Step-down technique

Eye-Related Factors That Can Be Associated With the Plane of Phacoemulsification

Purpose: To evaluate the effect of eye-related factors such as biometric and surgical parameters, nuclear sclerosis (NS) grade, and pupil and capsulorhexis diameters on the plane of phacoemulsification (PP).

Material and Methods: This prospective study included 328 eyes of 328 patients who underwent phacoemulsification surgery. The phaco-chop technique was performed in all patients and changes in PP that occurred during surgery were recorded. Patients were grouped as follows: Group 1, > 75% of lens nucleus emulsified in the capsular bag; Group 2, > 75% of lens nucleus emulsified at the pupillary plane; and Group 3, > 50% of lens nucleus emulsified in the anterior chamber. The association between PP and eye-related factors was evaluated.

Results: There were 153 patients (46.7 %) in Group 1, 104 patients (31.7 %) in Group 2 and 71 patients (21.6 %) in Group 3. The factors associated with PP were anterior chamber depth (ACD) (p = 0.020) and NS grade (p = 0.028). No significant relationship was detected between PP and age, surgical parameters or other biometric values. Moreover, PP was found to be more anterior in patients with soft cataracts and deeper ACD values (p values were 0.002 and 0.036, respectively).

Conclusion: The present study has reported that PP may move to more anterior, as softer cataracts may increase the fear of posterior capsule rent. Moreover, PP may move to more posterior due to shallow anterior chambers or high-grade cataracts that could potentially increase the fear of endothelial injury.

[Cataract surgery and the small eye: relative anterior microphthalmos, high hyperopia and nanophthalmos]

Relativer anteriorer Mikrophthalmus, hochgradige Hyperopie und Nanophthalmus bezeichnen klein gebaute Augen mit unterschiedlichem morphologischem Verhältnis zwischen Vorderabschnitt und Achsenlänge. Im Rahmen dieses Beitrags werden intraoperative Herausforderungen und chirurgische Lösungsansätze für die Kataraktoperation bei Patienten mit einer der 3 genannten morphologischen Veränderungen diskutiert. Zusätzlich wird auf mögliche, vorliegende Komorbiditäten, wie z. B. das Glaukom, und die präoperative Planung eingegangen.

Comparison of ocular wavefront aberrations in subluxated lenses before and after lens extraction with intraocular lens implantation

PURPOSE

To compare the change in ocular higher-order wavefront aberrations (HOAs), visual acuity, and modulation transfer function (MTF) after lens extraction with intraocular lens (IOL) implantation in patients with subluxated lenses.

SETTING

Iladevi Cataract & IOL Research Centre, Ahmedabad, India.

DESIGN

Prospective case series.

METHODS

Eyes with subluxated lenses having lens extraction with IOL implantation were included. Capsular bag fixation with in-the-bag IOL implantation or sutured or sutureless scleral fixation of the IOL was performed. Aberrometry was performed preoperatively and 6 months postoperatively. The following were compared: root-mean-square (RMS) value for total ocular HOAs, coma aberration, spherical aberration, MTF, and corrected distance visual acuity (CDVA).

RESULTS

Of the 39 eyes with subluxated lenses, 26 eyes had Cionni ring fixation, 9 had sutured scleral fixation, and 4 had intrascleral fixation of the IOL. The mean preoperative and postoperative values, respectively, were as follows: RMS HOAs, 10.5 μm ± 9.5 (SD) and 4.73 ± 4.6 μm (P < .001); coma aberration, 2.46 ± 2.4 μm and 0.11 ± 0.1 μm (P = .03); and spherical aberration, 0.37 ± 0.9 μm and 0.02 ± 0.06 μm (P = .02). The MTF improved significantly in all eyes (mean 0.05 ± 0.02 preoperatively and 0.32 ± 0.16 postoperatively) (P = .005). The CDVA was statistically significant improved 6 months postoperatively.

CONCLUSION

Lens extraction with IOL fixation in eyes with subluxated lenses significantly reduced ocular HOAs and improved the MTF.

Effect of fluidics on corneal endothelial cell density, central corneal thickness, and central macular thickness after phacoemulsification with torsional ultrasound

Aim:

To study the relative effects of high and low fluidic parameters on endothelial cell density (ECD), central corneal thickness (CCT), and central macular thickness (CMT) after phacoemulsification with torsional ultrasound.

Settings and Design:

Prospective, randomized clinical trial based on a tertiary eye hospital.

Subjects and Methods:

The study included 65 patients in each group. Patients were randomized to either the high or the low flow group using a computerized random number table. The study was patient and examiner masked. All patients underwent phacoemulsification with torsional ultrasound. Visual acuity, ECD, CCT, and CMT were measured for all patients preoperatively at 2 weeks and 6 weeks postoperatively.

Statistical Analysis Used:

The Shapiro–Wilks test was used to assess the normality of the data. Mann–Whitney U-test with the P value set at 0.05 was used to compare the two groups.

Results:

Cumulative dissipated energy was significantly higher in the low flow group (16.44 ± 9.07 vs. 11.74 ± 6.68; P = 0.002). No statistically significant difference was noted between the two groups in the ECD, CCT, CMT, or corrected distance visual acuity at the end of 6 weeks.

Conclusions:

No significant difference was noted in the postoperative outcome between high and low flow groups. Parameters can be modified to suit the surgeon's preference, as both high and low flow parameters were found to have comparable postoperative outcomes.

Real-time intraocular pressure measurement during phacoemulsification in dogs ex vivo

This study was performed to evaluate changes in intraocular pressure (IOP) during standard coaxial phacoemulsification using 4 different bottle heights (BHs) and 2 different incision sizes. Coaxial phacoemulsification was performed with a venturi-based machine in 8 enucleated canine eyes through 3.0 and 3.2 mm clear corneal incisions (CCIs). A pressure transducer inserted in the peripheral cornea monitored the IOP in real-time. The surgery was subdivided into 4 stages: sculpt-segment removal, irrigation/aspiration, capsular polishing and viscoelastic removal. The mean IOP and the difference between the maximum and minimum IOPs were calculated at each stage and compared. The ultrasound time and volume of irrigation fluid used were recorded. The mean IOP increased with an elevation in the BH. The mean IOP in the irrigation/aspiration stage was significantly higher than that in the sculpt-segment removal stage at the same BH. The difference between the maximum and minimum IOP at each stage was greater in the 3.2 mm than the 3.0 mm CCIs, although the mean IOP was lower with the 3.2 mm than the 3.0 mm CCIs. The ultrasound time and irrigation fluid volume were greater with the 3.2 mm than the 3.0 mm CCIs. Therefore, fluidic parameters during each stage could be reassessed and adjusted to reduce complications arising from an elevated IOP. Phacoemulsification with 3.0 mm CCIs at a lower BH might lead to less stress on the eye from IOP fluctuations, ultrasound energy and irrigation fluid.

Real-time dynamic intraocular pressure fluctuations during microcoaxial phacoemulsification using different aspiration flow rates and their impact on early postoperative outcomes: a randomized clinical trial

PURPOSE

To compare the impact of varying fluidic parameters on intraoperative intraocular pressure (IOP) fluctuations and postoperative outcomes.

METHODS

Prospective randomized study of 80 eyes undergoing cataract surgery that were randomly assigned to low (aspiration flow rate: 20 cc/min; bottle height: 90 cm; vacuum: 400 mm Hg) and high (aspiration flow rate: 40 cc/min; bottle height: 110 cm; vacuum: 400 mm Hg) fluidic parameter groups. Real-time dynamic intraoperative IOP was measured during nuclear fragment removal. Mean maximum and minimum IOP and percentage reduction in IOP from maximum were compared between groups. Postoperatively, the rate of change in central corneal thickness and anterior chamber inflammation at days 1 and 7, endothelial cell density at 3 months, and corneal clarity on day 1 were compared.

RESULTS

Minimum IOP in the low and high parameters groups was 35 ± 4.0 and 34.5 ± 6.8 mm Hg, respectively. Maximum IOP in the low and high parameters groups was 69 ± 3.0 and 85 ± 1.2 mm Hg, respectively (P < .002). Mean percent reduction from maximum was 59% in the high parameters group compared to 41% in the low parameters group, with the difference being statistically significant (P < .002). Rate of change in central corneal thickness was greater in the high parameters group at postoperative days 1 and 7 (P < .001). Anterior chamber inflammation and corneal clarity on the first postoperative day were significantly better in the low parameters group.

CONCLUSIONS

Higher aspiration flow rate and bottle heights are associated with high intraoperative IOPs of up to 85 mm Hg. Prolonged elevated IOP during cataract surgery was found to have more anterior segment inflammation and more edematous corneas.

Fluid dynamics and intraocular pressure using venturi phacoemulsification machine in dogs ex vivo

OBJECTIVE

To optimize fluid dynamics through measuring intraocular pressure (IOP) in a venturi phacoemulsification machine in dogs.

PROCEDURES

In step I, flow and IOP of the test chamber were measured using a pressure transducer with the bottle height (BH) set at 50, 70, 100, and 120 cm and the vacuum from 30 to 450 mmHg. A 19-gauge phaco and a 0.3-mm irrigation/aspiration (I/A) handpiece were used. In step II, flow and IOP were measured in an enucleated canine eye with a 3.0- and a 3.2-mm clear corneal incision (CCI), respectively. IOP was measured using the pressure transducer at a 30-mmHg vacuum to allow corneal deformation, to define the fluidic parameters for preventing surge.

RESULTS

Flow was directly proportional to the BH and vacuum, whereas IOP was directly proportional to the BH and inversely to the vacuum. Flow with an I/A handpiece was significantly less than with a phaco handpiece, explaining why IOP with an I/A handpiece was significantly higher than with a phaco handpiece. With the I/A handpiece, vacuum parameters less than 450 mmHg did not result in corneal deformation. IOP with a 3.2-mm CCI was significantly lower than with a 3.0-mm CCI, with the 3.2-mm flow being greater than the 3.0-mm flow.

CONCLUSIONS

BH during the I/A stage could be reduced to avoid unnecessary stress on the canine eye when using a venturi system. Although phacoemulsification with a 3.2-mm CCI could induce lower IOP, a 3.0-mm CCI might lessen the irrigation flow stress on the eye.

A prospective evaluation of posterior capsule opacification in eyes with diabetes mellitus: a case-control study

AIM

To compare the development of posterior capsule opacification (PCO) between eyes with and without diabetes mellitus after single-piece hydrophobic acrylic intraocular lens implantation 4 years postoperatively.

METHODS

In this prospective, observational case-control study carried out at Iladevi Cataract and IOL Research Centre, Ahmedabad, India, 75 consecutive eyes with diabetes mellitus (cases) were compared with 75 age-matched eyes with age-related cataract (controls). A detailed, preoperative and posterior segment evaluation was carried out in eyes with diabetes mellitus to detect the presence or absence of diabetic retinopathy (DR). The Mann-Whitney U-test was applied to compare the differences in the development of PCO between the two groups.

RESULTS

There was no difference in median PCO between cases and controls at 1 month (2.0 vs 1.50, P<0.068), but cases had a higher median PCO at 12 months (2.95 vs 1.30, P<0.001). At 4 years, there was no significant difference in median PCO between cases and controls (3.75 vs 2.25, P=0.273). The duration of diabetes increased the incidence of PCO at 4 years (P=0.02). Severity of DR had no influence on the progress of PCO at 4 years (P=0.69).

CONCLUSION

Diabetes mellitus did not increase the incidence of PCO at 4 years. The duration of diabetes increased the risk of PCO. The severity of retinopathy did not influence the development of PCO.

Comparison of the effect of torsional and microburst longitudinal ultrasound on clear corneal incisions during phacoemulsification

PURPOSE

To compare incision integrity after clear corneal microcoaxial phacoemulsification using longitudinal and torsional ultrasound (US).

SETTING

Iladevi Cataract & IOL Research Centre, Ahmedabad, India.

DESIGN

Prospective randomized experimental clinical trial.

METHODS

Part 1 comprised an experimental study of rabbit eyes. Group 1 received longitudinal US. Group 2 received torsional US. The right eye of each rabbit served as a control. Samples were processed for histomorphology and collagen I denaturation by immunofluorescence. Part 2 comprised a clinical trial of patients. Group 1 received torsional US. Group 2 received longitudinal US. At the end of surgery, trypan blue 0.0125% was instilled. After 2 minutes, 0.1 mL of aqueous was aspirated and its optical density measured.

RESULTS

In part 1, incision histomorphology was comparable in both modalities. Collagen denaturation tests (immunofluorescence, dot blot analysis) showed no irregularity in collagen arrangement in either group. In Group 2, Descemet membrane was detached and endothelial cells were minimal at the roof of the incision. In part 2, trypan blue ingress into the anterior chamber was significantly greater in Group 1 than in Group 2 (mean 3.40 + 0.6 log units versus and 3.77 + 0.82 log units) (P<.007).

CONCLUSIONS

Incision histomorphology in the torsional group showed minimal Descemet membrane detachment and minimal endothelial cell loss at the roof of the incision. Minimal ingress of trypan blue into the anterior chamber was observed with torsional US, indicating better wound integrity than with longitudinal US.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Cionni ring and in-the-bag intraocular lens implantation for subluxated lenses: a prospective case series

PURPOSE

To report the intraoperative performance and postoperative outcomes of the Cionni-modified capsule tension ring (CTR) implantation in eyes with subluxated lenses.

DESIGN

Prospective, observational case series.

METHODS

This study was carried out at Iladevi Cataract & IOL Research Centre, Ahmedabad, India. The study population comprised 41 eyes with subluxated lenses that underwent lens extraction, capsular bag fixation with modified CTR, and in-the-bag single-piece AcrySof intraocular lens (IOL) implantation. Main outcome measures were intraoperative performance and postoperative best-corrected visual acuity (BCVA), IOL centration, and complications.

RESULTS

The mean age was 29.46 ± 16.16 years (3-68 years). Mean extent of subluxation was 6.1 ± 1.0 clock hours. Preoperatively, vitreous was detected in the anterior chambers of 5 eyes (12.2%). Two-port anterior chamber vitrectomy was performed in 2 eyes. Mean follow-up was 45.8 ± 2.9 months. Mean preoperative BCVA was 0.66 ± 0.22 logMAR (35 eyes). Mean postoperative BCVA at final follow-up was 0.33 ± 0.21 logMAR (41 eyes) (P < .001). BCVA improved in 35 eyes (85.4%) at the last follow-up. In 3 eyes (7.3%) IOL decentration was noted and repositioning was required in 2 eyes. Posterior capsule opacification developed in 14 eyes (34.2%); 12 eyes (29.3%) required Nd:YAG capsulotomy. Other complications included cystoid macular edema in 1 eye (2.4%), posterior synechiae in 1 eye (2.4%), and retinal detachment in 1 eye (2.4%).

CONCLUSION

In-the-bag implantation of a Cionni-modified CTR with IOL appears to be a safe option in eyes with subluxated cataract, ensuring a stable IOL with few complications.

Comparison of posterior capsule opacification with hydrophobic acrylic and hydrophilic acrylic intraocular lenses

PURPOSE

To compare posterior capsule opacification (PCO) 3 years postoperatively in contralateral eyes with a single-piece hydrophobic acrylic and 1 of 2 single-piece hydrophilic acrylic intraocular lenses (IOLs) with different configurations.

SETTING

Iladevi Cataract and IOL Research Institute, Ahmedabad, India.

DESIGN

Prospective randomized clinical trial.

METHODS

A hydrophobic Acrysof (hydrophobic group) or a hydrophilic C-flex (hydrophilic group C) or Akreos Adapt IOL (hydrophilic group A) was randomized for implantation in the fellow eye or vice versa of each patient. The Evaluation of Posterior Capsule Opacification (EPCO) area, EPCO score, and neodymium:YAG (Nd:YAG) capsulotomy rates were compared using digital photographs.

RESULTS

The study enrolled 68 patients. Although there was no significant difference at 1 month, the median EPCO score was statistically significantly lower in the hydrophobic group than in hydrophilic group C (P = .00) and hydrophilic group A (P = .000) at 3 years. There were no significant differences in the median EPCO area at 1 month; however, the area was statistically significantly less in the hydrophobic group than in hydrophilic group C and hydrophilic group A at 3 years (both P = .000). Four (12.9%) of 31 eyes in hydrophilic group C and 5 (16%) of 31 eyes in hydrophilic group A required an Nd:YAG capsulotomy; no eye in the hydrophobic group required a capsulotomy (P = .04 and P = .02, respectively).

CONCLUSION

Posterior capsule opacification was significantly less with the Acrysof hydrophobic acrylic IOL at 3 years.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Comparison between Ringer's lactate and balanced salt solution on postoperative outcomes after phacoemulsfication: a randomized clinical trial

Aim:

To compare the effects of balanced salt solution (BSS) and Ringer's lactate (RL) on corneal thickness, endothelial morphology, and postoperative anterior chamber inflammation in eyes undergoing phacoemulsification.

Setting:

Iladevi cataract and IOL research center, Ahmedabad, India.

Materials and Methods:

This prospective randomized study comprised 90 consecutive patients with age-related cataract who were randomly assigned to either Group 1 (n = 45) with BSS or Group 2 (n = 45) with RL. Observations made included measurement of central corneal thickness (CCT), presence of anterior chamber flare and cells, endothelial cell loss, and change in coefficient of variation (CV). Data was analyzed using Mann Whitney test and test of proportion.

Results:

Mean increase in CCT on postoperative Day 1 was 58 µm and 97 µm in Groups 1 and 2 respectively (P = 0.01). Increase in CCT at one month was 10µm and 11µm in Groups 1 and 2 respectively (P = 0.99); increase in CCT at three months was 3 µm and 6 µm in Groups 1 and 2 respectively (P = 0.86). Number of eyes with flare grades in a range of 0 to 3 was statistically higher in Group 2 on postoperative Day 1 (P = 0.004, 0.016, <0.001, 0.047 for Grade 0, 1, 2 and 3 respectively). Number of eyes with cells of Grade 3 on first postoperative day was significantly higher in Group 2 as compared to Group 1 (P = 0.004). Three months postoperatively, endothelial cell loss was 5.5% and 7.8% in Groups 1 and 2 (P = 0.21) and change in CV was 3 and 5.4 in Groups 1 and 2 (P = 0.20) respectively.

Conclusion:

BSS offers a significant advantage over RL in terms of increase in corneal thickness and postoperative inflammation on the first postoperative day in patients undergoing phacoemulsification.

DisCoVisc versus the soft-shell technique using Viscoat and Provisc in phacoemulsification: randomized clinical trial

PURPOSE

To compare the effects and outcomes of DisCoVisc (hyaluronic acid 1.6%-chondroitin sulfate 4.0%) with those of the soft-shell technique using Viscoat (sodium hyaluronate 3.0%-chondroitin sulfate 4.0%) and Provisc (sodium hyaluronate 1.0%) in phacoemulsification.

SETTING

Iladevi Cataract & IOL Research Centre, Ahmedabad, India.

METHODS

This prospective randomized clinical trial comprised 100 eyes having phacoemulsification by the same surgeon using a standardized technique. Eyes were randomly assigned to DisCoVisc (Group 1) or Viscoat and Provisc (Group 2). Preoperative and postoperative examinations included absolute change in pachymetry, percentage difference in endothelial cell density (ECD) and coefficient of variation (CV), and anterior segment inflammation.

RESULTS

The mean postoperative central corneal thickness (CCT) in Group 1 and Group 2 was 590.96+/-46.05 microm and 586.94+/-50.57 microm, respectively, at 1 day; 554.14+/-35.45 microm and 551.65+/-37.69 microm, respectively, at 7 days; and 533.74+/-29.12 microm and 536.44+/-35.59 microm, respectively, at 1 month. The between-group differences in CCT were not statistically significant. At 3 months, the mean ECD was 2427.06+/-243.26 cells/mm2 and 2475.30+/-222.83 cells/mm2, respectively, and the mean CV, 42.38+/-7.94 cells/mm2 and 41.66+/-7.71 cells/mm2, respectively. There was no significant difference in the mean ECD between preoperatively and 3 months postoperatively or in corneal thickness between preoperatively and 1, 7, and 30 days postoperatively.

CONCLUSION

A single injection of DisCoVisc was effective, and its postoperative outcomes were comparable to those of combined Viscoat and Provisc.

Intraoperative performance and postoperative outcomes of microcoaxial phacoemulsification

PURPOSE

To evaluate the intraoperative performance and postoperative outcomes after microcoaxial phacoemulsification.

SETTING

Iladevi Cataract & IOL Research Centre, Ahmedabad, India.

METHODS

A prospective observational case series comprised 84 eyes with age-related uncomplicated cataract having microcoaxial phacoemulsification through a 2.2 mm clear corneal incision by a standard surgical technique. Phacoemulsification parameters (Infiniti Vision System, Alcon) were microburst width, 30 ms; preset power, 50%; vacuum, 650 mm Hg; aspiration flow rate, 25 cc/minute. A single-piece Alcon AcrySof intraocular lens was implanted with the C cartridge (Alcon) cartridge. The incision was measured at the end of surgery. Observations included surgical time (from commencement of sculpting to end of epinucleus removal), cumulative dissipated energy (CDE), wound burns, intraoperative complications, postoperative increase in mean central corneal thickness (CCT) at 1 day and 1 month, mean % decrease in endothelial cell density (ECD), absolute mean change in coefficient of variation (cv) 3 months, and uncorrected visual acuity (UCVA) at 1 day. Data were analyzed using a 1-sample t test with 95% confidence intervals (CIs).

RESULTS

The mean follow up was 3 months +/- 0.3 (SD). The mean incision size at the end of surgery was 2.3 +/- .09 mm; mean surgical time, 4.5 +/- 1.5 minutes; and mean CDE, 2.3 +/- 2.2 seconds. No wound burns or other intraoperative complications occurred. The postoperative CCT increased by a mean of 16 microm at 1 day (95% CI, 8-25; P = .66;) and by a mean of 3.14 microm at 1 month (95% CI, 2.26-4.05; P = .92). The ECD decreased by a mean of 5.8% (95% CI, 6.8-3.5; P = .82) and the mean coefficient of variation, by 3.3 (95% CI, 4.5-2.0; P = .65). At 1 day, the UCVA was 20/20 in 29% of cases, 20/20 to 20/40 in 58%, and 20/40 to 20/50 in 12%.

CONCLUSION

Microcoaxial phacoemulsification was safely and effectively performed, achieving consistent and satisfactory postoperative outcomes.

Anterior capsule cover and axial movement of intraocular lens

PURPOSE

To measure optic shift (OS) of a single piece monofocal intraocular lens (IOL) with varying relationships between anterior capsule cover and IOL optic.

METHODS

This is a prospective randomized masked study of 150 eyes undergoing phacoemulsification. Eyes received either option: 360 degrees total capsule cover (group I); partial cover (group II); or no cover (group III). OS was calculated as difference in anterior chamber depth after administration of cyclopentolate 1% and pilocarpine 2% on IOLMaster at separate visits at 6 months follow-up. Subsequently, using retro-illumination photographs, percentage area of capsule cover was calculated. OS within and between groups I and II was analyzed. The impact of one quartile change in area of capsule cover on percentage change in OS was measured for both groups. Unpaired t-test, correlation, and regression were applied.

RESULTS

In groups I, II, and III, mean age of patients was 56.68+/-6.38, 57.09+/-7.34, 59.15+/-6.35 years, respectively; mean OS (mm) was 1.25+/-0.28, 1.20+/-0.24; 0.95+/-0.26 (P=0.013), respectively; and percentage area of capsule cover (%) was 47.35+/-10.48, 33.83+/-10.11, 0.16+/-0.13 (P=0.001), respectively. Mean percentage area of capsule cover in group I vsgroup II was significant (P=0.001). OS was 1.22+/-0.26 mm in groups I and II (combined) vs0.95+/-0.26 mm in group III (P=0.004, (0.06, 0.33)). OS in group I vsgroup II was not significant (P=0.46). Correlation coefficient was r=0.38 (P<0.001). With every increment on quartile (a quartile is any of the three values which divide the sorted data set into four equal parts, so that each part represents one-fourth of the sample or population) class of area of capsule cover the OS increased by 0.12 mm.

CONCLUSION

The OS differed significantly between total and partial cover groups combined vsno cover group.

Contrast sensitivity and glare disability after implantation of AcrySof IQ Natural aspherical intraocular lens

PURPOSE

To evaluate contrast sensitivity and glare disability after implantation of an AcrySof IQ Natural SN60WF aspherical intraocular lens (IOL) (Alcon Laboratories).

SETTING

Iladevi Cataract & IOL Research Centre, Ahmedabad, India.

METHODS

One hundred twenty consecutive patients who had phacoemulsification in a prospective triple-masked trial were randomized to receive an AcrySof SA60AT IOL (40 eyes), AcrySof Natural SN60AT IOL (40 eyes), or AcrySof IQ SN60WF IOL (40 eyes). At 3 months, contrast sensitivity was measured using the CSV-1000E contrast sensitivity chart test face (Vector Vision) at 3, 6, 12, and 18 cycles per degrees (cpd) under photopic conditions (85 cd/m(2)) and mesopic conditions (2.7 cd/m(2)) with 4.0 mm and 6.0 mm fixed central apertures, with and without glare. The Kruskal-Wallis test was used and a pair-wise comparison performed. The main outcome measure was the difference in contrast sensitivity between IOLs at each spatial frequency.

RESULTS

The best corrected visual acuity was similar between the 3 IOL groups (P = .6). The AcrySof IQ group had significantly higher contrast sensitivity at 18 cpd under photopic conditions (P = .008); at 3, 6, 12, and 18 cpd during mesopic testing with a 4.0 mm aperture without glare (P = .018, P = .011, P = .007, and P = .0001, respectively) and with glare (P = .003, P = .006, P = .005, and P = .004, respectively); and at all spatial frequencies during mesopic testing with a 6.0 mm aperture without glare (P = .018, P = .006, P = .009, and P = .0001, respectively) and with glare (P = .019, P = .002, P = .01, and P = .017, respectively).

CONCLUSION

Eyes with the AcrySof IQ SN60WF IOL had significantly higher contrast sensitivity than eyes with an AcrySof SA60AT or AcrySof Natural SN60AT IOL at all spatial frequencies during mesopic testing (with and without glare) with 4.0 and 6.0 mm artificial pupil.

Effect of trypan blue staining on the density and viability of lens epithelial cells in white cataract

PURPOSE

To assess the effect of anterior capsule staining with trypan blue 0.0125% on the density and viability of the lens epithelial cells (LECs).

SETTING

Iladevi Cataract and IOL Research Center, Ahmedabad, India.

METHODS

This randomized prospective study comprised 40 eyes having phacoemulsification for white mature cataract. Patients were randomized to have the anterior capsule stained with 0.1 mL trypan blue 0.0125% solution before the anterior capsulorhexis (Group 1, n = 20) or to have no anterior capsule staining before the anterior capsulorhexis (Group 2, n = 20). The density and viability of LECs were analyzed. The first 20 samples (10 from Group 1, 10 from Group 2) were stained with hematoxylin-eosin for cell density analysis using image-analysis software. The remaining 20 samples (10 from each group) were stained with a solution containing 0.5 microM calcein AM and 5 microM propidium iodide for 10 minutes at 37 degrees C for viability assay.

RESULTS

The mean cell density in Group 1 (with staining) was 3533.15 cells/mm(2) +/- 664.01 (SD). This was significantly lower than the mean of 4235.59 +/- 414.93 cells/mm(2) in Group 2 (no staining) (P = .01). The mean capsule area covered with LECs (80.75% +/- 8.04% versus 94.63% +/- 3.78%) and the mean live LECs in the covered area (51.69% +/- 11.54% versus 68.67% +/- 9.15%) were also significantly lower in Group 1 (P = .002).

CONCLUSION

Staining the anterior capsule with trypan blue affected the density and viability of LECs.

Analysis of patients with good uncorrected distance and near vision after monofocal intraocular lens implantation

PURPOSE

To analyze factors contributing to uncorrected visual acuity of at least 6/12 for distance and at least J4 for near (pseudoaccommodation) after monofocal intraocular lens (IOL) implantation.

SETTING

Iladevi Cataract and IOL Research Center, Ahmedabad, India.

METHODS

In a case-controlled study of 30 eyes (30 patients) that had phacoemulsification, those with pseudoaccommodation were assigned to cases and 30 eyes (30 patients) without pseudoaccommodation were designated as controls. Controls were matched by identical best corrected visual acuity, age, and postoperative duration. Subjective refraction was done with retinoscopy. Factors analyzed included corneal astigmatism, pupil size, axial IOL movement, amplitude of accommodation, axial length (AL), and age. Corneal astigmatism was noted on topography and interpreted as against the rule (ATR) (180 +/- 15 degrees), with the rule (WTR) (90 +/- 15 degrees), and oblique (OB) (45/135 +/- 30 degrees). Pupil size was noted on topographic display and AL and anterior chamber depth (ACD) on immersion A-scan. The axial IOL movement was calculated as the difference in ACD after instillation of cyclopentolate 1% (Cyclopent) and subsequently pilocarpine nitrate 2% (Carpinol) at separate visits, and amplitude of accommodation was measured with static and dynamic retinoscopy. Multivariate logistic regression and odds ratio with 95% confidence intervals were determined.

RESULTS

Mean spherical equivalent was -0.45 +/- 0.63 diopter (D) in cases and -0.35 +/- 0.83 D (P = .61) in controls. Multivariate logistic regression in cases versus controls: corneal astigmatism (ATR versus WTR and OB collectively): 10.19 [1.8,57.44], P = .009; pupil size: 0.45 [0.07,2.71], P = .38; axial IOL movement: 1.39 [0.51,0.77], P = .514; amplitude of accommodation: 2.95 [0.93,9.3], P = .065; AL: 0.55 [0.29,1.02], P = .058; and age: 0.98 [0.5,1.95], P = .963.

CONCLUSION

The study suggests a significant role of ATR corneal astigmatism in good uncorrected distance and near vision after monofocal IOL implantation.

AcrySof Natural SN60AT versus AcrySof SA60AT intraocular lens in patients with color vision defects

PURPOSE

To determine whether implantation of the AcrySof Natural intraocular lens (IOL) worsened the severity of existing color deficit in congenital partial red-green color deficient individuals (CPRG).

METHODS

A prospective controlled randomized double-masked analysis of 30 consecutive patients with CPRG defect and bilateral cataracts received a Natural IOL (test group) in 1 eye and a single-piece AcrySof IOL (control group) in the other eye. Patients were tested unilaterally to detect CPRG defect using Ishihara pseudoisochromatic plates and the Farnsworth D-15 test. Plates 1 to 21 measured the Ishihara error score; plates 22 to 25 indicated severity of defect based on clarity of both numerals as partial mild/moderate (both visible), partial severe defect (only 1 visible). The D-15 test is based on number of diametrical crossings on the circular diagram; severity is graded as mild (1 crossing), moderate (2 crossings), or severe (>2 crossings). Tests were performed before and after IOL implantation at 1, 3, and 6 months. At mean follow-up of 6.13 months +/- 1.2 (SD), analysis of variance test judged the difference in error scores and cross tabulation represented change in number of diametrical crossings.

RESULTS

The mean age was 62.3 +/- 8.5 years. All patients were men. Before IOL implantation, all patients had moderate CPRG defect on both tests. The Ishihara error score in the test and control groups did not reveal statistically significant differences (P = .505 and P = .119, respectively). With D-15, none of the patients in the test or control group showed >2 crossings.

CONCLUSION

The implantation of AcrySof Natural IOL did not worsen the preexisting severity of color defect in CPRG individuals.

Cataract Surgery in Relative Anterior Microphthalmos

PURPOSE

To determine the prevalence of relative anterior microphthalmos (RAM) and evaluate intraoperative performance and surgical outcome in eyes with RAM undergoing cataract surgery.

DESIGN

Nested case-control series.

PARTICIPANTS

One thousand four hundred consecutive patients undergoing cataract surgery were evaluated to determine the prevalence of RAM. Relative anterior microphthalmos is defined as horizontal corneal diameter (HCD) < or =11 mm, anterior chamber depth (ACD) < or =2.2 mm, and axial length (AL) >20 mm, with no other morphologic malformation.

METHODS

Patients were examined preoperatively for HCD, ACD, and AL. Horizontal corneal diameter was measured with calipers. Anterior chamber depth and AL were measured with immersion shell with water. Associated ocular pathologic conditions were recorded. Two control groups were identified. Group I (normal eyes; n = 84) had HCD >11 mm, ACD >2.2 mm, and AL >20 mm. Group II (eyes with small corneal diameter; n = 84) had HCD < or =11 mm, ACD >2.2 mm, and AL >20 mm.

MAIN OUTCOME MEASURES

Patients with RAM and controls were evaluated for intraoperative performance and postoperative outcome. The 2-tailed Fisher exact test was applied to compare the performance of RAM with each of the control groups. The odds ratio (OR) with 95% confidence intervals (95% CI) was determined.

RESULTS

The prevalence of RAM was 6% (84 of 1400 eyes; 95%CI, 0.048-0.074). Relative anterior microphthalmos was associated with the presence of small pupil, 34 (40.48%); corneal guttae, 31 (36.9%); glaucoma, 29 (34.5%); and pseudoexfoliation, 6 (7.14%). Intraoperatively, RAM was associated with overall surgical difficulty because of less working space in 59 eyes (70.24%; OR, 63.7; 95% CI, 18.3-221; P<0.001) compared with control groups I and II; uveal trauma in 12 (14.28%); Descemet's detachment in 5 (5.95%); and posterior capsule rupture in 2 (2.38%). Postoperatively, RAM was associated with transient corneal edema in 63 eyes (75%; OR, 9.0; 95% CI, 4.4-18.0; P<0.001; OR, 5.4; 95% CI, 2.7-10.5; P<0.001) on the first postoperative day.

CONCLUSIONS

The prevalence of RAM was 6%. Relative anterior microphthalmos with its associations posed significant intraoperative difficulties. The occurrence of transient corneal edema was frequent.