Visante Anterior Segment Optical Coherence Research Articles

Quantitative analysis of dynamic iris changes in primary angle-closure disease with long axial lengths: the Handan Eye Study.

To investigate dynamic iris changes in patients with primary angle-closure disease (PACD) with long axial length (AL) compared to those with short and medium AL. This observational cross-sectional study enrolled participants aged 35 years or older from the Handan Eye Study follow-up examination who were diagnosed with PACD and underwent Visante anterior segment optical coherence tomography (ASOCT) imaging under light and dark conditions. The right eye of each participant was included in the analysis. AL was categorized as short (<22.0 mm), medium (≥22.0 to ≤23.5 mm), or long (>23.5 mm). Anterior segment parameters, including iris dynamic changes, were compared among the three groups with different ALs. Data from 448 patients with PACD were analyzed. We found that 10.9% of included eyes had a long AL with a flatter cornea; larger central anterior chamber depth, angle opening distance, anterior chamber width, anterior chamber area, and volume; and smaller lens thickness and lens vault (LV) (P < 0.05) than those with short AL. No significant difference existed between the three groups in iris thickness, iris cross-sectional area (IA), iris curvature, or pupil diameter (PD) change between light and dark (P > 0.05). The significant associated factors for IA changes were area recess area (ARA) in the dark, LV in the dark, and PD change from light to dark (P < 0.05). Dynamic and static iris parameters were consistent across patients with PACD with short, medium, or long AL and may contribute to the pathogenesis of angle closure in atypical PACD.

Pentacam versus anterior segment OCT in measuring intended versus achieved ablation depth post-myopic LASIK correction

BackgroundAccurate quantitative measurements of central corneal thickness (CCT) provide valuable, clinical information for preoperative assessment, surgical planning, and follow-up in myopic patients who have undergone LASIK correction. Typically, an ultrasound is used to measure such parameters. However, noncontact devices such as the Visante anterior segment optical coherence tomographer [AS-optical coherence tomography (OCT)] and Pentacam are becoming more popular to measure ocular parameters. It is important to assess the level of similarity between these two optical devices to compare between the intended and achieved ablation depth after LASIK procedures in cases of myopia and myopic astigmatism.MethodsThis cross-sectional, prospective study included 80 eyes of 40 patients attending Beni-Suef University Hospital between November 2018 and November 2019. All patients underwent LASIK surgery for the correction of myopia with or without myopic astigmatism with spherical equivalent ranging from − 1.5 to − 12 diopters.ResultsNo statistically significant difference was observed between the intended ablation depth and the clinically measured ablation depth calculated by Pentacam and AS-OCT 3 months after surgery (P > 0.05).ConclusionWhen planning corneal refraction surgery, ablation depth readouts calculated by the computer software of the excimer laser used in this study are reliable. Both Pentacam and AS-OCT are accurate, sensitive, and specific in measuring the CCT and calculating ablation depth. Pentacam provides slightly higher accuracy and sensitivity compared with AS-OCT. LASIK is a safe, predictable, and effective procedure in the treatment of simple myopia and myopic astigmatism.

Central Corneal Thickness Among Filipino Patients in an Ambulatory Eye Surgery Center Using Anterior Segment Optical Coherence Tomography.

ObjectiveThe purpose of the study was to determine the central corneal thickness (CCT) among Filipino patients that may contribute to different glaucoma diagnosis using the anterior segment optical coherence tomography in an ambulatory eye surgery center.MethodsA single-center retrospective, cross-sectional study design including 1232 eyes of 641 patients of the Asian Eye Institute, Makati, Philippines from January 2019 to December 2019 who had their CCT measured with Visante anterior segment optical coherence tomography (AS-OCT). CCT was correlated with age, sex, presence of diabetes and/or hypertension, and glaucoma diagnosis.ResultsAmong 641 patients who had their CCT measured by Visante AS-OCT, 723 eyes of 369 patients were included. Nearly half of the study population were normal or glaucoma suspects. The mean CCT among Filipino patients was 535.59 ± 34.06 µm. Ocular hypertensive patients had the thickest CCT, while normal tension glaucoma patients had the thinnest CCT. After adjusting for multiple variables, CCT had a direct relationship with the presence of diabetes, IOP level and the diagnosis of ocular hypertension, while inverse relationship with age. Most of the patients presenting with angle closure glaucoma were females aged 60 and above.ConclusionVisante AS-OCT is a non-contact and non-aerosol generating instrument allaying the fear of disease transmission from contact or aerosolization of tears. Our study confirms similar relationships of CCT with age, presence of diabetes, IOP level, and diagnosis of ocular hypertension or normal tension glaucoma among Filipino patients with the available literature from other ethnicities.

Imaging of filtering blebs after implantation of the Ex-PRESS shunt with the use of the Visante optical coherence tomography.

To analyze the features of the filtering blebs following implantation of the Ex-PRESS glaucoma device (model P-50) with the aid of the Visante anterior segment optical coherence tomography (AS-OCT). Five patients with open angle glaucomas were included in the study. They all underwent implantation of the Ex-PRESS device under a scleral flap. The surgical procedure was augmented with the use of mitomycin C subconjunctivally. The filtering blebs were analyzed with the Visante AS-OCT with the scans taken along the axis of the implantation of the glaucoma device. All filtering blebs were graded as diffuse functioning. The morphological characteristics of the blebs were similar to those of the trabeculectomy. However the use of the Ex-PRESS implant tend to form a characteristic episcleral lake at the site of the plate of the implant. The use of the Ex-PRESS implant produces filtering blebs similar to those of the trabeculectomy with the formation of a characteristic episcleral lake at the site of the plate of the implant.

A program to analyse optical coherence tomography images of the ciliary muscle.

To describe and validate bespoke software designed to extract morphometric data from ciliary muscle Visante Anterior Segment Optical Coherence Tomography (AS-OCT) images. Initially, to ensure the software was capable of appropriately applying tiered refractive index corrections and accurately measuring orthogonal and oblique parameters, 5 sets of custom-made rigid gas-permeable lenses aligned to simulate the sclera and ciliary muscle were imaged by the Visante AS-OCT and were analysed by the software. Human temporal ciliary muscle data from 50 participants extracted via the internal Visante AS-OCT caliper method and the software were compared. The repeatability of the software was also investigated by imaging the temporal ciliary muscle of 10 participants on 2 occasions. The mean difference between the software and the absolute thickness measurements of the rigid gas-permeable lenses were not statistically significantly different from 0 (t=-1.458, p=0.151). Good correspondence was observed between human ciliary muscle measurements obtained by the software and the internal Visante AS-OCT calipers (maximum thickness t=-0.864, p=0.392, total length t=0.860, p=0.394). The software extracted highly repeatable ciliary muscle measurements (variability ≤6% of mean value). The bespoke software is capable of extracting accurate and repeatable ciliary muscle measurements and is suitable for analysing large data sets.

Reproducibility of Angle Metrics Using the Time-Domain Anterior Segment Optical Coherence Tomography: Intra-Observer and Inter-Observer Variability

Purpose: To evaluate the reproducibility of anterior chamber angle measurements obtained by the Zeiss Visante anterior segment optical coherence tomography (AS-OCT).Methods: Twenty eyes from 20 normal subjects with open anterior chamber angles were studied. The anterior chamber angle was imaged using the Visante AS-OCT. The angle-opening distance (AOD 500, AOD 750), trabercular iris space area (TISA 500, TISA 750) and scleral spur angle (SS angle) at the inferior angle location were measured. All the subjects underwent imaging in a darkened room (1 foot candles measured at the eye). Images were graded in a masked fashion by certified Doheny Image Reading Center graders. For intra-grader reproducibility assessments, images were re-graded by the same grader 1 week later after random sorting of images. For inter-grader assessments, a second masked grader independently reviewed the images. Intraclass correlation coefficients (ICC) were used to assess reproducibility.Results: Inferior angle measurements of AOD (500, 750), TISA (500, 750) and SS angle for 20 normal eyes were calculated. The intra-observer ICC calculations showed excellent reproducibility for all measurements (AOD 500 = 0.95, AOD 750 = 0.97, TISA 500 = 0.93, TISA 750 = 0.94, SS = 0.96; p < 0.001 for all). The inter-observer ICC calculations showed lower reproducibility for all measurements (AOD 500 = 0.71, p < 0.001; AOD 750 = 0.82, p < 0.001; TISA 500 = 0.49, p = 0.08; TISA 750 = 0.61, p = 0.02; SS = 0.75).Conclusion: Determination of anterior chamber angle measurements was possible with the time-domain AS-OCT, but only modest inter-observer reproducibility was found even among experienced graders.

In Vitro Pilot Analysis of Uniformity, Circularity, and Concentricity of DSAEK Donor Endothelial Grafts Prepared by a Microkeratome

The aim of this study was to analyze Descemet stripping automated endothelial keratoplasty donor endothelial grafts, prepared by using a microkeratome, in terms of uniformity, circularity, and concentricity. In this pilot study, 12 human donor corneas were prepared by means of a microkeratome and imaged using the Visante anterior segment optical coherence tomography along 4 meridians. The microkeratome enters and exits the corneal tissue at an angle, creating a donor graft bed with a uniform stromal (US) thickness in between the angled edges. We termed the angled portion the "nonuniform stromal transitional annulus" (STA), the point of entry and exit of the microkeratome the "epithelium-to-epithelium" (E-E) diameter, and the length of the US bed the "US" diameter. The E-E and US diameters were measured to create a model of each donor graft, from which circularity and concentricity were calculated. The STA length and height were measured, and the slope was calculated. The mean E-E diameter was 10.69 ± 0.32 mm (range, 9.46-11.75 mm) and the mean US diameter was 8.96 ± 0.40 mm (range, 7.62-10.28 mm). The microkeratome generated elliptical rather than circular cuts, with a mean eccentricity of 0.34 ± 0.098 (range, 0.22-0.58). Eccentricity values between 0 and 1 represent ellipses, with zero characterizing a circle. The US ellipses and E-E ellipses were not concentric, with a mean deviation of the centers of the shapes of 177.06 ± 92.06 μm (range, 21.95-322.22 μm). The mean STA length was 0.73 ± 0.31 mm (range, 0.25-1.89 mm), the mean height was 0.43 ± 0.08 mm (range, 0.28-0.64 mm), and the mean slope was 34.11 ± 14.00° (range, 8.43-53.67°). Microkeratome cuts created nonuniform, noncircular nonconcentric donor grafts. Asymmetry and nonuniformity of donor tissue may help explain suboptimal visual outcomes.

Visante Anterior Segment Optical Coherence Tomography Analysis of Morphologic Changes After Deep Sclerectomy With Intraoperative Mitomycin-C and No Implant Use

To assess long-term intrascleral space maintenance after nonpenetrating deep sclerectomy (NPDS) without implant placement and with application of intraoperative mitomycin-C, using Visante anterior segment optical coherence tomography (AS-OCT). This cross-sectional, observational, case series study examined 47 eyes from 47 consecutive patients who had undergone NPDS 58.34±23.77 months earlier. All participants underwent a complete ophthalmologic examination. The presence of intrascleral space and its maximum anteroposterior and transverse lengths, maximum height, and volume were evaluated. The thickness of the trabeculo-Descemet membrane, presence and type of any subconjunctival filtering bleb, as well as scleral and suprachoroidal hyporeflectivity were analyzed. Relationships between intraocular pressure (IOP) levels and AS-OCT parameters were established. AS-OCT examinations revealed an open intrascleral space in all cases. The IOP was negatively correlated with the maximum anteroposterior length, maximum height, and volume of intrascleral space. Significant differences in IOP were found between eyes with low-reflective blebs and eyes with other subconjunctival bleb types. The overall surgical success rate was 89.4%. NPDS without implant placement and with intraoperative mitomycin C application seems to be an effective and well-tolerated method to reduce IOP with long-term effectiveness, casting doubt on the mandatory use of intrascleral implants in nonpenetrating glaucoma surgery.

Posterior chamber phakic intraocular lens implantation for high myopia.

To evaluate the efficacy, safety and stability of posterior chamber phakic intraocular lens implantation for the correction of high myopia. Retrospective case review of 82 eyes (43 patients) undergoing implantable Collamer lens (ICL) placement by a single surgeon (Xiao-Wei Gao) to correct preoperative mean spherical equivalents between -9.00 diopter (D) and -23.00D. Main outcome measures included uncorrected visual acuity (UCVA), refraction, best spectacle-corrected visual acuity (BSCVA), endothelial cell density (ECD), intraocular pressure (IOP), lens transparency, postoperative uveitis. Visante anterior segment optical coherence tomography (AS-OCT) was used to measure anterior chamber depth (ACD) and the position of ICL. Mean follow-up was 6.54±3.26 months (range 3-12 months). Predictability of the manifest spherical equivalent (SE) refraction to within ±1.00D was achieved in 88% of eyes and ±0.50D in 72.5% of eyes. The mean postoperative manifest SE refraction was -1.85±0.72D, with 96.34% of eyes maintaining or gaining ≥1 line(s) of BSCVA. The mean 3-month postoperative ECD decreased but had no statistically difference compared with the preoperative ECD. Of the 7 eyes (8.54%) with a mild transient increase in intraocular pressure (up to 30mmHg), none required a second surgical procedure or prolonged topical medication. There was no loss of lens transparency. Pigmented precipitates were observed in 5 eyes (6.09%). The mean preoperative ACD measured with AS-OCT was 3.28±0.14mm, three months after surgery, the mean ACD was 2.45±0.22mm. Anterior chamber depth showed a statistically significant reduction. One eye (1.22%) had ICL spontaneous rotation, 81 eyes (98.78%) of the lens remained correctly centered. The implantation of ICL is an effective surgical option for the management of high myopia. But its long time effect and safety still need more time to prove.

Repeatability of OCT Lens Thickness Measures With Age and Accommodation

To investigate crystalline lens thickness (LT) across a range of ages and accommodative demands and to evaluate the repeatability of LT measurements using the Visante Anterior Segment Optical Coherence Tomographer (AS-OCT) (Zeiss Meditec, Germany) under non-cycloplegic conditions. Participants were 98 visually normal adults aged 18-75 years, stratified into age groups of 18-29, 30-39, 40-49, 50-59, and 60-75 years of age. Images of the crystalline lens were taken using the Visante AS-OCT during stimulation of accommodation at demands of 0, 1, 2, 3, 4, 5, and 8 D with accommodative response measured in a subgroup of participants. Images were analyzed and LT measured assuming a refractive index of 1.42. Repeat measures were taken from 86 participants for each accommodative demand at a second visit. The mean unaccommodated LT for all participants was 4.07 ± 0.40 mm. An average increase in LT of 20 μm per year was calculated (linear regression, R² = 0.61, F(1,89) = 143.92, p < 0.00001). Increase in LT with accommodation was shown to be significant in the 18- to 29-year-olds (repeated measures ANOVA, F(6,105) = 96.31, p < 0.00001), 30- to 39-year-olds (F(6,93) = 71.25, p < 0.00001), and 40- to 49-year-olds (F(6,90) = 12.60, p < 0.01) with little or no measureable change in the older age groups. Eighty-six participants returned for a second visit. The mean difference in LT in the unaccommodated state for all participants between visit 1 and visit 2 was 0.0006 mm (95% limits of agreement of -0.07 to 0.07 mm). The 95% limits of agreement were widest for youngest age groups and narrowest for the oldest participants. This study is the first to report the repeatability of LT measures using the Visante AS-OCT in the non-cyclopleged eye. It has also demonstrated the ability of the Visante AS-OCT to detect small changes in lens thickness with accommodation.

Effect of overnight wear of the Triggerfish® sensor on corneal thickness measured by Visante® anterior segment optical coherence tomography

To evaluate the effect of overnight wear of the Triggerfish(®) contact lens sensor (CLS) on central corneal thickness (CCT) using the Visante(®) anterior segment optical coherence tomography (AS-OCT). Twelve healthy subjects were studied in a sleep laboratory. An ophthalmic examination including ultrasonic CCT, corneal topography, specular microscopy and AS-OCT CCT was performed. Starting at 7 pm, the Triggerfish(®) CLS was fitted on one randomly selected eye. Similar AS-OCT measurements were taken on both eyes every 2 hr from 8 pm to 8 am. The CLS was removed just after the 8 am measurement session. Measurements were repeated at 9 am. Twenty-four eyes of 12 subjects were studied (mean age, 22.1 ± 2.4 years; four men/eight women). CCT significantly increased during the night in both CLS and control eyes (p < 0.01). The maximal change was +4.4 ± 1.7% in the CLS eyes and +2.9 ± 1.8% in the control eyes (p < 0.05). Throughout the night, CCT significantly increased more in eyes with CLS than in control eyes (p < 0.05). There were significantly more corneal curvature irregularities after overnight wear of the CLS than in the control eye: +1.63 Dioptre (D) versus -0.02 D in the 3-mm central zone and +3.17 D versus +0.01 D in the 5-mm central zone (p < 0.01). CCT and corneal curvature irregularities increased slightly but significantly more in eyes with the Triggerfish(®) CLS than in control eyes during overnight wear. Further studies are required to determine whether the corneal curvature changes modify the signal recorded by the sensor.

Mean central corneal thickness and corneal power measurements in pigmented and white rabbits using Visante optical coherence tomography and ATLAS corneal topography

To document central corneal thickness (CCT) and power measurements in pigmented and white rabbits using Visante anterior segment optical coherence tomography (AS-OCT) and the Humphrey ATLAS Corneal Topography System (HACTS). Fourteen female rabbits (seven pigmented and seven white rabbits) were involved in this study. Twenty-eight eyes underwent AS-OCT and HACTS examination. Central corneal thickness, corneal power in the steepest and flattest meridians, astigmatism, pupil diameter (PD), and white-to-white (WTW) were calculated. The CCT was 390 ± 14.2 and 373 ± 7.2 μm for pigmented and white rabbits, respectively. The CCT values showed statistical difference between the two breeds (P = 0.017). The corneal power in the steepest meridian was 44.6 ± 1.9 Diopter (D) in pigmented rabbits and 47.8 ± 1.5 D in white rabbits. The corneal power in the flattest meridian was 44.0 ± 2.1 D in pigmented rabbits and 47.4 ± 1.5 D in white rabbits. The astigmatism, PD, and WTW values were 0.6 ± 0.22 D, 7.9 ± 0.9, and 14.5 ± 0.1 mm in pigmented rabbits, respectively. The corresponding values in white rabbits were 0.4 ± 0.23 D, 7.5 ± 0.5, and 13.5 ± 0.2 mm. There was a statistically significant difference in corneal power in the steepest and flattest meridians and for WTW. No such difference was observed for astigmatism or PD between them. Differences exist in the CCT, corneal power, and WTW between 5-month-old pigmented and white rabbits. Such difference should be considered when designing cornea-related experiments in rabbits.

The Effect of Phenylephrine on the Ciliary Muscle and Accommodation

To objectively measure changes in the human ciliary muscle dimensions in vivo after instillation of topical phenylephrine, a mydriatic and vasodilating agent. A cross-sectional study of 25 healthy young adults was conducted. Measurements of pupil size, accommodation, and ciliary muscle thickness were made both before and 30 min after instillation of 1% proparacaine and 2.5% phenylephrine. Accommodation was measured in three ways: subjectively using a push-up technique and Royal Air Force (RAF) rule, and objectively using both the Grand Seiko autorefractor and PowerRefractor. Images of the temporal ciliary muscle were acquired using the Visante Anterior Segment Optical Coherence Tomographer (OCT). Ciliary muscle images were objectively analyzed using a computer-based segmentation technique. Amplitude of accommodation using the push-up test was reduced by about 1 D with phenylephrine (p < 0.001). Phenylephrine did not change the accommodative response to a 4 D Badal target as measured by either autorefraction or photorefraction (p > 0.30). There was statistically significant thickening of the anterior region and thinning of the posterior region of the ciliary muscle with accommodation (p < 0.001, all locations). Phenylephrine did not affect either baseline ciliary muscle thickness or the accommodative contraction of the muscle (p > 0.09). Low-dose phenylephrine does not affect ciliary muscle dimensions, ciliary muscle contractility, or accommodative response to a 4 D near target.

Comparison of intraoperative ultrasound pachymetry and postoperative optical coherence tomography of anterior segment in the measurement of flap thickness in eyes receiving laser in situ keratomileusis.

To compare the measurement of flap thickness using intraoperative ultrasound pachymetry and postoperative Visante anterior segment optical coherence tomography (Visante-OCT) in eyes receiving laser in situ keratomileusis (LASIK). Seventeen patients (34 eyes) received LASIK using a Technolas-217Z100 laser and AMADEUSⅡ mechanical microkeratome (140μm head). Flap thickness was assessed with an ultrasound pachymeter intraoperatively and a Visante -OCT postoperatively at 1 week and 1 month. The intraoperative mean flap thickness by ultrasound pachymetry was (124±13.9) μm (range: 96.5 to 160 μm), and mean flap thickness by Visante-OCT was (145±7.13) μm (range: 130 to 158 μm) and (143±5.32) μm (range: 132 to 155 μm) postoperatively at 1 week and 1 month respectively (F =63.52, P<0.01). Intraoperative subtraction pachymetry underestimated flap thickness compared with postoperative Visante-OCT (P<0.01). There was no significant difference between postoperative Visante-OCT measurements at 1 week and 1 month after LASIK (P=0.16). The 95% limit of agreement (LoA) of flap thickness between ultrasound Visante-OCT and pachymetry was -5.40 to 42.10 μm. OCT overestimates flap thickness compared with intraoperative ultrasound pachymetry when using the AMADEUSⅡ mechanical microkeratome.

Correlation of Straylight and Visual Acuity in Long-Term Follow-up of Manual Descemet Stripping Endothelial Keratoplasty

Long-term quality of vision after Descemet stripping endothelial keratoplasty (DSEK) was evaluated and correlated with corneal characteristics and subjective complaints. Thirty-four eyes were examined; patients had a single visit 6 to 64 months after DSEK for Fuchs dystrophy. Best-corrected distance acuity (BCDA) and straylight were analyzed. To better evaluate long-term postoperative BCDA changes, longitudinal data were used from earlier visits. Corneal thickness was measured with the Visante anterior segment optical coherence tomography. Interface, stromal, and endothelial haze were semiquantitatively graded using the slit lamp. Vision-related quality of life was evaluated with the 39-item National Eye Institute Visual Function Questionnaire and a straylight questionnaire. Correlation analysis comparing corneal characteristics with visual quality was performed. Mean postoperative time was 1027 ± 453 days. Mean BCDA at this time was 0.33 ± 0.19 logarithm of the minimal angle of resolution. BCDA remained stable with long-term postoperative follow-up. Straylight averaged 1.47 ± 0.19, on average 0.12 log units higher than normal for age-related pseudophakic eyes (P < 0.001). BCDA correlated with corneal haze (r = 0.50), whereas straylight showed a nonsignificant association (P = 0.12). Neither BCDA nor straylight correlated with corneal thickness. Mean Visual Function Questionnaire 39 score was 77/100, and mean score of the straylight questionnaire was 46/100. Quality of vision after DSEK does not return to normal levels of age-matched pseudophakic eyes, with decreased BCDA and increased straylight. Questionnaire scores indicate mild (Visual Function Questionnaire 39) to moderate (straylight) subjective visual impairment. Corneal thickness and haze do not offer an adequate explanation for the decreased visual quality.

A comparison of intrascleral bleb height by anterior segment OCT using three different implants in deep sclerectomy

To compare intrascleral blebs characteristics after deep sclerectomy (DS) with three intrascleral implants using the Visante anterior segment optical coherence tomography. This is a cross-sectional study including 60 eyes of 51 patients that underwent DS with Sk-Gel, Esnoper, and Aquaflow implant. Intraocular pressure (IOP) measurement, slit-lamp examination, and Visante scans were performed the same day in all the patients. Visante scans were done through the intrascleral bleb at 45°, 90°, and 135° and the bleb height was measured. Sk-Gel was used in 19 eyes (31.66%), Esnoper in 22 eyes (36.66%), and Aquaflow in 19 eyes (31.66%). The median time lapsed from the surgery was 15.50 months 25th and 75th percentiles (p(25) 8.25; p(75) 20). The median IOP was 13 mm Hg (p(25) 10; p(75) 15), with no significant differences among implants (P = 0.232). Overall, the correlation between the scleral bleb height and the IOP was statistically significant at 45° (r=-0.359; P = 0.004), 90° (r = -0.410; P = 0.001), and 135° (r = -0.417; P = 0.001). However, Sk-Gel did not show any statistically significant correlation between the scleral height and IOP whereas the other two groups (Esnoper and Aquaflow) showed a significant correlation. There were no differences in the bleb height among implants. There was a moderate inverse correlation between the scleral bleb height and the IOP measurement after DS with Esnoper and Aquaflow implants. There were no differences in bleb height among the three implants.

Anterior segment optical coherence tomography study of the surgical outcome of the filtrating surgery in glaucoma

AbstractPurpose To study the outcome of various filtrating surgery techniques in patients with glaucoma witthe Visante Anterior Segment Optical Coherence Tomograph (AS‐OCT)Methods Fourty seven patients (47 eyes) (age 55 to 87) were enrolled after they had undergone filtrating surgery for glaucoma (Sclerectomy, Trabeculectomy, and combined surgery associating phacoemulsification and Sclerectomy or Trabeculectomy). Antimetabolites were used in all patients (mitomycin C or 5‐Fluoro Uracile). Intraocular pressure was recorded 6 months, 3 months and 1 month before surgery as well as 3 months, 6 months, 1 year and 2 years postoperatively. Each time the patients underwent full ophtalmological examination with subjective slit lamp evaluation of the bleb. Morphological evaluation of the bleb was performed with the Visante AS‐OCT in all patients after a minimum period of one year after surgery. The trabeculectomy / sclerectomy site as well as the morphology of the scleral flap, the conjunctival flap, the iris, and the relationship between these structures were analyzedResults In most cases, a good correlation was observed between the AS‐OCT evaluation of the bleb and the measured IOP. AS‐OCT was helpful in determining the functional properties of filtration blebs in cases in which the target IOP was no reached.Conclusion AS‐ OCT is a valuable tool for an accurate functional evaluation of the outcome of filtrating surgery in patients with glaucoma.

Bilateral Explantation of Visian Implantable Collamer Lenses Secondary to Bilateral Acute Angle Closure Resulting from a Non-Pupillary Block Mechanism

To report a case of bilateral non-pupillary block angle closure glaucoma after Visian Implantable Collamer Lens (ICL, STAAR Surgical) surgery. A 35-year-old woman with high myopia, white-to-white measurements of 11.8 mm in the right eye and 11.9 mm in the left eye, and anterior chamber depths >3 mm in both eyes underwent simultaneous bilateral ICL implantation with 13.2-mm lenses. Persistent, bilateral acute angle closure developed despite multiple patent peripheral iridotomies and iridectomies. Visante anterior segment optical coherence tomography (AS-OCT, Carl Zeiss Meditec) revealed profound vaulting of the ICLs and angle closure. Both ICLs were explanted. After explantation, ultrasound biomicroscopy demonstrated a sulcus-to-sulcus diameter of 10.8 mm in the right eye and 11.2 mm in the left eye. The correlation between white-to-white and sulcus-to-sulcus measurements were poor in this patient, resulting in extreme vaulting of the ICL and angle closure from a non-pupillary block mechanism. Proper identification of the mechanism of angle closure is aided by AS-OCT. For non-pupillary block mechanisms, ICL extraction is necessary.

Thickness Measurements of Donor Posterior Disks After Descemet Stripping Endothelial Keratoplasty With Anterior Segment Optical Coherence Tomography

To evaluate donor posterior disk thickness measured with anterior segment optical coherence tomography after Descemet stripping endothelial keratoplasty. Fifteen patients (17 eyes) after Descemet stripping endothelial keratoplasty, using manually dissected donor posterior disks, were measured with the Visante anterior segment optical coherence tomography (Carl Zeiss Meditec Inc, Dublin, CA). Optical coherence tomography scans were made in a radial pattern, 45 degrees apart, starting in the horizontal axis. Thickness measurements of the donor posterior disks were taken centrally and at fixed radii toward the periphery and were correlated to postoperative change in spherical equivalent (SE), best-corrected visual acuity (BCVA, in Snellen), and improvement in BCVA. Median BCVA was 20/30 (range 20/60-20/20) postoperatively. Median postoperative improvement in BCVA was 4 lines (range 1-11). Median follow-up time was 15.5 months (range 6-32 months). Median postoperative change in SE was -0.25 diopters (range -4.25 to +3.00 diopters). Median central disk thickness was 128.3 microm (range 55-181 microm) and increased significantly toward the periphery: median disk thickness at the 1.5 mm radius was 140.8 microm (range 72-199 microm) and at the 3.0 mm radius was 161.5 microm (range 102-245 microm). No correlation was found between (central) donor disk thickness and postoperative BCVA or change in SE. A nonstatistically significant trend was seen toward more improvement in BCVA with thinner donor disks. Optical coherence tomography measurements of the manually dissected donor posterior disk showed significant variation in thickness, without a statistically significant effect on postoperative BCVA or improvement thereof. Central thickness varied significantly from the peripheral thickness within donor posterior disk.

Corneal Deturgescence after Descemet Stripping Automated Endothelial Keratoplasty Evaluated by Visante Anterior Segment Optical Coherence Tomography

To evaluate postoperative corneal deturgescence after Descemet stripping endothelial keratoplasty (DSAEK) using the Visante anterior segment optical coherence tomography (OCT) system (Carl Zeiss Meditec Inc, Dublin, California, USA). Retrospective case series. We included 21 eyes (9 males and 12 females; mean age +/- standard deviation, 76.3 +/- 12 years). The Visante OCT system was used to determine the central and peripheral endothelial keratoplasty graft thickness and total central and peripheral corneal thickness. Central graft thickness decreased from the first day (243.3 +/- 92 microm) to the last visit (147.8 +/- 44 microm; P = .0001). The rate of central graft thinning slowed during the following intervals: during the first week (47 microm), at 1 week to 1 month (40 microm), and at 1 to 6 months (25 microm), with a mild increase at 6 to 9 months (5 microm). Peripheral graft thickness continued to decrease from postoperative day 1 (318.5 +/- 99 microm) to the last visit (196.7 +/- 50 microm; P = .0001). There was a decrease in total central corneal thickness from day 1 (903.8 +/- 179 microm) to the last visit (671 +/- 93 microm; P = .0001). All patients were imaged with the Visante OCT at the first 4 defined postoperative intervals; however, only 9 eyes were imaged at the last interval of 6 to 9 months. After DSAEK, there is a greater thinning of the central graft compared with the peripheral graft. The central cornea thickness decreases and peripheral corneal thickness increases. Central corneal graft deturgescence stabilizes by 6 months after surgery.