Definition and research guide
This page combines a MeSH definition, publication statistics and selected research abstracts. It is a starting point for reading the literature, not a medical textbook or a systematic evidence review.
Content available: 4 complete abstracts (1,073 words), 10 references. Full article text is not stored or reproduced here; follow the PMID, DOI or PMC links to read the original sources and their access terms.
Definition
An exudate between the retina and choroid from various sources including the vitreous cavity, subarachnoid space, or abnormal vessels.
Definition: NLM Medical Subject Headings (MeSH) scope note (Public domain (U.S. National Library of Medicine); attribution requested). View the MeSH record.
Also known as: Fluid, Subretinal; Sub-Retinal Fluid; Fluid, Sub-Retinal; Sub Retinal Fluid; Intraretinal Fluid; Fluid, Intraretinal; Intraretinal Fluids.
Where it fits in the MeSH classification
- Broader topics
- Exudates and Transudates
Related concepts
Research landscape
PubMed indexes 1,083 records tagged with the MeSH heading “Subretinal Fluid” (counts retrieved 2026-10-31). 425 of them (39.2%) were published from 2020 onward, and the busiest period so far is 2010-2019 with 641 records.
Reviews account for 43 records (4.0%) and meta-analyses for 6. Randomized controlled trials number 84 (7.8%) as a share of all records on the topic.
Show the data
| Period | Records |
|---|---|
| through 1999 | 15 |
| 2000-2009 | 2 |
| 2010-2019 | 641 |
| 2020 onward | 425 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 43 | 4.0% |
| Meta-analyses | 6 | 0.6% |
| Randomized controlled trials | 84 | 7.8% |
Method: PubMed query "Subretinal Fluid"[MeSH Terms] with publication-type and date filters, retrieved 2026-10-31.
Reading the evidence in anatomy and physiology
Anatomy describes how body structures are built and physiology describes how they normally work, so most findings here are descriptive or mechanistic rather than evidence about treatment. Much of what is known comes from dissection, imaging, tissue studies and experiments in animals, and measurements in healthy volunteers can differ from those in people with disease or at different ages. Normal ranges vary between individuals and populations. Check whether a result was measured in people or in another species, the age and health of the participants, and the method used.
Evidence from open-access studies
These open-access studies come from PubMed’s best-match results for this heading (papers whose main topic it is), ranked here by citation count, with one recent addition. Each abstract is reproduced in full under its recorded open licence so that you can read the authors’ own words. They illustrate the literature; they are not a systematic summary of it. Citation counts measure attention, not reliability or clinical benefit.
The role of sub-retinal fluid in determining treatment outcomes in patients with neovascular age-related macular degeneration--a phase IV randomised clinical trial with ranibizumab: the FLUID study [1]
Abstract reading summary — source excerpts
- Opening excerpt
- BackgroundWith increasing experience using anti-VEGF therapy for the treatment of neovascular age-related macular degeneration (nAMD), ophthalmologists have shifted away from a "one size fits all" to an "individualised" approach based on disease activity with the aim of achieving a fluid-free retina.
- Closing excerpt
- Date of registration: 24th October 2013.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (346 words)
BackgroundWith increasing experience using anti-VEGF therapy for the treatment of neovascular age-related macular degeneration (nAMD), ophthalmologists have shifted away from a "one size fits all" to an "individualised" approach based on disease activity with the aim of achieving a fluid-free retina. The FLUID study investigates the non-inferiority of a Treat and Extend (T&E) protocol of 0.5 mg ranibizumab, which allows treatment extension in the presence of incomplete resolution of sub-retinal fluid (SRF) ≤200 μm at the foveal centre relative to a T&E protocol that requires complete resolution of all retinal fluid (i.e., both SRF and intra-retinal fluid [IRF]) in patients with nAMD.Methods/designThis 24 month, randomised, phase IV trial has completed recruitment of treatment-naïve patients randomised 1:1 to ranibizumab "intensive" treatment (complete resolution of IRF and SRF) or ranibizumab "relaxed" treatment (resolution of IRF or >200 μm SRF only at foveal centre). Patients in both arms follow a T&E regimen where extension decisions are based upon assessment of lesion activity: loss of ≥5 letters of visual acuity, new haemorrhage, presence of IRF and SRF on an optical coherence tomography (OCT) scan. The determination of SRF is conducted at a reading centre while the assessment of IRF is physician-determined. The primary endpoint is the mean change in best-corrected visual acuity (BCVA) from baseline to 24 months. Secondary endpoints include the mean change in central retinal thickness (CRT) from baseline to 12 and 24 months, the number of ranibizumab injections administered at 12 and 24 months, and the pharmacogenomic assessment of AMD Gene Consortium-identified single-nucleotide polymorphisms (SNPs) and their association with treatment response. Three hundred and forty seven (347) patients have been recruited by 16 Australian sites within approximately 16 months. A protocol to adjudicate on SRF has been established by the central reading centre and is demonstrating good concordance with investigator assessment.DiscussionThis study will provide important insights into retreatment criteria for managing nAMD using a T&E regimen. The current paper describes the clinical rationale for using a less intensive treatment approach using ranibizumab and details of the treatment protocol.Trial registrationTrial registration numberNCT01972789. Date of registration: 24th October 2013.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 27009515 · DOI · PMC4806513
Impact of Sub-Retinal Fluid on the Long-Term Incidence of Macular Atrophy in Neovascular Age-related Macular Degeneration under Treat & Extend Anti-Vascular Endothelial Growth Factor Inhibitors [2]
Abstract reading summary — source excerpts
- Opening excerpt
- Sub-retinal fluid (SRF) has been discussed as a protective factor against macular atrophy in eyes with neovascular age-related macular degeneration (nAMD).
- Closing excerpt
- SRF might be an indicator of a more benign form of nAMD.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (245 words)
Sub-retinal fluid (SRF) has been discussed as a protective factor against macular atrophy in eyes with neovascular age-related macular degeneration (nAMD).To gauge the impact of SRF on macular atrophy, a database of 310 nAMD eyes was screened for eyes manifesting an SRF-only phenotype under treat & extend anti-VEGF treatment, defined as nAMD expressing CNV exudation beyond the three monthly anti-VEGF loading doses by SRF only without any signs of exudative intra-retinal fluid (IRF) for ≥3 years. Incidence of macular atrophy and treatment responses were evaluated on multimodal imaging, including optical coherence tomography (OCT), blue autofluorescence (BAF) and near-infrared (NIR) confocal scanning laser ophthalmoscopy and fluorescence and indocyanine green angiography (FAG/ICGA). In total, 27 eyes (8.7%) of 26 patients with a mean follow-up of 4.2 ± 0.9 (3-5) years met the inclusion criteria. Mean age was 72 ± 6 (range: 61-86) years. The SRF only phenotype was seen from baseline in 14 eyes (52%), and in 13 eyes (48%) after a mean 1.0 ± 1.3 (1-3) injections. In years 1 to 5, mean 7.5, 5.9, 6.1, 6.1 and 7.0 anti-VEGF injections were given (p = 0.33). Cumulative macular atrophy incidence was 11.5% at year 1, 15.4% throughout years 2 to 4, and 22.4% at year 5. In conclusion, eyes manifesting activity by SRF only in treat & extend anti-VEGF regimen for nAMD seem to exhibit rather low rates of macular atrophy during long-term follow-up. SRF might be an indicator of a more benign form of nAMD.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 32415240 · DOI · PMC7229002
Model-to-Data Approach for Deep Learning in Optical Coherence Tomography Intraretinal Fluid Segmentation [3]
Abstract reading summary — source excerpts
- Opening excerpt
- ImportanceAmid an explosion of interest in deep learning in medicine, including within ophthalmology, concerns regarding data privacy, security, and sharing are of increasing importance.
- Closing excerpt
- Although the clinical relevance of these results is limited at this time, this proof-of-concept study suggests that such a paradigm should be further examined in larger-scale, multicenter deep learning studies.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (249 words)
ImportanceAmid an explosion of interest in deep learning in medicine, including within ophthalmology, concerns regarding data privacy, security, and sharing are of increasing importance. A model-to-data approach, in which the model itself is transferred rather than data, can circumvent many of these challenges but has not been previously demonstrated in ophthalmology.ObjectiveTo determine whether a model-to-data deep learning approach (ie, validation of the algorithm without any data transfer) can be applied in ophthalmology.Design, setting, and participantsThis single-center cross-sectional study included patients with active exudative age-related macular degeneration undergoing optical coherence tomography (OCT) at the New England Eye Center from August 1, 2018, to February 28, 2019. Data were primarily analyzed from March 1 to June 20, 2019.Main outcomes and measuresTraining of the deep learning model, using a model-to-data approach, in recognizing intraretinal fluid (IRF) on OCT B-scans.ResultsThe model was trained (learning curve Dice coefficient, >80%) using 400 OCT B-scans from 128 participants (69 female [54%] and 59 male [46%]; mean [SD] age, 77.5 [9.1] years). In comparing the model with manual human grading of IRF pockets, no statistically significant difference in Dice coefficients or intersection over union scores was found (P > .05).Conclusions and relevanceA model-to-data approach to deep learning applied in ophthalmology avoided many of the traditional hurdles in large-scale deep learning, including data sharing, security, and privacy concerns. Although the clinical relevance of these results is limited at this time, this proof-of-concept study suggests that such a paradigm should be further examined in larger-scale, multicenter deep learning studies.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 32761143 · DOI · PMC7411940
Risk factors for the development of subretinal fluid in the fellow eyes of patients with chronic central serous chorioretinopathy [4]
Abstract reading summary — source excerpts
- Opening excerpt
- PurposeTo assess the risk of subretinal fluid (SRF) development in the fellow eye of chronic central serous chorioretinopathy (cCSC) patients with unilateral SRF at baseline.
- Closing excerpt
- No statistically significant risk factors were identified after correction for multiple testing; however, certain trends were observed.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (233 words)
PurposeTo assess the risk of subretinal fluid (SRF) development in the fellow eye of chronic central serous chorioretinopathy (cCSC) patients with unilateral SRF at baseline.MethodsMedical records of 334 presumed cCSC patients were retrospectively reviewed. Multimodal imaging was evaluated, and the available optical coherence tomography (OCT) scans were screened for SRF development in the fellow eye during follow-up.ResultsOf 213 confirmed cCSC cases, 74 (35%) had bilateral SRF at baseline. Among 102 patients with unilateral SRF that met all inclusion criteria, 7/102 (7%) developed SRF in the fellow eye over a mean follow-up of 20.4 months. Retinal pigment epithelial (RPE) alterations in the fellow eye were present at baseline in 7/7 (100%) who developed SRF, compared to 59/95 (62%) in those who did not (p = 0.042). Subfoveal choroidal thickness (SFCT) was higher in the SRF-developing group (482.3 vs. 365.9 μm; p = 0.306), although not significantly. Hyperautofluorescence on fundus autofluorescence (FAF) at baseline occurred in 6/7 (86%) of the SRF-developing group versus 25/91 (28%) who did not (p = 0.004). The ellipsoid zone was interrupted in 5/7 (71%) of SRF-developing patients versus 28/95 (30%) who did not develop SRF (p = 0.005).ConclusionThe risk of SRF development in the fellow eye of cCSC patients with unilateral SRF is relatively low over a follow-up period of almost 2 years. No statistically significant risk factors were identified after correction for multiple testing; however, certain trends were observed.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 41676886 · DOI · PMC13460357
Key reviews and meta-analyses
The most cited review-type papers among PubMed’s best-match results for this heading, listed with bibliographic details only. Follow the links for the full text and access terms.
- Research article AI-based monitoring of retinal fluid in disease activity and under therapy [5]
- Research article RETINAL FLUID AND THICKNESS AS MEASURES OF DISEASE ACTIVITY IN NEOVASCULAR AGE-RELATED MACULAR DEGENERATION [6]
- Research article Persistent subretinal fluid after surgery for rhegmatogenous retinal detachment: hypothesis and review [7]
- Research article EXTENT AND LOCATION OF INTRARETINAL AND SUBRETINAL FLUID AS PROGNOSTIC FACTORS FOR THE OUTCOME OF PATIENTS WITH OPTIC DISK PIT MACULOPATHY [8]
- Research article Impact of residual retinal fluid on treatment outcomes in neovascular age-related macular degeneration [9]
- Research article Peripapillary fluid: Obvious and not so obvious! [10]
References
- Arnold JJ, Markey CM, Kurstjens NP, Guymer RH. The role of sub-retinal fluid in determining treatment outcomes in patients with neovascular age-related macular degeneration--a phase IV randomised clinical trial with ranibizumab: the FLUID study. . 2016. PMID 27009515 · DOI · PMC4806513
- Siedlecki J, Fischer C, Schworm B, Kreutzer TC, Luft N, Kortuem KU, et al.. Impact of Sub-Retinal Fluid on the Long-Term Incidence of Macular Atrophy in Neovascular Age-related Macular Degeneration under Treat & Extend Anti-Vascular Endothelial Growth Factor Inhibitors. . 2020. PMID 32415240 · DOI · PMC7229002
- Mehta N, Lee CS, Mendonça LSM, Raza K, Braun PX, Duker JS, et al.. Model-to-Data Approach for Deep Learning in Optical Coherence Tomography Intraretinal Fluid Segmentation. . 2020. PMID 32761143 · DOI · PMC7411940
- Feenstra HMA, Cakar T, Brinks J, Boon CJF, van Dijk EHC. Risk factors for the development of subretinal fluid in the fellow eyes of patients with chronic central serous chorioretinopathy. . 2026. PMID 41676886 · DOI · PMC13460357
- Schmidt-Erfurth U, Reiter GS, Riedl S, Seeböck P, Vogl WD, Blodi BA, et al.. AI-based monitoring of retinal fluid in disease activity and under therapy. Prog Retin Eye Res. 2022. PMID 34166808 · DOI
- Kaiser PK, Wykoff CC, Singh RP, Khanani AM, Do DV, Patel H, et al.. RETINAL FLUID AND THICKNESS AS MEASURES OF DISEASE ACTIVITY IN NEOVASCULAR AGE-RELATED MACULAR DEGENERATION. Retina. 2021. PMID 33949342 · DOI · PMC8297539
- Veckeneer M, Derycke L, Lindstedt EW, van Meurs J, Cornelissen M, Bracke M, et al.. Persistent subretinal fluid after surgery for rhegmatogenous retinal detachment: hypothesis and review. Graefes Arch Clin Exp Ophthalmol. 2012. PMID 22234351 · DOI
- Steel DH, Williamson TH, Laidlaw DA, Sharma P, Matthews C, Rees J, et al.. EXTENT AND LOCATION OF INTRARETINAL AND SUBRETINAL FLUID AS PROGNOSTIC FACTORS FOR THE OUTCOME OF PATIENTS WITH OPTIC DISK PIT MACULOPATHY. Retina. 2016. PMID 26166800 · DOI
- Zur D, Guymer R, Korobelnik JF, Wu L, Viola F, Eter N, et al.. Impact of residual retinal fluid on treatment outcomes in neovascular age-related macular degeneration. Br J Ophthalmol. 2025. PMID 39033013 · DOI · PMC11866303
- Arora S, Zur D, Iovino C, Chhablani J. Peripapillary fluid: Obvious and not so obvious!. Surv Ophthalmol. 2024. PMID 38016521 · DOI
About this article
- Sources
- NLM Medical Subject Headings (definition, synonyms); NCBI PubMed (counts, identifiers); Europe PMC (open-access abstracts and citation counts).
- Verification
- Every reference was resolved against PubMed on 2026-10-31; title, year and DOI matched.
- Review state
- automated source verified; no human expert review has been recorded yet.
- Version
- 1, last updated 2026-10-31.
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Evidence strength
EvidenceHelix's computed view of the study designs behind this topic: how common meta-analyses, randomized trials and reviews are, how recent the literature is, and a plain-language reading. It describes the design mix of the literature. It is not a quality appraisal of any study, and it is not medical advice.