Crystalline lens accommodation and anterior chamber depth

1989 ◽  
Vol 9 (1) ◽  
pp. 36-40 ◽  
Author(s):  
Henri Obstfeld
Keyword(s):  
Anterior Chamber ◽  
Anterior Chamber Depth ◽  
Crystalline Lens

Effect of a Suction Device for Femtosecond Laser on Anterior Chamber Depth and Crystalline Lens Position Measured by OCT

2009 ◽  
Vol 25 (11) ◽  
pp. 1005-1011 ◽  
Author(s):  
Kathleen S. Kunert ◽  
Marcus Blum ◽  
Matthias Reich ◽  
Manfred Dick ◽  
Christoph Russmann
Keyword(s):  
Femtosecond Laser ◽  
Anterior Chamber ◽  
Anterior Chamber Depth ◽  
Crystalline Lens ◽  
Suction Device ◽  
Lens Position

scholarly journals Repeatability and reproducibility of axial length, anterior chamber depth and crystalline lens thickness measurements using the Nidek US-500 Echoscan

2015 ◽  
Vol 74 (1) ◽  
Author(s):  
Khathutshelo P. Mashige
Keyword(s):  
Anterior Chamber ◽  
Axial Length ◽  
Repeated Measures ◽  
Anterior Chamber Depth ◽  
Correlation Coefficients ◽  
Crystalline Lens ◽  
Angle Closure ◽  
Lens Thickness ◽  
Primary Angle Closure Glaucoma ◽  
The Right

Aim: The reliability of an instrument used to collect data for clinical and research purposes is greatly important, especially when it is used to determine changes in measured ocular parameters over time. The purpose of this study was to determine the intra-session repeatability and inter-session reproducibility of axial length (AL), anterior chamber depth (ACD) and crystalline lens thickness (LT) measurements using the Nidek US-500 Echoscan.Method: Fifty successive automatic measurements of the above parameters were taken on the right eyes only of 12 healthy subjects aged 23–44 years old, followed by similar repeated measures after 1 week. Sample standard deviations (s.d.), precision (P) and coefficient of repeatability (COR) were calculated to determine intra-session repeatability. Coefficient of reproducibility (CRP), Bland and Altman plots, concordance correlation coefficients (CCC) and paired t-tests that compared measurements obtained in the first and second sessions, were used to determine inter-session reproducibility.Results: Both the intra-session repeatability and inter-session reproducibility were within acceptable limits for the three variables assessed.Conclusion: The study showed that the Nidek US-500 Echoscan provides accurate, repeatable and reproducible measurements of AL, ACD and LT in healthy eyes. This finding will be of interest to optometrists and ophthalmologists who measure these parameters when diagnosing, managing and investigating conditions such as primary angle-closure glaucoma and keratoconus.

scholarly journals Correlation between intraoperative and postoperative vaulting of the EVO implantable Collamer lens: a retrospective study of real-time observations of vaulting using the RESCAN 700 system

2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Nian Guan ◽  
Xiao-Nong Zhang ◽  
Wan-Jun Zhang
Keyword(s):  
Retrospective Study ◽  
Anterior Chamber ◽  
Multivariable Analysis ◽  
Anterior Chamber Depth ◽  
Crystalline Lens ◽  
Implantable Collamer Lens ◽  
Chamber Volume ◽  
Anterior Chamber Volume ◽  
Intraoperative Optical Coherence Tomography ◽  
Corneal Endothelial Cell Density

Abstract Background Implantable Collamer lens (ICL) vaulting is one of the most important parameters for the safety, aqueous humor circulation, and lens transparency after ICL implantation. This study aimed to investigate the factors associated with the actual vaulting after refractive EVO-ICL surgery. Methods This retrospective study included patients who underwent EVO-ICL surgery at a tertiary eye hospital between October and December 2019. A RESCAN 700 was used for the intraoperative and CIRRUS HD-OCT was used for postoperative observation of vaulting. Subjective and objective refractions, anterior ocular segment, corneal morphology, intraocular pressure (IOP), anterior chamber volume (ACV), crystalline lens rise (CLR), white-to-white distance (WTW), anterior chamber depth (ACD), axial length, corneal endothelial cell density (ECD), and fundoscopy were examined. A multivariable analysis was performed to determine the factors independently associated with 1-month postoperative vaulting. Results Fifty-one patients (102 eyes) were included. Compared with the eyes with normal vaulting, those with high vaulting had higher preoperative diopter values (P = 0.039), lower preoperative corrected visual acuity (P = 0.006), lower preoperative IOP (P = 0.029), higher preoperative ACD (P = 0.004), lower preoperative CLR (P = 0.046), higher ICL spherical equivalent (P = 0.030), higher intraoperative vaulting (P < 0.001), and lower IOP at 1 month (P = 0.045). The multivariable analysis showed that the only factor independently associated with high vaulting at 1 month after surgery was the intraoperative vaulting value (odds ratio = 1.005, 95% confidence interval: 1.002–1.007, P < 0.001). The intraoperative and 1-month postoperative vaulting values were positively correlated (R2 = 0.562). Conclusions The RESCAN700 system can be used to perform intraoperative optical coherence tomography to predict the vaulting value of ICL at 1 month.

scholarly journals Vault changes and pupillary responses to light in myopic and toric implantable collamer lens

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ying Xiong ◽  
Yingyan Mao ◽  
Jing Li ◽  
Xiuhua Wan ◽  
Meng Li ◽  
...  
Keyword(s):  
Anterior Chamber ◽  
Pupil Size ◽  
Anterior Chamber Depth ◽  
Crystalline Lens ◽  
Main Concern ◽  
Optical Parameters ◽  
Implantable Collamer Lens ◽  
Lighting Conditions ◽  
Pupillary Responses ◽  
Significant Difference

Abstract Background Achieving an appropriate vault is the main concern after the implantation of Implantable Collamer Lens (ICLs) for surgical correction of high myopia. The vault will vary with time and optical parameters, such as accommodation and pupil size. This research is to evaluate the vault change in Myopic and Toric ICLs under different lighting conditions; and to analyze the relationship between vault changes and pupillary responses to light. Methods We enrolled and analyzed 68 eyes from 68 patients who were implanted with Myopic EVO ICLs; we also included 60 eyes from 60 patients who were implanted with Toric EVO ICLs. The anterior chamber depth, pupil size and the post-operative vault were evaluated, 1 week after the operation, using a Visante Optical Coherence Tomography (OCT) under different lighting conditions. For each eye that was assessed, we calculated the vault change, which is defined as the difference between vault under mesopic condition and photopic condition; and the rate of vault change, which is defined as the vault change divided by mesopic vault. Results No significant difference was noted with the anterior chamber depth between mesopic and photopic conditions in either group. A significant decrease in vault and pupil size was detected under photopic condition in both groups. We found no difference in vault change between Myopic and Toric EVO ICLs under different lighting conditions. Moreover, the rate of vault change had a significant decrease with increased mesopic vault (baseline value). Conclusions Too low a mesopic vault has a big rate of vault change, which may cause the contact of ICL with crystalline lens in photopic state; Too high a mesopic vault would constrict the posterior movement of pupil. The findings of the study suggest that, for patients with high or low vault, we should be more careful and must perform checks in different lighting conditions.

Keratometry, biometry, and prediction of intraocular lens power in adult tigers (Panthera tigris)

2021 ◽  
pp. 1-7
Author(s):  
Cameron D. Owens ◽  
Tammy M. Michau ◽  
Justin Boorstein ◽  
Elizabeth R. Wynn ◽  
Richard J. McMullen
Keyword(s):  
Anterior Chamber ◽  
Intraocular Lens ◽  
Anterior Chamber Depth ◽  
Crystalline Lens ◽  
Applanation Tonometry ◽  
Normal Adult ◽  
Panthera Tigris ◽  
Clinically Normal ◽  
Iol Power ◽  
Lens Power

Abstract OBJECTIVE To calculate the necessary pseudophakic intraocular lens (IOL) power to approximate emmetropia in adult tigers. ANIMALS 17 clinically normal adult tigers. PROCEDURES 33 eyes of 17 clinically normal adult tigers underwent routine ophthalmic examination and B-scan ultrasonography while anesthetized for unrelated procedures. Specific ultrasound data (globe measurements and corneal curvature) and estimated postoperative IOL positions were utilized to calculate predicted IOL power by use of Retzlaff and Binkhorst theoretical formulas. Applanation tonometry and refraction were also performed. RESULTS Mean ± SD axial globe length was 29.36 ± 0.82 mm, preoperative anterior chamber depth was 7.00 ± 0.74 mm, and crystalline lens thickness was 8.72 ± 0.56 mm. Mean net refractive error (n = 33 eyes) was +0.27 ± 0.30 diopters (D). By use of the Retzlaff formula, mean predicted IOL power for the postoperative anterior chamber depth (PACD), PACD – 2 mm, and PACD + 2 mm was 43.72 ± 4.84 D, 37.62 ± 4.19 D, and 51.57 ± 5.72 D, respectively. By use of the Binkhorst equation, these values were 45.11 ± 4.91 D, 38.84 ± 4.25 D, and 53.18 ± 5.81 D, respectively. Mean intraocular pressure for all eyes was 14.7 ± 2.69 mm Hg. CLINICAL RELEVANCE The calculated tiger IOL was lower than reported values for adult domestic felids. Further studies evaluating actual PACD and pseudophakic refraction would help determine the appropriate IOL power to achieve emmetropia in this species.

Management of Anterior Chamber Depth After Trabeculectomy

1988 ◽  
Vol 106 (6) ◽  
pp. 767-768 ◽  
Author(s):  
RICHARD J. MACKOOL ◽  
JORGE N. BUXTON
Keyword(s):  
Anterior Chamber ◽  
Anterior Chamber Depth

scholarly journals Polypharmacy-associated potential contraindications of drug prescriptions in patients with primary angle closure disease in a real-world setting

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Fumiaki Tanaka ◽  
Naoki Shibatani ◽  
Kazumi Fujita ◽  
Hiroaki Ikesue ◽  
Satoru Yoshimizu ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Anterior Chamber ◽  
Anterior Chamber Depth ◽  
Japanese Patients ◽  
Median Number ◽  
Angle Closure ◽  
Primary Angle Closure ◽  
Primary Angle Closure Glaucoma ◽  
Number Of Patients ◽  
Multiple Drugs

Abstract Background Primary angle closure disease (PACD) is a type of glaucoma in which the intraocular pressure (IOP) is increased because of the blockage of the anterior chamber angle. Medications contraindicated for patients with PACD, such as anticholinergics, cause mydriasis, and can elevate IOP. However, anticholinergics are currently contraindicated only for primary angle closure glaucoma (PACG) in Japanese package inserts. In this study, we investigated the prescription status of medications contraindicated for PACD, such as anticholinergics, in patients with PACD scheduled for eye surgeries. Methods Forty-three Japanese patients diagnosed with PACD at Kobe City Eye Hospital, Japan, and scheduled hospitalization for eye surgeries between December 2017 and July 2018, were included. Data, including sex, age, diagnosis, IOP, anterior chamber depth, and patients’ regular medications prior to hospitalization, were collected for each patient from the electronic medical records. Results The number of patients with chronic primary angle closure (CPAC) and acute primary angle closure (APAC) was 35 (81.4%) and 8 (18.6%), respectively. Among all the 43 patients with PACD, 8 (18.6%) received 15 medications that are potentially contraindicated for PACD by non-ophthalmologist. According to medication categories, benzodiazepine hypnotics were the most commonly prescribed. Among the 8 patients with APAC, 2 (25.0%) had routinely received medications contraindicated for PACD. The median number of all kinds of prescriptions on the day of hospitalization was significantly higher for patients who received medications contraindicated for PACD than for those who did not receive them (p = 0.010). Conclusions About 20% of patients with PACD received medications potentially contraindicated for PACD, such as anticholinergics. Attention should be paid to patients prescribed multiple drugs for adverse events, such as increase in intraocular pressure.

scholarly journals Subtle changes of the crystalline lens after cycloplegia: a retrospective study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Cheng Dai ◽  
Meng Liu ◽  
Xiaodong Lv ◽  
Binzhong Li
Keyword(s):  
Retrospective Study ◽  
Children And Adolescents ◽  
Population Change ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Crystalline Lens ◽  
Equivalent Diameter ◽  
Crystalline Morphology ◽  
Significant Difference ◽  
Before And After

Abstract Background The purpose of this study was to evaluate the shape of the crystalline lens in terms of biometry and diopters before and after cycloplegia using the CASIA2 swept-source (SS) optical coherence tomography (OCT) system on the anterior segment. Methods This was a retrospective study. Children and adolescents (26 males and 29 females, aged 4–21 years) with simple ametropia were selected for optometry and CASIA2 imaging at 2 separate visits before and after cycloplegia. Diopter values were derived from the spherical power (S) obtained by optometry. Biometric parameters of the crystalline lens, including the anterior chamber depth (ACD), anterior and posterior curvature of the lens (ACL and PCL), lens thickness (LTH), lens decentration (LD), lens tilt (LT), and equivalent diameter of the lens (LED), were measured by the CASIA2 system. The differences in these parameters after compared with before cycloplegia were determined, and their relationships were analyzed. Results Fifty-five participants (106 eyes) were initially enrolled. There was a significant difference (P < 0.05) in the S (t=-7.026, P < 0.001), ACD (t=-8.796, P < 0.001), ACL (t=-13.263, P < 0.001) and LTH (t = 7.363, P < 0.001) after compared with before cycloplegia. The change in the PCL (t = 1.557, P = 0.122), LD (t = 0.876, P = 0.383), LT (t = 0.440, P = 0.661) and LED (t=-0.351, P = 0.726) was not statistically significant (P > 0.05). There was a significant (P < 0.05) correlation of the change in the S with that in the ACL (r = 0.466, P < 0.001), LTH (r=-0.592, P < 0.001), and LED (r = 0.223, P = 0.021) but not the PCL (r = 0.19, P = 0.051), LD (r=-0.048, P = 0.0628) or LT (r=-0.022, P = 0.822). Furthermore, the change in the ACD was closely related to the change in crystalline morphology. However, in children and adolescents, we found that the change in crystalline morphology was unrelated to age. Conclusions Changes in lens morphology after compared with before cycloplegia are mainly related to the ACL and LTH, but there is no difference in the PCL, LD, LT, or LED. In the adolescent population, change in the S is related to change in the ACL, LED and LTH. However, age is unrelated to the shape and tendency of the crystalline lens. Further research is required to determine whether the same conclusion applies to different age groups and different refractive states (myopia, hyperopia, emmetropia) .

scholarly journals Intraocular Pressure Reduction after Femtolaser Assisted Cataract Surgery and Its Association with the Use of Ultrasound

Medicina ◽  
2021 ◽  
Vol 57 (5) ◽  
pp. 437
Author(s):  
Hana Abouzeid ◽  
Walter Ferrini ◽  
Murielle Bochud
Keyword(s):  
Intraocular Pressure ◽  
Linear Regression ◽  
Cataract Surgery ◽  
Anterior Chamber ◽  
Anterior Chamber Depth ◽  
Multiple Linear Regression Model ◽  
Study Data ◽  
Department Of Ophthalmology ◽  
Duration Of Surgery ◽  
Ocular Pressure

Background and Objectives: To quantify the change in intraocular pressure (IOP) after phacoemulsification in patients having undergone femtolaser assisted cataract surgery (FLACS), and study the influence of the use of ultrasound on this change. Setting: Jules-Gonin Eye Hospital, University Department of Ophthalmology, Lausanne, Switzerland. Materials and Methods: Interventional study. Methods: All consecutive cases operated with FLACS and with complete data for the studied parameters were selected for inclusion in the study. Data had been prospectively collected and was analysed retrospectively. Linear regression was performed to explore the association of change in IOP with time of measure, ultrasound use, sex, age, and duration of surgery. Results: There was a mean decrease in intraocular pressure of 2.5 mmHg (CI 95% −3.6; −1.4, p < 0.001) postoperatively. No association between the change in intraocular pressure and ultrasound time or effective phaco time was observed when the data were analyzed one at a time or in a multiple linear regression model. There was no association with sex, age, nuclear density, presence of pseudoexfoliation, duration of surgery, and time of ocular pressure measurement. Eyes with preoperative IOP ≥ 21 mmHg had a more significant IOP reduction after surgery (p < 0.0001) as did eyes with an anterior chamber depth <2.5 mm (p = 0.01). Conclusion: There was a decrease in intraocular pressure six months after FLACS in our study similar to that in the published literature for standard phacoemulsification. The use of ultrasound may not influence the size of the decrease, whereas the preoperative IOP and anterior chamber depth do. FLACS may be as valuable as standard phacoemulsification for cases where IOP reduction is needed postoperatively.

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