Optical Coherence Tomography Signs Research Articles

Multilayered Exudative Bacillary Layer Detachment in Active Choroidal Neovascularization: A New Optical Coherence Tomography Sign.

In this article, we present three cases diagnosed with active choroidal neovascularization (CNV): two cases diagnosed with neovascular age-related macular degeneration (nAMD), and one case with myopic CNV in an elderly eye that presented a characteristic and unique optical coherence tomography (OCT) sign consisting of well-defined, circular-shaped multiple concentric layers of alternating iso-hyperreflective material located between the external limiting membrane and outer photoreceptor layers, which seems to be a multilayered bacillary layer detachment (BALAD). Multilayered exudative BALAD in active CNV may be a new and characteristic OCT sign. [Ophthalmic Surg Lasers Imaging Retina 2024;55:92-94.].

Hyperpigmentary abnormalities in age-related macular degeneration: association with progression and impact on visual sensitivity

Background/aimsTo investigate the additional prognostic value of quantifying the extent of colour fundus photography (CFP)-defined hyperpigmentary abnormalities (HPAs) compared with their presence alone for predicting progression to late-stage age-related macular...

Comparison of signs of choroidal melanoma spreading into the retina according to optical coherenct tomography and pathomorphological studies

The most common factors determining the unfavorable choroidal melanoma (CM) prognosis are: patient's advanced age, tumor size, epithelioid histotype, developed vascularization and extrascleral tumor extension. Also, there are indications ofan unfavorable vital prognosis when hemorrhages appear in the tumor area. There are suggestions that retinal changes detected by optical coherence tomography (OCT) are comparable to the results of morphological studies, and the structure of the choroid determined by EDI-OCT (enhanced depth imaging) matches its morphological structure. Purpose: to assess the possibility of in vivo detection of morphological signs of CMspreading into the retina according to OCT data. Materials and methods. 5 CM patients aged 55.20 ± 10.57 who subsequently underwent primary enucleation, were tested by OCT that showed the maximum CM elevation of 4.85 ± 1.76 mm, and the maximum diameter of13.09 ± 4.14 mm. Results. The correlation of tomographic and histological picture was obtained in the following signs: destruction of Bruch's membrane, presence of hyperreflective changes at the level of retinal pigment epithelium (deposits and extended areas of its thickening), photoreceptors changes, neuroepithelial detachment, the intraretinal cavities. A partial correlation took place for signs of subretinal transudate and infiltration of the outer layers of the retina. No correlation was obtained for the signs of infiltration of inner retina layers and the inner limiting membrane rupture with CM dissemination on a retinal surface. The cases of divergent interpretation between OCT and morphological studies are as­ sociated with the presence of fibrosis foci due to a formation of superficial tumor necrosis and foci of proliferation of the pigment epithelium with its dissemination into the inner retina layers. Conclusion. Comparison of OCT signs ofM C with pathomorphological data obtained from 5 enucleated eyes made it possible to expand the interpretation of OCT signs of CM spreading beyond the Bruch's membrane with the forma­tion of tumor growth zones in the retina.

Capabilities of optical coherence tomography in examination of senile scleral plaques

To assess the morphological characteristics of SSP using spectral optical coherence tomography (OCT). The study examined 13 patients (21 eyes) with average age of 77.1±6.3 years. OCT scanning was performed to determine OCT signs of SSP, the length (parallel to the limb), the width and height of the SSP, as well as the depth and thickness of the overlying sclera. A combination of nasal and temporal SSP was observed in 14 eyes, and nasal only SSP was detected in 6 eyes. In all cases, OCT presented a characteristic picture of SSP observed as an intrascleral cavity with hyperreflective content with lower reflectivity than the surrounding tissues, and clear borders represented by unchanged scleral fibers. The length of the SSP parallel to the limb was 3296±820 µm, the width - 2312±436 µm, the height of the SSP cavity - 482±89 µm. The depth of SSP site was 213±36 µm, the thickness of the overlying sclera - 125±29 µm. Updated information about SSP structure can be used in the development of standard surgical algorithms contributing to prevention of postoperative complications.

Macular volume and fovea thickness as OCT-criteria for multiple sclerosis. Preliminary results

Background. The characteristic optical coherence tomography (OCT) changes in the optic nerve head in patients with multiple sclerosis are known and have been described many times, however, the state of the macular area is described in a small number of publications.The aim: to analyze the changes in the macular area of the retina in patients with multiple sclerosis, to identify the OCT signs pathognomonic for this disease and to trace their changes over time as the disease progresses.Material and methods. In addition to the standard ophthalmological examination, 28 patients (55 eyes) diagnosed with multiple sclerosis underwent OCT of the macular zone to determine the thickness of the fovea and the volume of the macula in the 6 mm zone. The follow-up period was 6–12 years. The endpoints were the primary treatment and the most recent inspection.Results. At the initial examination, the visual acuity was 0.96 ± 0.24 (95% CI: 0.9–1.03), fovea thickness – 253.0 μm (Q1–Q3: 233.0–264.0), macular volume – 5.471 mm3 (Q1–Q3: 5.281–5.625). In 37 cases (67.3 %), the macular volume was below normal. The initial fovea thickness was below normal in 9 cases (16.4 %). At the end of the study, visual acuity did not change statistically (p = 0.824) and amounted to 0.96 ± 0.25 (95% CI: 0.90–1.04). The fi nal thickness of the fovea was 247.5 μm (Q1–Q3: 233.0–260.0), changes are statistically significant (p = 0.02). Number of cases with a thickness below normal in the fi nal study was 11 (20 %), change of frequency of cases was not statistically signifi cant (p = 0.5). The fi nal macular volume was 5.393 mm3 (Q1–Q3: 5.197–5.565), the changes are statistically significant (p = 0.023). The final number of cases with a volume below the norm was 42 (76.4 %), the change in the frequency of cases is close to statistically signifi cant (p = 0.063). At all stages of the study, there was no case of an isolated decrease in the thickness of the fovea without a decrease in the volume of the macula.Conclusion. The decrease in the volume of the macula with time while maintaining the thickness of the fovea within the normal range can be attributed to the pathognomonic OCT signs of multiple sclerosis. This criterion can be used for a comprehensive assessment of the course and therapy of this disease.

Optical coherence tomography versus ophthalmic examination findings in the management of anterior scleritis: A prospective study

The goal of this work was to analyze optical coherence tomography (OCT) findings compared to ophthalmic examination results in the management of anterior scleritis. We carried out a prospective study including patients presenting with anterior scleritis who underwent complete clinical examinations and OCT at baseline and at the final follow-up visit. The mean age was 46years. The superior and temporal quadrants were clinically the most involved regions and showed the greatest thickness on the OCT images. Nodules were observed clinically in 6 patients, while OCT revealed them in 9 cases. OCT revealed 3 cases of sub-clinical necrosis. Separation of fibers, scleral edema, dilated vessels, fluid pockets and increased scleral thickness were the most common signs of the disease. Mean total scleral thickness and mean scleral-episcleral complex thickness were significantly improved after treatment (P=0.001 and P=0.00; respectively). Post-streptococcal syndrome (PSS) was diagnosed in 3 cases of non-necrotizing anterior scleritis. Necrotizing forms were low-grade and were associated with systemic diseases in 2 out of 3 patients. OCT signs persisted for a substantial time after resolution of clinical signs. OCT helped to distinguish necrosis and scleral nodules in subclinical cases. Non-necrotizing forms of scleritis supported the diagnosis of PSS, while necrotizing forms suggested systemic diseases. Complete resolution of a scleral inflammation could be followed more objectively with OCT than by clinical examination.

Imaging Biomarkers of 1-Year Activity in Type 1 Macular Neovascularization.

PurposeThe purpose of this study was to evaluate the predictive value of optical coherence tomography (OCT) and OCT angiography (OCTA) parameters at baseline on lesion's activity at the 1-year follow-up in type 1 macular neovascularizations (MNVs) treated with 1-year fixed regimen of intravitreal aflibercept injections (q8 IAIs).MethodsAll patients were imaged by structural OCT to evaluate central macular thickness (CMT), subretinal fluid (SRF), subretinal hyper-reflective material (SHRM), intraretinal fluid (IRF) and intraretinal hyper-reflective dots (HRDs), and by Swept-Source OCTA to measure baseline MNV area, perfusion density (PD), vessel length density (VLD), and vessel diameter index. At the end of q8 IAI, patients were classified in two groups: active-MNV (A-MNV) and inactive-MNV (I-MNV), considering the OCT signs of activity. Three binary logistic regression models were developed: (1) OCT-based, (2) OCTA-based, and (3) OCT/OCTA-based model.ResultsThirty-one treatment-naïve type 1 MNVs were enrolled (13 A-MNV and 18 I-MNV). No differences were observed in baseline OCT and OCTA characteristics between A-MNV and I-MNV. Among the models developed, model 3 that combined OCT/OCTA parameters showed a performance of 87.5% and excellent sensitivity for A-MNV lesions (100%). By analyzing the model, the A-MNV group appears more likely to show at baseline SRF, greater CMT, wider MNV area, and lower PD and VLD compared to I-MNV.ConclusionsOur study demonstrated that the combination of baseline OCT and OCTA parameters allowed to achieve a good models’ performance in the prediction of MNV activity permitting to correctly classifying the active lesions at the end of follow-up period, with excellent sensitivity.Translational RelevanceOCT/OCTA could integrate statistical models potentially useful for artificial intelligence.

OPTICAL COHERENCE TOMOGRAPHY FEATURES OF CHOROIDAL NEOVASCULARIZATION AND THEIR CORRELATION WITH AGE, GENDER, AND UNDERLYING DISEASE.

To investigate the influence of age, gender, and underlying disease on the optical coherence tomography (OCT) features of choroidal neovascularization (CNV) secondary to inflammation, myopia (mCNV), and age-related macular degeneration (AMD-CNV). Demographic and clinical data of eyes with treatment-naive inflammatory CNV, mCNV, and Type 2 AMD-CNV were collected. Optical coherence tomography images were reviewed to determine the presence of pitchfork sign, pigment epithelial detachment, subretinal fluid (SRF), intraretinal cysts, subretinal hyperreflective material, atrophy, and outer retinal disruption graded 1 to 4. The influence of demographics and underlying etiology on OCT signs was investigated. One hundred and eighty-five eyes from 179 patients were enrolled. The mean [SD] age was 36 [±14.4], 62 [±18], and 77 [±8] for the inflammatory CNV, mCNV, and AMD-CNV, respectively (P < 0.001). Multiple linear regression showed that the presence of pitchfork sign was negatively associated with age (P < 0.0001), regardless of underlying disease. By contrast, the SRF, pigment epithelial detachment, intraretinal cysts, and the outer retinal disruption were all positively influenced by age, regardless of gender and underlying disease (all P < 0.01). Logistic regression showed that none of the OCT signs increased the likelihood for diagnosis of inflammatory CNV. By contrast, the absence of SRF was suggestive for mCNVs, and the presence of pigment epithelial detachment and SRF was suggestive for AMD-CNVs. The age of the patient had a significant effect on the OCT appearance of the CNV, particularly the presence of a pitchfork sign, regardless of the underlying etiology. The absence of SRF was suggestive for a diagnosis of mCNVs. The presence of SRF and pigment epithelial detachment was suggestive for AMD-CNVs.

Optical coherence tomography features of the repair tissue following RPE tear and their correlation with visual outcomes

To assess the optical coherence tomography (OCT) features of the repair tissue after retinal pigment epithelial (RPE) tear in neovascular age-related macular degeneration. Retrospective, observational study. Medical and imaging records of patients that developed tears after starting anti-VEGF treatment and with at least 12 months of follow-up were reviewed. OCT reflectivity of the RPE-subretinal hyperreflective tissue (SHT) complex was measured at 6, 12 and 18 months (when available). Reflectivity of the adjacent unaffected RPE-Bruch’s membrane was taken as internal reference. Other variables: grade and rip occurrence (early/late); number of intravitreal injections; type of macular neovascularization; sub-macular hemorrhage (SMH) at onset. Forty-nine eyes (age: 76.1 ± 7.0 years; VA: 0.54 ± 0.27 LogMAR) were included. Thirty-eight eyes had OCT signs of healing during the follow-up, with 21 showing SMH at baseline. Final VA positively correlated with the number of injections and negatively correlated with the RPE-SHT reflectivity and the presence of SMH (p < 0.001). Reflectivity of the RPE-SHT complex was positively associated with time and SMH at baseline (p < 0.05). In our study, most eyes showed signs of tissue repair after RPE tear. The reflectivity of repair tissue, the SMH presence and the number of anti-VEGF injections appeared to be major predictors of visual outcomes.

&lt;p&gt;The Pigtail Sign: A New Spectral Domain Optical Coherence Tomography Finding After Inverted ILM Flap Surgery for Idiopathic Macular Hole&lt;/p&gt;

PurposeTo report a new spectral domain optical coherence tomography (OCT) finding called the pigtail sign. It was found during follow-up of idiopathic macular hole cases after inverted internal limiting membrane (ILM) flap surgery.MethodsThis is a retrospective case series of 12 eyes (12 patients) who underwent inverted ILM flap technique for idiopathic macular hole closure. Spectral domain optical coherence tomography images were analyzed for the presence of this new finding.ResultsA new spectral domain OCT finding of a curved coiled line hanging above the surface of the retinal layers was seen in all patients. The mean preoperative best corrected visual acuity (BCVA) logMAR value was 1.25 ± 0.11. At the 6-month follow-up visit, the mean LogMAR BCVA was 0.35 ± 0.18. All the cases showed macular hole closure after surgery.ConclusionThis new spectral domain OCT sign can be seen in some OCT scans during follow-up of idiopathic macular hole cases after inverted ILM flap surgery.

Foveal Crack Sign: An OCT Sign Preceding Macular Hole After Vitrectomy for Rhegmatogenous Retinal Detachment

To describe an optical coherence tomography (OCT) sign preceding macular hole (MH) formation after pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment (RRD). Retrospective observational case series. Patients who underwent PPV for RRD at Osaka Rosai Hospital between January 2014 and December 2017 were examined. First, the medical records of the patients who had secondary MH after RRD repair were examined, and their sequential changes of the OCT images until MH formation were evaluated. Second, the OCT findings and the medical records of all patients who underwent PPV for RRD were evaluated based on the findings of the cases of secondary MH. Ten eyes of 10 patients who had secondary MH after PPV for RRD were enrolled. Before MH formation, all eyes had parafoveal epiretinal membrane (ERM) and a characteristic OCT sign that was termed a foveal crack sign (FCS), a hyperreflective vertical line in the foveola with a deformation of the fovea. FCS was found 255 ± 217days after PPV for RRD, and MH developed 232 ± 171days after FCS appearance. Furthermore, among 518 eyes that underwent PPV for RRD, FCS with parafoveal ERM was found in 3 eyes without succeeding MH after RRD repair. FCS of these 3 eyes were found 363 ± 4days after PPV for RRD. In all cases of secondary MH formation after PPV for RRD, FCS with parafoveal ERM was found before MH formation. This sign may predict secondary MH formation caused by ERM traction.

Polypoidal Choroidal Vasculopathy in Congolese Patients.

Purpose Polypoidal choroidal vasculopathy (PCV) is a visually debilitating disease that mostly affects people of African and Asian heritage. Indocyanine green angiography (ICGA) is the recommended exploratory method for definitive diagnosis. The disease has been extensively described in Asians and Caucasians, but not in Africans. This study was conducted to document the clinical presentation and optical coherence tomography features of polypoidal choroidal vasculopathy (PCV) in Congolese patients. Methods A prospective case series of patients with PCV was performed between January 2017 and June 2019. Routine ocular examination was performed including best corrected visual acuity measurement, slit-lamp examination, dilated direct fundoscopy, and spectral domain optical coherence tomography (OCT). The diagnosis was based on a combination of clinical and OCT signs. Results Fourteen patients were diagnosed with PCV during this period. The average age was 64.7 ± 6.9 years. There were 8 females. Ten (71.4%) patients had systemic hypertension. Most patients (n = 9, 64.3%) had bilateral involvement. Blurred vision was the most common complaint (71.4%). The main clinical presentation was subretinal exudates, seen in 19 (82.6%) eyes of 11 (78.6%) patients and subretinal hemorrhage in 10 (43.5%) eyes. Macular localization was found in 16 eyes (69.5%) of 12 (85.7%) patients. Drusen were observed in 35.7% of the patients. On OCT imaging, thumb-like pigment epithelial detachment and subretinal exudation were the most frequent features, observed in 92.9% and 71.4% of the patients, respectively. Conclusions PCV in Congolese patients showed features that are more similar to those observed in Caucasians. In this setting where indocyanine green angiography is not available, OCT facilitates the diagnosis of PCV.

Non-Invasive Diagnosis of Polypoidal Choroidal Vasculopathy as a Variant of the Course of Age-Related Macular Degeneration

Purpose: to study noninvasive diagnostic options for polypoidal choroidal vasculopathy (PCV) — a subtype of neovascular agerelated macular degeneration — by monitoring clinical progression, defining optical coherence tomography (OCT) findings specific for PCV and evaluating diagnostic utility of OCT angiography.Patients and methods. The study included 254 patients (292 eyes) with neovascular age-related macular degeneration. All patients underwent complex eye examination: visual acuity test, slit lamp biomicroscopy, ophthalmoscopy with 60 and 78D fundus lenses, fundoscopy with color filters, spectral-domain OCT, OCT angiography and biometry. Fluorescein angiography was performed in 66 cases. Indocyanine green angiography was employed in 16 patients with PCV. All statistical analyses were performed with IBM SPSS Statistics 19 software package.Results. In 14 of 16 patients (87.5%) indocyanine green angiography revealed round hyperfluorescent lesions which corresponded to ophthalmoscopy findings — subretinal reddish orange nodules localized primarily in the parafovea. In 11 cases (68.8%) the nodules were associated with hemorrhage and in 14 cases (87.5%) — with hard yellowish exudates. Comparative analysis of retinal anatomy allowed for defining typical OCT signs of PCV that distinguish the clinical entity from type 1 and 2 choroidal neovascular membranes: neurosensory retinal detachment in the parafovea (80.0%, p &lt; 0.001) and hard exudates (71.9%, p &lt; 0.001). OCT findings characteristic of PCV are dome-shaped pigment epithelium detachment (100%), bubble sign (94.74%), notch sign (68.4%) and double layer sign (92.9%).Conclusion. Noninvasive diagnosis of polypoidal choroidal vasculopathy should encompass clinical signs, fundoscopy findings, OCT-based morphometry and OCT angiography criteria. OCT angiography has high diagnostic value and enables detection of branching vascular network and polypoidal formations.

Optical Coherence Tomography Features of Tuberculous Serpiginous-like Choroiditis and Serpiginous Choroiditis

ObjectiveTo investigate optical coherence tomography (OCT) characteristics of tuberculous serpiginous-like choroiditis (Tb-SLC) and serpiginous choroiditis (SC) and to perform OCT to differentiate between these conditions. MethodsThis retrospective, case-control study examined consecutively enrolled patients with active Tb-SLC or SC. Patients underwent comprehensive ocular examinations and imaging (OCT, color fundus photography, autofluorescence imaging, fluorescein angiography, and indocyanine green angiography). Findings were examined and compared between eyes with SC and Tb-SLC. ResultsNine patients with active Tb-SLC (14 eyes) and 8 with active SC (12 eyes) were included. The following OCT findings were observed significantly more often in the Tb-SLC group than in the SC group: vitreal hyper-reflective spots [5 Tb-SLC eyes (36%), no SC eyes; P = 0.02], intraretinal edema [11 Tb-SLC eyes (79%), 3 SC eyes (25%); P = 0.01], sub-retinal pigment epithelium (RPE) drusenoid deposits [11 Tb-SLC eyes (79%), 2 SC eyes (17%); P < 0.01], and choroidal granulomas [8 Tb-SLC eyes (57%), 2 SC eyes (17%); P = 0.03]. A hyporeflective, wedge-shaped band was observed more often in the SC group [5 Tb-SLC eyes (36%), 9 SC eyes (75%); P = 0.045] than in the Tb-SLC group. The incidence of other OCT signs did not differ between the groups and included outer nuclear layer hyper-reflection, outer retinal tabulation, and choriocapillaris point-like hyper-reflection. ConclusionVitreal hyper-reflective spots, intraretinal fluid, sub-RPE drusenoid deposits, and choroidal granulomas on OCT images may indicate Tb-SLC. Additionally, a hyporeflective, wedge-shaped band may indicate SC. Therefore, OCT is likely helpful in differentiating between Tb-SLC and SC.

Morphogenesis of choroidal melanomas in OCT imaging

To specify clinicomorphologic correlations between OCT signs related to CM and its pathomorphological state as described in literature. The study included 33 patients with predominantly small CM who were examined with EDI-OCT. The following surface profiles were revealed: small and medium sized CM with even and uneven surface and with a plateau on the top; medium sized CM with flattened edge. Bruch's membrane (BM) had folds along the tumor edge in medium and big CM. In mushroom-shaped CM, extended defective areas could be observed. Increase of optical density in the inner parts of choroidal complex were seen over time. In CM of 2.9 mm and less, cavities were observed in the middle layers of choroid in the tumor area. In roughly half of the cases, vascular distention was seen in choroid in the tumor periphery. Changes of retinal pigment epithelium (RPE) included its thickening and presence of hyperreflective foci. In CM with prominence of more than 2.17 mm at the top, the changes included the formation of a 'single unitary block' at the level of BM/RPE and neurosensory retinal layers. Intraretinal cysts could be seen on top of the tumor at the level of outer retinal layers in CM with prominence of more than 1.5 mm. Comparison of OCT images of CM with various biometric parameters with literature data on pathomorphological changes helped specify early pathomorphological symptoms in perifocal choroid (a feature of initial CM) and highly dynamic phasing of secondary changes in the retina.

Diagnostic value of optical coherence tomography for oral leukoplakia assessment

The article presents a comparative analysis of the results of in vivo scanning of oral mucosa leukoplakia with optical coherence tomography (OCT) method and pathological studies in 15 patients (9 females and 6 males aged 27-82). The study revealed specific OCT signs of leukoplakia: even disorder of tissue layering and less clear visualization of lamina propria. OCT is an important stage in the differential diagnosis of leukoplakia of the oral mucosa and significantly complements the clinical and pathomorphological study.

Anterior segment optical coherence tomography for the diagnosis of corneal dystrophies according to the IC3D classification

Corneal dystrophies are categorized according to the International Committee for Classification of Corneal Dystrophies (IC3D) classification, and their treatment depends on the affected structures and layer of the cornea. Therefore, estimating the depth and extent of the morphological changes due to the specific dystrophy is crucial when deciding between different treatment options. Besides superficial laser treatments and penetrating keratoplasty, minimal invasive lamellar keratoplasties such as Descemet membrane endothelial keratoplasty, deep anterior lamellar keratoplasty, or Descemet stripping automated keratoplasty have become increasingly popular to exchange the specific opaque layers in dystrophic eyes. To determine the morphological changes of the cornea in the different dystrophies, in addition to slit-lamp examination, anterior segment optical coherence tomography has become an important tool with nearly histological resolution. Nonetheless, only a few case series describe the characteristics of changes seen on anterior segment optical coherence tomography. Therefore, we summarize anterior segment optical coherence tomography signs and correlate with slit-lamp examination, as well as the histopathological findings, of corneal dystrophies according to the IC3D classification.

Comparing optical coherence tomography findings in different aetiologies of infectious necrotising retinitis

AimsTo compare optical coherence tomography (OCT) features of active necrotising infectious retinitis (NIR) due to toxoplasmosis or herpesviruses and to determine distinctive OCT signs for these two causes of infectious...

Are we making good use of our public resources? The false-positive rate of screening by fundus photography for diabetic macular oedema.

A large proportion of patients diagnosed with diabetic maculopathy using fundus photography and hence referred to specialist clinics following the current screening guidelines adopted in Hong Kong and United Kingdom are found to be false-positive, implying that they did not have macular oedema. This study aimed to evaluate the false-positive rate of diabetic maculopathy screening using the objective optical coherence tomography scan. This was a cross-sectional observational study. Consecutive diabetic patients from the Hong Kong West Cluster Diabetic Retinopathy Screening Programme with fundus photographs graded R1M1 were recruited between October 2011 and June 2013. Spectral-domain optical coherence tomography imaging was performed. Central macular thickness of ≥300 μm and/or the presence of optical coherence tomography signs of diabetic macular oedema were used to define the presence of diabetic macular oedema. Patients with conditions other than diabetes that might affect macular thickness were excluded. The mean central macular thickness in various subgroups of R1M1 patients was calculated and the proportion of subjects with central macular thickness of ≥300 μm was used to assess the false-positive rate of this screening strategy. A total of 491 patients were recruited during the study period. Of the 352 who were eligible for analysis, 44.0%, 17.0%, and 38.9% were graded as M1 due to the presence of foveal 'haemorrhages', 'exudates', or 'haemorrhages and exudates', respectively. The mean (±standard deviation) central macular thickness was 265.1±55.4 μm. Only 13.4% (95% confidence interval, 9.8%-17.0%) of eyes had a central macular thickness of ≥300 μm, and 42.9% (95% confidence interval, 37.7%-48.1%) of eyes had at least one optical coherence tomography sign of diabetic macular oedema. For patients with retinal haemorrhages only, 9.0% (95% confidence interval, 4.5%-13.5%) had a central macular thickness of ≥300 μm; 23.2% (95% confidence interval, 16.6%-29.9%) had at least one optical coherence tomography sign of diabetic macular oedema. The false-positive rate of the current screening strategy for diabetic macular oedema was 86.6%. The high false-positive rate of the current diabetic macular oedema screening adopted by the United Kingdom and Hong Kong may lead to unnecessary psychological stress for patients and place a financial burden on the health care system. A better way of screening is urgently needed. Performing additional spectral-domain optical coherence tomography scans on selected patients fulfils this need.

A new OCT sign of invasive squamous cell carcinoma of the cornea

Case reportA case is reported of an unusual progressive corneal opacification and neovascularization caused by a squamous cell carcinoma (SCC) of the cornea. A patient with a white stromal infiltrate, consistent with herpetic stromal keratitis, showed a very particular image in optical coherence tomography (OCT), resembling a “tongue of lava” sliding between corneal lamellae. Histopathological analysis confirmed the diagnosis of SCC. DiscussionTo our knowledge this is the first report in the literature of this peculiar image with OCT. Squamous cell carcinoma is an extremely rare cause of progressive corneal opacification and neovascularization, and a delayed diagnosis may lead to unsuccessful treatment and loss of the eyeball.