Laser polarization-variable autofluorescence of the network of optically anisotropic biological tissues:Diagnostics and differentiation of early stages of cancer of cervia uteri

This research presents the results of investigation of laser_polarization fluorescence ofbiological layers(histological sections,cy tological smears)in the task of diagnostics and differ-en tiation of early stages of cancer:Dysplasia-cervical microinvasive carcinoma of cervic uteri.The analytical conditions of polarization-optimal probing of biological layers were determinedbasing on the model of linear birefringence and dichroism of birefringent(fibrllar,porphyrin)networks.The technique of polarization-variable laser autofluorescence was developed andexperimentally tested.The objective criteria(statistical moments)of differentiation of histo-logical sections autofluorescent images of endometrium biopsy and cytological smears of itmucous coat were defined.The operational characteristics(sensitivity,speifity,accuracy)ofthis technique were determined concerning the positions of probative medicine,and clinical efficiency.

Autofluorescence excitation-emission matrices for diagnosis of colonic cancer

AIM: To investigate the autofluorescence spectroscopic differences in normal and adenomatous coionic tissues and to determine the optimal excitation wavelengths for subsequent study and clinical application. METHODS: Normal and adenomatous coionic tissues were obtained from patients during surgery. A FL/FS920 combined TCSPC spectrofluorimeter and a lifetime spectrometer system were used for fluorescence measurement. Fluorescence excitation wavelengths varying from 260 to 540 nm were used to induce the autofluorescence spectra, and the corresponding emission spectra were recorded from a range starting 20 nm above the excitation wavelength and extending to 800 nm. Emission spectra were assembled into a three-dimensional fluorescence spectroscopy and an excitation-emission matrix (EEM) to exploit endogenous fluorophores and diagnostic information. Then emission spectra of normal and adenomatous coionic tissues at certain excitation wavelengths were compared to determine the optimal excitation wavelengths for diagnosis of coionic cancer. RESULTS: When compared to normal tissues, low NAD (P)H and FAD, but high amino acids and endogenous phorphyrins of protoporphyrin IX characterized the high-grade malignant coionic tissues. The optimal excitation wavelengths for diagnosis of coionic cancer were about 340, 380, 460, and 540 nm. CONCLUSION: Significant differences in autofluorescence peaks and its intensities can be observed in normal and adenomatous coionic tissues. Autofluorescence EEMs are able to identify coionic tissues.

Autofluorescence imaging endoscopy for identifi cation and assessment of inflammatory ulcerative colitis

AIM:To validate the clinical relevance of autofluores-cence imaging(AFI)endoscopy for the assessment of inflammatory ulcerative colitis(UC).METHODS:A total of 572 endoscopic images were se-lected from 42 UC patients:286 taken with white light imaging(WLI)and 286 with AFI from the same sites.WLI images were assessed for overall mucosal inflammation according to Mayo endoscopic subscore(MES),and for seven characteristic endoscopic features.Likewise,AFI photographs were scored according to relative abundance of red,green and blue color com-ponents within each image based on an RGB additive color model.WLI and AFI endoscopic scores from the same sites were compared.Histological evaluation of biopsies was according to the Riley Index.RESULTS:Relative to red(r=0.52,P<0.01)or blue(r=0.56,P<0.01)color component,the green color component of AFI(r=-0.62,P<0.01)corresponded more closely with mucosal inflammation sites.There were signif icant differences in green color components between MES-0(0.396±0.043)and MES-1(0.340± 0.035)(P<0.01),and between MES-1 and ≥ MES-2(0.318±0.037)(P<0.01).The WLI scores for "vascu-lar patterns"(r=-0.65,P<0.01),"edema"(r=-0.62,P<0.01),histology scores for "polymorphonuclear cells in the lamina propria"(r=-0.51,P<0.01)and "crypt architectural irregularities"(r=-0.51,P<0.01)showed correlation with the green color component of AFI.There were significant differences in green color components between limited(0.399± 0.042)and extensive(0.375±0.044)(P=0.014)polymorpho-nuclear cell inf iltration within MES-0.As the severity of the mucosal inflammation increased,the green color component of AFI decreased.The AFI green color com-ponent was well correlated with the characteristic en-doscopic and histological inflammatory features of UC.CONCLUSION:AFI has application in detecting inflammatory lesions,including microscopic activity in the co-lonic mucosa of UC patients,based on the green color component of images.

Fundus autofluorescence in central serous chorioretinopathy: association with spectral-domain optical coherence tomography and fluorescein angiography

and FA for identifying pathological abnormalities in CSC. The characteristics of IA AF in CSC were attributable to the modification of melanin in the RPE. IR- AIM: To evaluate the correlation among changes in fundus autofluorescence (AF) measured using infrared fundus AF (IR -AF) and short-wave length fundus AF (SW -AF) with changes in spectral -domain optical coherence tomography (SD -OCT) and fluorescein angiography (FA) in central serous chorioretinopathy (CSC). METHODS: Two hundred and twenty consecutive patients with CSC were included. In addition to AF, patients were assessed by means of SD -OCT and FA. Abnormalities in images of IA -AF, SW -AF, FA were analyzed and correlated with the corresponding outer retinal alterations in SD-OCT findings. RESULTS: Eyes with abnormalities on either IR-AF or SW-AF were found in 256 eyes (58.18%), among them 256 eyes (100%) showed abnormal IR -AF, but SW-AF abnormalities were present only in 213 eyes (83.20%). The hypo-IR-AF corresponded to accumulation of subretinal liquid, collapse of retinal pigment epithelium (APE) or detachment of APE with or without RPE leakage point in the corresponding area. The hyper -IR -AF corresponded to the area with loss of the ellipsoid portion of the inner segments and sub -sensory retinal deposits or focal melanogenesis under sensory retina. The hypo-SW-AF corresponded to accumulation of subretinal liquid or atrophy of RPE. The hyper -SW -AF associated with sub -sensory retinal deposits, detachment of RPE and focal melanogenesis. CONCLUSION: IR-AF was more sensitive than SW-AF AF should be used as a common diagnostic tool for identifying pathological lesion in CSC.

Autofluorescence imaging and magnification endoscopy

It is well known that angiogenesis is critical in the transition from premalignant to malignant lesions.Consequently,early detection and diagnosis based on morphological changes to the microvessels are crucial.In the last few years,new imaging techniques which utilize the properties of light-tissue interaction have been developed to increase early diagnosis of gastrointestinal(GI) tract neoplasia.We analyzed several "red-flag" endoscopic techniques used to enhance visualization of the vascular pattern of preneoplastic and neoplastic lesions(e.g.trimodal imaging including autofluorescence imaging,magnifying endoscopy and narrow band imaging).These new endoscopic techniques provide better visualization of mucosal microsurface structure and microvascular architecture and may enhance the diagnosis and characterization of mucosal lesions in the GI tract.In the near future,it is expected that trimodal imaging endoscopy will be practiced as a standard endoscopy technique as it is quick,safe and accurate for making a precise diagnosis of gastrointestinal pathology,with an emphasis on the diagnosis of early GI tract cancers.Further large-scale randomized controlled trials comparing these modalities in different patient subpopulations are warranted before their endorsement in the routine practice of GI endoscopy.

Comparison of autofluorescence and optical coherence tomography findings in acute and chronic central serous chorioretinopathy

AIM:To discuss and compare the fundus autofluorescence(FAF)and optical coherence tomography(OCT)in acute or chronic central serous chorioretinopathy(CSCR).METHODS:Medical records of 100 cases of CSCR were reviewed.Acute and chronic cases were evaluated according to the duration of decreased visual acuity,serous retinal detachment(RD)and focal leakage on fluorescein angiography(FA).Chi-square test was used for statistical analysis.RESULTS:Forty cases had acute and 60 cases had chronic CSCR.FAF showed focal hypo-autofluorescence in 34(85%)and iso-autofluorescence in 6(15%)of acute cases and hypo-autofluorescence in 51(85%),hyperautofluorescence in 6(10%)and iso-autofluorescence in3(5%)of chronic cases.OCT showed serous RD with distinct borders correlated with FAF findings(hypoautofluorescence)in all acute CSCR cases.In chronic CSCR group,OCT showed serous RD with indistinct borders correlated with FAF findings.The differences between the OCT and FAF findings of the two groups were significant(P=0.000).CONCLUSION:OCT and FAF findings can support the clinical observations in differential diagnosis of acute and chronic CSCR and help clinicians to evaluate retinal pigment epithelium,outer segments of photoreceptors and the components of serous RD.

Role of wide-field autofluorescence imaging and scanning laser ophthalmoscopy in differentiation of choroidal pigmented lesions

·AIM:Toevaluatethe diagnostic properties of wide-field fundus autofluorescence(FAF) scanning laser ophthalmoscope(SLO) imaging for differentiating choroidal pigmented lesions.·METHODS: A consecutive series of 139 patients were included, 101 had established choroidal melanoma with13 untreated lesions and 98 treated with radiotherapy.Thirty-eight had choroidal nevi. All patients underwent a full ophthalmological examination, undilated wide-field imaging, FAF and standardized US examination. FAF images and imaging characteristics from SLO were correlated with the structural findings in the two patient groups.·RESULTS: Mean FAF intensity of melanomas was significantly lower than the FAF of choroidal nevi. Only 1out of 38 included eyes with nevi touched the optic disc compared to 31 out of 101 eyes with melanomas. In 18 out of 101 melanomas subretinal fluid was seen at the pigmented lesion compared to none seen in eyes with confirmed choroidal nevi. In 'green laser separation', a trend towards more mixed FAF appearance of melanomas compared to nevi was observed. The mean maximal and minimal transverse and longitudinal diameters of melanomas were significantly higher than those of nevi.·CONCLUSION: Wide-field SLO and FAF imaging may be an appropriate non-invasive diagnostic screening tool to differentiate benign from malign pigmented choroidal lesions.

Infrared autofluorescence, short-wave autofluorescence and spectral-domain optical coherence tomography of optic disk melanocytomas

AIM： To investigate the findings of infrared fundus autofluorescence（IR-AF） and spectral-domain optical coherence tomography（SD-OCT） in eyes with optic disc melanocytoma（ODM）.· METHODS： IR-AF findings and those of other ophthalmologic imaging examinations, including short-wave autofluorescence（SW-AF）, fluorescein angiography（FA）, fundus color photography, and SD-OCT of 8 eyes of 8 consecutive cases with ODM were assessed.·RESULTS： The ODMs in all cases（100%） presented similar IR-AF, SW-AF, and FA findings. On IR-AF images, ODMs showed outstanding hyper-AF with well-defined outline. On SW-AF images, the area of ODMs presented as hypo-AF. FA images revealed the leaking retinal telangiectasia on the surface of the ODMs. On SDOCT images in 8 cases（100%）, the ODMs were sloped with highly reflective surface, which were disorganized retina and optic nerve layers. In 7 cases（87.5%）, peripapillary choroids were involved. The melanocytomas of 8 cases（100%） presented as optically empty spaces. Vitreous seeds were found in one case（12.5%）.· CONCLUSION： IR-AF imaging may provide a new modality to evaluate the pathologic features of ODMs,and together with SW-AF imaging, offers a new tool to study biological characteristics associated with ODMs.SD-OCT is a valuable tool in delimitating the tumor extension and providing morphological information about the adjacent retinal tissue.

Fundus autofluorescence imaging of patients with idiopathic macular hole

AIM:To investigate the role of fundus autofluo rescence(FAF) both in the diagnosis and the preoperative and postoperative evaluation of patients with idiopathic macular hole(MH).METHODS:Forty eyes of 40 patients diagnosed as idiopathic MH between May 2010 and May 2011 were included in this retrospective study.All patients underwent full ophthalmologic examinations and imagings including fluorescein angiography,fundus autofluorescence(FAF) and optical coherence tomography.Thirty of these patients underwent MH surgery.FAF findings were associated with duration of symptoms,visual acuity at presentation,stage of MH,and postoperative anatomical correction.RESULTS:The mean duration of patients’ symptoms was 3.8±2.0(1-9) months.The MH was stage 2 in 4(10%),stage 3 in 24(60%) and stage 4 in 12(30%) eyes.The median preoperative best corrected visual acuity was 20/200(between 20/800 and 20/100).Twenty-eight of cases(70%) showed a stellate appearance with dark radiating striae.Having a visual acuity ≥20/200 was significantly more common in eyes with stellate appearance(P【0.001).The mean duration of symptoms was significantly shorter in eyes with stellate appearance(2.75±0.8 vs 6.33±1.61 months)(P【0.001).The frequency of stage 4 MH was significantly higher in eyes with nonstellate appearance(P【0.001).Anatomical correction of MH was achieved in 91.3%(21/23) of eyes with stellate appearance and 71.4%(5/7) of eyes without this appearance(P=0.225).CONCLUSION:Stellate appearance in FAF is associated with earlier stages of macular hole,better visual acuity at presentation,shorter duration of symptoms,thus more favorable prognosis.

Autofluorescence imaging endoscopy can distinguish non-erosive reflux disease from functional heartburn: A pilot study

AIM: To investigate whether autofluorescence imaging (AFI) endoscopy can distinguish non-erosive reflux disease (NERD) from functional heartburn (FH).METHODS: In this prospective observational trial, 127 patients presenting with typical reflux symptoms for &#x0003e; 6 mo were screened. All the participants underwent endoscopy, during which white light imaging (WLI) was followed by AFI. Finally 84 patients with normal esophageal appearance on WLI were enrolled. It was defined as being suggestive of NERD if one or more longitudinal purple lines longer than one centimeter were visualized in the distal part of the esophagus during AFI endoscopy. Ambulatory 24-h multichannel intraluminal impedance and pH monitoring was also performed. After standard proton-pump inhibitor (PPI) tests, subjects were divided into an NERD group and an FH group and the diagnostic performance of AFI endoscopy to differentiate NERD from FH was evaluated.RESULTS: Of 84 endoscopy-negative patients, 36 (42.9%) had a normal pH/impedance test. Of these, 26 patients with favorable responses to PPI tests were classified as having NERD. Finally 10 patients were diagnosed with FH and the others with NERD. Altogether, 68 (81.0%) of the 84 patients were positive on AFI endoscopy. In the NERD group, there were 67 (90.5%) patients with abnormal esophageal findings on AFI endoscopy while only 1 (10%) patient was positive on AFI endoscopy in the FH group. The sensitivity and specificity of AFI in differentiating NERD from FH were 90.5% (95%CI: 81.5%-96.1%) and 90.0% (95%CI: 55.5%-99.7%), respectively. Meanwhile, the accuracy, positive predictive value and negative predictive value of AFI in differentiating between NERD and FH were 90.5% (95%CI: 84.2%-96.8%), 98.5% (95%CI: 92.1%-99.9%) and 56.3% (95%CI: 30.0%-80.2%), respectively.CONCLUSION: Autofluorescence imaging may serve as a complementary method in evaluating patients with NERD and FH.

Detection accuracy for epithelial dysplasia using an objective autofluorescence visualization method based on the luminance ratio

The autofluorescence visualization method （AVM） uses blue excitation light to assist in the diagnosis of epithelial dysplasia. It detects epithelial dysplasia as a black area, which is known as fluorescence visualization loss （FVL）. In this study, we evaluated the detection accuracy for epithelial dysplasia of the tongue using the objective AVM and assessed its possible clinical utility. Seventy-nine tongue specimens clinically suspected to have leukoplakia or squamous cell carcinoma （SCC） were analyzed. First, the AVM was subjectively performed using the Visually Enhanced Lesion scope （VELscope）, and the iodine-staining method was then performed. After biopsy, the histopathological results and the luminance ratio between the lesion and healthy tissue were compared, and a receiver operating characteristic curve was created. The cutoff value for the objective AVM was determined; the lesion was considered FVL-positive or -negative when the luminance ratio was higher or lower than the cutoff value, respectively. The histopathological diagnoses among the 79 specimens were SCC （n = 30）, leukoplakia with dysplasia （n = 34）, and leukoplakia without dysplasia （n= 15）. The cutoff value of the luminance ratio was 1.62, resulting in 66 FVL-positive and 13 FVL-negative specimens. The luminance ratio was significantly higher in the epithelial dysplasia-positive than -negative group （P〈O.O00 1）. The objective AVM showed much higher consistency between histopathological results than did the two methods （kappa statistic = 0.656）. In conclusion, objective autofluorescence visualization has a potential as an auxiliary method for diagnosis of epithelial dysplasia.

Evaluating role of bone marrow-derived stem cells in dry age-related macular degeneration using multifocal electroretinogram and fundus autofluorescence imaging

AIM：To evaluate the role of bone marrow-derived stem cells in the treatment of advanced dry age-related macular degeneration（AMD）using multifocal electroretinogram（mf-ERG）and fundus autofluorescence imaging.METHODS：Thirty patients（60 eyes）with bilateral central geographic atrophy（GA）were recruited.Worse eye of each patient received autologous bone marrow-derived hematopoietic stem cells（BM-HSCs）（group 1）and the fellow eye with better visual acuity served as control（group2）.The effect of stem cell therapy was determined in terms of visual acuity,amplitude and implicit time in mf-ERG and size of GA on fundus autofluorescence imaging.These tests were performed at presentation and first,third and sixth month follow up.Adverse events（if any）were also monitored.RESULTS：At 6mo follow-up there was no statistically significant improvement in median log MAR best corrected visual acuity（BCVA）in either group.Mf-ERG revealed significant improvement in amplitude and implicit time in the intervention group.A significant decrease was also noted in greatest linear dimension（GLD）of GA in the eyes receiving stem cells[6.78±2.60 mm at baseline to 6.56±2.59 mm at 6mo（P=0.021）].However,no such improvement was noted in the control group.CONCLUSION：Electrophysiological and anatomical improvement in the intervention group sheds light on the therapeutic role of BM-HSCs.Further studies are required to determine the stage of disease at which the maximal benefit can be achieved and to standardize the dose andfrequency of stem cell injection.

Characteristics of normal human retinal pigment epithelium cells with extremes of autofluorescence or intracellular granule count

Background:Cells of the retinal pigment epithelium(RPE)accumulate different kinds of granules(lipofuscin,melanolipofuscin,melanosomes)within their cell bodies,with lipofuscin and melanolipofuscin being autofluorescent after blue light excitation.High amounts of lipofuscin granules within the RPE have been associated with the development of RPE cell death and age-related macular degeneration(AMD);however,this has not been confirmed in histology so far.Here,based on our previous dataset of RPE granule characteristics,we report the characteristics of RPE cells from human donor eyes that show either high or low numbers of intracellular granules or high or low autofluorescence(AF)intensities.Methods:RPE flatmounts of fifteen human donors were examined using high-resolution structured illumination microscopy(HR-SIM)and laser scanning microscopy(LSM).Autofluorescent granules were analyzed regarding AF phenotype and absolute number of granules.In addition,total AF intensity per cell and granule density(number of granules per cell area)were determined.For the final analysis,RPE cells with total granule number below 5th or above the 95th percentile,or a total AF intensity±1.5 standard deviations above or below the mean were included,and compared to the average RPE cell at the same location.Data are presented as mean±standard deviation.Results:Within 420 RPE cells examined,42 cells were further analyzed due to extremes regarding total granule numbers.In addition,20 RPE cells had AF 1.5 standard deviations below,28 RPE cells above the mean local AF intensity.Melanolipofuscin granules predominate in RPE cells with low granule content and low AF intensity.RPE cells with high granule content have nearly twice(1.8 times)as many granules as an average RPE cell.Conclusions:In normal eyes,outliers regarding autofluorescent granule load and AF intensity signals are rare among RPE cells,suggesting that granule deposition and subsequent AF follows intrinsic control mechanisms at a cellular level.The AF of a cell is related to the composition of intracellular granule types.Ongoing studies using AMD donor eyes will examine possible disease related changes in granule distribution and further put lipofuscin´s role in aging and AMD further into perspective.

A physically active lifestyle is related to a lower level of skin autofluorescence in a large population with chronic-disease(LifeLines cohort)

Background:Physical activity(PA)has substantial health benefits and is important in combatting chronic diseases,which have been associated with elevated levels of advanced glycation endproducts(AGEs).AGEs play a role in the aging process,and an association between PA and AGEs has been reported.We aimed to investigate the relationship between PA and AGE accumulation in a general population and in a population with chronic diseases.Methods:This large cross-sectional population study used data from adult participants in the LifeLines project,with participant information drawn from the LifeLines database as well data from patients with diabetes mellitus or renal and/or cardiovascular diseases.Tissue AGE accumulation was assessed non-invasively by skin-autofluorescence(SAF)using an AGE reader(DiagnOptics Technologies BV,Groningen,the Netherlands).PA was assessed using the short questionnaire to assess health-enhancing physical activity(SQUASH).Multivariate linear regression analyses were adjusted for age,body mass index,sex,and smoking status.Results:Data from 63,452 participants(general population n=59,177,chronic disease n=4275)were analyzed.The general population was significantly younger(43.58±11.77 years,mean±SD)and had significantly lower SAF(1.90±0.42 arbitrary units(AU))compared to the population with chronic disease(age:55.51±12.07 years;SAF:2.27±0.51 AU).In the group with chronic disease,more hours of moderate to vigorous physical activities per week were associated with lower SAF(β=-0.002,95%confidence interval(95%CI):-0.002 to-0.001).For the general population,there was no association between hours of moderate to vigorous activity and SAF(β=3.2×10^(-5),95%CI:0.000-0.001,p=0.742).However,there was an association in the general population between total hours of PA per week and SAF(β=4.2×10^(-4),95%CI:0.000-0.001,p<0.001),but this association was not found in the chronic disease population(β=-3.2×10^(-4),95%CI:-0.001 to 0.000,p=0.347).Conclusion:Our study demonstrates that an inverse relationship exists between PA and AGE accumulation in the population with chronic disease.More hours of moderate to vigorous activity is associated a significantly decreased SAF.More PA is associated a lower SAF,even after for the established predictors(age,body mass index,smoking status,and sex).Our findings could help to promote health and prolong longevity.

ALTERATIONS IN AUTOFLUORESCENCE SIGNAL FROM RAT SKIN EX VIVO UNDER OPTICAL IMMERSION CLEARING

For the first time,the changes in autofluorescence spectra of ex vivo rat skin have been experimentally investigated using the combination of fluorescence spectroscopy and optical immersion clearing.The glucose,glycerol and propylene glycol solutions were used as clearing agents.The optical clearing was performed from the dermal side of skin imitating the in vivo injection of clearing agent under the dermal layers.In this contribution,the common properties of autofluorescence variation during optical immersion clearing were determined.The tendency of autofluorescence signal to decrease with reduction of scattering in tissue was noticed and discussed in detail.However,the differences in the shape of spectral curves under application of different clearing agents showed that optical clearing affects the autofluorescence properties of tissue differently depending on the type of clearing liquid.The results obtained are useful for the understanding of tissue optical clearing mechanisms and for improving techniques such as fluorescence spectroscopy.

LIMITATIONS OF CANCER MARGIN DELINEATION BY MEANS OF AUTOFLUORESCENCE IMAGING UNDER CONDITIONS OF LASER SURGERY

Limitations of cancer margin delineation and surgical guidance by means of autofluorescence imaging under conditions of laser ablation were investigated and preliminary results are presented.PinPoint^(TM)(Novadaq Technologies Inc.,Canada)was used to capture digital images and Er:YAG laser(2.94μm,Glissando,WaveLight^(TM),Germany)was exploited to cause laser ablation on both normal and cancer sites of the specimen.It was shown that changes of the autofluorescence image after ablation extend beyond the actual sizes of the ablation loci.The tumor tissue after the laser ablation starts to emit fluorescent light within the green wavelength band(490-550nm)similar to normal tissue stating that the current technology of in-process tissue classification fails.However,when the autofluorescence was collected in the red range(600-750nm),then the abnormal/normal contrast was reduced,but still present even after the laser ablation.The present study highlights the importance of finding a proper technology for surgical navigation of cancer removal under conditions of high power effects in biological tissues.

Evaluation of fundus autofluorescence patterns in age-related macular degeneration

AIM： To study the various morphological patterns of fundus autofluorescence （FAF） images in patients with age-related macular degeneration （AMD） in Indian population.METHODS： Totally 179 eyes of 104 patients with clinical diagnosis of AMD were recruited into the study. Autofluorescence images were captured using confocal scanning laser ophthalmoscope and the patterns of FAF were classified.RESULTS： Of 179 eyes, 27 （15.08%） were early AMD, 58 （32.41%） were intermediate AMD, 94 eyes （52.51%） were late AMD. Of 94 eyes with late AMD, 79 （84.04%） were neovascular AMD and 15 （15.96%） were central geographic atrophy. In eyes with early and intermediate AMD, 9 patterns of FAF were noted. Six patterns （normal, minimal change, focal increased, patchy increased, linear, reticular） were similar to that in the published classification. Two patterns （lacelike and speckled） described in the published classification were not found. Three new patterns （focal hypo-fluorescence, patchy hypo-fluorescence, mixed focal hypo-fluorescence and hyper-fluorescence） were detected. In eyes with neovascular AMD, 6 morphological patterns of FAF were noted. Two patterns （mixed hypo-fluorescence and hyper-fluorescence, central hypo-fluorescence with hyper-fluorescent rim） were similar to that in published classification. Two patterns （normal, near normal or normal background fluorescence in the centre of hypo-fluorescent area） described in the published classification were not found. Four new patterns （minimal change, hypo-fluorescent patch, central hypo-fluorescence with surrounding reticular, bull’s eye） were recognized. In eye with central geographic atrophy 5 morphological patterns were noted and these were similar to that in published classification.CONCLUSION： Phenotypic differences in the pattern of FAF exist in the study population compared to existing classification systems.

Green-light fundus autofluorescence in diabetic macular edema

AIM:To evaluate the role of central green-light fundus autofluorescence (FAF) in diabetic macular edema(DME). METHODS:A consecutive series of 92 study eyes with diabetic retinopathy were included. Out of those, 51 diabetic eyes had DME and were compared to 41 diabetic eyes without DME. In all subjects, green-light FAF images were obtained, quantified and classified into various FAF patterns. Cross-sectional optical coherence tomography (OCT) scans were obtained for evaluation of Inner/Outer segment (IS/OS) layer integrity, measurements of central RPE-IS/OS layer thickness as well as classification of DME into various subtypes. ·RESULTS:Meancentralgreen-lightFAFintensityofeyes with DME (1.289 ±0.140)log did not significantly differ from diabetic patients without DME (1.317 ±0.137)log. Most classifiable FAF patterns were seen in patients with cystoid DME. Mean central retinal thickness (CRT) of all study eyes with DME was (501.9±112.4)μm compared to (328.2±27.0)μm in diabetic patients without DME. Patients with DME had significantly more disrupted photoreceptor IS/OS layers than diabetic patients without DME (28/51 vs 5/41, P 【0.001). Mean RPE-IS/OS thickness of patients with DME (60.7±14.1)μm was significantly (P【0.001) lower than in diabetic eyes without DME (73.5 ±9.4)μm. Correlation analysis revealed non-significant correlations of green-light FAF intensity and OCT parameters in all subtypes of DME. ·CONCLUSION:Our results indicate a poor correlation of central green-light FAF intensity with CRT, IS/OS layer integrity or RPE-IS/OS layer thickness in diabetic patients with or without DME and its various subtypes. Thus, central green-light FAF is not suitable for detection of retinal thickening in DME.

AUTOFLUORESCENCE EXCITED BY ENDOSCOPIC XENON ION LASER IN THE DIAGNOSIS OF GASTRIC CANCER

Endoscopic xenon ion laser induced autofluorescence spectra in various gastric diseases were tested in 104 patients diagnosed by endoscopy and biopsy, including 28 gastric cancer, 9 gastric ulcer, 46 chronic atrophic gastritis, and 21 superficial gastritis. The autofluorescence spectrum excited with the 365 nm line of pulsed xenon ion laser was measured. The xenon ion laser beam having an output energy of 0.5 mJ with a duration of 0.6μs and a repetition rate of 10 Hz was used as the excitation source. A coaxial optical cable for laser light and autofluorescent light transmission was inserted via the biopsy channel of an endoscope into the cavity of stomach. The tip of opitcal cable was aimed at the gastric tissue and autofluorescence spectrum was plotted on X-Y recorder. As the monochromator scanned in the range 500-750 nm, a single-pulse fluorescence spectrum could be obtained by using an optical multichannel analyser, and then this fluorescence spectrum was stored in the computer. The whole procedure could be completed within 15 seconds. The results of the present study show that autofluorescence spectra of gastric cancer have characteristic peaks near 630 nm and 690 nm, while no such peaks appear in the spectra of the corresponding normal regions. A consistency of 75% was observed in gastric cancer as compared with the pathologic diagnosis. It is claimed that this is a harmless, safe, simple, and fast procedure in the diagnosis of gastric cancer.

The application of ultra-wide-field fundus autofluorescence in early metastatic choroidal tumor screening

I am Dr.Ke Yao,from Eye Center,the Second Affiliated Hospital,School of Medicine,Zhejiang University,Hangzhou,China.I write to present three cases with metastatic choroidal tumor using an ultra-wide-field scanning laser ophthalmoscope.