Changes In Anterior Chamber Research Articles

Biochemical Changes in Anterior Chamber of the Eye in Diabetic Patients-A Review.

This article aims to provide a comprehensive review of the biochemical changes observed in the anterior chamber of the eye in diabetic patients. The increased levels of inflammatory markers, alterations in antioxidant defense mechanisms, and elevated levels of advanced glycation end products (AGEs) in the aqueous humor (AH) are explored. Additionally, the impact of these biochemical changes on diabetic retinopathy progression, increased intraocular pressure, and cataract formation is discussed. Furthermore, the diagnostic and therapeutic implications of these findings are presented. This study explores potential biomarkers for detecting diabetic eye disease at an early stage and monitoring its progression. An investigation of the targeting of inflammatory and angiogenic pathways as a potential treatment approach and the role of antioxidant agents in managing these biochemical changes is performed.

Effects of the periocular botulinum toxin on the ocular surface and anterior chamber: a prospective study in patients with hemifacial spasm and blepharospasm

PurposeTo analyze using Pentacam®, the corneal and anterior chamber changes following periocular botulinum toxin injection in patients with facial dystonia.MethodsProspective study that included patients with facial dystonia that were going to receive a periocular botulinum toxin injection for the first time or six months or more after the previous injection. A Pentacam® examination was carried out in all patients before and 4 weeks after the injection.ResultsThirty-one eyes were included. Twenty-two had a diagnosis of blepharospasm and nine of hemifacial spasm. Analysis of corneal and anterior chamber parameters revealed a significant decrease in iridocorneal angle after botulinum toxin injection (from 35 ± 10º to 33.8 ± 9.7º, p = 0.022). No other corneal or anterior chamber parameters changed significantly after the injection.ConclusionsPeriocular botulinum toxin injection causes narrowing of the iridocorneal angle.

Posterior corneal surface and anterior chamber changes after Small incision lenticule extraction and Femtosecond laser‐assisted laser in‐situ keratomileusis

AbstractWe aimed to evaluate the posterior corneal and anterior chamber changes following small incision lenticule extraction (SMILE) and femtosecond laser‐assisted laser in situ keratomileusis (FS‐LASIK). This retrospective study included 93 eyes for SMILE and 228 eyes for FS‐LASIK. Posterior corneal curvature, anterior chamber biometrics, and posterior corneal aberrations preoperatively and at 1 week and 3 months after surgery were evaluated. The correlation between surgical‐related factors and posterior corneal morphology changes, posterior corneal morphology changes, and posterior corneal aberration alterations were determined. There was an increase in mean posterior corneal radius (PCC R) and flat posterior corneal radius (PCC R1) and decrease in anterior chamber depth and anterior chamber volume in the SMILE and FS‐LASIK group (all p < 0.05). A significant difference was observed in posterior corneal higher‐order aberrations before and after the FS‐LASIK (p = 0.006). A negative correlation was found between alterations of PCC R and changes of posterior corneal spherical aberrations in the SMILE (r = −0.289) and FS‐LASIK group (r = −0.383). In conclusion, posterior corneal and anterior chamber biometrics are changed after SMILE and FS‐LASIK. Innovatively, we find that changes in posterior corneal morphology are correlated with posterior corneal aberration alterations.

Swept-source optical coherence tomography detects anterior-chamber changes in patients with angle-closure after laser peripheral iridotomy

Purpose: This study aimed to compare anterior-chamber parameters acquired by a swept-source anterior-segment optical coherence tomography before and after laser peripheral iridotomy. Methods: This study prospectively evaluated 14 patients with primary-angle closure and six patients with primary-angle closure glaucoma. Gonioscopy and anterior-segment optical coherence tomography using the DRI OCT Triton® were performed before and after laser peripheral iridotomy. Anterior-segment optical coherence tomography parameters were studied using scleral spur as reference: angle opening distance at 250, 500, and 750 µm, trabecular-iris space at 500 µm, trabecular-iris angle, trabecular-iris contact length, and iris curvature. Result: Anterior-segment optical coherence tomography identified 61% of the patients with two or more quadrants closed. Gonioscopy identified more closed angles than anterior-segment optical coherence tomography before laser peripheral iridotomy. In angle parameters, only the angle opening distance of 250 µm at the nasal quadrant was not significantly increased after laser peripheral iridotomy. The iris curvature and trabecular-iris contact length showed a significant reduction induced by the laser procedure. Even in eyes in which gonioscopy did not identify angular widening after laser peripheral iridotomy (n=7), the angle opening distance of 750 µm increased (nasal, 0.15 ± 0.10 mm to 0.27 ± 0.16 mm, p=0.01; temporal, 0.14 ± 0.11 mm to 0.25 ± 0.12 mm, p=0.001) and the iris curvature decreased (nasal, 0.25 ± 0.04 mm vs. 0.11 ± 0.07 mm, p=0.02; temporal, 0.25 ± 0.07 mm vs. 0.14 ± 0.08 mm, p=0.007). Conclusion: Anterior-chamber changes induced by laser peripheral iridotomy could be quantitatively evaluated and documented by DRI OCT Triton®.

Changes in Anterior Chamber After Myopic and Hyperopic FS-LASIK.

This study evaluated the changes and explored influential factors in the anterior chamber after femtosecond laser-assisted in situ keratomileusis (FS-LASIK) on the basis of patients with different degrees of myopia, refractive status, and age. Patients underwent uneventful FS-LASIK for the treatment of ametropia. All patients with myopia were classified into a low age group (18-40years) or high age group (> 40years). Patients in the low age group (18-40years) were subdivided into myopia and hyperopia groups. According to the preoperative spherical equivalent values, the myopia group was further divided into low myopia, moderate myopia, and high myopia groups. We measured the magnitude of anterior chamber depth (ACD), angle (ACA), volume (ACV), lens rise, central corneal thickness (CCT), and mean pupil power (MPP) of all patients using Sirius (version 3.2, CSO, Italy) before and 3months post operation. A total of 140 eyes of 87 patients were evaluated. The magnitudes of ACD, ACA, and ACV decreased significantly postoperatively in both low age (P < 0.001, P < 0.001, P < 0.001, respectively) and high age group (P < 0.001, P < 0.001, P < 0.001, respectively) of patients with myopia, while an increasing tendency of ACD (2.85 ± 0.38mm preoperatively vs 2.89 ± 0.09mm postoperatively) and ACA (39.16° ± 7.30° preoperatively vs 39.37° ± 7.68° postoperatively) was found in hyperopia. There was no correlation between different degrees of myopia and the changes in the anterior chamber. Anterior chamber parameters decreased significantly and approximately in the same degree in low and high age groups postoperatively, while an increasing tendency of ACD and ACA was found in hyperopia, indicating that it is probably a corneal magnification effect that influences changes in the anterior chamber.

Effects of Miosis on Anterior Chamber Structure in Glaucoma Implant Surgery.

We investigated changes in anterior chamber (AC) structure after miosis in phakic eyes and pseudophakic eyes with glaucoma. In this prospective study, patients scheduled for glaucoma implant surgery were examined using anterior segment optical coherence tomography before and after miosis. Four AC parameters (AC angle, peripheral anterior chamber (PAC) depth, central anterior chamber (CAC) depth, and AC area) were analyzed before and after miosis, and then compared between phakic and pseudophakic eyes. Twenty-nine phakic eyes and 36 pseudophakic eyes were enrolled. The AC angle widened after miosis in both the phakia and pseudophakia groups (p = 0.019 and p < 0.001, respectively). In the phakia group, CAC depth (p < 0.001) and AC area (p = 0.02) were significantly reduced after miosis, and the reductions in PAC depth, CAC depth, and AC area were significantly greater than in the pseudophakia group (all p < 0.05). Twenty-five patients (86.2%) in the phakia group and 17 (47.2%) in the pseudophakia group had reduced CAC depth (p = 0.004). Although miosis increased the AC angle in both groups, AC depth decreased in most phakic eyes and a substantial number of pseudophakic eyes. Preoperative miosis before glaucoma implant surgery may interfere with implant tube placement distant from the cornea during insertion into the AC.

Evaluation of Anterior Segment Parameters by Pentacam Imaging after Prophylactic Laser Peripheral Iridotomy

Aims: To detect anterior segment changes after prophylactic laser peripheral iridotomy (LPI) using Pentacam. Settings and Design: Ophthalmology Department, Benha University from March 2015 to March 2016. MATERIAL AND METHODS: 25 primary angle closure suspect (PACS) eyes (group I) and 25 primary angle closure (PAC) eyes and unaffected fellow ones of acute angle closure (AAC-F) (group II) were evaluated with Pentacam before and 1 week after neodymium: yttrium: aluminum garnet (Nd: YAG) LPI. We measured the anterior chamber angle (ACA), central anterior chamber depth (CACD), peripheral anterior chamber depth (PACD), anterior chamber volume (ACV), K readings (K1 and K2), central corneal thickness (CCT) and pupil diameter (PD). Statistical analysis: Statistical Package of Social Sciences version 20 was used. P value of less than or equal (0.05) was considered statistically significant. Paired t-test was used to investigate the differences before and after LPI. RESULTS: The two groups of 35 Egyptian patients (18 men and 17 women) were included. Mean age was 59.4 years old. Mean spherical equivalent was 1.84 ± 0.58 diopters. There were no statistically differences between these groups either in age or in refraction (P >0.05). In both groups, statistically significant differences were found before and 1 week after LPI in mean ACA, PACD, ACV (all P 0.05). CONCLUSIONS: Anterior chamber changes after LPI can be demonstrated by Pentacam objectively and quantitatively. LPI is effective treatment in primary angle closure patients.

Pupillary and Anterior Chamber Changes Following Upper Eyelid Blepharoplasty.

This study investigated the preoperative and postoperative pupillary and anterior chamber (AC) characteristics of patients undergoing upper eyelid blepharoplasty. This prospective, cross-sectional study examined 32 eyes from 20 dermatochalasis patients. Following a detailed ophthalmological examination, quantitative pupillometry and Scheimpflug corneal topography were used to evaluate the pupil and AC characteristics of eyes on the day of operation and postoperative days 1 and 7. Static and dynamic pupillometry characteristics, including scotopic, mesopic, low photopic, and high photopic pupil diameter (PD), resting diameter, amplitude, latency, duration, and velocity of pupil contraction, and latency, duration, and velocity of pupil dilation, were measured. Additionally, AC volume, depth, and angle parameters were analyzed. There were significant differences between scotopic, mesopic, and resting PD and the amplitude of pupil contraction. Pairwise comparisons showed that postoperative day 1 scotopic, mesopic, and resting PD and amplitude of pupil contraction measurements were significantly higher than preoperative measurements (p = 0.008, p < 0.001, p = 0.006, and p = 0.033, respectively). Additionally, scotopic and resting PD were significantly lower on postoperative day 7 compared with postoperative day 1 (p = 0.001 and p = 0.041, respectively). However, there were no significant differences in AC parameters. This study revealed that static and dynamic pupil measurements changed following blepharoplasty, with postoperative increased PD occurring particularly under low-light conditions. Therefore, low-light environments should be avoided following blepharoplasty, and patients with angle-closure risk factors should be closely monitored in the early postoperative period.

Color and Temporal Frequency Sensitive Eye Growth in Chick.

PurposeLongitudinal chromatic aberration can provide luminance and chromatic signals for emmetropization. A previous experiment examined the role of temporal sensitivity to luminance flicker in the emmetropization response. In the current experiment, we investigate the role of temporal sensitivity to color flicker.MethodsFive-day-old chicks were exposed to sinusoidal color modulation of blue/yellow (N = 73) or red/green LEDs (N = 84) at 80% contrast for 3 days. The modulation frequencies used were as follows: 0, 0.2, 1, 2, 5, and 10 Hz. There were 5 to 16 chicks per condition. Mean illumination was 680 lux. Changes in ocular components were measured using Lenstar, and refraction was measured with a Hartinger refractometer.ResultsEyes grew less when exposed to high temporal frequencies and more at low temporal frequencies. With blue/yellow modulation, the temporal variation was small; eyes grew 268 ± 15 μm at 0 Hz and 224 ± 12 μm at 10 Hz, representing a 16.4% growth reduction. With red/green modulation, eyes grew 336 ± 31 μm at 0 Hz and 218 ± 20 μm at 10 Hz, representing a 35% growth reduction. Choroidal and anterior chamber changes compensated for eye growth, reducing refractive effects; blue/yellow refraction changes ranged from −0.63 to 1.04 diopters.ConclusionsAt high temporal frequencies, color is not a factor, but at low temporal frequencies, red/green modulation produced maximal growth. The pattern of changes observed in each ocular component with changes in the temporal frequency and/or the color of the stimulus was consistent with the idea that the natural sunlight spectrum may be optimal for emmetropization.

Anterior Segment Dimensions Following Laser Iridotomy in Acute Primary Angle Closure and Fellow Eyes

To compare the change in anterior segment morphology after laser peripheral iridotomy (LPI) in acute primary angle closure (APAC) and their fellow eyes. Prospective, fellow eye-matched case series. In this study 42 individuals with unilateral episode of APAC were enrolled and the anterior segment optical coherence tomography (ASOCT) images were obtained in both eyes at baseline and at 6weeks after LPI. A linear mixed-effects model was used to compare changes in anterior chamber and angle variables with consideration of laterality as the random effect and pupil diameter as the fixed effect. APAC eyes had smaller angle parameters (P= .013 for all), less central anterior chamber depth (cACD) (P < .001), and lower anterior chamber area (ACA) (P < .001), as well as greater lens vault (LV) (P= .007), compared with fellow eyes. LPI resulted in angle widening with a significant increase in opening distance (P < .01 for all) in both APAC and fellow eyes. cACD (P= .003) and ACA (P < .001) increased and LV (P= .002) decreased in APAC eyes. However, there was no significant change in cACD (P= .190) and LV (P= .430) in fellow eyes. In both APAC eyes and fellow eyes, iris curvature decreased after LPI (P < .001). The changes in angle parameters, ACA, and iris curvature were not significantly different between the 2 groups. In APAC eyes and their fellow eyes, LPI resulted in significant anterior chamber angle widening and increased anterior chamber area. In APAC eyes, the iris flattened, cACD deepened, and the lens shifted posteriorly after resolution of the attack. However, in fellow eyes, the increase in ACA was mainly owing to decreased iris curvature.

Changes of anterior chamber morphometry with age in children using hand‐held spectral domain optical coherence tomography

PurposeTo identify the change of anterior chamber measurements with age in children using Hand‐Held Spectral Domain Optical Coherence Tomography (HH‐SDOCT).MethodsA cross‐sectional study involved 93 normal children (mean age = 5.19 ± 4.1 years, range: 2 days to 15 years). HH‐SDOCT (Leica Microsystems Ltd) was used to image anterior chamber angle. B‐scan showing both clear nasal and temporal angles were analysed using ImageJ. The iridocorneal angle landmarks: scleral spur (SS), Schwalbe`s line (SL) and angle recess (AR) were identified and used to calculate trabecular meshwork length (TML), scleral spur angle opening distance (SSAOD), Schwalbe`s line angle opening distance (SLAOD), trabecular iris surface area (TISA), TISA500, SS limbal distance (SSLD) and SL limbal distance (SLLD), nasal SS to temporal SS distance (SS‐SSD), nasal SL to temporal SL distance (SL‐SLD) and pupil diameter (PD). Linear mixed models were used to determine the correlation between ocular parameters and demographic data with log age.ResultsAll measured parameters were significantly influenced by age (all P values &lt;0.05). The changes of parameters per age were measured in 591 angle images. In the first year, TML increased by 159.6 μm (30.5%), SSAOD 120.4 μm (112.4%), SLAOD 347.4 μm (95.7%), TISA 0.19 mm² (133.4%), TISA500 0.13 mm² (96.4%), SSLD 33.7 μm (4.2%), SLLD ‐ 30.3 μm (3.9%), SS‐SSD 2.4 mm (23.3%), SL‐SLD 2.0 mm (21.4%) and PD 2.4 mm (114.3%). No significant changes were detected with gender or between both eyes (P values &gt; 0.05).ConclusionsHH‐SDOCT can be an effective technique in understanding the morphometric changes of anterior chamber in children from birth. Our findings highlight the need for normative age adjusted data to detect abnormalities in angle measures clinically.

Intraocular Pressure Reduction after Phacoemulsification versus Manual Small-Incision Cataract Surgery: A Randomized Controlled Trial

To compare reduction in intraocular pressure (IOP) and change in anterior chamber angle configuration between eyes undergoing phacoemulsification versus those undergoing manual small-incision cataract surgery (MSICS). Prospective, randomized, double-masked, parallel assignment clinical trial. Five hundred eyes of 500 participants 40 to 70 years of age with normal IOP, gonioscopically open angles, and age-related cataract. Eyes underwent phacoemulsification or MSICS after a 1:1 randomization and allocation code. Best-corrected vision, IOP, comprehensive slit-lamp evaluation, and anterior segment (AS) optical coherence tomography (OCT) were performed at baseline and at 1, 3, and 6 months follow-up. Change in IOP (ΔIOP) and AS OCT parameters between baseline and 6 months after surgery. Six months, similar IOP reduction was observed in eyes undergoing phacoemulsification (ΔIOP=2.7±2.9 mmHg) and MSICS (ΔIOP= 2.6±2.6 mmHg; P= 0.70). Widening of the angle opening distance (AOD) 500 μm from the scleral spur (median ΔAOD500= 103 μm; interquartile range= 39-179 μm) was also similar in both groups (P= 0.28). Multivariate linear regression analysis showed that eyes with higher baseline IOP experienced significantly greater reduction in IOP at 6 months (ΔIOP= 0.46-mmHg reduction for every 1-mmHg increment in baseline IOP; 95% confidence interval [CI], 0.4-0.5 mmHg; P < 0.001). After adjusting for covariates, the magnitude of widening of AOD500 was not associated significantly with reduction in IOP (1.33-mmHg reduction for every 1-mm increment in AOD500; P= 0.07). Baseline AOD500 (β=-0.60-mm change/1-mm increment of baseline AOD; 95% CI,-0.67 to-0.53 mm) and anterior chamber depth (β= 0.07-mm change/1-mm increment of baseline anterior chamber depth; 95% CI, 0.04-0.1 mm) were significant predictors of AOD500 widening at 6 months. Both phacoemulsification and MSICS led to significant and similar IOP reductions 6 months after surgery, and both surgeries produced similar changes in anterior chamber and angle parameters. Higher baseline IOP was associated with greater IOP reduction; IOP reduction also can be attributed partly to changes in angle and anterior chamber configuration, although these parameters were unable to predict significantly predict IOP drop at 6 months.

Laser peripheral iridotomy changes anterior chamber architecture.

The pressure gradient between anterior and posterior chamber in acute angle closure (AAC) and primary angle closure suspects is balanced by a sufficient laser peripheral iridotomy (LPI). The anterior chamber changes induced by LPI in patients with unilateral AAC were examined and compared to healthy eyes to define threshold values, which may help to discriminate between healthy and diseased eyes. Using Scheimpflug photography, anterior chamber depth (ACD), anterior chamber volume (ACV), anterior chamber angle (ACA), and central corneal thickness (CCT) were measured before and after LPI in both eyes of unilateral AAC cases. These measurements were compared to a group of healthy control eyes to determine threshold values for ACD, ACV, and ACA. The ACD, ACV, and ACA increased significantly in the 25 AAC eyes after LPI. The ACD, ACV, ACA, and CCT values in the AAC eyes obtained before LPI were compared to a control group of 59 healthy eyes with wide open chamber angles. The cutoff values revealed by receiver operating characteristic analysis were 2.1 mm for ACD, 90.5 mm2 for ACV, and 27.25° for ACA. Our results confirm the significant changes of the anterior segments architecture induced by LPI in AAC eyes. The found threshold values for ACD, ACV, and ACA may help in daily clinical routine to discriminate between healthy eyes and those in need for a prophylactic LPI.

The Course of the Changes in Anterior Chamber Parameters After Laser Peripheral Iridotomy: Follow-up for 6 Months With a Scheimpflug-Placido Disc Topographer.

To evaluate the course of the changes in anterior chamber (AC) parameters using a Scheimpflug-Placido disc topographer before and through 6 months after laser peripheral iridotomy (LPI). A total of 109 eyes of 56 consecutive patients classified as primary angle closure suspect (PACS), primary angle closure (PAC), and primary angle closure glaucoma (PACG) were included in this prospective, interventional, observational case series. Anterior chamber volume (ACV), central anterior chamber depth (CACD), and anterior chamber angle (ACA) were measured by Scheimpflug photography preoperatively and at 1, 3, and 6 months after LPI. With respect to the parameters above, alterations in the measurements were assessed to determine whether the effects induced by LPI on AC morphology persisted with time. At 1 month after LPI, mean ACV, CACD, and ACA increased significantly in all groups (P<0.05). However, in eyes with PACG, significant reductions at 3 months in ACA [0.00 (-1.00 to 0.00) degrees, median (Md) [quartile 1 (Q1) to quartile 3 (Q3)], P=0.032] and at 6 months in ACV [-1.00 (-2.25 to 1.00) μL, P=0.043) and CACD (-0.01 (-0.02 to 0.00) mm, P=0.006) were shown. On analysis of all eyes together, a weak correlation was found between axial length and the change in CACD (r=0.266, P=0.007). Eyes with ACA≤25 degrees widened by 6.6±2.8 degrees versus 4.9±2.4 degrees in eyes with ACA>25 degrees at 1 month after the procedure (P=0.002). Scheimpflug-Placido disc topographer detected significant changes in the AC parameters after LPI in all groups. However, compared with PACS and PAC, the PACG showed significant alterations in the AC parameters through 6 months.

Dynamic dark‐light changes in anterior chamber and iris parameters in angle closure patients with novel automatic algorithm using anterior segment optical coherence tomography (AS‐OCT)

AbstractPurpose To describe the dynamic dark‐light changes in anterior chamber (AC) measurements and iris parameters in angle closure patients compared to normal angle patients using a fully automatic algorithm developed for anterior segment optical coherence tomography (AS‐OCT).Methods 10 patients (17 eyes with closed angles) and 8 patients (15 eyes with normal angles) on gonioscopic grading were recruited. We acquired images in both dark and light conditions using Visante OCT. Custom software analyzed the images using the iris rim as the landmark instead of the sclera spur. The parameters analyzed included angle opening distance and angle recess area, at 750μm from the iris rim (AOD 750 &amp; ARA 750), AC depth and width, lens vault and iris curvature, thickness, length and area. We analyzed the amount of change from dark to light in both groups of patients.Results In both conditions, angle closure patients had significantly smaller AOD and ARA, but there was no difference in iris parameters between the 2 groups. In both groups of patients, there was significant change in iris length, area, thickness and ARA when moving from dark to light conditions. The AOD changed significantly in normal patients but not in angle closure patients. There was no difference in the magnitude of change in the above parameters, when changing from dark to light conditions, in both groups of patients.Conclusion The automated algorithm can identify differences between the AC measurements and iris parameters in both groups of patients. The lighting condition affects the measurements taken regardless of diagnosis. As such, lighting control should be consistent.

Endothelial distance after phakic iris-fixated intraocular lens implantation: a new safety reference

PurposeTo evaluate the distance between the endothelial surface of the cornea to the anterior edge of an Artiflex® phakic intraocular lens (IOL) implant to improve the safety profile of this implant.MethodsThis is a retrospective clinical case series of 45 patients who had Artiflex phakic IOL implantation (Artiflex p-IOL) with a follow-up period of 3 years. A Pentacam HR imaging system was used to measure the distance from various points of the anterior edge of the Artiflex IOL to the endothelial surface of the cornea, which we called endothelial–IOL (E–IOL) distance, in 45 eyes. The E–IOL distances were assessed at 1, 3, 6, 12, 24, and 36 months. Corresponding correlations of central endothelial distance to temporal and nasal edges and center of the IOL anterior surface were tabulated.ResultsMean follow-up was 21.39±11.28 months. A statistically significant reduction of the E–IOL distance was observed over the follow-up period (P<0.05), with the mean annual reduction being 24.70 μm. A strong positive correlation between the E–IOL distance of the edges of the IOL and the central distance was observed (correlation coefficients nasal/central: month 1, 0.905; month 36, 0.806; temporal/central: month 1, 0.906; month 36, 0.806; P<0.001). Moderate negative correlations were found between the spherical equivalent power of the implanted IOL and the E–IOL distance (correlation coefficients −0.271 to −0.412, P>0.05). For an E–IOL distance of the IOL edge >1500 μm, the distance from the endothelium to the central point of the p-IOL optic should be a minimum of 1,700 μm to improve the safety profile for Artiflex p-IOL implantation and reduce the potential complication of accelerated endothelial cell loss.ConclusionAfter Artiflex IOL implantation, the mean annual reduction of the E–IOL distance was 25 μm. A negative correlation existed between the spherical equivalent power of the implanted IOL and the postoperative E–IOL distance. The minimum E–IOL distance from the center of the IOL to minimize the risk of endothelial cell loss was 1.7 mm. This distance, as is the 1.5 mm initially proposed by Baikoff, is a postoperative value. We cannot make that assumption for the preoperative evaluation, as the morphometry of the anterior chamber changes with the implant.

Anterior chamber changes after suspending contact lens wear in keratoconus

Purpose: This study reports on changes in anterior chamber (AC) parameters after suspending RGP (rigid gas- permeable) contact lens wear for one week in 16 patients with moderate to severe keratoconus. Possible alterations in corneal profile parameters were also explored.

Anterior Segment Optical Coherence Tomography of Long-Term Phakic Angle-Supported Intraocular Lenses

To evaluate the long-term age-related anterior chamber changes by anterior segment optical coherence tomography (OCT) and the impact of such changes on the stability and behavior of angle-supported phakic intraocular lenses (IOLs). A retrospective consecutive observational cohort study. A total of 23 eyes with high myopia implanted with an angle-supported phakic IOL between 1990 and 1996 at Vissum Corporación Oftalmológica de Alicante were included in the study. Patients were evaluated using OCT. Anterior chamber depth, anterior chamber width, crystalline lens rise, and the distance between phakic IOL and endothelium were measured. Fifteen years after implantation, anterior chamber depth was 2.9 ± 0.3 mm, crystalline lens rise 748.18 ± 393.13 μm, and phakic IOL-endothelium distance 2.1 ± 0.30 mm. The predictive model showed that 30 years after implantation, endothelial cell count was less than 600 cells/mm(2) in patients with a preoperative spherical equivalent of -25 diopters (D). Twenty years after implantation, the safety zone of 1.5 mm between endothelium and the lens will not be respected in patients with a preoperative spherical equivalent of -20 D. The findings of this study could have an important influence on the decision about the indication to implant angle-supported phakic IOLs in young patients with a long postoperative life expectancy, as age-related changes in the anatomy of the anterior segment may create a long-term hazard for the implanted eye.

Changes in anterior segment after‐iridotomy with nd: yag laser for narrow angle measured with spectral domain OCT

AbstractPurpose To evaluate the anterior chamber variations after‐iridotomy with Nd: Yag laser in eyes with narrow angle.Methods Twenty one patients with shalow anterior chamber were studied. Spectral domain OCT (Heidelberg, Germany) was performed before and seven days after laser peripheral iridotomy treatment in all cases. Spetial attention was taken to evaluate angle changes. Main measures were: anterior chamber volumen, central anterior chamber depth and temporal angle wide.Results Thirty two eyes of twenty one patients , 15 females and 6 males, age average 66.28 years old were measured. The preoperative angle wide at the temporal angle was 25.9 ± 4,8 degrees and postoperative was 27.1 ± 10 degrees. Morphological changes were evident with a deeper chamber and disruption in iris parenchyma.Conclusion Spectral domain OCT is a potential tool to evaluate changes in anterior chamber in narrow angle someted to iridotomy with Nd: Yag laser. The procedure is effective to increase anterior chamber volumen, central anterior chamber depth and angle wide in all cases.

Assessment of angle and anterior chamber changes after keratoplasty

AbstractPurpose To quantify angle and anterior chamber changes after corneal transplantation using Visante OCT®Methods In this retrospective study, Visante OCT® examinations were performed in patients, awaiting keratoplasty, preoperatively(J‐1) and one month postoperatively(M+1). The anterior chamber depth(ACD), the angle‐opening distance at 500µm(AOD), the trabecular‐iris space area at 500µm(TISA) and the scleral spur angle(SPA) in the temporal and nasal quadrants were measured. Patients were classified based on their surgery: the surgery was penetrating keratoplasty(PK group), it was descemet’s stripping automated endothelial keratoplasty(DSAEK group). Preoperative and postoperative measurements were compared using signed rank test of Wilcoxon.Results Twenty patients were evaluated: fifteen(75%) in the DSAEK group, five(25%) in the PK. Mean anterior chamber depth width increased from 3,31mm(SD 0,69) to 3,35mm(SD 0,341) after PK(p=1) , and from 3,32mm(SD 0,666) to 3,44mm(SD 0,591)after DSAEK(p=0,719). In the temporal quadrant, after DSAEK, mean anterior chamber angle width increased from 0,281mm(SD 0,126) to 0,334mm(SD 0,100)(p=0,03) in the TISA and after PK ,mean anterior chamber angle width decreased from 0,273mm(SD 0,054)to 0,248mm(SD 0,118) (p=0,812). In the nasal quadrant, after DSAEK, mean anterior chamber angle width increased from 0,253mm(SD 0,089) to 0,285mm(SD 0,085)(p=0,207) in the TISA and after PK, from 0,269mm(SD 0,114)to 0,321mm (SD 0,069) (p=0,437).Conclusion The angle change significantly in the temporal quadrant after corneal transplantation. Larger study need to be perform to confirm the angle changes.