Comparison of different smartphone cameras to evaluate conjunctival hyperaemia in normal subjects

Despite the significant advantages that smartphones’ cameras can provide in teleophthalmology and artificial intelligence applications, their use as black-box systems for clinical data acquisition, without adequate information of the quality of photographs can compromise data accuracy. The aim of this study is to compare the objective and subjective quantification of conjunctival redness in images obtained with calibrated and non-calibrated cameras, in different lighting conditions and optical magnifications. One hundred ninety-two pictures of the eye were taken in 4 subjects using 3 smartphone cameras{Bq, Iphone, Nexus}, 2 lighting levels{high 815 lx, low 122 lx} and 2 magnification levels{high 10x, low 6x}. Images were duplicated: one set was white balanced and color corrected (calibrated) and the other was left as it was. Each image was subjective and objectively evaluated. There were no significant differences in subjective evaluation in any of the conditions whereas many statistically significant main effects and interaction effects were shown for all the objective metrics. The clinician’s evaluation was not affected by different cameras, lighting conditions or optical magnifications, demonstrating the effectiveness of the human eye’s color constancy properties. However, calibration of a smartphone’s camera is essential when extracting objective data from images

Intraocular Scattering, Blinking Rate, and Tear Film Osmolarity After Exposure to Environmental Stress

Purpose: Dry environments, such as those in offices or aircraft cabins, can potentially generate ocular discomfort and alter the tear film. We compare light scatter, blinking rate, and tear osmolarity in young and older subjects after exposure to low humidity using a controlled environmental chamber. Methods: Two groups of healthy subjects were recruited; younger (N = 13, 27 ± 6 years) and older (N = 23, 71 ± 7 years). Measurements were carried out before and after 90-minute exposure to low relative humidity (5%) and constant temperature (23 degrees). Ocular light scatter was measured using a double-pass instrument (OQAS, Visiometrics, Spain). Blinking rate was monitored using an infrared video camera. Tear osmolarity was measured using the TearLab system (Escondido, CA, USA). Results: Ocular light scatter increased by a factor of 10% after exposure to low humidity in the older group (P = 0.03) but did not change significantly in the younger group. Blinking rate increased significantly (40% more blinks) in both groups but there was no difference between the groups. No significant differences in osmolarity were shown between two age groups or as result of environmental stress. Conclusions: Exposure to dry environment increased light scatter in older subjects. Although more blinks were triggered in both younger and older groups to prevent corneal dehydration, there was no difference between the groups. Blink rate and osmolarity are not associated with the difference in light scatter. Translational Relevance: Our work approaches a clinical care problem using basic research methods (measuring ocular scatter and blink ratio)

Differences in dry eye questionnaire symptoms in two different modalities of contact lens wear: silicone-hydrogel in daily wear basis and overnight orthokeratology

Purpose. To compare the ocular surface symptoms and signs in an adult population of silicone-hydrogel (Si-Hy) contact lens (CL) wearers with another modality of CL wear, overnight orthokeratology (OK). Materials and Methods. This was a prospective and comparative study in which 31 myopic subjects were fitted with the same Si-Hy CL and 23 underwent OK treatment for 3 months. Dry eye questionnaire (DEQ) was filled in at the beginning of the study and then after 15 days, 1 month, and 3 months using each CL modality. The tear quality was evaluated with noninvasive tear break-up time. Tear production was measured with Schirmer test. Tear samples were collected with Schirmer strips being frozen to analyze the dinucleotide diadenosine tetraphosphate (Ap4A) concentration with High-Performance Liquid Chromatography (HPLC). Results. After refitting with ortho-k, a reduction in discomfort and dryness symptoms at the end of the day ( < 0.05, 2 ) was observed. No significant changes were observed in Ap4A concentration in any group. Bulbar redness, limbal redness, and conjunctival staining increased significantly in the Si-Hy group ( < 0.05, Kruskal–Wallis test). Conclusion. Discomfort and dryness symptoms at the end of the day are lower in the OK CL group than in the Si-Hy CL group.The authors thank Paragon Vision Science and CooperVision for donating the lenses. This work was partially supported by the Xunta de Galicia by a predoctoral grant of the Plan I2C 2011–2015 and the Spanish SAF2013-44416-R and RETICS RD12/0034/0003. It was also partially supported by Portuguese Foundation for Science and Technology (FCT) in the framework of projects PTDC/SAU-BEB/098391/2008 and PTDC/SAU-BEB/098392/2008

Performance of three multipurpose disinfecting solutions with a silicone hydrogel contact lens

"Article ID 216932"To evaluate the clinical performance of a silicone hydrogel (Si-Hy) soft contact lens (CL) in combination with three differentmultipurpose disinfecting solutions (MPDSs).Methods.Thiswas a prospective, randomized, single-masked, crossover, and comparative study in which 31 habitual soft CL wearers were randomly assigned to one of the three MPDSs (Synergi, COMPLETE RevitaLens, and OPTI-FREE PureMoist) for 1 month with a 1-week wash-out period between each exposure. All subjects were successfully refitted with a Si-Hy CL (Biofinity). Subjects were then scheduled for follow-up visits after 1 month of lens wear, being evaluated at 2 and 8 hours after lens insertion. Visual Analogue Scales (VAS) were used to gauge comfort rating. Results. The tarsal conjunctiva showed a significantly different degree of lid redness between the MPDSs at the 2-hour visit (P < 0.05, Kruskal- Wallis test), being lower for COMPLETE RevitaLens compared to the other two MPDSs (Mann-Whitney U test). Furthermore, a significantly different degree of lid roughness at the 8-hour visit was seen (P < 0.05, Kruskal-Wallis test), being higher for Synergi (Mann-Whitney U test).Thesubjective comfort was similar with the threeMPDSs. Conclusion. Tarsal conjunctival response should be also considered in the context of the clinical performance of MPDs at the ocular surface.This work has been funded by an unrestricted grant from AMO Germany GmbH and it was also partially supported by Xunta de Galicia, Spain (Predoctoral Grant) and Fundacao para a Ciencia e Tecnologia, Portugal

Are artificial intelligence chatbots a reliable source of information about contact lenses?

[Abstract]: Introduction Artificial Intelligence (AI) chatbots are able to explain complex concepts using plain language. The aim of this study was to assess the accuracy of three AI chatbots answering common questions related to contact lens (CL) wear. Methods Three open access AI chatbots were compared: Perplexity, Open Assistant and ChatGPT 3.5. Ten general CL questions were asked to all AI chatbots on the same day in two different countries, with the questions asked in Spanish from Spain and in English from the U.K. Two independent optometrists with experience working in each country assessed the accuracy of the answers provided. Also, the AI chatbots’ responses were assessed if their outputs showed any bias towards (or against) any eye care professional (ECP). Results The answers obtained by the same AI chatbots were different in Spain and the U.K. Also, statistically significant differences were found between the AI chatbots for accuracy. In the U.K., ChatGPT 3.5 was the most and Open Assistant least accurate (p < 0.01). In Spain, Perplexity and ChatGPT were statistically more accurate than Open Assistant (p < 0.01). All the AI chatbots presented bias, except ChatGPT 3.5 in Spain. Conclusions AI chatbots do not always consider local CL legislation, and their accuracy seems to be dependent on the language used to interact with them. Hence, at this time, although some AI chatbots might be a good source of information for general CL related questions, they cannot replace an ECP.This study was partially funded by Xunta de Galicia through the Project “CONSOLIDACIÓN E ESTRUTURACIÓN 2023” (Ref. ED431B 2023/07). Nery Garcia-Porta is supported financially by a Maria Zambrano contract at USC under the grants call for the requalification of the Spanish university system 2021–2023, funded by the European Union— NextGenerationEU. Ana I. Gómez-Varela acknowledges the grant RYC2022-035710-I funded by MCIN/AEI/ https://doi.org/10.13039/501100011033 and by ESF Investing in your future.Xunta de Galicia; ED431B 2023/0

Peripheral myopization using a dominant design multifocal contact lens

Purpose: The purpose of this study was to characterize the central and peripheral refraction across the horizontal meridian of the visual fi eld without and with a multifocal dominant design soft contact lens of different add powers (+1.00 D to +4.00 D) in emmetropic eyes. Methods: Twenty right eyes from 20 emmetropic patients (mean spherical equivalent central refraction —0.06 ± 0.54 D) with a mean age of 21.6 ± 2.3 years were fi tted with Proclear Multifocal dominant design (Coopervision, Pleasanton, CA, USA). Lenses had add powers from +1.00 to +4.00 D in 1.00 D steps. The central and peripheral refraction was measured along the horizontal meridian up to 35º of eccentricity in the nasal and temporal retinal area in 5º steps using a open-fi eld autorefractometer. Results: Only the +3.00 and +4.00 D add powers generated a signifi cant change in the peripheral refractive pattern compared to central refraction and compared with the no-lens wearing situation. The average myopic increase with these lenses was —3.00 D and —5.00 (p < 0.001) at the margins of inspected nasal and temporal visual fi eld, respectively. Conclusions: Multifocal dominant design soft contact lenses are able to change the peripheral refractive profi le in emmetropic eyes increasing relative peripheral myopia. Lenses with +3.00 D add power seem to be the best option to create such effect due to signifi cant peripheral myopization.Objetivo: El objetivo de este estudio fue caracterizar la refracción central y periférica a través del meridiano horizontal del campo visual con y sin lente de contacto blanda multifocal de diseño dominante de diferentes adiciones (+1,00 D a +4,00 D) en ojos emétropes. Métodos: Se colocaron lentes multifocales de diseño dominante Proclear (Coopervision, Pleasanton, Estados Unidos) en 20 ojos derechos de 20 pacientes emétropes (media del equivalente esférico de refracción central, —0,06 ± 0,54 D) con una media de edad de 21,6 ± 2,3 años. Las lentes tenían adiciones desde +1,00 hasta +4,00 D en pasos de 1,00 D. Se evaluó la refracción periférica a través del meridiano horizontal hasta 35º de excentricidad en el campo retiniano nasal y temporal en pasos de 5º utilizando un autorrefractómetro de campo abierto. Resultados: Solamente las potencias de +3,00 y +4,00 D produjeron un cambio signifi cativo en el patrón de refracción periférica en comparación con la refracción central y en comparación con la evaluación sin lente. El aumento medio de la miopía con estas lentes fue de —3,00 D y —5,00 (p < 0,001) en los límites de los campos visuales nasal y temporal explorados, respectivamente. Conclusiones: Las lentes de contacto blandas, multifocales y de diseño dominante tienen la capacidad de cambiar el perfi l de refracción periférica en ojos emétropes incrementando la miopía relativa periférica. Aparentemente, las lentes con potencia de +3,00 D serían la mejor opción para generar ese efecto debido a la miopización periférica significativaMRIS -Ministry of Research, Innovation and Science(SAF2008-01114-E

Characterization of the ocular surface temperature dynamics in glaucoma subjects using long-wave infrared thermal imaging

We evaluated the dynamics of ocular surface temperature using thermal imaging in 21 glaucoma subjects and 19 healthy subjects. On opening of the eye, subjects with glaucoma showed significantly cooler temperatures in the central cornea compared to the control group. The upper eyelid was also significantly cooler just before the eye opened. Immediately after opening the eye, the dynamic of temperature change was different in the two groups. In subjects with glaucoma, the eyes cooled significantly faster, with an average decrease of 0.49°C during the first second compared to 0.24°C in the control group. Our results support the hypothesis that both the stability of the tear film and changes in the ocular blood supply in subjects with glaucoma play an important role in thermal dynamics of the ocular surface

The potential influence of Schirmer strip variables on dry eye disease characterisation, and on tear collection and analysis

Purpose: The use of the Schirmer strips (SS) as a tool in the characterisation of dry eye disease, depends upon the quantitative assessment of tear production and constituents. The aim of this study was to ascertain the extent to which the properties of commercially available SS can vary and the way in which this baseline information may relate to their comparability in clinical use. Methods: Five SS were analysed: Clement Clarke®, TearFlo®, Bio Schirmer®, Omni Schirmer® and JingMing®. Various aspects of their physical appearance and physicochemical behaviour were measured, including size, weight, and thickness together with surface morphology (assessed by SEM) and aqueous uptake and release behaviour (including the influence of each strip on protein retention and eluent osmolarity). Results: All physical parameters varied between the strips studied for example the Clement Clark was the largest, thickest, and heaviest strip assessed in this study. SEM images showed that each of the SS had unique surface morphologies. Statistically significant differences among the strips were found for uptake (p = 0.001) and release volume (p = 0.014). Clement Clarke absorbed the highest volume over a fixed time period (23.8 ± 1.6 μl) and Omni the lowest (19.3 ± 0.5 μl). Clement Clarke showing the highest eluent osmolarity value (5.0 ± 0.0 mOsm/L) and TearFlo the lowest (2.8 ± 0.4 mOsm/L). Conclusion: The five strips investigated in this study indicate that there is no standardisation of commercial strips, despite the fact that the need for standardisation was recognised over fifty years ago. This study provides useful baseline information relating to SS comparability in clinical use