To determine the ocular spherical aberration after using preoperative corneal spherical aberration guided aspheric IOL selection for cataract surgery.Twenty-six eyes of cataract patients were scheduled for cataract surgery with aspheric IOL implantation based on preoperative corneal spherical aberration (SA) measured by Galilei corneal topography. The target postoperative total wavefront spherical aberration was zero. Three types of LOL were used in this study: TecnisZA9003 (Abbott Medical Optics Inc) with spherical aberration of -0.27 microm; Acrysof LQ SN60WF (Alcon Inc.) with spherical aberration of -0.20 microm and B&L Akreos with zero spherical aberration. Ocular spherical aberration was measured with a Wave Light machine 3 months postoperatively to demonstrate the total ocular spherical aberration.The preoperative mean corneal spherical aberration in the 3 groups was 0.351 +/- 0.08, 0.181 +/- 0.04, and 0.056 +/- 0.03 microns respectively. All 26 eyes of 26 patients completed the 3-month follow-up visit. Postoperative ocular spherical aberration of the 3 groups were: TecnisZA9003 (10 eyes) +0.023 +/- 0.011 microm; Acrysof IQ SN60WF (11 eyes) +0.045 +/- 0.018 microm; and B&L Akreos (5 eyes) +0.018 +/- 0.008 microm. These values were significantly lower than the predicted values in the Tecnis and Akreos groups and there was no correlation between the actual postoperative ocular spherical aberration and the predicted ocular spherical aberration in all groups.The implantation of an aspheric intraocular lens based on preoperative corneal spherical aberration is effective in reducing total ocular spherical aberration and improving visual function.
With spherical intraocular lens (IOL) implantation, unaided vision of cataract patients with pre-existing corneal astigmatism is unsatisfactory because astigmatic spectacles will always be needed for clear vision. Toric IOL has been proven to be a major improvement in cataract surgery for spectacle independence. Aspheric property, reported to improve visual quality in a non-toric IOL, has now been added to toric IOL for even better unaided vision.To compare visual and aberrometric outcomes of 2 toric IOL, spherical and aspheric, at 3 months after implantation.Cataract surgery was performed in cataract patients with pre-existing corneal astigmatism using 2 types of toric IOLs, a spherical toric IOL, Acrys of SN60T (Group A) and a aspheric toric IOL, Acrts of SN6AT, (Group B) as a randomized control trial. The uncorrected distance (UDVA) and corrected (CDVA) distance visual acuities, residual astigmatism, spherical equivalent (SE) and spherical aberration were evaluated 3 months after implantation.The present study included 44 eyes. No statistically significant difference was found in UDVA, CDVA and residual astigmatism between both groups. The UDVA of 0.1 logMAR or better was found in 78.26% in Group A and 85.71% in Group B. In Group A, 78.26% of eyes and in Group B, 76.19% had a refractive astigmatism value within 0.50 diopter at KP90 (polar value along the 90-degree meridian). The spherical equivalent (SE) was within ±0.5 diopter of emmetropia in 91.30% in Group A and in 80.95% in Group B. Group B had significantly lower spherical aberration Z (4, 0) than Group A.Both groups had similar clinical effectiveness for unaided visual acuity, aided visual acuity and astigmatism correction. Group B had significantly less spherical aberration induction when compared with Group A.
Terahertz (THz) imaging of corneal tissue water content (CTWC) is a proposed method for early, accurate detection and study of corneal diseases. Despite promising results from ex vivo and in vivo cornea studies, interpretation of the reflectivity data is confounded by the contact between corneal tissue and rigid dielectric window used to flatten the imaging field. This work develops a novel imaging system and image reconstruction methods specifically for nearly spherical targets such as human cornea. A prototype system was constructed using a 650-GHz multiplier source and Schottky diode detector. Resolution and imaging field strength measurement from characterization targets correlate well with those predicted by the quasioptical theory and physical optics analysis. Imaging experiments with corneal phantoms and ex vivo corneas demonstrate the hydration sensitivity of the imaging system and reliable measurement of CTWC. We present successful acquisition of noncontact THz images of in vivo human cornea, and discuss strategies for optimizing the imaging system design for clinical use.
Reflection mode Terahertz (THz) imaging of corneal tissue water content (CTWC) is a proposed method for early, accurate detection and study of corneal diseases. Despite promising results from ex vivo and in vivo cornea studies, interpretation of the reflectivity data is confounded by the contact between corneal tissue and dielectric windows used to flatten the imaging field. Herein, we present an optical design for non-contact THz imaging of cornea. A beam scanning methodology performs angular, normal incidence sweeps of a focused beam over the corneal surface while keeping the source, detector, and patient stationary. A quasioptical analysis method is developed to analyze the theoretical resolution and imaging field intensity profile. These results are compared to the electric field distribution computed with a physical optics analysis code. Imaging experiments validate the optical theories behind the design and suggest that quasioptical methods are sufficient for designing of THz corneal imaging systems. Successful imaging operations support the feasibility of non-contact in vivo imaging. We believe that this optical system design will enable the first, clinically relevant, in vivo exploration of CTWC using THz technology.
Purpose Dysthyroid optic neuropathy (DON) is a severe visual loss condition in thyroid eye disease (TED). This study aimed to identify factors affecting moderate-to-severe TED or DON in Thai populations. Methods We retrospectively reviewed the records of 230 TED patients at Rajavithi Hospital between January 1, 2017, and October 31, 2022. Results Mild, moderate-to-severe TED, and DON were found in 60.43%, 22.61%, and 16.96% of participants, respectively. Female predominance was noted in all groups. The proportion of older age, hyperthyroidism, current smokers, and type 2 diabetes mellitus (T2DM) participants were significantly higher in the DON group. Multivariable logistic-regression analysis revealed that hyperthyroidism and current smoking significantly increased the risk of developing moderate-to-severe TED (OR = 3.001, p = 0.010, and OR = 4.153, p = 0.015, respectively). Exophthalmos was the strongest predictor (OR = 6.834, p < 0.001). Regarding DON risk factors, older age (≥55 years) had OR = 3.206 ( p = 0.003), hyperthyroidism had OR = 3.228 ( p = 0.005), and being a current smoker had OR = 3.781 ( p = 0.011). T2DM posed the greatest risk of DON development (OR = 4.111, p = 0.004). Conclusions Hyperthyroidism and current smoking are significant risk factors for moderate-to-severe TED and DON. TED patients with diabetes mellitus or older age should be closely monitored and informed about their risk of developing DON.
We report a case of non-arteritic anterior ischaemic optic neuropathy (NAION) associated with neovascular glaucoma (NVG). A 63-year-old man who had undergone cataract surgery 3 months previously presented with sudden visual loss in his right eye. Ocular examination revealed a relative afferent pupillary defect, intraocular pressure (IOP) of 27 mm Hg, and 360° neovascularisation. Fundus examination revealed a pale and swollen optic disc with diabetic retinopathy. NAION associated with NVG was diagnosed. NVG, leading to reduced optic nerve perfusion pressure, concurrent with ischaemic processes of diabetic retinopathy, resulted in NAION.
The purpose is to report ocular surface erosion of health personnel who were exposed to evaporated CoronaVac during a vaccination campaign. A campaign for CoronaVac vaccination was conducted in a closed space of 11.04 × 5.96 m, partially divided into 6 rooms with interconnected area among the rooms. A total of 20 health personnel worked in the vaccination rooms. On the third day of campaign, a vial, containing a single dose of 0.5 mL, of the vaccine was dropped accidentally onto the floor and broken by an administering nurse. A total of 15 personnel had symptoms and signs of ocular surface erosion at the average time from the accident to the onset of 10.2 ± 7.1 h; 4 personnel also had skin rash. These personnel included all 13 persons who already worked in the rooms when the accident occurred and continued for additional 4–6 h and 2 personnel who presented in the rooms 1–2 h after the accident and stayed for 2–3 h. Proximity and timing suggest CoronaVac correlation with the ocular and skin reactions. Cautions should be taken to avoid broken vials, spills, and aerosolization of CoronaVac during the vaccination.
BACKGROUND Dry eye (DE) is a chronic inflammatory disease of the ocular surface of the eye that affects millions of people throughout the world. Smartphone use as an effective health care tool has grown exponentially. The “Dry eye or not?” app was created to evaluate the prevalence of symptomatic DE, screen for its occurrence, and provide feedback to users with symptomatic DE throughout Thailand. OBJECTIVE The purpose of this study was to compare the prevalence of symptomatic dry eye (DE), blink rate, maximum blink interval (MBI), and best spectacle-corrected visual acuity (BSCVA) between people with and without symptomatic DE and to identify risk factors for symptomatic DE in Thailand. METHODS This cross-sectional study sourced data from the “Dry eye or not?” smartphone app between November 2019 and July 2020. This app collected demographic data, Ocular Surface Disease Index (OSDI) score, blink rate, MBI, BSCVA, and visual display terminal (VDT) use data. The criterion for symptomatic DE was OSDI score ≥13. RESULTS The prevalence of symptomatic DE among individuals using this smartphone app in Thailand was 85.8% (8131/9482), with the Northeastern region of Thailand having the highest prevalence, followed by the Northern region. Worse BSCVA (median 0.20, IQR 0.40; <i>P</i>=.02), increased blink rate (median 18, IQR 16; <i>P</i><.001), reduced MBI (median 8.90, IQR 10.80; <i>P</i><.001), female sex (adjusted OR 1.83; 95% CI 1.59-2.09; <i>P</i><.001), more than 6 hours of VDT use (adjusted OR 1.59; 95% CI 1.15-2.19; <i>P</i>=.004), and lower than bachelor’s degree (adjusted OR 1.30; 95% CI 1.03-1.64; <i>P</i>=.02) were significantly associated with symptomatic DE. An age over 50 years (adjusted OR 0.77; 95% CI 0.60-0.99) was significantly less associated with symptomatic DE (<i>P</i>=.04). CONCLUSIONS This smartphone DE app showed that the prevalence of symptomatic DE in Thailand was 85.8%. Signs and risk factors could be also evaluated with this smartphone DE app. Screening for DE by this app may allow for the development of strategic plans for health care systems in Thailand.
Purpose To evaluate the economic impact of treating severe infectious keratitis (IK) at one tertiary referral center in Thailand by analyzing the direct costs of treatment and estimating the indirect costs, and to determine whether cultured organisms had any effect on treatment expenditure. Methods A retrospective study was conducted of patients with severe IK who had been hospitalized between January 2014 and December 2021 in Rajavithi Hospital. Data from medical records were collected from the time of the patients’ admission until the point at which they were discharged and treated in the outpatient department and their IK was completely healed, or until evisceration/enucleation was performed. The direct costs of treatment included fees for services, medical professionals and investigation, as well as for operative and non-operative treatment. The indirect costs consisted of patients’ loss of wages, and costs of travel and food. Results A total of 335 patients were studied. The median direct, indirect and total costs were US$65.2, range US$ 6.5–1,119.1, US$314.5, range US$50.8–1,067.5, and US$426.1, range 57.5–1,971.5 respectively. There was no statistically significant difference between direct, indirect, or total treatment costs for culture-negative and culture-positive patients. Among those who were positive, fungal infections entailed the highest total cost of treatment, and this difference was statistically significant (p<0.001). In terms of direct and indirect costs, patients with fungal infections had the greatest direct costs, and this figure was statistically significant (p = 0.001); however, those with parasitic infections had the highest indirect treatment costs, and this was also statistically significant (p<0.001). Conclusion Severe IK can cause serious vision impairment or blindness. Indirect costs represented the majority of the expense at 73.8%. There was no difference between direct, indirect, and total treatment costs for patients who were culture-negative or positive. Among the latter, fungal infections resulted in the highest total cost of treatment.
