05 ）. There were statistically significant difference between high diopter group and other groups in Q value （q= 4. 0037, P〈0. 05; q= 3. 1218,P 〈0. 05）. There were no statistically significant differ- ence in low group and middle groups（q =0. 8818, P 〉0. 05）. There were no correlation found between Q value and corneal thick- ness ,corneal curvature or ocular axis （ F = 2. 6877,P 〉 0. 05 ; F =1.6407, P〉0. 05; F= 0. 7176,P〉0.05）. Conclusion In Chinese myopic population for refractive surgery, Q value were Gauss distribution and corneal curvature of majority population become prolate. Correlations existed between Q value and the degree of refractive error, but not between Q value and sex, central corneal thickness , corneal curvature or ocular axis. Key words: refractive surgery; myopia; Q value

Preparation and evaluation of a lubricious treated cartridge used for implantation of intraocular lenses

In the last decades, many surface modification technologies have been developed in an attempt to improve the function of medical device surfaces by adding or enhancing surface characteristics. These value-added processes included treatment to affect lubricity, hemocompatibility and drug delivery. A unique hydrophilic, lubricious coating was developed to treat hydrophobic polymer surfaces. The coating platforms described are composed of a polyelectrolyte molecular film containing hydrophilic, lubricant molecules. The molecular film is then further cross-linked with di-functional aldehyde molecules to form an interpenetrating network (IPN). The IPN entraps lubricant molecules in the matrix and provides for prolonged stability of the lubricity. This coating was applied to cartridges which were used to deliver intraocular lenses (IOLs) that replaced the cataractous crystalline lenses in patients In order to determine the safety and effectiveness of the coating, a rabbit in vivo study was designed to evaluate the ease of implantation and postoperative response to implantation of the foldable acrylic IOLs. The performance evaluation of the lubricious treated cartridges focused on the ease of insertion and post-IOL implantation response. It was found that the UNFOLDER™ Emerald Insertion System (Advanced Medical Optics) with lubricious treated cartridges generally required lower insertion forces than the standard UNFOLDER™ Emerald cartridges. The postoperative inflammatory response following lens extraction and posterior chamber implantation of low (6D), medium (20D) and high (30D) diopter foldable acrylic IOLs with both treated and standard cartridges was mild. Inflammation generally resolved by 3 weeks. Thus, in this animal study, the coating was shown to be effective in assisting the delivery of IOLs through cartridges, without causing any adverse effects.

The role of ultraviolet-B in corneal healing following excimer laser in situ keratomileusis.

Corneal photoablation with the 193 nm argon fluoride excimer laser during photorefractive keratectomy (PRK) in high diopter range is frequently associated with subepithelial haze and consequent refractive regression due to avascular corneal wound healing. The wound healing response can be augmented by Ultraviolet-B (UV-B) exposure originating from sun or solarium. Clinically Laser in situ Keratomileusis (LASIK) even in high diopter range is associated with less subepithelial haze and regression than PRK. In an animal model, the morphologic changes of the rabbit cornea were evaluated following LASIK and secondary UV-B exposure. Light microscpic changes were found to be insignificant. Transmission electron microscopy (TEM) normal epithelium, epithelial adhesion structures and normal anterior stroma showed in the LASIK treated UV-B irradiated rabbit eyes. Around the peripheral LASIK cut, migrating keratocytes with pseudopodia were observed. Under the flap (160 microm depth) the overall stromal collagen structure was normal, some activated keratocytes and mild extracellular matrix formation within and around keratocytes were noted. Within activated keratocytes TEM showed prominent rough endoplasmic reticulum, Golgi apparatus, mitochondria and extracellular vacuoles, which showed resolution with time. These changes were much milder than in PRK treated-UV-B irradiated eyes. Secondary UV-B caused no long-term disturbance in corneal transparency in LASIK and UV-B treated rabbit eyes.

Examination of subepithelial scarring with ultrasound biomicroscopy following photorefractive keratectomy

Subepithelial haze and concomittant refractive regression are the most important complications of photorefractive keratectomies (PRK) in the higher diopter range. Twenty previously photokeratectomized myopic eyes, which showed a certain level of subepithelial scarring, were examined in the present study. The range of PRK treatment varied between — 4.0 and - 12.0 D (on average - 7.4 ± 3.88 D). Subsequent subepithelial haze was graded between 0.5 and 4.0, according to Hanna et al. The first ultrasound biomicroscopy (UBM) was performed between 1 and 3 months following PRK with the 50–80 MHz transducer of a Zeiss-Humphrey Model 840 ultrasound biomicroscope. A control UBM examination was carried out in each patient 3 months after the initial assessment. The severity of subepithelial haze correlated with the previous photo-ablation depth. Below and including Haze Grade 2.0, UBM showed loss of the Bowman’s membrane and a slight thinning of the central 5.5 mm diameter cornea. Above Grade 2.0, the reflectivity of the anterior stromal parts began to increase. Between Grades 3.0 and 4.0, a hyper-reflective one-third of the anterior stroma with irregular borders was observed. In conclusion, haze graded below 2.0 was not observable with UBM. Haze graded more than 2.0 caused increased anterior stromal reflectivity in the central cornea. Ultrasound biomicroscopy was found to be a suitable method for presenting and following data over time for each patient with serious haze phenomena after excimer laser photo-ablation.