Optical coherence tomography enhanced depth imaging of chorioretinal folds in patients with orbital tumors

AIM:To characterize spectral-domain optical coherence tomography(SD-OCT)features of chorioretinal folds in orbital mass imaged using enhanced depth imaging(EDI).METHODS:Prospective observational case-control study was conducted in 20 eyes of 20 patients,the uninvolved eye served as a control.All the patients underwent clinical fundus photography,computed tomography,EDI SDOCT imaging before and after surgery.Two patients with cavernous hemangiomas underwent intratumoral injection of bleomycin A5;the remaining patients underwent tumor excision.Patients were followed 1 to 14mo following surgery(average follow up,5.8mo).RESULTS:Visual acuity prior to surgery ranged from 20/20 to 20/200.Following surgery,5 patients’visual acuity remained unchanged while the remaining 15 patients had a mean letter improvement of 10(range 4 to 26 letters).Photoreceptor inner/outer segment defects were found in 10 of 15 patients prior to surgery.Following surgical excision,photoreceptor inner/outer segment defects fully resolved in 8 of these 10 patients.CONCLUSION:Persistence of photoreceptor inner/outer segment defects caused by compression of the globe by an orbital mass can be associated with reduced visual prognosis.Our findings suggest that photoreceptor inner/outer segment defects on EDI SD-OCT could be an indicator for immediate surgical excision of an orbital mass causing choroidal compression.

Optical coherence tomography with or without enhanced depth imaging for peripapillary retinal nerve fiber layer and choroidal thickness

AIM:To assess peripapillary retinal nerve fiber layer(RNFL) and choroidal thickness obtained with enhanced depth imaging(EDI) mode compared with those obtained without EDI mode using Heidelberg Spectralis optical coherence tomography(OCT).METHODS:Fifty eyes of 25 normal healthy subjects and 32 eyes of 20 patients with different eye diseases were included in the study.All subjects underwent 3.4 mm diameter peripapillary circular OCT scan centered on the optic disc using both the conventional and the EDI OCT protocols.The visualization of RNFL and choroidoscleral junction was assessed using an ordinal scoring scale.The paired t-test,intraclass correlation coefficient(ICC),95% limits of agreement(Lo A),and Bland and Altman plots were used to test the agreement of measurements.RESULTS:The visibility score of RNFL obtained with and without EDI was of no significant difference(P=0.532),the visualization of choroidoscleral junction was better using EDI protocol than conventional protocol(P<0.001).Peripapillary RNFL thickness obtained with EDI was slightly thicker than that obtained without EDI(103.25±9.42 μm vs 101.87±8.78 μm,P=0.010).The ICC of the two protocols was excellent with the value of 0.867 to 0.924,the 95% Lo A of global RNFL thickness was between-10.0 to 7.4 μm.Peripapillary choroidal thickness obtained with EDI was slightly thinner than that obtained without EDI(147.23±51.04 μm vs 150.90±51.84 μm,P<0.001).The ICC was also excellent with the value of 0.960 to 0.987,the 95% Lo A of global choroidal thickness was between-12.5 to 19.8 μm.CONCLUSION:Peripapillary circular OCT scan with or without EDI mode shows comparable results in the measurement of peripapillary RNFL and choroidal thickness.

Peripapillary choroidal thickness in Chinese children using enhanced depth imaging optical coherence tomography

AIM:To evaluate the peripapillary choroidal thickness(PPCT) in Chinese children,and to analyze the influencing factors.METHODS: PPCT was measured with enhanced depth imaging optical coherence tomography(EDI-OCT) in 70children(53 myopes and 17 non-myopes) aged 7 to 18 y,with spherical equivalent refractive errors between 0.50and-5.87 diopters(D).Peripapillary choroidal imaging was performed using circular scans of a diameter of 3.4 mm around the optic disc.PPCT was measured by EDI-OCT in six sectors: nasal(N),superonasal(SN),superotemporal(ST),temporal(T),inferotemporal(IT)and inferonasal(IN),as well as global RNFL thickness(G).RESULTS: The mean global PPCT was 165.49±33.76 μm.The temporal,inferonasal,inferotemporal PPCT were significantly thinner than the nasal,superonasal,superotemporal segments PPCT were significantly thinner in the myopic group at temporal,superotemporal and inferotemporal segments.The axial length was significantly associated with the average global(β=-0.419,P =0.014),superonasal(β=-2.009,P=0.049) and inferonasal(β=-2.000,P=0.049) PPCT.The other factors(gender,age,SE) were not significantly associated with PPCT.CONCLUSION: PPCT was thinner in the myopic group at temporal,superotemporal and inferotemporal segments.The axial length was found to be negatively correlated to PPCT.We need more further studies about the relationship between PPCT and myopia.

Utility of high-resolution anterior segment optical coherence tomography in the diagnosis and management of sub-clinical ocular surface squamous neoplasia

Background:To evaluate the frequency and characteristics of sub-clinical ocular surface squamous neoplasia(OSSN)detected by high-resolution anterior segment tomography(HR-OCT)in patients with clinically unapparent disease following topical treatment.Methods:A retrospective chart review of patients with OSSN identified through a pharmacy database at the Bascom Palmer Eye Institute from January 2013 to December 2018 was conducted.Patients undergoing primary therapy with topical 5-fluorouracil 1%(5-FU)(4 times a day for 7 days with a 21-day break)or interferon-alpha-2b(IFN)(4 times a day)were reviewed.Patients were separated into two groups.Group 1 included individuals whose clinical resolution of OSSN aligned with complete resolution on HR-OCT.Group 2(sub-clinical OSSN group)included individuals with clinical OSSN resolution but with features of persistent disease on HR-OCT.Patients excluded included those treated at an outside institution and those who used topical therapy as a surgical adjunct.Results:A total of 95 patients(95 eyes)were reviewed.Sub-clinical OSSN was detected at a frequency of 17%in our study patients(n=16 patients,9 treated with 5-FU and 7 treated with IFN).In the 16 individuals,the mean time to clinical resolution was 3.6±1.0 cycles for 5-FU and 4.0±0.0 months for IFN.An additional 2.1±0.8 cycles for 5-FU and 1.2±0.4 months for IFN were needed to achieve HR-OCT resolution of OSSN.Recurrence in Group 1 was noted in 10 patients(12%)while no recurrences occurred in Group 2,the cohort with subclinical disease that received the extended medical therapy.The mean follow-up was 24.0±17.9 months.Conclusion:We found that at least 17%of individuals with apparent clinical resolution of OSSN have sub-clinical disease detected on HR-OCT.This information can be used to optimize treatment and extend therapy past the point of clinical resolution.

Measurement of choroidal thickness and macular thickness during and after pregnancy

AIM: To investigate the effect of pregnancy on subfoveal choroidal thickness(SFCT) and macular thickness in both pregnant and not pregnant healthy women.METHODS: Twenty-nine healthy pregnant women in their third trimester and 36 age-matched healthy women were enrolled in a prospective, cross-sectional study.Foveal and parafoveal thickness in the four quadrants and SFCT were measured by optical coherence tomography(OCT) in the healthy pregnant women(i.e.study group) and healthy women(i.e. control group).OCT measurements were again measured 3mo after delivery in the study group.RESULTS: Mean SFCT measurements in the control group, pregnant women of the study group, and after delivery of the study group were 320.86 ±59.18 μm,387.97 ±59.91 μm, and 332.40 ±26.03 μm, respectively.There was a statistically significant difference in the mean SFCT values between pregnant women of the study group and the control group(P =0.000). Foveal and parafoveal thickness values were not statistically significant in either the study or control group.CONCLUSION: SFCT increases during pregnancy and returns to normal range in the three months after delivery. Macular thickness does not show any change during pregnancy.

Anisotropic Total Variation Regularization Based NAS-RIF Blind Restoration Method for OCT Image

Based on anisotropic total variation regularization(ATVR), a nonnegativity and support constraints recursive inverse filtering(NAS-RIF) blind restoration method is proposed to enhance the quality of optical coherence tomography(OCT) image. First, ATVR is introduced into the cost function of NAS-RIF to improve the noise robustness and retain the details in the image.Since the split Bregman iterative is used to optimize the ATVR based cost function, the ATVR based NAS-RIF blind restoration method is then constructed. Furthermore, combined with the geometric nonlinear diffusion filter and the Poisson-distribution-based minimum error thresholding, the ATVR based NAS-RIF blind restoration method is used to realize the blind OCT image restoration. The experimental results demonstrate that the ATVR based NAS-RIF blind restoration method can successfully retain the details in the OCT images. In addition, the signal-to-noise ratio of the blind restored OCT images can be improved, along with the noise robustness.