Decrease In Anterior Chamber Depth Research Articles

Age-related increase in lens thickness and changes in the profile of anterior chamber angle in patients with moderate and high axial hyperopia

PURPOSE. To determine the age-related increase in lens thickness (LT), decrease in anterior chamber depth (ACD) and anterior chamber angle (ACA) in patients with short axial length (APA) of the eyes.METHODS. The study included 100 patients (200 eyes) with short AL (23 mm or less), with a transparent lens or with initial stage of age-related cataract: 46 men and 54 women, aged 19 to 85 years. The LT and ACD, ACA parameters were assessed using optical coherence tomography.RESULTS. In the total population of patients, LT increased by an average of 32 μm per year. At the same time, ACD and ACA decreased by an average of 14 µm and 0.3° per year, respectively (p<0.001). In men, LT increased by 35 μm per year, while in women it increased by 29 μm per year, the difference was not statistically significant (p=0.071). But the decrease in ACA in men averaged 0.38° per year, while in women it was 0.23° per year, this difference was statistically significant (p=0.003). In addition, the rate of decrease in the ACD in men and women also differed statistically significantly: 18 µm versus 11 µm per year (p=0.018).CONCLUSION. 1. According to our data, the annual increase in LT in eyes with short AL averages 32 μm, the decrease in ACD and ACA is on average 14 μm and 0.3° per year, respectively.2. We did not find a statistically significant gender difference in the rate of annual increase in LT, although the rate of decrease in ACA and ACD in men turned out to be statistically significantly higher.3. The obtained data on the annual changes in such morphometric parameters as LT, ACA and ACD in eyes with short AL are key in the formation of primary angle-closure glaucoma (PACG). It may allow a more precise prediction of the timeline of an increased risk of PACG in each particular case.

Effects of Haemodialysis on Anterior Segment Parameters of the Eye in Patients with Endstage Renal Disease: A Cross-sectional Study

Introduction: Ocular manifestations of Haemodialysis (HD) are one of the important causes of morbidity in End-stage Renal Disease (ESRD) patients. According to studies, the incidence rate of glaucoma in the dialysis group was higher than that in the non dialysis group. Angle-closure glaucoma was found to be more common, which depends on anterior chamber morphology. Aim: To assess the effect of HD on Intraocular Pressure (IOP), Anterior Chamber Depth (ACD), and Lens Thickness (LT) in patients with ESRD. Materials and Methods: This was a single-centre crosssectional observational study conducted in the Department of Ophthalmology on 170 eyes of 87 patients undergoing HD for at least three months. The study was conducted between October 2020 and October 2022 at the Dialysis Centre of Bharati Vidyapeeth (DTU) Medical College and Hospital, Pune, Maharashtra, India. These patients underwent ophthalmological evaluation pre- and postdialysis. IOP, ACD, and LT were measured 30 minutes prior to and 30 minutes after the HD session. The paired t-test was used to compare differences in means, and a p-value of <0.05 was considered significant. Results: The mean age of the study participants was 57.63±11.95 years. There was a decrease in mean ACD by 0.08±0.29 mm (p=0.0001) and an increase in mean LT by 0.06±0.42 mm (p-value=0.0001) postdialysis. The changes in IOP were variable and not statistically significant (p=0.45). Conclusion: Postdialysis, a significant increase in LT was observed corresponding to a decrease in ACD. Although the change in IOP was variable, this change might be more significant in pre-existing narrow-angle patients undergoing dialysis. As a result, the present study underscores the urgency of refining screening protocols for HD patients to effectively address these identified ocular changes and associated risks.

Evaluation of Corneal Topography Changes Following Deep Anterior Lamellar Keratoplasty in Patients with Keratoconus

Background. The aim of this study is to evaluate the morphologic changes of the cornea and anterior chamber by using corneal topography (CT) in patients undergoing deep anterior lamellar keratoplasty (DALK) due to keratoconus. Patients and methods. This observational case-control study included total 53 eyes of 53 patients with keratoconus and underwent DALK surgery. All patients were evaluated preoperatively and 3 months after suture removal with CT. In CT, anterior chamber depth (ACD), iridocorneal angle (ICA), anterior chamber volume (ACV), central corneal thickness (CCT), maximum keratometric value (Kmax), flattest simulated meridian keratometry (SimK1), steepest simulated meridian keratometry (SimK2) and simulated keratometry average (SimKavg) results were compared before and after DALK surgery. Results. A significant increase was observed in CCT values after DALK surgery (p < 0.001). Patients showed statistically significant decrease in Kmax, SimK1, SimK2 and SimKavg values (p < 0.001 for all). Postoperative ACD and ACV values were significantly lower (p < 0.001). The ICA values showed no significant difference (p = 0.183) between preoperative and postoperative values (49,95 ± 5,85 and 46,30 ± 11,33 respectively). Conclusion. We determined a dramatic decrease in keratometric values, ACD and ACV values and an increase of corneal thickness after DALK surgery. Although DALK can be performed without interfering with the anterior chamber, has a significant effect in anterior chamber.

Complete resolution of hyperopic shift in anterior capsular contraction syndrome after Nd:YAG laser capsulotomy: a case report

Link of Video Abstract: https://youtu.be/UfCbUNzPIRE Background: Anterior capsular contraction syndrome (ACCS) is a disorder in which the anterior capsulectomy opening shrinks excessively. One of the many factors that have been discovered to aggravate the problem is a lack of zonular support for the lens capsule. The prognosis for non-progression of contractions after Nd:YAG anterior capsulotomy is quite excellent. This study aims to present a complete resolution of the hyperopic shift in an anterior capsular contraction syndrome (ACCS), a rare complication of cataract surgery. Case Illustration: This case report presented a 63-year-old female who developed ACCS in the right eye two years after uncomplicated cataract surgery and intraocular lens implantation. A moderate hyperopic shift of +3.00 D was noted in the affected eye at the initial presentation. Slit-lamp examination revealed an anterior capsule opacification and anterior capsular contraction with fibrosis surrounding the capsulorhexis opening. Ocular and systemic past medical history was unremarkable, and no known risk factors associated with contraction syndrome were found. Nd:YAG laser capsulotomy with six relaxing incisions was performed to release the anterior capsular contraction. Two weeks following capsulotomy, the patient’s visual acuity remarkably improved to LogMAR 0.00 without correction. The hyperopia was completely resolved, and a decrease in anterior chamber depth compared to pre-capsulotomy measurement was noted. ACCS is a possible complication following capsulorrhexis performed in uneventful cataract surgery, which may occur in patients with no known ocular or systemic risk factors. ACCS is commonly asymptomatic, and hyperopic shift is a rare manifestation of ACCS. The backward shift of the intraocular lens (IOL) induces hyperopia due to the anterior capsule contraction. The preferred treatment for ACCS is relaxing incisions using Nd:YAG laser capsulotomy. Conclusion: Hyperopic shift in ACCS is a rare complication of cataract surgery. However, prompt treatment of contraction release with Nd:YAG laser capsulotomy effectively restored visual function.

Beyond the Blur: Clinical Outcomes of Nd: YAG Laser Posterior Capsulotomy Intraocular Pressure, Refraction, Anterior Chamber Depth, and Macular Thickness

Background: Nd: YAG laser posterior capsulotomy is a commonly performed procedure to treat posterior capsular opacification following cataract surgery. While the procedure is known to effectively improve visual acuity, its potential impact on Intraocular Pressure (IOP), refraction, Anterior Chamber Depth (ACD), and macular thickness remains a subject of debate. This study aims to investigate the effects of Nd: YAG laser posterior capsulotomy on these ocular parameters. Methods: This study was designed as a prospective analysis conducted at a tertiary eye care center on patients who underwent Nd: YAG laser posterior capsulotomy between January 2020 and December 2020. Preoperative and postoperative measurements of IOP, refraction, ACD, and macular thickness were collected and compared. Statistical analyses were performed using paired t-tests, and p-values<0.05 were considered statistically significant. Results: A total of 30 eyes from 25 patients (mean age, 65.4±8.2 years) were included in the analysis. Following Nd: YAG laser posterior capsulotomy, the mean IOP from 15.2±2.3 mmHg to 17.0±2.7 mmHg (p<0.001). The refractive status showed a mean myopic shift of -0.35±0.16 diopters (p<0.001,). Additionally, there was a statistically significant reduction in ACD from 3.15±0.42 mm to 2.90±0.37 mm (p=0.003,). However, there was no statistically significant change in macular thickness after the procedure (p=0.287). Conclusion: Nd: YAG laser posterior capsulotomy leads to a mild but statistically significant increase in IOP and a small myopic shift in refraction. Additionally, the procedure results in a decrease in ACD but does not significantly affect macular thickness. Ophthalmologists should consider these effects when performing Nd: YAG laser posterior capsulotomy and carefully monitor patients postoperatively.

The effect of baseline intraocular pressure and anterior segment parameters on intraocular pressure after intravitreal bevacizumab injection

Purpose We aimed to compare the predictive effect of pre-injection intraocular pressure (IOP) and anterior segment parameters on post-injection IOP values after intravitreal bevacizumab injection for neovascular age-related macular degeneration (NVAMD) in phakic and pseudophakic patient groups. Material and methods This retrospective cross-sectional study included 65 eyes of 65 treatment-naive NVAMD patients. Patients were divided into two groups according to their lens status (35 phakic and 30 pseudophakic patients). Pre-injection IOP, anterior segment parameters measured with PENTACAM, and post-injection IOP values measured at the 5th minute were recorded. Univariate and multivariate regression analyses were used to recognise the predictive effect of pre-injection IOP and anterior segment parameters on post-injection IOP for each group. Results Multivariate regression analyses showed that the decrease in anterior chamber depth (ACD), and the increase in pre-injection IOP were significantly correlated with higher post-injection IOP in the phakic patient group (p = 0.019 and 0.031; respectively). No correlation was found in the pseudophakic patient group. Conclusion Pre-injection ACD and IOP values may be predictive of higher post-injection IOP in phakic patients. Preoperative assessment of these parameters could be beneficial in patients at risk of glaucoma.

Clinical Outcomes of Nd: YAG Laser Posterior Capsulotomy: Impact on Intraocular Pressure, Refraction, Anterior Chamber Depth, and Macular Thickness

Background: Nd: YAG laser posterior capsulotomy is a commonly performed procedure to treat posterior capsular opacification following cataract surgery. While the procedure is known to effectively improve visual acuity, its potential impact on intraocular pressure (IOP), refraction, anterior chamber depth (ACD), and macular thickness remains a subject of debate. This study aims to investigate the effects of Nd: YAG laser posterior capsulotomy on these ocular parameters. Methods: This study was designed as a prospective analysis conducted at a tertiary eye care center on patients who underwent Nd: YAG laser posterior capsulotomy at a tertiary eye care center between January 2020 and December 2020. Preoperative and postoperative measurements of IOP, refraction, ACD, and macular thickness were collected and compared. Statistical analyses were performed using paired t-tests, and p-values <0.05 were considered statistically significant. Results: A total of 30 eyes from 25 patients (mean age, 65.4 ± 8.2 years) were included in the analysis. Following Nd: YAG laser posterior capsulotomy, the mean intraocular pressure (IOP) increased from 15.2 ± 2.3 mmHg to 17.0 ± 2.7 mmHg (p < 0.001). The refractive status showed a mean myopic shift of -0.35 ± 0.16 diopters (p < 0.001,). Additionally, there was a statistically significant reduction in anterior chamber depth (ACD) from 3.15 ± 0.42 mm to 2.90 ± 0.37 mm (p = 0.003,). However, there was no significant change in macular thickness after the procedure (p = 0.287). Conclusion: Nd: YAG laser posterior capsulotomy leads to a mild but statistically significant increase in IOP and a small myopic shift in refraction. Additionally, the procedure results in a decrease in ACD but does not significantly affect macular thickness. Ophthalmologists should consider these effects when performing Nd: YAG laser posterior capsulotomy and carefully monitor patients postoperatively.

Evaluation of the Effect of Scleral Buckling on Anterior Segment and Refractive Changes Using Anterior Segment Optical Coherence Tomography

ABSTRACT Purpose To evaluate the changes of anterior segment and refractive parameters after scleral buckling (SB) surgery for uncomplicated rhegmatogenous retinal detachment (RRD) using anterior segment optical coherence tomography (AS-OCT). Methods Thirty-six RRD eyes were consecutively enrolled. Analysis concerned the central corneal thickness (CCT), anterior chamber depth (ACD), anterior chamber volume (ACV), iris-trabecular contact (ITC), angel opening distance (AOD), angle recess area (ARA), trabecular-iris space area (TISA)，trabecular iris angle (TIA) and refractive parameters, including average keratometry (AvgK), cylindrical power (CYL), regular astigmatism, asymmetry and high order irregularity (HOI) at baseline and 1 day, 1 month, 2 months, 6 months and 12 months postoperatively. AS-OCT was performed at RRD diagnosis and day 1, week 1, month 1 and month 6 after SB to evaluate the scleral buckling. Results A statistically significant postoperative CCT increase, ACD and ACV decrease were observed at 1 day and 1 month postoperatively. ITC analysis showed that the angle of the entire circumference narrowed at 1 month postoperatively. There was a significant decrease in all the angle parameters (AOD500/750, ARA500/750, TISA500/750, and ARA500/750) at 1 day and 1 month after SB surgery. However, all of the above parameters returned to the preoperative level at 12 months. Refractive parameters including AvgK, regular astigmatism, CYL, asymmetry, and HOI of anterior corneal surface and total corneal increased on the 1 day and 1 month after SB surgery and persisted even after 12 months follow-up. However, there was no significant difference in refractive parameters of posterior corneal surface during follow-up. Conclusion The changes in the structure of anterior segments after SB surgery were almost returned to the preoperative levels at 12 months postoperatively. However, SB surgery has a long-term effect on refractive parameters throughout a 12-month follow-up.

The role of anterior segment optical coherence tomography in the detection of predictors of ophthalmic hypertension associated with anti-VEGF injections

PURPOSE. To identify the predictors of increased intraocular pressure (IOP) after intravitreal injection (IVI) of an antiVEGF drug using anterior segment optical coherence tomography (AS-OCT), and to study changes in the iris-lens diaphragm produced by multiple injections in the treatment of neovascular form of age-related macular degeneration (nAMD).METHODS. IOP was measured with an ICare Pro tonometer before IVI, 1 minute after IVI, 30 minutes, 60 minutes and 180 minutes later. Anterior chamber depth (ACD), anterior chamber angle (ACA), and lens thickness were assessed using Revo NX tomograph (Optopol, Poland). The study was carried out before IVI, one month after the first IVI, one month after the third IVI, one year after the start of treatment. Axial length was measured once before IVI.RESULTS. An inverse correlation was found between axial length and an increase in IOP 1 min after IVI (r=0.65, p<0.001). According to AS-OCT data, one year after the start of treatment there was a significant decrease in ACD compared to the data before treatment (p><0.001), as well as a decrease in all parameters of ACA (p><0.05). Shorter axial length (R2 =0.45, p><0.05), shorter ACD (R2 =0.44, p><0.05), smaller ACA on the nasal (R2 =0.37, p><0.05) and temporal (R2 =0.39, p><0.05) sides in patients with their own lens led to a greater rise in IOP 1 min after IVI.CONCLUSION. Predictors of a sharp increase in IOP after IVI of an anti-VEGF drug in patients with nAMD that can be detected with AS-OCT are shorter ACD and smaller ACA. The following prognostic model was determined — with a 1-mm decrease in the axial length, an increase in IOP by 2.3 mm Hg should be expected, a decrease in ACA from the temporal side by 1° leads to an increase in IOP of 0.28 mm Hg>

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.

Unexpected ocular morphological changes after corneal refractive surgery: A review.

Corneal refractive surgery (CRS) currently is widely used to correct refractive errors because of its efficacy and reliability. Several studies dealt with the corneal modification induced by this type of surgery, but it is still debated if CRS can induce unexpected changes namely anterior chamber depth (ACD) and axial length (AL). A literature review was performed, including all articles regarding CRS and eye-variations from 1999 to December 2021. Excluding articles about specific systemic conditions (e.g., pregnancy), pathological conditions, post-surgical complications or about only corneal flattening and thinning post CRS, we found nine studies that met the search criteria. We divided the found articles according to the type of surgery performed (radial keratotomy, PRK/LASEK, lasik) and analyzed the results about ACD and AL. Finally, according to the literature, we can conclude that CRS not only gives a corneal flattening, thinning and biomechanical changes, but also induces AL and ACD decrease. This makes the AL and ACD measurements obtained before CRS uselessness in case of IOL power calculation.

Long-term results in patients with iris-fixated foldable phakic intraocular lenses for myopia and astigmatism.

To evaluate the long-term results of iris-fixated foldable phakic intraocular lens (pIOL) implantation for the management of myopia and astigmatism. Centro Hospitalar Universitário do Porto, Oporto, Portugal. Prospective clinical study. Patients who underwent Artiflex Myopia or Artiflex Toric iris-fixed pIOL implantation for the treatment of myopia or astigmatism between 2003 and 2011 were included. Refractive stability, refractive predictability, safety, efficacy, and cumulative probability of success were evaluated at 5 years, 10 years, and 15 years of follow-up. 5-year, 10-year, and 15-year follow-ups were completed by 199 of 217 (91.7%), 187 of 217 (86.2%), and 43 of 45 (95.6%) eyes implanted with pIOLs, respectively. The mean spherical equivalent was -8.36 ± 2.75 diopters (D), -0.11 ± 0.31 D, -0.33 ± 0.62 D, and -0.80 ± 1.32 D preoperatively and after 5 years, 10 years, and 15 years after surgery. At 5 years, 10 years, and 15 years after surgery, 100%, 95.6%, and 81.6% were within ±1.00 D. The safety and efficacy indexes were 1.07 and 1.06 at 5 years, 1.04 and 0.99 at 10 years, and 1.05 and 1.00 at 15 years of follow-up, respectively. Kaplan-Meier analysis showed survival rates of 97% at 5 years, 73% at 10 years, and 43% at 15 years of follow-up. Long-term results demonstrated that the implantation of Artiflex pIOLs was a stable, predictable, and effective procedure at 5 years, 10 years, and 15 years of follow-up. Annual follow-up visits to evaluate endothelial cell density and anterior chamber depth decrease, to alert patients to this need in the preoperative evaluation, is recommended.

Features of the postoperative period after glaucoma surgery in a patient with Sturge-Weber syndrome (clinical case)

PURPOSE. To evaluate the effectiveness of surgical treatment of secondary glaucoma and to present the clinical features of the postoperative period in a patient with Sturge-Weber syndrome (SWS). METHODS. A patient with SWS, choroidal hemangioma and secondary glaucoma was examined and treated (Ahmed valve implantation) at the S.N. Fedorov National Medical Research Center "MNTK "Eye Microsurgery" in Moscow. RESULTS. Hypotension, a decrease in anterior chamber depth, serous choroidal detachment were observed on the first day after surgery on the left eye. Posterior scleral trepanation and injection of viscoelastic into the anterior chamber was performed. On the next day, IOP normalization and complete choroidal attachment were achieved, but macular detachment of neuroepithelium occurred and was successfully treated with injections of glucocorticosteroids. After one month, the retina and choroid were attached, IOP was 16 mm Hg in the left eye without hypotensive drops, visual acuity was 1.0 in both eyes. CONCLUSION. Implantation of the Ahmed valve can be used in the treatment of secondary glaucoma in patients with SWS in order to reduce the IOP and minimize the risks of complications.

Short-term effects of two types of goggles on intraocular pressure and anterior eye segment biometrics

BackgroundTo evaluate and compare the changes in intraocular pressure and anterior eye segment biometrics during and after wearing two types of commonly used swimming goggles.MethodsIn a cross-sectional study, a total of 40 healthy adults aged between 18 and 60 years old were selected to wear two kinds of common swimming goggles (ocular socket and orbital goggles). Intraocular pressure and anterior segment biometry were evaluated before wearing, at 2 and 5 min of wearing, and at 5 min after removing the goggles. Intraocular pressure (IOP), corneal front keratometry values (K1, K2, Km), central corneal thickness (CCT), central anterior chamber depth (ACD), anterior chamber volume (ACV), and anterior chamber angle (ACA) were measured.ResultsThe IOP at 2 min (21.0 ± 2.2 mmHg) and 5 min (21.2 ± 2.3 mmHg) was significantly higher than before wearing goggles (17.7 ± 2.1 mmHg). The IOP after the goggles were removed and at 5 min after the goggles were removed was 18.4 ± 2.3 mmHg and 17.7 ± 2.1 mmHg, respectively. ACV, ACD, and ACA values all decreased while the googles were worn. After the goggles were removed, these changes gradually returned to baseline values, with no significant difference in the values before and after.ConclusionThis study proves that wearing orbital goggles can lead to an acute increase in IOP and a slight decrease in ACV, ACD, and ACA. However, once the goggles are removed, these indicators return to baseline levels, showing that wearing orbital goggles has no significant lasting effect on IOP and anterior segment parameters.

Anatomical and morphometric features of anterior eye segment structures in hyperopia and the risk of developing primary angle-closure glaucoma

To study features of anatomical and morphometric parameters of the structures of anterior eye segment in young patients with moderate and high hyperopia in order to identify the signs of an increased risk of developing primary angle-closure glaucoma (PACG) and its acute attack. The study included 160 eyes (80 patients) with axial length (AL) of less than 23 mm. Patients with moderate or high hyperopia were divided into two groups according to their age ranges (the 1st - 27 patients (54 eyes) under 40 years old; the 2nd - 27 patients (54 eyes) of 41-50 years old, the comparison group - 26 patients (52 eyes) of 42-50 years old with the initial stage of PACG. AL of the eyes, anterior chamber (AC) depth in the central zone, lens thickness (LT) in the optical zone were measured using IOL Master 700 («Carl Zeiss Meditec AG», Germany). AC volume and peripheral AC depth were measured using rotating Scheimpflug camera Pentacam («Oculus», Germany). While the average values of AL in patients of the 1st and 2nd groups were comparable, a statistically significant decrease in AC depth and a significant increase in LT were revealed in the 2nd group. There was a statistically significant increase in LT, a decrease in peripheral AC depth and AC volume in the comparison group relative to the 2nd group. In the 1st group: in 2 eyes of one 38-year-old patient the maximum proximity of all 3 indices to the median values of the group of patients with PACG was found; in 4 eyes of two other patients (35 and 38 years old), a combination of small AC volume with increased LT or small AC volume with small AC on the periphery was noted. Significant differences in terms of LT, peripheral AC depth and AC volume were found between age-comparable (41-50 years old) healthy individuals with short eyes and patients with initial PACG. In 11% of the eyes of healthy patients with hyperopia aged 21 to 40 years, there was a combination of two or three of the studied morphometric signs, which may indicate the risk of developing PACG.

A comparison of lens parameters in patients with various subtypes of primary angle-closure disease and the normal population: A prospective study.

To assess the role of lens parameters in the detection and progression of primary angle-closure disease (PACD) by combining A-scan and A-scan optical coherence tomography (AS-OCT) parameters. A cross-sectional study was conducted in a tertiary health-care center in eastern India. A total of 91 study subjects including cases and controls were included in the study. The parameters studied were lens thickness (LT), lens axial factor (LAF), relative lens position (RLP), and lens vault (LV). Anterior chamber depth (ACD) and axial length (AL) were also analyzed using A-scan. The LT was significantly more in all subtypes of PACD (from 4.24 ± 0.84 to 5.02 ± 0.18 mm) than in controls (4.04 ± 0.46 mm; P < 0.01). Similarly, LAF was significantly less among all subtypes of PACD compared to controls (P < 0.001). The RLP, calculated using the formula (ACD + 0.5 LT)/AL × 10, showed no significant difference (P > 0.05) between various study groups. The LV in acute angle-closure glaucoma (AcCG) patients was significantly higher compared to the control population (P < 0.01). Ocular parameters like ACD decreased, whereas LT and LAF increased from normal through primary angle closure (PAC) to primary angle-closure glaucoma (PACG). Logistic regression analysis found a significant association between a decrease in ACD and an increased risk of PACG (P-value was 0.0001) and an increase in LT and LAF with increased risk of PACG (P = 0.040 and P = 0.006, respectively). Inclusion of lens parameter assessment in the workup of a patient with PACD helps in detection and close monitoring of the progression from suspected to disease state.

Biometric changes after vitrectomy with silicone oil tamponade

Background: The Lenstar LS 900 (Haag-Streit AG, Koeniz, Switzerland) is an optical biometer, and its measurements are highly repeatable and precise in cataractous eyes. This study investigated changes in biometric parameters, including axial length (AL), anterior chamber depth (ACD), lens thickness (LT), vitreous cavity depth (VD), and central corneal thickness (CCT) before and after three-port 23-Gauge pars plana vitrectomy with silicone oil tamponade.&#x0D; Methods: This was a prospective follow-up study. Patients who were scheduled for surgery underwent a detailed slit-lamp examination and objective cycloplegic refraction preoperatively. In eligible cases, the Lenstar LS 900 was used to measure biometric parameters. At the 1-month postoperative follow-up, we repeated the same assessments for the silicone oil (SO)-filled eyes. Data were analyzed to assess the significance of changes and to test the possible correlation of values between the two time points.&#x0D; Results: Twenty-three patients with a mean ± SD age of 60 ± 12 years completed the study. Postoperatively, we found a significant increase in AL and a decrease in ACD and CCT (all P &lt; 0.05), with no significant changes in LT and VD. A significant correlation was found for ACD, CCT, and cylinder values between the two time points (all P &lt; 0.05). Postoperatively, the spherical and cylindrical components of refraction demonstrated a hyperopic shift, but did not change statistically significantly.&#x0D; Conclusions: The Lenstar LS 900 underestimated the ACD and overestimated the AL in SO-filled eyes when comparing pre- and postoperative values, in phakic as well as pseudophakic eyes. In planning for cataract surgery in this group of patients, it is more reasonable to calculate IOL power based on the biometric data of the fellow eye, although this may not eliminate possible errors. Further studies with a larger sample size, longer follow-up, and robust study design are necessary to confirm our preliminary results.

Ocular biometry characteristics in cataract surgery candidates: a cross-sectional study.

This study was conducted to investigate ocular biometry parameters in cataract surgery candidates in northern Tehran, Iran using OA-2000 biometry device. In this cross-sectional study, values of ocular biometry parameters, including axial length (AL), anterior chamber depth (ACD), mean corneal curvature (mean K), lens thickness (LT), corneal astigmatism (CA), and white-to-white (WTW) of 818 eyes with cataracts, were measured using the OA-2000 biometry device (Tomey, Nagoya, Japan). The participants were divided into si age subgroups, in 10-year intervals. Finally, the values of the biometry parameters were calculated, and the trend of changes was examined for both age and sex subgroups. The mean (standard deviation [SD]) of age of the participants was 63.82 (13.25) years. Mean (SD) of biometry parameters were as follows: AL, 23.36 (1.55) mm; ACD, 3.09 (0.40) mm; LT, 4.45 (0.55) mm; mean K, 44.51 (1.72) D; CA, 1.06 (0.94) D; and WTW, 11.81 (0.45) mm. Most of the parameters showed significant age-related changes in the total population. There was an increase in LT (P < 0.001) and mean K (P = 0.001), as well as a decrease in AL (P < 0.001) and ACD (P < 0.001) with age. Moreover, AL had a negative negligible correlation with LT (r = - 0.24; P < 0.001) and mean K (r = - 026; P < 0.001), as well as a weak positive correlation with ACD (r = + 0.44; P < 0.001). Our study revealed that the mean values of most biometric parameters varied across age and sex subgroups. Moreover, most of the parameters showed significant age-related changes in the total population.

Anterior chamber depth measurement before and after photorefractive keratectomy. Comparison between IOLMaster and Pentacam.

an accurate measurement of anterior chamber depth (ACD) both in eyes that underwent corneal refractive surgery (CRS) and in eyes that did not, can be crucial, as in case of intraocular lens (IOL) calculation in eyes that need to undergo cataract extraction, or during the evaluation of glaucomatous patients. The aim of this nonrandomized retrospective case series was to measure anterior chamber depth (ACD) before and after photorefractive keratectomy (PRK), comparing a rotating Scheimplfug camera (RSC) and a partial coherence interferometer (PCI). 125 right eyes of 125 patients were examined. ACD was measured with RSC and a PCI preoperatively and 1, 3 and 6 months postoperatively. The results were analyzed using Friedman and ANOVA test for repeated measures, Wilcoxon test, Pearson and Bland-Altmann correlation. Both instruments showed an ACD decrease after CRS. The mean preoperative difference in ACD between the two instruments was 0.11 ± 0.11 (range: -0.07 mm to 0.73 mm) (p < 0.05) (r = 0.92). The mean difference in ACD reduction between the two instruments was: 0.08 ± 0.11 (range: -0.35 to 0.39 mm) (p < 0.05, r = 0.93) at 1 month; 0.13 ± 0.11 (range: -0.09 mm to 0.48 mm) (p < 0.05, r = 0.93) at 3 months; 0.14 ± 0.15 (range: -0.16 to 0.82 mm) (p < 0.05) (r = 0.87), at 6 months. The ACD decrease shown with both instruments suggests the presence of anterior segment remodeling after PRK. RSC measurements were larger than PCI ones, both before and after PRK.

Evaluation of the effect of fasting on intraocular pressure, anterior segment parameters and density of crystalline lens and cornea.

To evaluate the effect of fasting on anterior chamber depth, anterior chamber volume and corneal and lens density by Scheimpflug technology and to measure intraocular pressure changes. Totals of 50 healthy fasting individuals in Ramadan (study group) and 50 healthy non-fasting subjects (control group) were included. Central corneal thickness (CCT), anterior chamber depth (ACD), anterior chamber volume (ACV), corneal density (CD) and lens density (LD) were evaluated with Scheimpflug technology. Intraocular pressure (IOP) was measured with applanation tonometry. Both eyes of each participant were examined and also compared. Comparison of groups: There was a statistically significant difference between CD, ACD, ACV and IOP (respectively, right/left eye: fasting: CD: 12.81 ± 0.76/12.73 ± 0.73; ACD: 2.92 ± 0.37mm/2.93 ± 0.37mm; ACV: 168.3 ± 41.82mm3/183.34 ± 32.46mm3; IOP: 13.80 ± 1.22mmHg/14.88 ± 2.73mmHg; non-fasting: CD: 13.28 ± 1.01/13.17 ± 0.77; ACD: 3.06 ± 0.31mm/3.07 ± 0.31mm; ACV: 167.46 ± 42.92mm3/180.68 ± 31.45mm3; IOP: 13.60 ± 1.65mmHg/14.74 ± 2.93mmHg) values on the right side (p < 0.01, p = 0.03, p = 0.04, p = 0.01, respectively). Although there was a statistically significant difference between the ACV, CD and IOP values on the left side (p < 0.01, p = 0.03, p = 0.01, respectively), no statistical significance was found for the ACV value on the left side (p = 0.08). The results demonstrated that, while fasting did not lead to any change in LD and CCT, it caused a small decrease in ACD and ACV, and a significant decrease in CD and IOP values. Scheimpflug technology seems to be a valuable tool for the evaluation of anterior segment changes in patients who are fasting.