Phacoemulsification Parameters Research Articles

Nuclear Grades based on Lens Opacities Classification System III associated with Phacoemulsification Parameters and Postoperative Central Corneal Thickness

Abstract
 Introduction & Objectives : To determine association of nuclear cataract grades based on Lens Opacities Classification System (LOCS) III with phacoemulsification parameters and postoperative Central Corneal Thickness (CCT) and visual acuity.
 Methods : This was a prospective observational study in patient with uncomplicated senile cataract who gave consent and underwent phacoemulsification. Institutional Ethics Committee clearance was taken for the study. Preoperative nuclear cataract was evaluated using Lens Opacities Classification System (LOCS) III. Only nuclear grading NO and NC was obtained. All procedures was performed using peristaltic phaco machine and in the bag IOL implantation. Phacoemulsification parameters (US Total Time and CDE) were noted and compared in different grades of cataract. CCT change was recorded at day one after surgery.
 Results : Forty-six patients were evaluated. The mean USTT was 120.85 (56-252) seconds, mean CDE was 21.10 (5.70 – 43.38), and mean CCT change after surgery was 81.54(27 – 240). Nuclear grading of LOCS also had linear correlation with US Total Time (NO p<0.001, r=0.734; NC p<0.001, r=0.790) and CDE (NO p<0.001, r=0.728; NC p<0.001, r=0.685). There was significant correlation between CCT change with postoperative VA (p=0.002, r=0.443) and CDE (p<0.001, r= 0.553). CCT change also correlate with nuclear opacity (p=0.012, r=0.367) and nuclear color (p=0.035, r=0.312).
 Conclusion : Nuclear grading of LOCS III related to the amount of time and energy used in phacoemulsification, and also CCT change after surgery as a qualitative measurement of corneal edema. Increasing postoperative CCT affected patient's visual acuity after cataract surgery.

Pseudoexfoliative Syndrome in Cataract Surgery-A Quality Register Study and Health Economic Analysis in the Split-Dalmatia County, Croatia.

To investigate the impact of pseudoexfoliation (PEX) syndrome on intraoperative phacoemulsification (PHACO) parameters and assess the economic cost of PHACO surgery for cataracts in patients with and without PEX syndrome. This was a retrospective quality register study on 5889 patients (6236 eyes) who underwent PHACO cataract surgery in the Eye Clinic, Clinical Hospital Centre Split, Croatia, over a 7-year period (May 2015 to December 2022), in accordance with the Guidelines of the Helsinki Declaration and approval from the Research Ethics Committee of the University Hospital Centre Split, Croatia. Inclusion criteria were patients with either presenile or senile cataract or cataract related to PEX syndrome who undertook PHACO procedure by the same experienced surgeon using the same PHACO device (Infiniti Vision System, Alcon Laboratories, Inc., Fort Worth, TX, USA). Eyes were categorized according to PEX presence- (PEX group) or absence (Group without PEX). The following recorded data about intraoperative PHACO parameters were collected: Cumulative Dissipated Energy (CDE), Ultrasound total time, PHACO time, torsional time, aspiration time, estimated fluid used, and duration of the surgical procedure. In the economic analysis, all PHACO parameters were considered, with a specific focus on the duration of the surgical procedure, costs associated with additional medical materials and devices, complications during surgery, and surgery procedure Diagnosis-Related Group (DRG) codes. A total of 4535 cases were eligible for inclusion in the study, 278 (6.13%) were diagnosed with PEX and 4257 (93.87%) had no PEX. Significantly higher PHACO parameters were observed in the PEX group. Similarly, a statistically significant increase in the values of all PHACO parameters was observed with the increase in nuclear lens density. Intraoperative complications were more frequent in the PEX group. Zonular weakness requiring the use of a capsular tension ring (CTR) and posterior capsular rupture occurred 30 and 13 times more often, respectively, in the PEX group. The expected cost of the PHACO procedure was found to be 1.4 times higher in patients with PEX, compared to those without PEX, for all types of nuclear cataract. All PHACO parameters are significantly higher in patients with PEX. The costs associated with PHACO surgery for cataracts are greater for patients with PEX and are not covered by the present DRG codes, which highlights the need to accordingly adjust the DRGs for PHACO procedures in PEX patients, in order to maintain the quality of healthcare provided for these vulnerable patients.

Comparison of dominant- and non-dominant-hand cateract surgery outcomes by a single surgeon

PurposeTo compare dominant and non-dominant hand phacoemulsification surgery outcomes. MethodsThis retrospective, single-center study included 300 patients who underwent phacoemulsification surgery by a single, right-handed surgeon. The patients were divided into two groups according to whether the surgeon used his dominant or non-dominant hand during surgery. Right eye operations were performed with the right hand, and left eye operations were performed with the left hand. Detailed ophthalmological examinations were performed on all patients preoperatively and postoperatively. Intraoperative phacoemulsification parameters, the presence of intraoperative and postoperative complications, postoperative refractive errors, visual acuity, and surgically induced astigmatism values were compared between the groups. ResultsThere were 171 patients in the dominant hand phacoemulsification group and 129 patients in the non-dominant hand phacoemulsification group. The distributions of age, gender, systemic diseases, and lens opacification were similar between the groups (p>0.05, for all). No statistically significant difference was observed between the two groups in terms of total operation time, phaco power, ellips fx, or ultrasonic time (p>0.05, for all). There was also no significant difference in relation to intraoperative and postoperative complication distributions, postoperative third-month refractive errors, visual acuity, or surgically induced astigmatism values (p>0.05, for all). ConclusionThis study demonstrated that cataract surgery performed by a single surgeon can be effectively and safely performed using both hands on patients in a real operating theater environment. More objective results can be obtained with surgeries performed by a larger number of experienced surgeons.

Impact of Phacoemulsification Parameters on Central Retinal Thickness Change Following Cataract Surgery.

Cataract surgery can lead to inflammatory processes in the retina due to its invasive nature, resulting in prolonged recovery times and reduced functional outcomes. The aim of the current study is to explore the impact that phacoemulsification parameters have on macular thickness following surgery. This prospective single-center study enrolled 46 healthy patients (46 eyes) who underwent uneventful cataract surgery. Retinal thickness was assessed using optical coherence tomography (OCT) preoperatively, as well as 1, 4, and 12 weeks after surgery. The macula was divided into a central (CMT), inner (IMT), and outer ring (OMT). Cataract density was automatically determined using an anterior segment OCT and a custom MATLAB script. Corrected distance visual acuity (CDVA), intraocular pressure (IOP) as well as cumulative dissipated energy (CDE), ultrasound time (UT), and fluids used during phacoemulsification were recorded. Retinal thickness and volume increased significantly following cataract surgery, reaching its maximum 4 weeks post-operatively. Statistically significant correlations were found between the CDE and IMT, OMT and retinal volume change (rIMT = 0.356, rOMT = 0.298, rvolume = 0.357 with p < 0.05) as well as between the ultrasound time and IMT, OMT, and retinal volume change (rIMT = 0.369, rOMT = 0.293 and rvolume = 0.409 with p < 0.05). Changes in CMT did not correlate with any surgical metrics. Additionally, no correlation was found to the amount of fluid used, whether CDVA or IOP. However, a link between nuclear cataract density and changes in OMT (r = 0.310, p < 0.05) was established. How ultrasound energy impacts the choroidea, and to what extent retinal metabolism changes after surgery, needs to be explored in future studies.

Change in Subfoveal Choroidal Thickness following Cataract Surgery Imaged with Enhanced Depth Imaging Optical Coherence Tomography.

Due to its invasive nature, cataract surgery can lead to inflammatory processes in the posterior segment, which can result in prolonged recovery times, reduced functional outcomes, and late-onset complications. The aim of the current study was to identify wherever phacoemulsification parameters play a role in choroidal thickness change following cataract surgery. This prospective single-center study enrolled 31 patients (31 eyes) scheduled to undergo routine cataract surgery. Patients with previous ocular surgeries, pathologies or general disorders affecting vision were excluded. Patients were examined preoperatively, as well as 1, 4, and 12 weeks after surgery. Corrected distance visual acuity (CDVA), intraocular pressure (IOP) as well as cumulative dissipated energy (CDE), ultrasound time (UT), and fluids used during surgery were recorded. Subfoveal choroidal thickness was measured manually by two masked independent experts using enhanced depth imaging (EDI) optical coherence tomography (OCT). Furthermore, cataract density was automatically calculated using a custom MATLAB script and an anterior segment OCT. Subfoveal choroidal thickness increased significantly (p < 0.001, Student's paired sample t-test) and continuously during the 12-week-long follow-up period. Both the nuclear lens density and the improvement in CDVA correlated significantly with this increase (r = 0.413, p = 0.021 and r = 0.421, p = 0.018, respectively). Neither the CDE (r = 0.334, p = 0.071), the UT (r = 0.102, p = 0.629), the amount of fluid used (r = 0.237, p = 0.27) nor the decrease in IOP (r = - 0.197, p = 0.288) showed any significant correlation with the choroidal swelling. Cataract surgery leads to an increase in subfoveal choroidal thickness. While no statistically significant correlation to the phacoemulsification parameters could be established, this might be because of a selection bias due to the technological constraints of the OCT. Nevertheless, the choroid might play a central role in early- and late-onset complications.

Retrospective investigation of perioperative risk factors for immediate postoperative corneal erosions in dogs undergoing phacoemulsification.

To characterize the incidence, contributing risk factors, and healing characteristics of immediate postoperative corneal erosions (IPCE) in dogs undergoing routine phacoemulsification. Medical records of 313 canine eyes (159 dogs) undergoing routine phacoemulsification surgery. Medical records of dogs undergoing planned cataract surgery at UW Veterinary Care were retrospectively reviewed. Patient-related variables including age, skull conformation, diabetes status, and cataract stage at the time of surgery were recorded. Intraoperative variables per eye were also recorded including surgical technique, surgeon expertise level, average phacoemulsification power, and phacoemulsification time. Diagnosis of IPCE ≤ 24 h after completion of surgery and time to IPCE healing were recorded where follow-up data were available. Immediate postoperative corneal erosions were observed in 48/313 (15.3%) operated eyes. The presence of diabetes mellitus or brachycephalic skull conformation, preoperative Schirmer tear test (STT) value, surgical technique and surgeon experience level, phacoemulsification time, and absolute phacoemulsification time were not statistically significant risk factors for IPCE. Average phacoemulsification power was associated with IPCE (RR 1.52, p=.001). Time to IPCE healing was similar in diabetic and non-diabetic dogs (median [IQR] 8 [6-11] days and 8 [6-15] days, respectively). Diabetes mellitus, brachycephaly, and phacoemulsification parameters were not associated with IPCE healing at 7 or 14 days postoperatively. Higher average phacoemulsification power may be associated with the development of IPCE in canine eyes. The presence of diabetes mellitus or brachycephaly are not risk factors for the development of IPCE, nor are they factors that influence IPCE healing.

Predictors of intraocular pressure reduction after femtosecond laser-assisted cataract surgery versus conventional phacoemulsification surgery: a prospective trial.

To evaluate the association between postoperative intraocular pressure (IOP) reduction and phacoemulsification parameters in patients who underwent both conventional phacoemulsification surgery (CPS) and femtosecond laser-assisted cataract surgery (FLACS). This was a prospective multicenter comparative study that enrolled 90 participants who underwent cataract surgery at the University of Maryland Medical System and the Wilmer Eye Institute. Patients underwent FLACS in one eye and CPS in the fellow eye. IOP was measured prior to surgery and monitored through six months postoperatively. Demographic, clinical, biometric, and intraoperative variables including cumulative dissipated energy (CDE), aspiration time, and phacoemulsification time were analyzed for any significant association with postoperative IOP. Postoperative IOP reduction was the primary outcome variable. A secondary goal of the study was to determine differences in postoperative IOP reduction between CPS and FLACS cohorts. In total, 157 non-glaucomatous eyes were included. Using multivariable analysis, we found preoperative IOP to be consistently associated with postoperative IOP reduction in the entire cohort. At the 6-month follow-up visit, there was a 12.4% reduction in IOP (-2.2 ± 3.4mm Hg) seen, with no statistically significant difference between FLACS and CPS (12.3% ± 19.4% vs 12.5% ± 19.3%, respectively, p = 0.32). FLACS reduced the CDE required for phacoemulsification (6.6 ± 4.4%-seconds vs 8.6 ± 6.9%-seconds, respectively, p < 0.05). CDE was a predictor of IOP response at 6months, but subgroup analysis revealed that this trend was driven by seven eyes requiring high CDE, and for the majority of eyes, CDE did not influence the size of the decrease. The seven eyes experiencing highest CDE were less likely to show IOP reduction at 6months. Both FLACS and CPS resulted in similar and significant IOP reductions through 6months after surgery. Preoperative IOP was significantly associated with IOP reduction, and CDE generally did not influence the size of the decrease.

Adjusted femtosecond laser capsulotomy distance in white cataracts to decrease incomplete capsulotomy: a randomized comparative cohort study.

To compare safety and effectiveness between standard position and adjusted distance pre- and post-anterior capsule of femtosecond laser capsulotomy in white cataracts surgery. Selected white cataracts that underwent LenSx femtosecond laser capsulotomy were randomized into groups A (standard position, with 300µm symmetrically pre- and post-anterior capsule), B (increased distance with 400µm symmetrically pre- and post-anterior capsule), and C (unsymmetrical distances of 200µm pre- and 400µm post-anterior capsule, respectively). All these surgeries were performed by the same experienced surgeon. Complications, including incomplete capsulotomy and capsule tears, were recorded. In addition, femtosecond capsulotomy and phacoemulsification parameters, IOLs centrality and corrected distance visual acuity were assessed. A total of 113 eyes were included in this study. There were 8 (21.6%) incomplete capsulotomy and 1 anterior capsule tear in group A. Meanwhile, only 2 eyes (5.1%) had incomplete capsulotomy with none showing capsule tear in group B. In group C, only 1 eye (2.7%) had incomplete capsulotomy and no capsule tear occurred. Mean femtosecond laser capsulotomy time was longer in group B compared with groups A and C. Average cumulative dispersed energy, IOL centrality and corrected distance visual acuity were similar in all groups. Appropriate adjustment on femtosecond laser capsulotomy distance by reducing pre-anterior capsule and increasing post-anterior distance, may decrease incomplete capsulotomy and be more effective in white cataracts surgery. Clinical trial registration number: ChiCTR2100043863.

Correlation Between Degree of Lens Opacity and the Phacoemulsification Energy Parameters Using Different Imaging Methods in Age-Related Cataract.

PurposeTo compare the correlation between degree of lens opacity and the phacoemulsification energy parameter in patients with age-related cataract as determined by slit lamp, 25-MHz ultrasound biomicroscopy (UBM), and Scheimpflug imaging (Pentacam) and to evaluate the application of these three methods to measuring lens opacification.MethodsThis observational study was conducted in 319 patients (381 eyes) with different types of age-related cataract. The average age of patients was 67.3 ± 11.4 years. The degree of lens opacity acquired by slit lamp, 25-MHz UBM, and Pentacam was determined by the Lens Opacity Classification System III (LOCSIII), pixel units calculated by ImageJ, and lens density, respectively. We primarily analyzed and compared the correlation between lens opacity and the cumulative dissipated energy (CDE) values of phacoemulsification.ResultsCortical, nuclear, and posterior subcapsular (PSC) cataracts were evaluated as follows: LOCSIII grades 3.31 ± 1.42, 3.29 ± 1.49, and 0.91 ± 0.83; pixel units 120.91 ± 22.8, 93.2 ± 15.9, and 99.7 ± 13.0; and lens density 51.8 ± 31.2, 21.2 ± 6.10, and 53.3 ± 35.3, respectively. The CDE values were 12.1 ± 12.4, 13.5 ± 9.11, and 3.93 ± 1.96. In cortical cataract, there was a linear correlation among LOCSIII, pixel units, and CDE value (r = 0.560, r = 0.832, and r = 0.582, respectively; both P < 0.05), but lens density had no correlation with other parameters. In nuclear cataract, there was a linear correlation among LOCSIII, lens density, and CDE value (r = 0.747, r = 0.865, and r = 0.906, respectively; both P < 0.05), but pixel units had no correlation with other parameters. In PSC, only pixel units and LOCSIII showed a correlation.ConclusionsThe various imaging methods offered different advantages in terms of determining lens opacity, a feature related to types of age-related cataracts. Choosing the most suitable imaging method to evaluate lens opacification based on the type of age-related cataract is important for accurately predicting the phacoemulsification parameters for cataract surgery.Translational RelevanceDetermining the appropriate phacoemulsification strategy depends on quantitative analysis of the degree of lens opacity to reduce intraoperative and postoperative complications and to obtain the optimal postoperative visual outcome.

Comparison of the IOLMaster 700 and the Pentacam in the Analysis of the Lens Nuclear Density Before the Cataract Surgery.

Purpose: To evaluate the difference of the lens nuclear density measured before and after mydriasis by using the IOLMaster 700 (Carl Zeiss Meditec AG, Jena, Germany) and the Pentacam Scheimpflug imaging (Pentacam HR, Oculus Incorporation, Wetzlar, Germany) and investigate the relationship between the measurement data and the phacoemulsification parameters.Methods: Patients with age-related nuclear cataracts diagnosed on the slit-lamp examination were enrolled in the age range of 53–76 years. No patient had a history of ocular surgery, laser treatment, or general disorders affecting vision. The mean optical density (OD) was measured by the IOLMaster 700 by using the Image-Pro® Plus software before and after mydriasis. The Pentacam nucleus densitometry (PND) was obtained automatically from the Pentacam Scheimpflug imaging and compared with OD. The correlation between OD and effective phacoemulsification time (EPT), PND, and EPT were analyzed, respectively.Results: In this study, 53 eyes of 52 patients were evaluated. Before and after mydriasis, the mean OD values were 64.34 ± 23.31 and 63.81 ± 23.21 pixel units, respectively; the mean PND values were 28.51 ± 11.42 and 25.41 ± 11.31, respectively; and the mean EPT value was 6.24 ± 3.49. The Bland–Altman analysis showed that the lens nuclear densities of the two devices were highly consistent. There was no significant difference in the OD values (t = 0.455, p > 0.05) before and after mydriasis, but the difference has existed in the PND values (t = 2.509, p < 0.05). The OD and PND values were positively correlated with EPT before and after mydriasis (rOD−Before = 0.604, rOD−After = 0.593, rPND−Before = 0.701, and rPND−After = 0.891, p < 0.01).Conclusion: The combination of the IOLMaster 700 and the Image-Pro® Plus software can quantitatively evaluate the degree of the cataract lens opacification. It has good consistency with the Pentacam and is positively correlated with the phacoemulsification parameters. It is expected to become a new method to predict the phacoemulsification parameters before and during cataract surgery.

Comparative study of phacoemulsification parameters with and without nitinol filament nuclear disassembly.

The purpose of this study was to evaluate the impact of nitinol microfilament lens disassembly using the miLOOP device on phacoemulsification parameters in routine cataract surgery. Private practice in Cleveland, Ohio. Retrospective comparative consecutive case series. A chart review of consecutive cataract surgery cases in a single center operated by a single surgeon was conducted. Eyes were grouped by whether they underwent nitinol filament nuclear disassembly. Phacoemulsification energy, phacoemulsification time, and irrigation/aspiration (I/A) recorded during the operation were compared. Bilateral eyes were included only if the contralateral eye was in the opposite group. A total of 212 eyes in 131 patients were eligible for analysis, including 81 subjects with both eyes. Most eyes (93%) had grade 2+ or 3+ nuclear sclerotic cataracts. A total of 102 eyes (48%) underwent nitinol filament nuclear disassembly preceding phacoemulsification. For all eyes, there was a 16% reduction in phacoemulsification energy, with a larger drop in grade 3+ eyes (-22%). Phacoemulsification and I/A times also reduced significantly (-19% and -37%, respectively, P < .02). Nitinol microfilament nuclear disassembly reduced total phacoemulsification energy and time during cataract surgery, particularly in severe cataracts.

Study on dependence of phacoemulsification of senile cataract parameters on features of hydrodissection

The aimwas to study the dependence of senile cataract phacoemulsification (PE) parameters on hydrodissection (HD) features.&#x0D; Materials and methods.64 patients (64 eyes) who underwent PE of senile cataract using either viscodissection (VD) (main group) or regular HD (control group). Time parameters VD and HD duration, cortex aspiration, and total time of PE, along with calculation of mean volume of BSS in both groups were studied.&#x0D; Results.It took 1.8 times more time to perform VD compared to HD duration. The cortex aspiration step required 2.4 times less time in the eyes of main group in comparison with control group, as 10 eyes (31.2%) of the main group had spontaneous full cortex evacuation through ultrasound tip at epinucleus removal. Other 22 eyes (78.8%) of the main group needed aspiration of cortex, which occupied 1/61/3 capsule circumference. Though surgery time was comparable in both groups, mean volume of BSS spent was justifiably 1.5 times higher in the control group.&#x0D; Conclusion.Performed analysis showed that VD is an effective method which provides optimization of PE of senile cataract. Use of VD allowed exclusion of cortex aspiration in 31.2% of eyes in the main group and decrease of its duration by 2.4 times in comparison with the control group.

Comparison of phacoemulsification parameters in eyes with and without exfoliation syndrome

To evaluate and to compare the phacoemulsification machine parameters in eyes with and without XFS, requiring cataract surgery. Patients who underwent phacoemulsification and in-the-bag IOL implantation for cataract were included in this retrospective study. All surgeries were performed by the same experienced surgeon using the stop & chop technique with the same phacoemulsification device (Infiniti Vision System, Alcon Laboratories, Inc., USA). Patients were divided into two groups according to the presence of exfoliation material (XFM). Each group consisted of consecutive patients. Their characteristics and intraoperative phacoemulsification parameters were compared. Sixty-eight eyes of 68 patients [29 in the exfoliation syndrome (XFS) (-) group, 39 in XFS (+)] were enrolled. There were no statistical differences regarding preoperative patient characteristics. There was a statistically significant difference in total U/S time, phaco time, aspiration time and estimated fluid used between the XFS (+) and XFS (-) groups (P=0.021, P=0.017, P=0.009 and P=0.002, respectively). Considering that the use of a CTR (capsule tension ring) might be an important factor potentially affecting surgical parameters, the data were analyzed accordingly. Aspiration time and estimated fluid used remained statistically significant (P=0.046 and P=0.017, respectively); however, although the U/S total and phaco time were found to be longer in XFS (+) group compared to XFS (-) group, the difference did not show statistical significance (P=0.061 and P=0.059, respectively). There were no differences between groups regarding endothelial cell loss or any other postoperative complications. The presence of XFS results in longer total U/S time, phaco and aspiration time and more estimated fluid used in phacoemulsification, but this prolongation does not result in additional complications.

Cataract surgery in pseudoexfoliation syndrome

Phacoemulsification is a main method of cataract surgery. The presence of pseudoexfoliation syndrome (PEX) may involve the procedure in difficulty and contribute to development of intra- and postoperative complications. Purpose. To assess the effect of PEX on phacoemulsification. Materials and methods. 1010 patients (580 with PEX and 430 without PEX) admitted for cataract surgery, underwent phacoemulsification with implantation of various IOL types. An analysis of main phacoemulsification parameters was carried out: cumulative dissipated energy (CDE), aspirated BSS amount, time of surgery. The prevalence of some possible intraoperative complications was assessed: descemet membrane detachment, posterior capsule rupture, retrolental lens material, and zonular dialysis. Results. In patients with PEХ, local descemet membrane detachment and retrolental lens material were significantly more common, at the same time CDE was higher. Conclusion. When planning phacoemulsification, patients with PEX require more thorough preoperative examination, higher alertness during surgery and longer follow-up in the postoperative period.

Cataract surgery in pseudoexfoliation syndrome

Phacoemulsification is a main method of cataract surgery. The presence of pseudoexfoliation syndrome (PEX) may involve the procedure in difficulty and contribute to development of intra- and postoperative complications.&#x0D; Purpose. To assess the effect of PEX on phacoemulsification.&#x0D; Materials and methods. 1010 patients (580 with PEX and 430 without PEX) admitted for cataract surgery, underwent phacoemulsification with implantation of various IOL types. An analysis of main phacoemulsification parameters was carried out: cumulative dissipated energy (CDE), aspirated BSS amount, time of surgery. The prevalence of some possible intraoperative complications was assessed: descemet membrane detachment, posterior capsule rupture, retrolental lens material, and zonular dialysis.&#x0D; Results. In patients with PEХ, local descemet membrane detachment and retrolental lens material were significantly more common, at the same time CDE was higher.&#x0D; Conclusion. When planning phacoemulsification, patients with PEX require more thorough preoperative examination, higher alertness during surgery and longer follow-up in the postoperative period.

Assessment of Age-related Cataract using Scheimpflug Imaging System and its Correlation with Phacoemulsification Parameters

Assessment of Age-related Cataract using Scheimpflug Imaging System and its Correlation with Phacoemulsification Parameters

Preoperative Assessment of Crystalline Lens by A-Scan Quantitative Echography and Its Correlation with Phacoemulsification Parameters

Purpose: To evaluate the correlations between the total ultrasound energy consumed during phacoemulsification with various preoperative parameters, including the best- corrected distant visual acuity (BCDVA) and quantified metrics taken from A-scan ultrasound biometry. Patients and methods: A prospective observational interventional study included 40 eyes of 40 consecutive patients scheduled for cataract surgery. We assessed the lens internal reflectivity in the A-scan echograms within a range of 0% to 100%, and calculated the mean of all spikes. All eyes with cataract underwent clear corneal phacoemulsification. At the end of the operation we recorded the phacoemulsification time and mean percent power. The correlations of echographic and phacoemulsification data were assessed. Results: Quantitative echography in the 40 studied eyes with different types of cataract revealed acoustic reflections having various configurations according to the biomicroscopic type of cataract, i.e. cortical, nuclear and posterior subcapsular cataract. The mean spikes were 31.027% ± 25.5908, the mean lens thickness was 4.291 ± 0.6166, the mean best corrected distant visual acuity in decimal was 0.205±0.1435, the mean phaco power% was 6.400 ± 3.0701 and the mean phaco time is 84.225. There was statistically insignificant correlation between spikes% and phaco power% in the study group (p>0.05). There was statistically insignificant correlation between mean spikes% and lens thickness in the study group (p>0.05).There was statistically insignificant correlation between spikes% and phaco time (in seconds) in the study group (p>0.05). Conclusion: With regards to the predictive value of lens hardness changes in the acoustic properties identified by our method, it is not correlated with the ultrasound energy required intraoperatively. The A-scan is helpful for the clinical prediction of lens opacity location, but not predictive of lens hardness quantification.

Clinical Application of 25-MHz Ultrasound Biomicroscopy for Lens Opacity Degree Measurements in Phacoemulsification.

PurposeTo evaluate the correlation between lens opacity degrees and phacoemulsification cumulated dissipated energy (CDE) values in patients with age-related cataract by applying 25-MHz panoramic ultrasound biomicroscopy (UBM).MethodsThis observational study was conducted in 227 patients (294 eyes) with age-related cataract. Patient ages ranged from 45 to 91 years. According to the lens images acquired by 25-MHz UBM, the objective indexes of lens opacity degrees were determined by using the ImageJ software. The correlation between lens opacity degrees (pixel units) and CDE values of phacoemulsification were mainly analyzed.ResultsThe means of measurements were as follows: preoperative LogMAR corrected distance visual acuity, anterior chamber depth, and central lens thickness was 1.10 ± 0.61, 2.52 ± 0.51, and 4.34 ± 0.60 mm, respectively. The mean 25-MHz UBM-measured lens opacity degree was 101.30 ± 19.70 pixel units, and the mean CDE value was 9.74 ± 9.10. There was a linear correlation between pixel units and the CDE value, as well as LogMAR corrected distance visual acuity (r = 0.38 and 0.50, respectively; both P < 0.05). Age correlated with anterior chamber depth and lens thickness (r = −0.18 and 0.16, respectively; both P < 0.05) but not with pixel units (r = −0.08, P > 0.05).ConclusionThe 25-MHz UBM has significant advantages in displaying the opacity feature of age-related cataract. The 25-MHz UBM combined with ImageJ software can be used to evaluate the opacity degree of age-related cataract quantitatively and may help predict the phacoemulsification parameters in cataract surgery.Translational RelevanceCombination of the lens ultrasonic image and image analysis software enables researchers to evaluate lens opacity degree quantitatively and predict the parameters of phacoemulsification surgery.

Differences in energy and corneal endothelium between femtosecond laser-assisted and conventional cataract surgeries: prospective, intraindividual, randomized controlled trial.

To compare intraoperative phacoemulsification parameters and its effect on the corneal endothelium of eyes undergoing femtosecond laser-assisted cataract surgery (FLACS) versus conventional phacoemulsification (CP) cataract surgery. Two hundred eyes from one hundred patients were included in a prospective, non-blinded, randomized, controlled, intraindividual clinical study. One hundred eyes underwent FLACS while their one hundred fellow eyes underwent CP. All surgeries were performed using the Victus® femtosecond laser platform and Infinity® Vision System phacoemulsification machine. Primary outcome measure was endothelial cell density 6mo after surgery. Secondary outcome measures included central corneal thickness (CCT), average cell area, standard deviation, coefficient of variation and hexagonality before surgery and 6mo after surgery and endothelial cell density loss during this period were also evaluated. Intraoperative efficiency parameters [cumulative dissipated energy (CDE), total intraocular surgery time, total ultrasound time, total phacoemulsification time, total torsional energy time, total aspiration time, ultrasound energy, torsional amplitude and fluid required during surgery] were also collated. Data from these patients was not considered for analysis. Data from 92 patients were analysed. Postoperative endothelial cell density (cells/mm2) between groups (2211.88±392.49 CP; 2246.31±403.48 FLACS) was not statistically significant (P=0.869). Total ultrasound time, torsional energy time, CDE and fluid requirements were significantly lower the FLACS group (P<0.05). Other parameters did not show statistically significant difference between FLACS and CP. FLACS displays significant improvements in phacoemulsification parameters in comparison to CP. There are no significant differences in corneal endothelium measures between FLACS and CP.

Comparison of Cornea Endothelial Cells Density the After Aspiration of Dense Cataracts using Two Variants of Phacoemulsification Parameters

Purpose: to compare two types of phacoemulsification parameters (combination ultrasound and torsional US with IP) with estimating the number of postoperative complications caused by intraoperative trauma of corneal endothelial cells.Patients and methods. 72 patients underwent phacoemulsification with IOL implantation. Patients were randomly divided into two groups (main n = 33 and control n = 39). During the aspiration of lens fragments in the main group the combination ultrasound was used, while torsional US with IP was used in the control group. Endothelial cell counting and other examinations were performed 1 day, 1 week and 6 months after the surgery.Results. CDVA in the explored groups 1 week after the surgery was similar: the main group — 0.813 ± 0.228, the control group — 0.765 ± 0.250, There was also no statistically significant difference in the thickness of the cornea between the groups: the main group — 533.48 ± 12.41, the control group — 536.44 ± 10.92. At the same time, a statistically significant difference was found in the density of endothelial cells: the main group: 1871.30 ± 187.41 (after 1 week), 1865 ± 178.9 (after 6 months); control group: 1809.63 ± 225.43 (after 1 week), 1791 ± 230.82 (after 6 months). The percentage of cell loss was, respectively, lower in the main group at all times of observation: 3.90% (after 1 day), 4.54% (after 1 week), 4.9% (after 6 months). In the control group: 7.71% (after 1 day), 9.25% (after 1 week), 10.4% (after 6 months).Conclusions. Data obtained in this study has showed the advantages of combination ultrasound in comparison with torsional US with IP, when performing aspiration of dense lenses. Due to lower consumption of ultrasound energy and higher aspiration rate of the fragments, combination ultrasound can reduce the loss of corneal endothelial cells and decrease the number and severity of postoperative complications associated with it.