Comparing generative and retrieval-based chatbots in answering patient questions regarding age-related macular degeneration and diabetic retinopathy.

BACKGROUND/AIMS: To compare the performance of generative versus retrieval-based chatbots in answering patient inquiries regarding age-related macular degeneration (AMD) and diabetic retinopathy (DR). METHODS: We evaluated four chatbots: generative models (ChatGPT-4, ChatGPT-3.5 and Google Bard) and a retrieval-based model (OcularBERT) in a cross-sectional study. Their response accuracy to 45 questions (15 AMD, 15 DR and 15 others) was evaluated and compared. Three masked retinal specialists graded the responses using a three-point Likert scale: either 2 (good, error-free), 1 (borderline) or 0 (poor with significant inaccuracies). The scores were aggregated, ranging from 0 to 6. Based on majority consensus among the graders, the responses were also classified as 'Good', 'Borderline' or 'Poor' quality. RESULTS: Overall, ChatGPT-4 and ChatGPT-3.5 outperformed the other chatbots, both achieving median scores (IQR) of 6 (1), compared with 4.5 (2) in Google Bard, and 2 (1) in OcularBERT (all p ≤8.4×10-3). Based on the consensus approach, 83.3% of ChatGPT-4's responses and 86.7% of ChatGPT-3.5's were rated as 'Good', surpassing Google Bard (50%) and OcularBERT (10%) (all p ≤1.4×10-2). ChatGPT-4 and ChatGPT-3.5 had no 'Poor' rated responses. Google Bard produced 6.7% Poor responses, and OcularBERT produced 20%. Across question types, ChatGPT-4 outperformed Google Bard only for AMD, and ChatGPT-3.5 outperformed Google Bard for DR and others. CONCLUSION: ChatGPT-4 and ChatGPT-3.5 demonstrated superior performance, followed by Google Bard and OcularBERT. Generative chatbots are potentially capable of answering domain-specific questions outside their original training. Further validation studies are still required prior to real-world implementation.

Analysis of the pachychoroid phenotype in an Asian population: methodology and baseline study population characteristics.

AIM: To describe the clinical characteristics in a cohort of patients with the pachychoroid phenotype and to evaluate the association of ocular and systemic factors with type of complications observed. METHODS: We report baseline findings from a prospective observational study which recruited subjects with subfoveal choroidal thickness (SFCT) of ≥300 µm on spectral-domain optical coherence tomography (OCT). Multimodal imaging was used to classify eyes as uncomplicated pachychoroid (UP) or pachychoroid disease with pachychoroid pigment epitheliopathy (PPE), central serous chorioretinopathy (CSC) or pachychoroid neovasculopathy (PNV) subtypes. RESULTS: Among 181 eyes of 109 participants (mean age 60.6 years, 33 (30.3%) female, 95 (7.2%) Chinese), 38 eyes (21.0%) had UP. Of 143 eyes (79.0%) with pachychoroid disease, 82 (45.3%), 41 (22.7%) and 20 (11.0%) had PPE, CSC and PNV, respectively. Addition of autofluorescence and OCT angiography to structural OCT led to reclassification of 31 eyes to a more severe category. Systemic and ocular factors evaluated, including SFCT, were not associated with disease severity. Comparison of PPE, CSC and PNV eyes showed no significant difference in OCT features of retinal pigment epithelial (RPE) dysfunction, but disruption of the ellipsoid zone (PPE 30.5% vs CSC 70.7% vs PNV 60%, p<0.001) and thinning of inner nuclear/inner plexiform layers (PPE 7.3% vs CSC 36.6% vs PNV 35%, p<0.001) were more frequent in CSC and PNV eyes. CONCLUSIONS: These cross-sectional associations suggest pachychoroid disease manifestations may reflect progressive decompensation from the choroid to the RPE then retinal layers. Planned follow-up of this cohort will be beneficial in clarifying the natural history of the pachychoroid phenotype.

Five-year outcomes of eyes initially enrolled in the 2-year BEVORDEX trial of bevacizumab or dexamethasone implants for diabetic macular oedema.

BACKGROUND: The BEVORDEX trial compared outcomes of eyes with diabetic macular oedema (DMO) randomised to receive either intravitreal dexamethasone (DEX-) implant or bevacizumab over 2 years. We assessed long-term efficacy and safety outcomes 5 years from enrolment. METHODS: Patients received standard clinical care after they finished the study. Their files were reviewed for visual and anatomical outcomes, post-trial treatments and complications. RESULTS: Three-year and five-year data were available for 82% and 59% of eyes enrolled in the BEVORDEX study, respectively. Visual acuity gains at end of trial were generally lost by both treatment groups at 5 years but the macular thickness did not change from end of trial to 5 years. A similar proportion of eyes from each treatment group gained ≥10 letters at 5 years from enrolment in the BEVORDEX trial.Eyes that were initially randomised to the DEX-implant group had significantly fewer treatments but were more likely to develop proliferative diabetic retinopathy (PDR) over the 5-year period compared with eyes initially randomised to bevacizumab. The proportion of eyes that had cataract surgery by 5 years was similar between initial treatment groups. CONCLUSIONS: Eyes in the BEVORDEX trial had similar 5-year rates of cataract surgery, however, more eyes converted to PDR in the group initially treated with DEX-implant. Eyes that were initially treated for 2 years with either intravitreal DEX-implant of bevacizumab followed by standard of care had similar visual and anatomical outcomes at 5 years.

COVID-19-Related Retinal Micro-vasculopathy - A Review of Current Evidence.

PURPOSE: To evaluate the occurrence of retinal microvasculopathy in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and who developed coronavirus disease (COVID-19). DESIGN: Systematic review and meta-analysis. METHODS: The Pubmed and Embase databases were comprehensively searched to identify studies that reported retina vascular changes in eyes with COVID-19. Two independent reviewers selected papers and extracted data for analysis. Data of interest were extracted and analyzed in RevMan Web versions 3.3. Quality of evidence was assessed using the National Institute of Health quality assessment tool for a case-control study. RESULTS: Thirty-one studies reporting on 1373 subjects (972 COVID-19 and 401 controls) were included. Only case-control studies were included in the pooled analysis. There was a significantly higher likelihood of retinal microvasculopathy in subjects with COVID-19 compared to controls (odds ratio [95% confidence interval], 8.86 [2.54-27.53], P < .01). Optical coherence tomography angiography (OCTA) revealed reduced vessel density and enlarged foveal avascular zone in subjects with COVID-19 compared to controls. CONCLUSIONS: The results suggested that COVID-19-related retinal microvasculopathy is a significant ocular manifestation of COVID-19 and may herald future retinal complications. These microvascular impairments might have occurred antecedent to clinically visible changes and could be detected earlier by OCTA. These findings are significant, due to the large numbers with COVID-19, and need to be recognized by ophthalmologists as a potential long-term sequalae of the disease.

Diabetic macular ischaemia- a new therapeutic target?

Diabetic macular ischaemia (DMI) is traditionally defined and graded based on the angiographic evidence of an enlarged and irregular foveal avascular zone. However, these anatomical changes are not surrogate markers for visual impairment. We postulate that there are vascular phenotypes of DMI based on the relative perfusion deficits of various retinal capillary plexuses and choriocapillaris. This review highlights several mechanistic pathways, including the role of hypoxia and the complex relation between neurons, glia, and microvasculature. The current animal models are reviewed, with shortcomings noted. Therefore, utilising the advancing technology of optical coherence tomography angiography (OCTA) to identify the reversible DMI phenotypes may be the key to successful therapeutic interventions for DMI. However, there is a need to standardise the nomenclature of OCTA perfusion status. Visual acuity is not an ideal endpoint for DMI clinical trials. New trial endpoints that represent disease progression need to be developed before irreversible vision loss in patients with DMI. Natural history studies are required to determine the course of each vascular and neuronal parameter to define the DMI phenotypes. These DMI phenotypes may also partly explain the development and recurrence of diabetic macular oedema. It is also currently unclear where and how DMI fits into the diabetic retinopathy severity scales, further highlighting the need to better define the progression of diabetic retinopathy and DMI based on both multimodal imaging and visual function. Finally, we discuss a complete set of proposed therapeutic pathways for DMI, including cell-based therapies that may provide restorative potential.