PURPOSE. To evaluate the reliability of self-reported dry eye disease status and patient-related predictors of misclassification in contact lens wearers. ME THODS. Patients completed the Contact Lens Dry Eye Questionn...PURPOSE. To evaluate the reliability of self-reported dry eye disease status and patient-related predictors of misclassification in contact lens wearers. ME THODS. Patients completed the Contact Lens Dry Eye Questionnaire (CLDEQ) short form on two occ asions. Test-retest reliability of the CLDEQ composite score was determined usi ng the 95%limits of agreement (LoA) and an intraclass correlation coefficient ( ICC). The κstatistic was used to determine reliability of disease-classificati on-based CLDEQ composite score cutoff points. Predictors of misclassification w ere determined by multivariate logistic regression. RESULTS. The sample included 274 patients. The range of CLDEQ composite scores from both visits was -1.83 t o 4.50 and the mean difference between administrations was -0.05±0.75 (P=0.30) . The 95%LoA of the CLDEQ composite score were -1.51 to 1.42 and the ICC was 0 .61 (95%confidence interval CI: 0.53-0.68). Calculations using the lower lim it of the 95%CI showed that three administrations of the survey would be requir ed to obtain a more desirable ICC (0.70). The κstatistic for reliability of dry eye disease classification was 0.58 (95%CI: 0.48-0.67). Logistic regression s howed a significant interaction between gender (females) and younger age (P=0.02 ) in relation to misclassification of self-reported dry eye disease status. CON CLUSIONS. The reliability of selfreported dry eye disease classification in cont act lens wearers is moderate. In epidemiologic studies of factors associated wit h self-reported disease status, investigators may be well advised to consider u sing multiple administers of such outcome instruments and controlling for sociod emographic characteristics to maintain internal validity.展开更多
PURPOSE. To determine the distribution of perceived visual ability for functio nal vision performance among persons with low vision in the Indian state of Andh ra Pradesh. METHODS. As part of a population-based epidem...PURPOSE. To determine the distribution of perceived visual ability for functio nal vision performance among persons with low vision in the Indian state of Andh ra Pradesh. METHODS. As part of a population-based epidemiologic study, the And hra Pradesh Eye Disease Study (APEDS), a 16-item visual function questionnaire was designed and applied to 7363 persons older than 15 years, to record the leve ls of difficulty perceived by the subjects. Of these, 123 persons were found to have low vision. Rasch analysis was used to convert the ordinal difficulty ratin gs of these 123 persons into interval measures of perceived visual ability for f unctional vision. RESULTS. Content validity of the questionnaire was demonstrate d by good separation indices (3.17 and 5.44) and high reliability scores (0.91 a nd 0.97) for person and item parameters. Construct validity was shown with model fit statistics. Criterion validity of the questionnaire was shown by good discr imination among the general vision ratings. The functional situation that requir ed the least visual ability was "reaching an object farther or closer than you thought"; the situation requiring the most visual ability was"recognizing smal l objects."Bivariate regression analysis determined that for every unit of logM AR visual acuity, perceived visual ability for functional vision decreased by 2. 9 logit, which could explain 32%of the variability in the person measure. CONCL USIONS. The described assessment, across a range of visual problems, is a valid way to measure perceived ability for functional vision in persons with low visio n. Perceived visual ability varies with every unit of logarithm of the minimum a ngle of resolution (logMAR) visual acuity.展开更多
PURPOSE. To demonstrate that corneal light-backscatter can be measured object ively during corneal swelling by optical coherence tomography (OCT). METHODS. On e eye (randomly selected) of 20 non-contact-lens wearers (...PURPOSE. To demonstrate that corneal light-backscatter can be measured object ively during corneal swelling by optical coherence tomography (OCT). METHODS. On e eye (randomly selected) of 20 non-contact-lens wearers (10 men and 10 women; mean age, 35.6 ±9.6 years) was patched during 3 hours of soft contact lens (SC L) wear. The contralateral eye acted as the control. Central corneal images were captured before and after SCL wear at 20-minute intervals over 100 minutes usi ng optical coherence tomography (OCT) to obtain corneal thickness and light-bac kscatter profiles. OCT backscattered light of the epithelial layer (decided by t he thickness measurements) and 10 equally divided layers of the remaining cornea were analyzed with a custom soft ware program. Two baseline measurements were t aken at different visits before lens wear to test the repeatability of light-ba ckscatter measurements. RESULTS. From two baseline measurements, repeated measur ements showed good repeatability of normalized backscatter results. Immediately after contact lens removal, total central corneal thickness increased significan tly by 13.8%±2.3%(mean ±SD) compared with baseline (P=0.0001, paired t-test ) and then decreased during the deswelling course. Corneal backscattered light c hanged significantly (repeated-measures ANOVA Re-ANOVA: F(50,950)=2.22, P=0. 0001) after lens wear, and a significant increase in backscatter was found in th e epithelial layer (36.4%) and the most posterior corneal layer (35.6%) immedi ately after lens removal (post hoc test, P=0.005). There was a strong correlatio n (r=0.9375, P< 0.05) between the change in backscatter and corneal swelling dur ing the deswelling period. The backscatter recovery rate was approximately the s ame for both epithelial and posterior layers after lens removal. CONCLUSIONS. Li ght- backscattering analysis with OCT seems to be a promising and repeatable method of objectively measuring corneal backscatter. This study has demonstrated that corneal backscattered light increased in th展开更多
PURPOSE. To study some functional candidate genes in cataract families of Indi an descent. METHODS. Nine Indian families, clinically documented to have congeni tal/childhood cataracts, were screened for mutations in c...PURPOSE. To study some functional candidate genes in cataract families of Indi an descent. METHODS. Nine Indian families, clinically documented to have congeni tal/childhood cataracts, were screened for mutations in candidate genes such as CRYG (A→D), CRYBB2, and GJA8 by PCR analyses and sequencing. Genomic DNA sample s of either probands or any representative affected member of each family were P CR amplified and sequenced commercially. Documentation of single nucleotide poly morphisms (SNPs) and candidate mutations was done through BLAST SEARCH(http://ww w.ncbi.nlm.nih.gov/ blast/Blast.- cgi?). RESULTS. Several single nucleotide polymorphisms in CRYG, CRYBB2, and G JA8 genes were observed. Because they do not co-segregate with the phenotype, t hey were excluded as candidates for the cataract formation in these patients. However, a substitution (W151C in exon 6 of CRYBB2) was identi fied as the most likely causative mutation underlying the phenotype of central n uclear cataract in all affected members of family C176. Protein structural inter pretations demonstrated that no major structural alterations could be predicted and that even the hydrogen bonds to the neighboring Leu166 were unchanged. Surpr isingly, hydropathy analysis of the mutant βB2-crystallin featuring the amino acids at position 147 to 155, further increased the hydrophobicity, which might impair the solubility of the mutant protein. Finally, the Cys residue at positio n 151 might possibly be involved in intramolecular disulphide bridges with other cysteines during translation, possibly leading to dramatic structural changes. CONCLUSIONS. Exon 6 of CRYBB2 appears to be a critical region susceptible for mu tations leading to lens opacity.展开更多
PURPOSE. To determine in patients with ocular hypertension (OHT) or early glau coma (EOAG) the change in blood flow measured at the neuroretinal rim of the opt ic disc in response to a 15-Hz diffuse green luminance fl...PURPOSE. To determine in patients with ocular hypertension (OHT) or early glau coma (EOAG) the change in blood flow measured at the neuroretinal rim of the opt ic disc in response to a 15-Hz diffuse green luminance flicker, a stimulus that activates predominantly the ganglion cell magnocellular pathway. METHODS. Thirt een patients with EOAG, 29 with OHT, and 16 age-matched control subjects, all w ith excellent fixation, were examined. Blood flow (Fonh) at the neuroretinal rim of the optic disc was continuously monitored by laser Doppler flowmetry before and during exposure to a 15-Hz, 30°field green luminance flicker. The response of Fonh to this stimulus (RFonh)-was expressed as percentage change in Fonh be tween baseline and the last 20 seconds of flicker. Two to three temporal sites o f the disc were tested, and the highest RFonh was considered for further analysi s. RF onh results in patients were correlated with morphologic (cup-to-disc ar ea ratio, cup shape neuroretinal rim area) and functional (perimetric mean devia tion and pattern electroretinogram amplitude) clinical parameters. RESULTS. In t he patients with OHT or EOAG, Fonh and RFonh were both reduced compared with the ir respective values in the control group. Both quantities decreased significant ly with neuroretinal rim area when the patients’data were pooled. No significan t correlation was found between Fonh or RFonh and the other morphometric and fun ctional parameters. The group averaged time course of RFonh was not significantl y different from that in the normal subjects. CONCLUSIONS. Luminance flicker-ev oked RF onh is abnormally reduced in patients with OHT or EOAG, indicating an im pairment of neurally mediated vasoactivity. The data suggest that PERG-derived neural activity and flicker-evoked RFonh can be independently altered early in the disease process.展开更多
PURPOSE. To determine whether anterior ischemic optic neuropathy and compressi ve optic neuropathy in humans alter the photopic flash ERG and to investigate th e cellular origins of the waves that are affected by phar...PURPOSE. To determine whether anterior ischemic optic neuropathy and compressi ve optic neuropathy in humans alter the photopic flash ERG and to investigate th e cellular origins of the waves that are affected by pharmacologic agents in pri mates. METHODS. Photopic flash ERGs were recorded differentially, with DTL elect rodes, between the two eyes of 22 patients with diagnosed optic neuropathy (n=17 , anterior ischemic optic neuropathy AION; n=5, compressive optic neuropathy) and 25 age-matched control subjects and in 17 eyes of 13 monkeys (Macaca mulatt a). The stimulus consisted of brief (< 5 ms) red (λmax=660 nm) Ganzfeld flashes (energy range, 0.5-2.0 log td-s) delivered on a rod-saturating blue backgrou nd of 3.7 log sc td (λmax=460 nm). An eye of the patient with ischemic changes at the disc was classified as symptomatic if it showed visual field defects with a mean deviation (MD) of P< 2%. Recordings in macaque monkeys were made before and after inner retinal blockade with tetrodotoxin (TTX) (1.2-2.1 μM; n=7), TTX+N-methyl-D-aspart ate (NMDA; 1.4-6.4 mM; n=7), and cis-2, 3 piperidine dicarboxylic acid (PDA; 3 .3-3.8 mM; n=3). RESULTS. The PhNR amplitude was significantly reduced in both symptomatic (P=3.4×10 -8) and asymptomatic (P=0.036) eyes of patients with AIO N or compressive optic neuropathy (P=0.0054) compared with control subjects. The PhNR amplitude in the symptomatic eye showed a moderate correlation with field defects (P < 0.05) similar to previous findings in open-angle glaucoma. The a- wave also was reduced significantly in the symptomatic eye (P=0.0002) of patient s with AION. The i-wave, a positive wave on the trailing edge of the b-wave pe aking around 50 ms, became more prominent in eyes in which the PhNR was signific antly reduced. In monkeys, the PhNR was eliminated by TTX. The a-wave at the pe ak and later times was reduced by TTX, further reduced by NMDA, and eliminated a fter PDA in response to the red stimuli. PDA also eliminated the i-wave. CONCLU SIONS. PhNR amplitude is signif展开更多
PURPOSE. To determine the spatial properties of stimuli that elicit photophobi a (PP) in normal subjects: Does PP exhibit spatial summation? Are different para foveal quadrants (superior, inferior, temporal, and nasal...PURPOSE. To determine the spatial properties of stimuli that elicit photophobi a (PP) in normal subjects: Does PP exhibit spatial summation? Are different para foveal quadrants (superior, inferior, temporal, and nasal) of the retina differe ntially sensitive in PP) What is the relationship between PP sensitivity and ret inal eccentricity? What is the relationship between the spatial properties of PP and the spatial distribution of macular pigment (MP)? METHODS. A Maxwellian-vi ew optical system with a xenon light source was used to present the stimuli. Fou r normal subjects viewed stimuli of various sizes, retinal locations, and one of two chromatic contents: xenon-white and a broadband orange. The intensity of t he test stimulus was increased between trials until the PP threshold was reached . The squinting response corresponding to PP was assessed by electromyography an d used as an objective criterion of PP. Three parameters were examined: stimulus size, parafoveal retinal locus (superior, inferior, temporal, and nasal), and r etinal eccentricity (extending into the perifovea). Spatial profiles of MP were measured psychophysically using heterochromatic flicker photometry (HFP). RESULTS. Spatial summation for PP was found essentially to adhere to Pipers law(radiance proportional to square root of stimulus area). The PP response was greater to centrally than peripherally viewed targets. In this regard, MP acted as a spatially integrated filter in the attenuation of PP. CONCLUSIONS. The degr ee of spatial summation found for PP indicates that an increase of 1.0 log unit in field area results in an approximately 0.57-log-unit decrease in the radian ce required to elicit PP. PP appears to serve the function of retinal photoprote ction.展开更多
Purpose: To study the effect of bimatoprost 0.03% (Lumigan) on ocular hemodynamics in patients with open- angle glaucoma or ocular hypertension. Methods: One randomly selected eye of each of 26 patients with open- ang...Purpose: To study the effect of bimatoprost 0.03% (Lumigan) on ocular hemodynamics in patients with open- angle glaucoma or ocular hypertension. Methods: One randomly selected eye of each of 26 patients with open- angle glaucoma or ocular hypertension was enrolled. Each patient received a drop of bimatoprost 0.03% once daily for 1 month. The effect of bimatoprost on ocular circulation was assessed by color Doppler imaging (CDI), which measured peak systolic, end- diastolic blood flow velocities and resistance indices in the ophthalmic, posterior ciliary and central retinal arteries. Retrobulbar hemodynamics by CDI, intraocular pressure by Goldmann applanation tonometer, blood pressure by cuff, and heart rate by palpation were measured at baseline and at 1 month after bimatoprost treatment. Results: Blood flow velocities and r esistance indices in all retrobulbar vessels showed no statistically significant differences between baseline and bimatoprost condition (P > 0.05). Bimatoprost lowered intraocular pressure significantly (P < 0.001), with a mean change of 6.5 mmHg (27% ) after 1 month of treatment. The systolic (P=0.38) and diastolic (P=0.74) blood pressures and pulse rate (P=0.94) did not show statistically significant differences during the study period. Conclusions: The results of this study suggest that topical bimatoprost 0.03% significantly reduces intraocular pressure in patients with open- angle glaucoma or ocular hypertension. However, it does not have any effect on retrobulbar hemodynamics in open- angle glaucoma and ocular hypertension.展开更多
Background: Optic disc pit (ODP) maculopathy has a poor visual prognosis if left to its natural course. Several therapeutic approaches have been attempted. The cases of 11 patients evaluated with optical coherence tom...Background: Optic disc pit (ODP) maculopathy has a poor visual prognosis if left to its natural course. Several therapeutic approaches have been attempted. The cases of 11 patients evaluated with optical coherence tomography (OCT) and treated with vitrectomy- laser- gas and their functional and anatomical outcomes are presented. Methods: Retrospective interventional consecutive case series, including 11 eyes with ODP maculopathy. Pre- and postoperative best- corrected visual acuity (BCVA), OCT and angiography were recorded. All patients underwent pars plana vitrectomy, posterior hyaloid dissection peripapillary diode laser prior to retinal reapplication and C3F8 15% injection. Results: Mean preoperative BCVA was 20/126. Median preoperative BCVA was 1.0 LogMAR (range 1.3- 0.4). Eighty- two percent of patients gained 2 or more Snellen lines of vision (mean 4.4 lines gained). Mean final BCVA was 20/32, and median final BCVA was 20/30 in Snellen VA and 0.2 in LogMAR (range 0.7- 0) Preoperative OCT in all but one case confirmed the bilaminar structure of the macular detachment. Postoperative OCT helped in monitoring reabsorption of the macular detachment, which was achieved in all cases after an average of 6.5 months post- surgery. BCVA increased progressively as the subretinal fluid was reabsorbed (P=0.006). Mean duration of postoperative follow- up was 15 months. Recurrence was observed in two cases. Conclusions: In our series, the vit- rectomy- laser- gas procedure for ODP maculopathy improved vision and achieved satisfactory anatomic results in all 11 cases. OCT was useful in the diagnosis and follow- up of this pathology. However, the low incidence of this entity makes it difficult to obtain series large enough to determine the efficacy of the vitrectomy- laser- gas procedure and other treatment modalities and be able to suggest a procedure of choice.展开更多
Background: To evaluate the results of pars plana vitrectomy with peeling of the internal limiting membrane (ILM) in eyes with chronic macular oedema. Methods: PPV with indocyanine green (ICG) assisted peel ing of the...Background: To evaluate the results of pars plana vitrectomy with peeling of the internal limiting membrane (ILM) in eyes with chronic macular oedema. Methods: PPV with indocyanine green (ICG) assisted peel ing of the ILM was performed in 33 eyes with diabetic (21 eyes) or non- diabetic (12 eyes) macular oedema. Postoperatively, resolution of macular oedema, improvement of visual acuity (VA) and complications were documented. The peeled membranes were submitted for light and transmission electron microscopic evaluation. Results: The mean follow- up time was 12.2 month s. The macular oedema decreased or was resolved in 17 (81% ) eyes in the diabetic group and in 11 (92% ) eyes in the non- diabetic group. VA improved by at least 2 lines in 11 (52% ) eyes in the diabetic group and in 7 (58% ) eyes in the non- diabetic group. The difference between visual acuity improvements of the two groups was not statistically significant (P > 0.05). However, in the diabetic group the difference of visual improvement between cystoid and diffuse type of macular oedema eyes was statistically significant (14% versus 71% , P=0.02). Light and transmission electron microscopy showed the presence of ILM in all specimens. During the follow- up period no recurrence of macular oedema or epiretinal membrane formation was observed. Conclusion: Pars plana vitrectomy with peeling of the ILM and epiretinal membrane leads to the resolution of macular oedema in the majority of eyes. This however, is not always associated with VA improvement. In diabetic eyes, cystoid type of macular oedema appears to be a poor prognostic factor for improved VA.展开更多
Background: Fundus autofluorescence (AF) is derived from the lipofuscin contained by the retinal pigment epithelial cells. Using a scanning laser ophthalmoscope, two- dimensional AF measurements of the ocular fundus c...Background: Fundus autofluorescence (AF) is derived from the lipofuscin contained by the retinal pigment epithelial cells. Using a scanning laser ophthalmoscope, two- dimensional AF measurements of the ocular fundus can be achieved. Directly after conventional photocoagulation and also after selective RPE laser treatment (SRT) with ophthalmoscopically non- visi- ble laser lesions, irradiated areas reveal reduced AF, indicating RPE damage. Since the green treatment laser beam could also be used for AF excitation, the aim of this study was to evaluate whether absolute measurements of AF can be performed, and also possible changes in AF detected, online during SRT. Methods: SRT was carried out by use of a frequency- doubled Nd:YLF laser (wavelength 527 nm, pulse duration 1.7 μ s, repetition rate 500 and 100 Hz, number of pulses 100 and 30, single pulse energy 50- 130 μ J) in vitro (porcine RPE; retinal spot size 160 μ m) and during patient treatment (retinal spot size 176 μ m). During irradiation, fluorescence light from the RPE was decoupled from the laser light inside the slit lamp and detected by a photomultiplier or photodiode at wavelengths above 550 nm. Additionally, temperature- dependent fluorescence intensity measurements of A2- E, the main fluorescent component of lipofuscin, were performed in a different in- vitro setup. Results: The intensity of AFdecreased over the number of applied pulses during laser irradiation, and this trend was more pronounced in porcine RPE samples than during human treatment. In vitro, the AF intensity decreased by about 22% ; however, only a weak signal was detected. When treating patients, the AF intensity was strong and the rate of decay of fluorescence intensity with number of pulses was greater when irradiating at 500 Hz than at the 100 Hz repetition rate. However, for both repetition rates the AF decay was merely up to 6- 8% over the number of pulses per laser spot. Fluorescence intensity of A2- E decreased linearly with increasing temperature at about 1% per 1° C and展开更多
文摘PURPOSE. To evaluate the reliability of self-reported dry eye disease status and patient-related predictors of misclassification in contact lens wearers. ME THODS. Patients completed the Contact Lens Dry Eye Questionnaire (CLDEQ) short form on two occ asions. Test-retest reliability of the CLDEQ composite score was determined usi ng the 95%limits of agreement (LoA) and an intraclass correlation coefficient ( ICC). The κstatistic was used to determine reliability of disease-classificati on-based CLDEQ composite score cutoff points. Predictors of misclassification w ere determined by multivariate logistic regression. RESULTS. The sample included 274 patients. The range of CLDEQ composite scores from both visits was -1.83 t o 4.50 and the mean difference between administrations was -0.05±0.75 (P=0.30) . The 95%LoA of the CLDEQ composite score were -1.51 to 1.42 and the ICC was 0 .61 (95%confidence interval CI: 0.53-0.68). Calculations using the lower lim it of the 95%CI showed that three administrations of the survey would be requir ed to obtain a more desirable ICC (0.70). The κstatistic for reliability of dry eye disease classification was 0.58 (95%CI: 0.48-0.67). Logistic regression s howed a significant interaction between gender (females) and younger age (P=0.02 ) in relation to misclassification of self-reported dry eye disease status. CON CLUSIONS. The reliability of selfreported dry eye disease classification in cont act lens wearers is moderate. In epidemiologic studies of factors associated wit h self-reported disease status, investigators may be well advised to consider u sing multiple administers of such outcome instruments and controlling for sociod emographic characteristics to maintain internal validity.
文摘PURPOSE. To determine the distribution of perceived visual ability for functio nal vision performance among persons with low vision in the Indian state of Andh ra Pradesh. METHODS. As part of a population-based epidemiologic study, the And hra Pradesh Eye Disease Study (APEDS), a 16-item visual function questionnaire was designed and applied to 7363 persons older than 15 years, to record the leve ls of difficulty perceived by the subjects. Of these, 123 persons were found to have low vision. Rasch analysis was used to convert the ordinal difficulty ratin gs of these 123 persons into interval measures of perceived visual ability for f unctional vision. RESULTS. Content validity of the questionnaire was demonstrate d by good separation indices (3.17 and 5.44) and high reliability scores (0.91 a nd 0.97) for person and item parameters. Construct validity was shown with model fit statistics. Criterion validity of the questionnaire was shown by good discr imination among the general vision ratings. The functional situation that requir ed the least visual ability was "reaching an object farther or closer than you thought"; the situation requiring the most visual ability was"recognizing smal l objects."Bivariate regression analysis determined that for every unit of logM AR visual acuity, perceived visual ability for functional vision decreased by 2. 9 logit, which could explain 32%of the variability in the person measure. CONCL USIONS. The described assessment, across a range of visual problems, is a valid way to measure perceived ability for functional vision in persons with low visio n. Perceived visual ability varies with every unit of logarithm of the minimum a ngle of resolution (logMAR) visual acuity.
文摘PURPOSE. To demonstrate that corneal light-backscatter can be measured object ively during corneal swelling by optical coherence tomography (OCT). METHODS. On e eye (randomly selected) of 20 non-contact-lens wearers (10 men and 10 women; mean age, 35.6 ±9.6 years) was patched during 3 hours of soft contact lens (SC L) wear. The contralateral eye acted as the control. Central corneal images were captured before and after SCL wear at 20-minute intervals over 100 minutes usi ng optical coherence tomography (OCT) to obtain corneal thickness and light-bac kscatter profiles. OCT backscattered light of the epithelial layer (decided by t he thickness measurements) and 10 equally divided layers of the remaining cornea were analyzed with a custom soft ware program. Two baseline measurements were t aken at different visits before lens wear to test the repeatability of light-ba ckscatter measurements. RESULTS. From two baseline measurements, repeated measur ements showed good repeatability of normalized backscatter results. Immediately after contact lens removal, total central corneal thickness increased significan tly by 13.8%±2.3%(mean ±SD) compared with baseline (P=0.0001, paired t-test ) and then decreased during the deswelling course. Corneal backscattered light c hanged significantly (repeated-measures ANOVA Re-ANOVA: F(50,950)=2.22, P=0. 0001) after lens wear, and a significant increase in backscatter was found in th e epithelial layer (36.4%) and the most posterior corneal layer (35.6%) immedi ately after lens removal (post hoc test, P=0.005). There was a strong correlatio n (r=0.9375, P< 0.05) between the change in backscatter and corneal swelling dur ing the deswelling period. The backscatter recovery rate was approximately the s ame for both epithelial and posterior layers after lens removal. CONCLUSIONS. Li ght- backscattering analysis with OCT seems to be a promising and repeatable method of objectively measuring corneal backscatter. This study has demonstrated that corneal backscattered light increased in th
文摘PURPOSE. To study some functional candidate genes in cataract families of Indi an descent. METHODS. Nine Indian families, clinically documented to have congeni tal/childhood cataracts, were screened for mutations in candidate genes such as CRYG (A→D), CRYBB2, and GJA8 by PCR analyses and sequencing. Genomic DNA sample s of either probands or any representative affected member of each family were P CR amplified and sequenced commercially. Documentation of single nucleotide poly morphisms (SNPs) and candidate mutations was done through BLAST SEARCH(http://ww w.ncbi.nlm.nih.gov/ blast/Blast.- cgi?). RESULTS. Several single nucleotide polymorphisms in CRYG, CRYBB2, and G JA8 genes were observed. Because they do not co-segregate with the phenotype, t hey were excluded as candidates for the cataract formation in these patients. However, a substitution (W151C in exon 6 of CRYBB2) was identi fied as the most likely causative mutation underlying the phenotype of central n uclear cataract in all affected members of family C176. Protein structural inter pretations demonstrated that no major structural alterations could be predicted and that even the hydrogen bonds to the neighboring Leu166 were unchanged. Surpr isingly, hydropathy analysis of the mutant βB2-crystallin featuring the amino acids at position 147 to 155, further increased the hydrophobicity, which might impair the solubility of the mutant protein. Finally, the Cys residue at positio n 151 might possibly be involved in intramolecular disulphide bridges with other cysteines during translation, possibly leading to dramatic structural changes. CONCLUSIONS. Exon 6 of CRYBB2 appears to be a critical region susceptible for mu tations leading to lens opacity.
文摘PURPOSE. To determine in patients with ocular hypertension (OHT) or early glau coma (EOAG) the change in blood flow measured at the neuroretinal rim of the opt ic disc in response to a 15-Hz diffuse green luminance flicker, a stimulus that activates predominantly the ganglion cell magnocellular pathway. METHODS. Thirt een patients with EOAG, 29 with OHT, and 16 age-matched control subjects, all w ith excellent fixation, were examined. Blood flow (Fonh) at the neuroretinal rim of the optic disc was continuously monitored by laser Doppler flowmetry before and during exposure to a 15-Hz, 30°field green luminance flicker. The response of Fonh to this stimulus (RFonh)-was expressed as percentage change in Fonh be tween baseline and the last 20 seconds of flicker. Two to three temporal sites o f the disc were tested, and the highest RFonh was considered for further analysi s. RF onh results in patients were correlated with morphologic (cup-to-disc ar ea ratio, cup shape neuroretinal rim area) and functional (perimetric mean devia tion and pattern electroretinogram amplitude) clinical parameters. RESULTS. In t he patients with OHT or EOAG, Fonh and RFonh were both reduced compared with the ir respective values in the control group. Both quantities decreased significant ly with neuroretinal rim area when the patients’data were pooled. No significan t correlation was found between Fonh or RFonh and the other morphometric and fun ctional parameters. The group averaged time course of RFonh was not significantl y different from that in the normal subjects. CONCLUSIONS. Luminance flicker-ev oked RF onh is abnormally reduced in patients with OHT or EOAG, indicating an im pairment of neurally mediated vasoactivity. The data suggest that PERG-derived neural activity and flicker-evoked RFonh can be independently altered early in the disease process.
文摘PURPOSE. To determine whether anterior ischemic optic neuropathy and compressi ve optic neuropathy in humans alter the photopic flash ERG and to investigate th e cellular origins of the waves that are affected by pharmacologic agents in pri mates. METHODS. Photopic flash ERGs were recorded differentially, with DTL elect rodes, between the two eyes of 22 patients with diagnosed optic neuropathy (n=17 , anterior ischemic optic neuropathy AION; n=5, compressive optic neuropathy) and 25 age-matched control subjects and in 17 eyes of 13 monkeys (Macaca mulatt a). The stimulus consisted of brief (< 5 ms) red (λmax=660 nm) Ganzfeld flashes (energy range, 0.5-2.0 log td-s) delivered on a rod-saturating blue backgrou nd of 3.7 log sc td (λmax=460 nm). An eye of the patient with ischemic changes at the disc was classified as symptomatic if it showed visual field defects with a mean deviation (MD) of P< 2%. Recordings in macaque monkeys were made before and after inner retinal blockade with tetrodotoxin (TTX) (1.2-2.1 μM; n=7), TTX+N-methyl-D-aspart ate (NMDA; 1.4-6.4 mM; n=7), and cis-2, 3 piperidine dicarboxylic acid (PDA; 3 .3-3.8 mM; n=3). RESULTS. The PhNR amplitude was significantly reduced in both symptomatic (P=3.4×10 -8) and asymptomatic (P=0.036) eyes of patients with AIO N or compressive optic neuropathy (P=0.0054) compared with control subjects. The PhNR amplitude in the symptomatic eye showed a moderate correlation with field defects (P < 0.05) similar to previous findings in open-angle glaucoma. The a- wave also was reduced significantly in the symptomatic eye (P=0.0002) of patient s with AION. The i-wave, a positive wave on the trailing edge of the b-wave pe aking around 50 ms, became more prominent in eyes in which the PhNR was signific antly reduced. In monkeys, the PhNR was eliminated by TTX. The a-wave at the pe ak and later times was reduced by TTX, further reduced by NMDA, and eliminated a fter PDA in response to the red stimuli. PDA also eliminated the i-wave. CONCLU SIONS. PhNR amplitude is signif
文摘PURPOSE. To determine the spatial properties of stimuli that elicit photophobi a (PP) in normal subjects: Does PP exhibit spatial summation? Are different para foveal quadrants (superior, inferior, temporal, and nasal) of the retina differe ntially sensitive in PP) What is the relationship between PP sensitivity and ret inal eccentricity? What is the relationship between the spatial properties of PP and the spatial distribution of macular pigment (MP)? METHODS. A Maxwellian-vi ew optical system with a xenon light source was used to present the stimuli. Fou r normal subjects viewed stimuli of various sizes, retinal locations, and one of two chromatic contents: xenon-white and a broadband orange. The intensity of t he test stimulus was increased between trials until the PP threshold was reached . The squinting response corresponding to PP was assessed by electromyography an d used as an objective criterion of PP. Three parameters were examined: stimulus size, parafoveal retinal locus (superior, inferior, temporal, and nasal), and r etinal eccentricity (extending into the perifovea). Spatial profiles of MP were measured psychophysically using heterochromatic flicker photometry (HFP). RESULTS. Spatial summation for PP was found essentially to adhere to Pipers law(radiance proportional to square root of stimulus area). The PP response was greater to centrally than peripherally viewed targets. In this regard, MP acted as a spatially integrated filter in the attenuation of PP. CONCLUSIONS. The degr ee of spatial summation found for PP indicates that an increase of 1.0 log unit in field area results in an approximately 0.57-log-unit decrease in the radian ce required to elicit PP. PP appears to serve the function of retinal photoprote ction.
文摘Purpose: To study the effect of bimatoprost 0.03% (Lumigan) on ocular hemodynamics in patients with open- angle glaucoma or ocular hypertension. Methods: One randomly selected eye of each of 26 patients with open- angle glaucoma or ocular hypertension was enrolled. Each patient received a drop of bimatoprost 0.03% once daily for 1 month. The effect of bimatoprost on ocular circulation was assessed by color Doppler imaging (CDI), which measured peak systolic, end- diastolic blood flow velocities and resistance indices in the ophthalmic, posterior ciliary and central retinal arteries. Retrobulbar hemodynamics by CDI, intraocular pressure by Goldmann applanation tonometer, blood pressure by cuff, and heart rate by palpation were measured at baseline and at 1 month after bimatoprost treatment. Results: Blood flow velocities and r esistance indices in all retrobulbar vessels showed no statistically significant differences between baseline and bimatoprost condition (P > 0.05). Bimatoprost lowered intraocular pressure significantly (P < 0.001), with a mean change of 6.5 mmHg (27% ) after 1 month of treatment. The systolic (P=0.38) and diastolic (P=0.74) blood pressures and pulse rate (P=0.94) did not show statistically significant differences during the study period. Conclusions: The results of this study suggest that topical bimatoprost 0.03% significantly reduces intraocular pressure in patients with open- angle glaucoma or ocular hypertension. However, it does not have any effect on retrobulbar hemodynamics in open- angle glaucoma and ocular hypertension.
文摘Background: Optic disc pit (ODP) maculopathy has a poor visual prognosis if left to its natural course. Several therapeutic approaches have been attempted. The cases of 11 patients evaluated with optical coherence tomography (OCT) and treated with vitrectomy- laser- gas and their functional and anatomical outcomes are presented. Methods: Retrospective interventional consecutive case series, including 11 eyes with ODP maculopathy. Pre- and postoperative best- corrected visual acuity (BCVA), OCT and angiography were recorded. All patients underwent pars plana vitrectomy, posterior hyaloid dissection peripapillary diode laser prior to retinal reapplication and C3F8 15% injection. Results: Mean preoperative BCVA was 20/126. Median preoperative BCVA was 1.0 LogMAR (range 1.3- 0.4). Eighty- two percent of patients gained 2 or more Snellen lines of vision (mean 4.4 lines gained). Mean final BCVA was 20/32, and median final BCVA was 20/30 in Snellen VA and 0.2 in LogMAR (range 0.7- 0) Preoperative OCT in all but one case confirmed the bilaminar structure of the macular detachment. Postoperative OCT helped in monitoring reabsorption of the macular detachment, which was achieved in all cases after an average of 6.5 months post- surgery. BCVA increased progressively as the subretinal fluid was reabsorbed (P=0.006). Mean duration of postoperative follow- up was 15 months. Recurrence was observed in two cases. Conclusions: In our series, the vit- rectomy- laser- gas procedure for ODP maculopathy improved vision and achieved satisfactory anatomic results in all 11 cases. OCT was useful in the diagnosis and follow- up of this pathology. However, the low incidence of this entity makes it difficult to obtain series large enough to determine the efficacy of the vitrectomy- laser- gas procedure and other treatment modalities and be able to suggest a procedure of choice.
文摘Background: To evaluate the results of pars plana vitrectomy with peeling of the internal limiting membrane (ILM) in eyes with chronic macular oedema. Methods: PPV with indocyanine green (ICG) assisted peel ing of the ILM was performed in 33 eyes with diabetic (21 eyes) or non- diabetic (12 eyes) macular oedema. Postoperatively, resolution of macular oedema, improvement of visual acuity (VA) and complications were documented. The peeled membranes were submitted for light and transmission electron microscopic evaluation. Results: The mean follow- up time was 12.2 month s. The macular oedema decreased or was resolved in 17 (81% ) eyes in the diabetic group and in 11 (92% ) eyes in the non- diabetic group. VA improved by at least 2 lines in 11 (52% ) eyes in the diabetic group and in 7 (58% ) eyes in the non- diabetic group. The difference between visual acuity improvements of the two groups was not statistically significant (P > 0.05). However, in the diabetic group the difference of visual improvement between cystoid and diffuse type of macular oedema eyes was statistically significant (14% versus 71% , P=0.02). Light and transmission electron microscopy showed the presence of ILM in all specimens. During the follow- up period no recurrence of macular oedema or epiretinal membrane formation was observed. Conclusion: Pars plana vitrectomy with peeling of the ILM and epiretinal membrane leads to the resolution of macular oedema in the majority of eyes. This however, is not always associated with VA improvement. In diabetic eyes, cystoid type of macular oedema appears to be a poor prognostic factor for improved VA.
文摘Background: Fundus autofluorescence (AF) is derived from the lipofuscin contained by the retinal pigment epithelial cells. Using a scanning laser ophthalmoscope, two- dimensional AF measurements of the ocular fundus can be achieved. Directly after conventional photocoagulation and also after selective RPE laser treatment (SRT) with ophthalmoscopically non- visi- ble laser lesions, irradiated areas reveal reduced AF, indicating RPE damage. Since the green treatment laser beam could also be used for AF excitation, the aim of this study was to evaluate whether absolute measurements of AF can be performed, and also possible changes in AF detected, online during SRT. Methods: SRT was carried out by use of a frequency- doubled Nd:YLF laser (wavelength 527 nm, pulse duration 1.7 μ s, repetition rate 500 and 100 Hz, number of pulses 100 and 30, single pulse energy 50- 130 μ J) in vitro (porcine RPE; retinal spot size 160 μ m) and during patient treatment (retinal spot size 176 μ m). During irradiation, fluorescence light from the RPE was decoupled from the laser light inside the slit lamp and detected by a photomultiplier or photodiode at wavelengths above 550 nm. Additionally, temperature- dependent fluorescence intensity measurements of A2- E, the main fluorescent component of lipofuscin, were performed in a different in- vitro setup. Results: The intensity of AFdecreased over the number of applied pulses during laser irradiation, and this trend was more pronounced in porcine RPE samples than during human treatment. In vitro, the AF intensity decreased by about 22% ; however, only a weak signal was detected. When treating patients, the AF intensity was strong and the rate of decay of fluorescence intensity with number of pulses was greater when irradiating at 500 Hz than at the 100 Hz repetition rate. However, for both repetition rates the AF decay was merely up to 6- 8% over the number of pulses per laser spot. Fluorescence intensity of A2- E decreased linearly with increasing temperature at about 1% per 1° C and
