Comparing the efficacy and safety of phacoemulsification in white mature and other types of senile cataracts

Midperipheral mini-capsulorhexis as an additional step for safe phacoemulsification in white intumescent cataracts

The present article describes a novel surgical technique of a primary mini-capsulorhexis in midperiphery to minimize surgical complications in white intumescent cataracts. Patients with white mature cataracts with a convex anterior capsule or swollen lens fibers were selected. An initial puncture was made 3-4 mm away from the center, in the midperipheral anterior capsule, with a conventional cystitome. A mini-capsulorhexis (2-2.5 mm) was created. Loose cortical matter and fluidic contents were aspirated to reduce the intralenticular pressure. Two cuts were made at the margin of the mini-capsulorhexis, and an adequately sized secondary rhexis was completed, after which phacoemulsification was done. A circular curvilinear capsulorhexis was successfully achieved in all cases, including those with a small pupil. Rhexis could be completed in a patient where an initial extension occurred due to head movement. This refined technique aims to enhance the safety and precision of capsulorhexis in intumescent cataracts, thereby reducing the risk of complications such as the Argentinian flag sign. Further exploration and validation of this approach through clinical trials are warranted to establish its efficacy and safety profile.

Topical and subconjunctival anesthesia versus topical anesthesia alone in patients with senile cataracts undergoing phacoemulsification: a double-blind randomized controlled trial

BACKGROUND

This study compared topical anesthesia to a combination of topical anesthesia and subconjunctival anesthesia for phacoemulsification.

METHODS

This double-blinded parallel placebo-controlled randomized trial involved senile cataract patients scheduled for phacoemulsification between May and December 2022. Patients were randomly assigned to receive either topical anesthesia with 0.5% tetracaine hydrochloride and subconjunctival balanced salt solution injection (Control group) or topical anesthesia and subconjunctival injection with 2% lidocaine (Lidocaine group). Baseline parameters, cataract grades, and various outcomes were recorded, including pain scores at specific time points, patient cooperation scores, requests for additional anesthesia, and complications. Statistical methods included Fisher's exact test, the t-test, ordinal logistic regression, and linear regression with robust standard errors.

RESULTS

In total, 176 patients were included in the study after excluding 33 patients. A significant reduction in immediate postoperative pain was achieved in the Lidocaine group (p < 0.001) and was maintained for 2 h (p = 0.011). Additionally, better cooperation was observed in this group (p = 0.038). However, patients in the Lidocaine group experienced more pain during the subconjunctival injection (p = 0.001) and a significant increase in subconjunctival hemorrhage related to the injection (p < 0.001). Despite this, the rates of surgical complications were comparable between the groups, and all phacoemulsification procedures were successfully completed using the assigned anesthetic technique.

CONCLUSIONS

The addition of subconjunctival lidocaine injection to topical anesthesia reduced postoperative pain and improved patient cooperation during phacoemulsification. However, the lidocaine injection was painful, and it carried a higher risk of spontaneous-relief subconjunctival hemorrhage.

TRIAL REGISTRATION

Trial Registration Number: TCTR20220804003, date of registration August 4, 2022, retrospectively registered.

[Optimization of phacoemulsification technique for Morgagnian cataract]

PURPOSE

This study was conducted to develop a new optimized phacoemulsification technique for Morgagnian cataract taking into account the anatomical and topographic parameters of the lens nucleus.

MATERIAL AND METHODS

A working classification of Morgagnian cataract was developed based on the size of the nucleus: if the edge of the nucleus is visualized at the upper edge of the pupil or between the upper edge and the middle of the pupil, it was classified as an initial stage of Morgagnian cataract with a large nucleus; if the upper edge of the nucleus is visualized in the middle of the pupil and below, it was classified as an advanced stage of Morgagnian cataract with a small nucleus. The first group included six patients who underwent surgery using the scaffold technique with removal of the whole small nucleus into the anterior chamber. The second group included 11 patients who underwent surgery using the scaffold technique with removal of the last fragment of the nucleus into the anterior chamber.

RESULTS

The use of the scaffold technique with removal of the nucleus into the anterior chamber helped reduce the number of intraoperative complications to 16.7% in the first group, compared to 27.3% in the second group, and the percentage of endothelial cell loss to 10.1% in the first group, compared to 10.7% in the second group.

CONCLUSIONS

The anatomical and topographic features of the lens and the anterior segment of the eye in Morgagnian cataract with a small nucleus allow for preliminary implantation of an intraocular lens into the capsular bag to protect the posterior capsule during phacoemulsification of the nucleus with minimal mechanical, hydrodynamic and acoustic damage to the surrounding structures of the eye.

Association between anterior chamber biometry and posterior capsular defects

PURPOSE

To analyze the association between anterior chamber biometric factors and posterior capsular defects (PCDs) that occur during extracapsular cataract extraction.

SETTING

University Eye Hospital, Goethe University Frankfurt, Germany.

DESIGN

Population-based study.

PATIENTS AND METHODS

Extracapsular cataract extractions for inpatient cases within 4 years were retrospectively analyzed. The data on the occurrence of PCDs, age, sex, surgeon, and biometry were obtained. For cases with PCDs, the secondary ocular diseases, number of procedures, lens implant, visual acuity, and course were also recorded. Swept-source optical coherence tomography measurements allowed the measurement of lens thickness (LT) in addition to the usual biometry values.

RESULTS

A total of 1967 cataract surgeries (patients age: 70.56 ± 8.42, 1005 women; 962 men) were included, and PCDs were documented for 59 (2.54%; 31 women, 28 men) cases (patient age: 70.95 ± 8.52 years). There were no differences ( P = .76) related to the surgeons (n = 9) with minimal effect sizes. The mean LT, axial length, corneal curvature, and anterior chamber depth were 4950.36 ± 466.63 μm, 23.73 ± 1.77 mm, 43.89 ± 1.36 diopters, and 3.02 ± 0.71 mm, respectively. The Wilcoxon-Mann-Whitney test showed significant associations between LT ( P = .01) and PCDs with moderate relevance for the Rosenthal effect size (LT R = 0.34; ACD R = 0.29).

CONCLUSIONS

In addition to ACD, a tendency for the occurrence of PCD could be proven, especially for LT. Therefore, special attention should be paid to LT preoperatively for comprehensive risk stratification.

Accuracy of Different Lens Power Calculation Formulas in Patients With Mature Cataracts

Introduction To compare the prediction accuracy of lens power calculation formulas in patients undergoing mature cataract surgery. Methods A total of 90 operations involving the Alcon SA60AT IOL implant (Alcon, Geneva, Switzerland) were analyzed in terms of mean refractive prediction error (PE) and mean absolute prediction error (MAE) using backward calculation in a retrospective design. Results A negative PE was observed in SRK/T, Holladay 1, Holladay 2, Hoffer Q, Haigis, and Emmetropia Verifying Optical (EVO) formulas. In contrast, positive PEs were observed in Barrett Universal II (BAUII), Kane, and Radial Basis Function (RBF) formulas. Negative PE was observed with all formulas, except BAUII, in patients with a shallow anterior chamber depth (ACD). While the SRK/T, Holladay 1, BAU, Kane, and RBF formulas demonstrated positive PE, the Holladay 2, Hoffer Q, Haigis, and EVO formulas indicated negative PE. In patients with deep ACD, positive PE was observed in all formulas, barring Holladay 2 and EVO. No significant differences were identified between the formulas concerning MAE and percentages of 0.25 diopter (D), 0.50 D, 0.75 D, and 1.0 D across all study groups. Conclusion Although the new generation formulas provide very good results, achieving the best with a single formula is still impossible.

Visual Outcome and Complications in White Mature Cataracts after Phacoemulsification

PURPOSE

To identify risk factors and perioperative complications and assess postoperative visual outcome in patients of white mature cataracts undergoing phacoemulsification surgery.

METHODS

This cross-sectional study was conducted on 46 patients of white mature cataract undergoing phacoemulsification. Preoperatively, a detailed ocular examination was done, and anterior chamber depth (ACD) and lens thickness (LT) were measured on ultrasound biomicroscopy. Intraoperative and postoperative complications (on days 1, 7, and 30) and best-corrected visual acuity on postoperative day 30 were noted.

RESULTS

The mean age of patients was 60.78 ± 9.001 years. The study group consisted of 41.3% of males and 58.7% of females. 8 (19.56%) cases encountered complications during phacoemulsification surgery. The intraoperative complications were capsulorhexis-related in 5 (10.86%) patients, posterior capsular rent in 2 (4.3%) patients, and 1 (2.17%) case had zonular dialysis. There was no difference in mean ACD and LT in cases who developed complications and those who underwent uneventful surgery (P > 0.05). The commonly observed postoperative complications on day 1 were corneal edema (41.3%), anterior chamber flare (45.65%), and cells (39.13%) which resolved with routine topical medications. All patients showed a significant reduction in postoperative intraocular pressure (P < 0.001). A total of 37 (80.43%) eyes regained vision between 6/6 and 6/9 postoperatively (P < 0.001).

CONCLUSION

Phacoemulsification surgery is safe in white mature cataract that results in significant visual improvement. Common intraoperative complications are capsule related, while frequently encountered postoperative complications are corneal edema and anterior chamber reaction. Preoperative ACD and LT have no role in predicting intraoperative complications.

Novel nucleus management technique in hypermature morgagnian cataracts with liquified cortex during phacoemulsification

PURPOSE

To describe a novel nucleus management technique of variable size mobile nucleus in Hypermature Morgagnian cataracts.

METHODS

In this technique, under topical anesthesia, temporal tunnel incision and capsulorhexis were performed, and the capsular bag was inflated with 2% w/v hydroxypropylmethylcellulose. A chopper and phacoemulsification probe were used to consciously nudge the nucleus towards the capsular periphery (fornix) to immobilize the floating nucleus against the capsular bag recess. Firm nuclear impaling was achieved using longitudinal power in linear mode (range 0-70%), 650 mmHg vacuum, and aspiration flow rate of 42 ml/min. The nucleus was chopped by direct chop technique, total separation achieved, and fragments emulsified. Primary outcome measures included ease of nuclear holding, iatrogenic zonular stress/damage, posterior capsule tear, and endothelial cell loss.

RESULTS

This technique was performed in 29 consecutive cases from June 2019 - December 2021, and no intraoperative or postoperative complications were noted. The average phacoemulsification time and cumulative dissipated energy (CDE) were nearly similar in all cases.

CONCLUSION

This technique would make phacoemulsification much safer in eyes with hypermature cataract and liquified cortex with lower complication rates and maintenance of better endothelial integrity.

In situ assessment of lens elasticity with noncontact optical coherence elastography

Lens biomechanics has great potential for application in clinical diagnostics and treatment monitoring of presbyopia and cataracts. However, current approaches to lens elastography do not meet the desired safety or sensitivity for clinical application. In this regard, we propose a noncontact optical coherence elastography (OCE) method to facilitate quantitative in situ imaging of lens elasticity. Elastic waves induced by air-pulse stimulation on the limbus propagate to the lens and are then imaged using custom-built swept-source optical coherence tomography to obtain the elastic wave velocity and Young's modulus. The proposed OCE method was first validated by comparing the results of in situ and in vitro measurements of porcine lenses. The results demonstrate that the Young's modulus measured in situ was highly consistent with that measured in vitro and had an intraclass correlation coefficient of 0.988. We further investigated the elastic changes induced by cold storage and microwave heating. During 36-hour cold storage, the mean Young's modulus gradually increased (from 5.62 ± 1.24 kPa to 11.40 ± 2.68 kPa, P < 0.0001, n = 9) along with the formation of nuclear opacities. 15-second microwave heating caused a greater increase in the mean Young's modulus (from 6.86 ± 1.21 kPa to 25.96 ± 8.64 kPa, P < 0.0025, n = 6) without apparent cataract formation. Accordingly, this study reports the first air-pulse OCE measurements of in situ lenses, which quantified the loss of lens elasticity during simulated cataract development with good repeatability and sensitivity, thus enhancing the potential for adoption of lens biomechanics in the clinic.

Analysis of postoperative intraocular pathologies in patients with mature cataracts

Purpose

To examine the prevalence and risk factors of intraocular pathologies after mature cataract surgery.

Methods

The medical records of 115 patients (115 eyes) diagnosed with brunescent or white cataracts, who underwent surgery at a single primary center between January 2018 and August 2021 were retrospectively reviewed. Dense cataracts precluded preoperative fundus examination in all eyes; however, patients with fundus examination results within 3 months after cataract surgery were included. Logistic regression analyses were performed to identify factors associated with intraocular pathologies.

Results

Intraocular pathologies were observed in 37 eyes (32.2%) 11.8 ± 13.9 days postoperatively. The most common abnormalities were drusen (6.1%), myopic degeneration (5.2%) and diabetic retinopathy (4.3%). Intraocular pathology in the fellow eye was associated with posterior segment pathology in mature cataract eyes (odds ratio, 47.72; P < 0.001).

Conclusions

The prevalence of each intraocular pathology found after mature cataract surgery was unremarkable. This study provides clinically useful evidence for clinicians to explain the risk of posterior segment pathology in patients with mature cataracts.

Sewing needle microcapsulotomy to avert Argentinian flag sign

The Argentinian flag sign is a known complication in intumescent white cataracts, which arises instantly after an initial prick with a sharp hypodermic needle on a stretched out anterior capsule. Increased intralenticular pressure is believed to be responsible for propagation of the initial prick into a radial capsular tear. However, it is the linear cut configuration of the initial prick, created by the hypodermic needle on the tense anterior capsule, which spontaneously opens up and propagates toward the periphery along its margins. To overcome this, a new instrument was devised, sewing needle microcapsulotome, to puncture the capsule and create a single or multiple round openings with smooth margins, allowing the bag to decompress satisfactorily without yielding to disruptive intralenticular forces. This technique of sewing needle microcapsulotomy, to prevent the Argentinian flag sign, was found to be highly effective and safe in a series of surgeries on intumescent cataracts.

Improvement in Activities of Daily Living after Cataract Surgery in the Very Old

BACKGROUND

The benefits of cataract surgery for patients aged ≥90 years in terms of improvements in activities of daily living (ADL) have been poorly evaluated using only limited data. Using a large nationwide administrative database of hospitalized patients, we investigated the improvement of ADL after cataract surgery in the very old (age of ≥90 years).

METHODS

We identified 84,747 patients with cataracts aged 80 to 89 years and 7,253 patients with cataracts aged ≥90 years who underwent cataract surgery in both eyes during hospitalization from April 2014 to March 2015. A retrospective matched-pair cohort study was performed to compare the proportion of patients with improved ADL after cataract surgery. We also compared the length of hospital stay between the two groups.

RESULTS

Patients aged ≥90 years were more likely to be female and have a lower ADL score at admission. In the 1:4 matched-pair analysis with 7,253 versus 29,012 pairs, a lower proportion of patients aged ≥90 years had an improved ADL score (odds ratio, 0.33; 95% confidence interval, 0.29-0.36; P < 0.001) even after adjusting for other variables. Patients aged ≥90 years had a slightly shorter length of hospital stay than those aged 80 to 89 years (7.5 vs. 8.2 days, respectively; P < 0.001).

CONCLUSIONS

In this large nationwide cohort of patients with cataracts, those aged ≥90 years showed significantly poorer improvement of ADL than did patients aged 80 to 89 years. Cataract surgery before the age of 90 years may be recommended for patients with cataracts.

[Ultrasound biomicroscopy for examination of the anterior segment of the eye in patients with intumescent cataract]

According to a prospective review study by H. Gimbel, A. Willerscheidt (1993), among 2967 cataract cases analyzed in 1991, mature intumescent cataract was observed in 34 (1.15%) patients.

PURPOSE

To determine the parameters of the ocular anterior segment in patients with intumescent cataract and in their fellow eyes using ultrasound biomicroscopy (UBM) for identification of differential characteristics of intumescent cataract.

MATERIAL AND METHODS

The results of preoperative diagnostic examination of the anterior segment of the eye with UBM of 21 patients (21 eyes) with intumescent cataract and their 21 fellow eyes (42 eyes in total) were analyzed.

RESULTS

The mean anterior chamber depth according to UBM was 1.96±0.108 mm (from corneal endothelium), in the fellow eyes - 2.74±0.11 mm. The anterior chamber angle was 11.54±2.19°, in the fellow eyes - 20.63±4.08°. The lens thickness in the eyes with intumescent cataract was 5.26±0.13 mm, in the fellow eyes - 4.34±0.09 mm. The length of Zinn ligaments in the external, interior and superior ocular segments of the main group eyes were equal, in the inferior segments they were longer by 0.1 mm. The difference in Zinn ligament length in the eyes with intumescent cataract and fellow eyes was approximately 0.1-0.15 mm in all segments. The equatorial angle in the eyes with intumescent cataract was 32.52±0.92°, in the fellow eyes - 14.85±1.09°.

CONCLUSION

A differential symptom of intumescent cataract was identified - complete spherophakia, as confirmed by a specific UBM sign: increase of the equatorial angle by 17° in comparison with the fellow eye, while the length of Zinn ligament remains equal in all segments.

[Determination of intralenticular pressure in patients with intumescent cataract]

When the lens swells, a liquefied lenticular substance that increases intralenticular pressure accumulates in the lens bag making it difficult to perform standard capsulorhexis. Thus, determination of the intralenticular pressure value is of great importance for safe intumescent cataract phacoemulsification.

PURPOSE

To develop a technology for intralenticular pressure measurement in patients with intumescent cataract and to construct a mathematical model for its prognosis according to preoperative examination data.

MATERIAL AND METHODS

Intralenticular pressure was measured in 11 eyes with intumescent cataract. Before that, the following parameters of the anterior compartment of the eye were examined: anterior chamber depth, lens thickness according to ultrasound biomicroscopy (UBM), hypoechogenic layer (the anterior layer of liquefied lenticular masses), equatorial angle.

RESULTS

The intraoperative technology of the intralenticular pressure measurement was developed. The direct dependency between thickness of the swelling lens, hypoechogenic layer value (the anterior layer of liquefied lenticular masses), anterior chamber depth and intralenticular pressure magnitude was defined.

CONCLUSION

For the first time, the intraoperative intralenticular pressure was measured in patients with intumescent cataract. A dependency was defined between the thickness of the lens and the anterior layer of liquefied lenticular masses, anterior chamber depth, and intralenticular pressure magnitude; based on this, a mathematical model for intralenticular pressure measurement was constructed.

Microinterventional endocapsular nucleus disassembly: novel technique and results of first-in-human randomised controlled study

Aim

To assess the safety and efficacy of microinterventional endocapsular nuclear fragmentation in moderate to severe cataracts.

Methods

This was a prospective single-masked multisurgeon interventional randomised controlled trial (ClinicalTrials.gov NCT02843594) where 101 eyes of 101 subjects with grade 3‒4+ nuclear cataracts were randomised to torsional phacoemulsification alone (controls) or torsional phacoemulsification with adjunctive endocapsular nuclear fragmentation using a manual microinterventional nitinol filament loop device (miLOOP group). Outcome measures were phacoemulsification efficiency as measured by ultrasound energy (cumulative dispersed energy (CDE) units) and fluidics requirements (total irrigation fluid used) as well as incidence of intraoperative and postoperative complications.

Results

Only high-grade advanced cataracts were enrolled with more than 85% of eyes with baseline best corrected visual acuity (BCVA) of 20/200 or worse in either group. Mean CDE was 53% higher in controls (32.8±24.9 vs 21.4±13.1 with miLOOP assistance) (p=0.004). Endothelial cell loss after surgery was low and similar between groups (7‒8%, p=0.561) One-month BCVA averaged 20/27 Snellen in miLOOP eyes and 20/24 in controls. No direct complications were caused by the miLOOP. In two cases, capsular tears occurred during IOL implantation and in all remaining cases during phacoemulsification, with none occurring during the miLOOP nucleus disassembly part of the procedure.

Conclusions

Microinterventional endocapsular fragmentation with the manual, disposable miLOOP device achieved consistent, ultrasound-free, full-thickness nucleus disassembly and significantly improved overall phaco efficiency in advanced cataracts.

Trial registration number

NCT02843594

[Intumescent cataract surgery]

Intumescent cataract surgery is one of the topical problems of ophthalmology. The article reviews methods of intumescent cataract diagnostics and structural features of swelling lens. Manual or femtolaser-assisted anterior continuous circular capsulorhexis and intumescent cataract phacoemulsification techniques require further research.

Impact of lens thickness on complications of hypermature cataract surgery: A prospective study

PURPOSE

To assess the correlation between lens thickness (LT) measured by ultrasonography and duration of surgery as well as complications.

SETTING

The study was conducted in a hospital in the Parisian suburb of Bobigny, France.

DESIGN

A prospective and monocentric study was conducted. All patients undergoing surgery for hypermature cataract between January 2013 and March 2014 were included.

METHODS

Morphological features, including LT, axial length, anterior chamber depth and vitreous length were assessed using A-scan ultrasonography. The other parameters assessed were the duration of surgery, occurrence of complications during surgery, visual acuity (VA) and corneal edema score one week after surgery.

RESULTS

Thirty eyes of 29 patients were included. Mean LT was 4.11±0.64mm (median: 3.89mm). Mean surgery duration was 24.2±8.7min. Three patients experienced complications during surgery: 2 capsular breaks and 1 posterior lens dislocation. At one week, the mean decimal VA was 0.49±0.34 and the mean corneal edema score was 0.76±1.09. The Pearson correlation coefficient was r=0.27 (P>0.05) between LT and surgery duration while it was r=-0.53 (P=0.01) between VA and LT. No correlation was found for the other parameters studied.

DISCUSSION

In this study, the linear correlation between LT and the surgery duration was low. The visual recovery at day 7 appeared inversely correlated with the LT.

CONCLUSIONS

LT did not seem to be a marker for longer surgery duration but appeared related to the visual recovery at one week.

Risk factors for intraocular pressure rise following phacoemulsification

Purpose:

This study was designed to analyze the risk factors resulting in high intraocular pressure (IOP), which was accepted as IOP higher than 22 mmHg, following uncomplicated phacoemulsification.

Materials and Methods:

The records of 812 eyes of 584 patients who underwent uncomplicated phacoemulsification were evaluated. There were 330 men and 254 women ranging between the age of 26 and 89 years (65.4 ± 9.8 years). The preoperative, postoperative first day (day 1), first week (day 7), and first month (day 30) IOP values were analyzed. Data on history of diabetes, glaucoma, pseudoexfoliation (PXF), incision site, capsular staining with trypan blue, and surgeon were recorded. A multinomial regression analysis was performed to analyse the relationship of the factors with postoperative high IOP.

Results:

The mean IOP was 15.6 ± 4.3 mmHg preoperatively. Postoperatively that were changed to 19.7 ± 9.0 mmHg at day 1, 12.7 ± 4.5 mmHg at day 7, and 12.8 ± 3.7 mmHg at day 30. The factors such as surgeon, presence of PXF, diabetes, surgical incision site, and trypan blue were not related to the postoperative high IOP (P > 0.05, in all). The only factor that related to high IOP at all visits was glaucoma (P < 0.005).

Conclusion:

According to our results, preoperative diagnosis of glaucoma seems to be the only factor to affect the postoperative IOP higher than 22 mmHg.

Lens capsule-related problems in patients undergoing phacoemulsification surgery

PURPOSE

This study aimed to compare lens capsule-related problems in mature versus non-mature senile cataracts in patients undergoing phacoemulsification surgery.

METHODS

A total of 295 patients with senile cataract were divided into two groups according to lens maturation: 105 patients with mature senile cataract comprised Group 1 (study group) and the remaining 190 with non-mature senile cataract comprised Group 2 (control group). Prior to surgery, ophthalmological examination was undertaken. Patients' best-corrected visual acuity and intraocular pressure were measured and a slit-lamp examination and funduscopy performed. All examination data were recorded and any capsule-related problems during surgery were also recorded. Patient files were reviewed retrospectively and compared between groups. Fisher's exact test was used in the statistical analysis.

RESULTS

In Group 1, the capsule-related problems found were: inability to complete capsulorhexis (seven eyes [6.6%]), posterior capsular perforation (three eyes [2.8%]), and conversion to extracapsular surgery (one eye [0.9%]). A posterior capsular perforation was seen in one eye (1%) in the control group. An intraocular lens was inserted into the sulcus in six eyes (5.7%) and one anterior chamber (0.9%) in Group 1 and into the sulcus in one eye (0.5%) of Group 2. The lens was inserted into the capsular bag in all other patients.

CONCLUSION

Delaying surgery in patients with cataracts creates a high risk for capsule-related surgical complications. Although capsule dyes make capsulorhexis easier, capsulorhexis is the most problematic phase of phacoemulsification in mature cataracts.

Response of corneal hysteresis and central corneal thickness following clear corneal cataract surgery

PURPOSE

To evaluate the effect of routine phacoemulsification in corneal viscoelastic properties determined by corneal hysteresis (CH) and central corneal thickness (CCT) and to explore the impact of phaco energy on the above parameters.

METHODS

Forty-one eyes of 41 patients undergoing cataract surgery were enrolled in this prospective study. CH and CCT were measured preoperatively, 1 day and 1 week postoperatively. CCT measurement was performed using a non-contact optical pachymeter followed by ocular response analyzer (ORA) examination. Intraoperatively ultrasound time, average phaco power and effective phaco time (EPT) were recorded.

RESULTS

Mean CH was 10.05±1.86 mmHg preoperatively, 8.25±1.85 mmHg 1 day and 9.12±1.37 mmHg 1 week postoperatively (p<0.001). The mean CCT was 534±37.33 μm preoperatively, 592.22±46.34 μm 1 day and 563.21±49.84 μm 1 week postoperatively (p<0.001). CCT and CH were statistically significantly correlated preoperatively (p=0.01, r=0.396). This correlation was not sustained on the first postoperative day (p=0.094, r=0.265) and was re-established 1 week postoperatively (p=0.002, r=0.568). On the first postoperative day, the CCT increase was positively correlated with EPT (p=0.009, r=0.404), which was not found between CH change and EPT.

CONCLUSION

Structural corneal alterations following cataract surgery resulted in a statistical change in CH and CCT. These two parameters responded in a different manner that clearly demarcates their different nature. On the first postoperative day, CCT increase was correlated at a statistically significant level with intraoperative EPT. This correlation was not found with CH reduction. Other factors, besides cornea oedema or phacoemulsification energy, could be responsible for this CH modification.

Ultrasonographic analysis of senile cataractous lens of dogs and its correlation to phacoemulsification

This study aimed to evaluate the effectiveness of a computer-assisted ultrasound analysis of senile dogs cataractous lens and identify its correlation to phacoemulsification surgical parameters. Simultaneous A- and B- mode ultrasonic evaluation of the lens was performed on 15 dogs with cataract. A computer-assisted image analysis was used to objectively calculate the lens echogenicity. Following ultrasonographic examination the cataracts were removed by phacoemulsification and the ultrasonographic and phacoemulsification findings were compared to identify possible correlations. Lens echogenicity obtained by the computer-assisted ultrasonographic analysis correlated to the phacoemulsification time, such that the whiter the ultrasound image, the longer was the phacoemulsification time. The B-mode ultrasonography was helpful for the prediction of lens opacity location, but not predictive of lens hardness.

Results of coaxial phacoemulsification through a 1.8-mm microincision in hard cataracts

BACKGROUND AND OBJECTIVE

To assess the results of coaxial phacoemulsification through 1.8-mm coaxial microincision cataract surgery (C-MICS) phacoemulsification with foldable intraocular lens implantation in eyes with hard cataracts in comparison to eyes with soft cataracts.

PATIENTS AND METHODS

Group 1 consisted of 40 eyes of 40 patients with hard cataracts (grade ≥ 4, Lens Opacities Classification System III scale) and group 2 consisted of 45 eyes of 45 patients with non-mature cataracts (grade ≤ 2, Lens Opacities Classification System III scale). All surgeries were performed by two experienced surgeons under topical and intracameral anesthesia. Examinations were performed preoperatively and 1 month after the surgery. Examined parameters included distance-corrected visual acuity (DCVA), autorefractometry, keratometry, tonometry, endothelial cell counts, and biomicroscopy of the anterior and posterior segment. Surgically induced astigmatism was calculated with vector analysis.

RESULTS

Mean DCVA was 0.16 ± 0.16 preoperatively and 0.92 ± 0.21 postoperatively in group 1 (P < .05) and 0.62 ± 0.18 preoperatively and 0.97 ± 0.08 postoperatively in group 2 (P < .05). Mean surgically induced astigmatism was 0.48 ± 0.44 in group 1 and 0.53 ± 0.38 in group 2 (P > .05). Mean endothelial cell loss was 11.37% ± 12.87% in group 1 and 2.87% ± 9.66% in group 2 (P < .05).

CONCLUSION

Although density of cataract has an unfavorable influence on early postoperative corneal endothelial cell loss, it did not significantly influence final DCVA and surgically induced astigmatism. C-MICS is a safe and effective method of treatment of cataracts, including cataracts with hard nuclei, and usually leads to good functional outcomes.

Mini-rhexis for white intumescent cataracts

PURPOSE

To compare the intraoperative safety of two techniques of capsulorhexis for intumescent white cataracts: traditional one-stage continuous curvilinear capsulorhexis and two-stage continuous curvilinear capsulorhexis.

METHODS

This prospective comparative randomized study included two groups: the 1-CCC group (11 patients) received traditional one-stage continuous curvilinear capsulorhexis with 5-6 mm diameter, and the 2-CCC (13 patients) group received a deliberately small continuous curvilinear capsulorhexis that was secondarily enlarged, or a two-stage continuous curvilinear capsulorhexis. Patients were stratified according to cataract subset, which was characterized echographically. Six patients were considered as type 1, fifteen as type 2 and three as type 3. Type 1 included intumescent white cataracts with cortex liquefaction and extensive internal acoustic reflections, type 2 included white cataracts with voluminous nuclei, a small amount of whitish solid cortex, and minimal internal acoustic reflections, and type 3 included white cataracts with fibrous anterior capsules and few internal echo spikes.

RESULTS

With the one-stage technique, 46.15% of patients had leakage of the liquefied cortex; in addition, the surgeon perceived high intracapsular pressure in 61.53% of cases. Anterior capsule tears occurred in 23.07% of cases, discontinuity of capsulorhexis in 30.79% of cases and no posterior capsular rupture occurred. With the two-stage technique, leakage of the liquefied cortex occurred in 45.45% of cases; additionally, the surgeon perceived high intracapsular pressure in 36.36% of cases. No anterior capsule tears, discontinuity of capsulorhexis or posterior capsular rupture occurred. Considering each cataract subset, there was a higher incidence of leakage for type 2 as compared to types 1 and 3.

CONCLUSIONS

Two-stage continuous curvilinear capsulorhexis helps prevent unexpected radial tears of the initial capsulotomy from high intracapsular pressure, sudden radialization of the CCC and other intraoperative complications due to high intracapsular pressure, thus providing a safe cataract surgery in cases of white cataracts. These findings were supported by ultrasonography.

[Phacoemulsification in eyes with white cataracts: results and complications]

PURPOSE

To compare visual acuity and complications in phacoemulsification in eyes with white cataract and in eyes with immature senile cataract.

PATIENTS AND METHODS

This was a prospective study on 36 eyes in 34 patients with white cataract (group 1) and 36 eyes in 36 patients with immature senile cataract (group 2).

RESULTS

In group 1, mean preoperative visual acuity was 1/100 and mean postoperative visual acuity was 5/10 at 1 month. Posterior capsule tears occurred in four eyes (11%). In group 2, mean preoperative visual acuity was 2/10 and mean postoperative visual acuity was 7/10 at 1 month. No posterior capsule tear was observed. The preoperative visual acuity was significantly lower in group 1 (p=1.8x10(-14)). Postoperative visual acuities were not significantly different between the two groups (p=0.07). The increase in visual acuity was significantly higher in group 1 (p=2.2x10(-11)).

DISCUSSION

Our study shows that white cataract is not a risk factor of poor postoperative visual acuity and the increase in visual acuity is greater in the white cataract group than in the immature cataract group.

CONCLUSION

The results of phacoemulsification in white cataracts are satisfactory in spite of a high rate of posterior capsule rupture in our study.

Capsulorhexis Assisted by Slit Illuminator for White Cataract Without a Red Reflex

The authors investigated the clinical efficacy of a slit illuminator in a surgical microscope during capsulorhexis for white cataract. After staining the anterior capsule, the slit illuminator was adjusted to a width of 3 mm and a height of 12 mm using the slider to obtain a high-contrast image of the anterior capsule, and an angle of 30 degrees to both the left and right was possible using the arc guide. After the anterior capsular puncture was done, a capsulorhexis forceps was used to grasp the capsular edge and a continuous curvilinear capsulorhexis was successfully performed in all 10 cases. Using a slit illuminator in a surgical microscope seems to be a valuable technique for performing a continuous curvilinear capsulorhexis on a mature or intumescent cataract that has no red reflex and high intralenticular pressure.

Safety and Efficacy of Micro-Incisional Cataract Surgery with Bimanual Phacoemulsification for White Mature Cataract

BACKGROUND

To evaluate the safety and efficacy of micro-incisional cataract surgery (MICS) with bimanual phacoemulsification for the management of white mature cataract.

METHODS

Twenty-five eyes in 25 patients with mature cataract were prospectively recruited to undergo MICS with bimanual phacoemulsification. Serial changes in best-corrected visual acuity (BCVA), central corneal thickness (CCT) and endothelial cell density (ECD) were compared using the Wilcoxon signed-rank test.

RESULTS

MICS was successfully performed in 24 (96%) of the 25 eyes, with 1 eye requiring conversion to extracapsular cataract extraction due to radial tear during continuous curvilinear capsulorhexis. The median preoperative BCVA was hand movement. On day 1 postoperatively, the median BCVA improved to 0.6 (p < 0.001 compared with baseline). All patients had BCVA of 0.6 or better at 3 months after surgery (p < 0.001 compared with baseline). The mean increase in CCT at day 1 and week 1 postoperatively was 11.5 and 7.1%, respectively. The change in mean CCT was no longer significant at month 3 postoperatively (p = 0.82). The mean reduction in ECD at 3 months postoperatively was 7.8% (p = 0.037). None of the patients developed any postoperative complications.

CONCLUSIONS

MICS with bimanual phacoemulsification appeared to be a promising alterative for the management of white mature cataract.

A prospective study on trypan blue capsule staining under air vs under viscoelastic

AIM

To compare the safety and effectiveness of trypan blue capsule staining under air vs under viscoelastic.

METHODS

A total of 52 consecutive patients planned for phacoemulsification of white mature cataract were randomly assigned to trypan blue staining under air or under viscoelastic. Perioperative changes in best-corrected visual acuity (BCVA), central corneal thickness (CCT), and endothelial cell density (ECD) were compared between the two groups. The differences in operating and phacoemulsification times, staining pattern, and complications between the two groups were also recorded.

RESULTS

Phacoemulsification of white mature cataract was performed in 50 (96%) eyes. The median preoperative BCVA was hand movement. No significant differences in the baseline characteristics were found between the two groups. At 3 months after phacoemulsification, the median BCVA improved to 0.8. The mean CCT returned to preoperative level by 1 month postoperatively and the mean ECD loss was 11.9% 3 months postoperatively. No significant differences in median BCVA, mean phacoemulsification and operation times, mean CCT, and mean ECD were found between the two groups.

CONCLUSIONS

Trypan blue staining of the anterior lens capsule under air or under viscoelastic were similarly effective and safe methods for the phacoemulsification of white mature cataract.

Effects of trypan blue on cell viability and gene expression in human retinal pigment epithelial cells

AIM

To evaluate the effects of trypan blue on cell viability and gene expression in human retinal pigment epithelial (RPE) cells.

METHODS

Three concentrations (0.06 mg/ml, 0.6 mg/ml, and 4 mg/ml) of trypan blue were applied to human ARPE19 cells for 1 minute. Cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. RPE cells were sampled daily for 6 consecutive days to assess the effects of trypan blue on cell viability. The effects of trypan blue on the expression of apoptosis related and cell cycle arrest gene expressions including c-fos, c-jun, p53, and p21 were performed using reverse transcription-polymerase chain reaction and immunostaining.

RESULTS

The MTT assay showed a concentration dependent suppression effect of trypan blue on cell viability, with higher reduction in the 0.6 mg/ml and 4 mg/ml trypan blue treated groups. No significant change in the expression of c-fos and c-jun was found with all three concentrations of trypan blue. An increase in p53 expression was found in the 4 mg/ml trypan blue treated group at 10-30 minutes after trypan blue application. Immunostaining showed a mild, albeit insignificant, increase of p53 expression in the RPE cells. No significant increase in p21 expression was observed in the 0.06 mg/ml trypan blue treated group but there were significant increases in p21 expression in both the 0.6 mg/ml (p = 0.032) and the 4 mg/ml (p = 0.025) treated groups.

CONCLUSIONS

Trypan blue may lead to toxicity on cultured RPE cells as indicated by the reduction in cell viability and changes in the expression of apoptosis related and cell cycle arrest genes at higher concentrations. The application of 0.06 mg/ml trypan blue for 1 minute appeared to have no significant effect on cultured RPE.