Viscoelastic-related glaucomas

The safety and efficacy of phacoemulsification surgery in uncomplicated cataracts with and without an ophthalmic-viscosurgical-device

PURPOSE

To compare and evaluate the results of phacoemulsification surgery involving and not involving an ophthalmic-viscosurgical-device (OVD).

METHODS

A prospective, randomized controlled trial included 60 eyes of 60 patients scheduled to receive phacoemulsification surgery. In order of presentation, patients were randomized into two groups to undergo different surgical techniques: the OVD-free group (n = 30) and the OVD group (n = 30). Each patient's operating time, total ultrasonography (U/S) time, cumulative dissipated energy (CDE), aspiration time, and volume of balanced salt solution (BSS) aspirated were recorded. At 1 day, 1 week, and 1 and 3 months postoperation, measurements of endothelial cell density (ECD) and intraocular pressure (IOP), were taken and compared between the groups.

RESULTS

Total U/S time (p = .567) and CDE (p = .168) were similar between the groups. In the OVD group, operating time (p = .011), aspiration time (p < .001), and volume of BSS aspirated (p < .001) were greater than in the OVD-free group. The change in ECD between the groups was not statistically significant at all visits (p = .433, p = .147, p = .379, p = .534; respectively). Although IOP increased in the OVD group at 1 day postoperation (p = .001), no difference emerged between the groups at 3 months postoperation (p = .121).

CONCLUSION

Phacoemulsification surgery without an OVD took less time than with the OVD and caused no significant loss in ECD. Surgeons concerned about elevated IOP following cataract surgery should apply the OVD-free method.

Surgical and Perioperative Considerations for the Treatment of Cataract in Eyes with Glaucoma: A Literature Review

Cataract surgery in the presence of glaucoma poses certain challenges that need to be addressed to offer the maximum benefit without complications. In this paper, we are reviewing the preoperative assessment, surgical options, the planning, and postoperative care. Cataract surgery can help reduce the intraocular pressure alone or combined with MIGS. When performed in patients with glaucoma, it can transiently increase the intraocular pressure and later on decrease the IOP to levels lower than the postoperative. The preoperative IOP and biometric characteristics are the main predictors of the postoperative course of IOP. The combination of cataract surgery with trabeculectomy remains controversial, in terms of best timing of each operation.

Pure phaco: phacoemulsification without ophthalmic viscosurgical devices

The ophthalmic viscosurgical device (OVD) is an essential part of modern phacoemulsification surgery. Many times, OVDs are blamed for intraocular pressure spikes, toxic anterior segment syndrome, and capsular bag distension syndrome. To avoid these complications, we developed a technique in which phacoemulsification can be done without using OVDs. The irrigating cannula, on a continuous irrigation mode, was introduced through a side port, and capsulorhexis and incision construction were performed under an irrigating balanced salt solution. No hydroprocedure was performed. Phacoemulsification was done by chopping technique. At the end of the procedure, the intraocular lens was implanted by wound assistance technique under a continuous irrigation mode.

Correlation between changes in intraocular pressure and refractive error indices post Cataract Surgery

Objective:

To evaluate the correlation between refractive errors and change in intraocular pressure in patients undergoing cataract surgery.

Methods:

This interventional retrospective case study was carried out from September 2018 to April 2019 at Bodla Eye Care and Multan Medical and Dental College, Multan. A total of 127 eyes were recruited in the study among which six were excluded. Out of remaining 121, 53 eyes were emmetropes, 41 were mild myopes and 27 were high myopes. Single surgeon performed the procedure. Pre-operative investigations of IOP and refractive error were done by goldmann tonometry and auto refractometry. IOP was reviewed at day 1, 7, 14 and 28 post cataract surgeries.

Results:

Out of 121 eyes, 53 eyes were emmetropes, 41 were mild myopes and 27 were high myopes, who underwent phacoemulsification. There was an elevation of 2-3mm Hg at Day-1, in emmetropes and mild myopes, and further on, a constant drop was noticed on follow ups. In high myopes a significant fluctuation of IOP was noted in first fourteen days followed by an unremarkable gradual decline afterwards.

Conclusion:

Cataract surgery helps lowering the IOP in patients with refractive errors. Mild myopic and emmetropic patients showed a linear swift pattern while high myopes presented instable and gradual reduction in IOP. A total decrease of 1-2mm Hg was seen at the end of the study depicting that relation between IOP and cataract surgery is insignificant.

Changes of intraocular pressure after cataract surgery in myopic and emmetropic patients

To investigate the intraocular pressure (IOP) changes after cataract surgery, and its relationship with refractive conditions.IOP after phacoemulsification with intraocular lens (IOL) implantation was retrospectively reviewed. Patients were classified into 3 groups by refractive conditions: emmetropia, mild to moderate myopia, and high myopia. Basic information was collected including age, sex, place of IOL, and operating surgeon, with IOP and refractive conditions measured before surgery, and 1, 7, 30, and 90 days after surgery.The study comprised 353 eyes from 353 patients, of which 175 were emmetropia, 130 were mild to moderate myopia, and 48 were high myopia. A lower IOP than baseline was observed at 7, 30, and 90 days after surgery in emmetropic and mild to moderate myopia, while in high myopia, IOP was instable from 1 to 30 days, and reduced only in 90 days after surgery. Changes of IOP was more significant from 1 to 7 days in emmetropic and mild to moderate myopic patients, but from 30 to 90 days in high myopia. Patients over 75 showed a lower IOP at each follow-up than patients younger and female showed a higher baseline IOP than male. Different surgeons might influence the IOP fluctuation at first 90 days but not the final IOP.All patients with different refractive conditions showed a remarkably lower IOP at 90 days after cataract surgery. However, high myopia lowered the speed of IOP reduction, which might be explained by the anatomical changes of eye structure.

Effects of Topical Dorzolamide on IOP after Phacoemulsification with Different Types of Ophthalmic Viscosurgical Devices

PURPOSE

To evaluate the effect of topical dorzolamide on postoperative intraocular pressure (IOP) after routine phacoemulsification surgery with different type of ophthalmic viscosurgical device (OVD).

METHODS

Patients who were scheduled for phacoemulsification with intraocular lens (IOL) implantation were evenly divided into four groups. Group I (83 eyes) received one drop of topical dorzolamide immediately after surgery and 1.4% NaHa (BD Visc) was used as a cohesive OVD during IOL implantation. Group II (83 eyes) did not receive any topical antiglaucoma medication after operation and 1.4% NaHa was used as a cohesive OVD. Group III (83 eyes) received topical dorzolamide and 1% NaHa (Healon) was used, and Group IV (83 eyes) did not receive any topical and 1% NaHa was used in operation. Mean postoperative IOPs were compared between groups.

RESULTS

Eyes with 1.4% NaHa usage (18.2+/-9.2 mmHg) had higher mean postoperative IOPs than eyes with 1% NaHa usage (15.5+/-5.3 mmHg) (p=0.002). Mean postoperative IOPs were lower in eyes with dorzolamide application (15.6+/-7.2 mmHg) than in eyes without any medication (18.1+/-8.5 mmHg) both in eyes with 1.4% NaHa and 1% NaHa usage (p=0.003). Dorzolamide application caused an average 2.5 mm decrease in mean postoperative IOPs in both groups.

CONCLUSIONS

Effects of OVDs on IOP rises after phacoemulsification surgery are closely related to their molecular structure. Increase in viscosity rendered higher postoperative IOP increments. However, topical dorzolamide application effectively reduced postoperative IOP increments in eyes with both Healon and BD Visc use.

Comparison of Intraocular Lens Position Change Following Two Different Implantation Techniques

PURPOSE

To assess the decentration and tilt of one-piece foldable acrylic intraocular lens following two different intraocular lens implantation techniques.

METHODS

This prospective, randomized clinical study conducted on 102 eyes of 91 patients who underwent cataract surgery between September 2015 and May 2016 at Ulucanlar Eye Training and Research Hospital, Ankara, Turkey. Intraocular lens implantations were performed with the help of an ophthalmic viscosurgical device or a hydroimplantation technique during surgery. The main outcomes, which were evaluated one day and one month after surgery, were corrected distant visual acuity, intraocular lens tilt, and decentration at the vertical and horizontal meridians. All outcomes were compared between and within implantation technique groups.

RESULTS

Angle of tilt and decentration of intraocular lens at the vertical and horizontal meridians showed no significant change within the ophthalmic viscosurgical device and hydroimplantation groups during follow-up (p > 0.05 for all). However, intraocular lens at both meridians were significantly lower in the hydroimplantation group (Vertical: p = 0.004, Horizontal: p = 0.015), and intraocular lens decentration tilt at both meridians were significantly lower in the hydroimplantation group than in the ophthalmic viscosurgical device group (Vertical: p = 0.004, Horizontal: p = 0.039). Postoperative corrected distant visual acuity outcomes showed no difference between and within the groups during follow-up (p > 0.05 for all).

CONCLUSIONS

The intraocular lens implantation technique had an important effect on intraocular lens position. The hydroimplantation technique induces central placement of one-piece foldable acrylic intraocular lenses postoperatively by reducing decentration and the angle of tilt.

Safety of hydroimplantation in cataract surgery in patients with pseudoexfoliation syndrome

AIM

To evaluate the safety of hydroimplantation in cataract surgery in patients with pseudoexfoliation syndrome.

METHODS

This prospective randomized study comprised 100 eyes of 100 consecutive patients who underwent cataract surgery and implantation of foldable intraocular lens (IOL). Each eye was assigned to group 1 or group 2. Hydroimplantation without using viscoelastic agent as group 1 (n=50), and hydroxypropylmethylcellulose (Eyevisc, Biotech, India) was used in group 2 (n=50).

RESULTS

There were no statistically significant differences in central corneal thickness (CCT) and corneal endothelial cell count (ECC) between both groups at each visit and percentage change in CCT and ECC (P>0.05). The mean intraocular pressure (IOP) at postoperative 5h increased statistically significantly in group 2 (P<0.001). There was no statistically significant difference in IOP between two groups, before and after surgery excluding the 24h postoperative IOP, but patients in group 2 had higher IOP than that in the group 1 at 24h after surgery (P=0.035). No case in either group experienced posterior capsular rupture, or zonular dialysis. Fixation of the globe during IOL implantation was better in group 1 than that in group 2.

CONCLUSION

Hydroimplantation has advantages in terms of IOP changes and duration of the surgery and seems to be safe in patients with pseudoexfoliation syndrome.

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.

Update on veterinary cataract surgery

PURPOSE OF REVIEW

The purpose of this review is not to specifically discuss the techniques of veterinary cataract surgery, but rather to emphasize some of the differences between the veterinary and human cataract patients, procedures and outcomes.

RECENT FINDINGS

In general, veterinary cataract surgery has more similarities than differences when compared to its human counterpart. This is especially true when comparing pediatric cataract patients. Veterinary cataract surgery has changed dramatically in recent years with regards to surgical technique, ocular pharmacology, viscoelastic devices, phacoemulsification, and the most recent advancement, intraocular lens implantation for dogs, cats, and horses.

SUMMARY

It is hoped that the exchange of information between the human and veterinary specialties can be of benefit to both groups as we all work to improve outcomes and resolve complications.

Intraocular pressure and endothelium cell counts after cataract surgery with chitosan and sodium hyaluronate (Healon GV): 3-year follow-up results of a randomised clinical trial

INTRODUCTION

The purpose of this study was to evaluate the long-term effects of chitosan 0.1% and sodium hyaluronate 1.4% (Healon GV(R); Advanced Medical Optics, Santa Ana, CA, USA) on intraocular pressure (IOP) and endothelial cell loss.

METHODS

This randomised study comprised 140 eyes of 140 patients with age-related cataracts undergoing phacoemulsification followed by posterior chamber intraocular lens (IOL) implantation; 70 received chitosan 0.1%, and 70 received sodium hyaluronate 1.4%. The IOP was measured with standard Goldman applanation tonometry pre-operatively and 1 day, 1 week, 1 month, 3 months, 1 year and 3 years postoperatively. Endothelial cell counts were performed pre-operatively and 1 week, 1 month, 3 months, 1 year and 3 years postoperatively using a Pro/Koester WFSCM contact endothelial microscope.

RESULTS

There were no significant differences found in postoperative IOP levels among the chitosan and sodium hyaluronate groups (P>0.05). No significant differences were found in postoperative mean endothelial cell counts at all time points between the chitosan and sodium hyaluronate groups (P>0.05).

CONCLUSION

Chitosan has the same effects as sodium hyaluronate on IOP and endothelium cells counts after cataract surgery and IOL implantation, and therefore may be an alternative ophthalmic viscoelastic device.

Use of trypan blue for penetrating keratoplasty

Use of trypan blue for penetrating keratoplasty was developed to facilitate the procedure. Trypan blue is injected before and after the addition of 0.25 mL of an ophthalmic viscosurgical device (OVD), sodium hyaluronate, to stain the internal and external cut edge of the cornea as well as the OVD, enabling the surgeon to improve visualization of the incision and suture depth, improve alignment of host and donor tissues, and ensure that all OVD is removed.

Reconstitution of Trabecular Meshwork GAGs: Influence of Hyaluronic Acid and Chondroitin Sulfate on Flow Rates

PURPOSE

This study was undertaken to determine whether the concentration of hyaluronic acid (HA) and of chondroitin sulfate (CS) occurring in the normal and the primary open-angle glaucoma (POAG) trabecular meshwork (TM) influences flow rates in vitro as a function of pressure.

METHODS

We tested 100, 500, and 4000 kDa molecular weight HA, CS, reconstituted normal and POAG TM HA-CS and juxtacanalicular connective tissue (JCT) HA-CS in a micro test chamber to determine initial and steady-state flow rates. The resistance and permeability (Ko) were calculated; Linear Newtonian mechanics were used to determine the possible contributions of the hydrophobic interactions of HA.

RESULTS

Initial flow rates increased in the pressure range of 5 to 20 mm Hg for the three HA preparations and the flow rates declined in the pressure range of 20 to 40 mm Hg. Flow rates of reconstituted normal TM and JCT were optimum at 10 mm Hg and then declined with increasing pressure. Flow rates of reconstituted POAG TM and JCT were optimum only at 5 mm Hg and then declined. The steady-state rate of POAG JCT HA-CS at 10 mm Hg was slow: the transition time (ie, the time required to start an increase in flow rate) was 29 hours and the lag time (ie, the time required to obtain steady-state flow rate) was 17 hours. The maximum flow rate in POAG JCT HA-CS decreased by 37.2% from the normal JCT HA-CS. The calculated resistance of reconstituted POAG JCT HA-CS was approximately 18% of the total resistance of the human JCT compared with 10% in the normal JCT.

CONCLUSIONS

Hyaluronic acid and CS contribute to flow resistance and influence flow rate in vitro. The influence of HA is particularly sensitive to an increase in the pressure gradient, which may be caused by unfolding of the hydrophobic interactions of HA polymers that further entangles the HA polymer. The POAG JCT HA-CS concentrations represent a significant factor in outflow resistance in POAG, particularly at higher pressures.

Effect of topical brinzolamide 1% and brimonidine 0.2% on intraocular pressure after phacoemulsification

PURPOSE

To compare the effectiveness of brinzolamide 1% (Azopt) and brimonidine 0.2% (Alphagan) with a placebo in preventing an early increase in intraocular pressure (IOP) after phacoemulsification.

SETTING

Department of Ophthalmology, Baskent University, School of Medicine, Ankara, Turkey.

METHODS

In this prospective double-masked study, 90 eyes of 90 patients having clear corneal phacoemulsification were randomly divided into 3 groups of 30 eyes each. One hour before surgery, 1 group received 1 drop of brinzolamide 1%, another received 1 drop of brimonidine 0.2%, and the third received 1 drop of a balanced saline solution (placebo). The IOP was measured preoperatively and 3 and 16 to 20 hours postoperatively.

RESULTS

Three hours postoperatively, the mean IOP increased by 4.2 mm Hg +/- 7.0 (SD), 3.2 +/- 6.4 mm Hg, and 5.3 +/- 4.2 mm Hg in the brinzolamide, brimonidine, and placebo groups, respectively. The IOP increase from baseline was significant in all 3 groups (all P<.01), with no difference between the groups (P>.05). The change in IOP at 16 to 20 hours was 0.2 +/- 2.8 mm Hg, 0.2 +/- 2.4 mm Hg, and -0.8 +/- 2.4 mm Hg, respectively. The changes were not significant compared to baseline (all P>.05). Six eyes (20%) in the brinzolamide group, 5 eyes (16.7%) in the brimonidine group, and 7 eyes (23.3%) in the placebo group had an IOP higher than 25 mm Hg 3 hours postoperatively; the difference between groups was not significant (P =.8).

CONCLUSION

Prophylactic use of 1 drop of brinzolamide or brimonidine was not more effective than a placebo in controlling early postoperative IOP elevations after clear corneal phacoemulsification.

Secondary glaucomas in the dog in North America

OBJECTIVE

To determine the prevalence of secondary glaucomas in dogs associated with cataract formation, lens luxation or displacement, cataract surgery, uveitis, hyphema and intraocular neoplasia.

METHODS

Information was obtained from the Veterinary Medical Data Base (VMDB) from all veterinary medical teaching hospitals in North America from March 1964 to March 2003. Secondary glaucomas were diagnosed at the same examination or after the primary diagnosis was made, and included those associated with cataract formation, lens luxation, cataract surgery, uveitis of unknown cause, hyphema of unknown cause, and intraocular neoplasia. The data were evaluated by decade, breed, gender and age of presentation.

RESULTS

A total of 1 592 831 dogs were presented, and 9695 canine secondary glaucomas. Secondary glaucoma associated with cataract formation represented 81% of all the canine secondary glaucomas. Breeds (n = 7890 dogs) predisposed to secondary glaucoma and cataracts had an overall prevalence of 0.5%, but nearly 20% of all the cataractous dogs developed secondary glaucoma in at least one eye. For the years 1994-2003, these breeds included the American Cocker Spaniel; Boston Terrier; Toy, Miniature and Standard Poodle; English Springer Spaniel; Bichon Frise; and Labrador Retriever. The other forms of secondary glaucoma occurred less frequently, and included those glaucomas with lens luxation or displacement (779 dogs; 12.0%), postcataract surgery (528 dogs; 5.1%), with uveitis from unknown cause (399 dogs; 7.1%), with hyphema from unknown cause (117 dogs; 7.3%), and with intraocular neoplasia (19 dogs; 3.5%). The risk of the secondary glaucomas from 1984 to 2002 was highest after the intracapsular lens extraction (ICLE), less in the extracapsular technique (ECLE), and lowest for the phacoemulsification/phacofragmentation method.

CONCLUSION

Prevalence of the canine secondary glaucomas ranges from 0.25% (1964-1973), 0.46% (1974-1983), 0.79% (1984-1993), to 0.80% (1994-2003) and are as frequent as the primary or breed-related glaucomas during these same time periods.

Efficacy of anterior chamber decompression in controlling early intraocular pressure spikes after uneventful phacoemulsification

PURPOSE

To determine the efficacy of anterior chamber decompression in the management of intraocular pressure (IOP) spikes in the early period after uneventful phacoemulsification.

SETTING

Royal Free Hospital, Department of Ophthalmology, Royal Free and University College London Medical School, London, United Kingdom.

METHODS

This prospective case series comprised 11 consecutive patients with otherwise healthy eyes who an IOP of at least 40 mm Hg 4 to 6 hours after phacoemulsification. After anterior chamber decompression, the IOP was measured at 0, 15, 30, 45, and 60 minutes or until it exceeded 40 mm Hg.

RESULTS

The mean IOP 4 to 6 hours postoperatively was 47.09 mm Hg +/- 7.92 (SD) (range 40 to 68 mm Hg). After decompression, the IOP dropped significantly to a mean of 4.73 +/- 3.00 mm Hg at 0 minutes (P<.001) and then increased progressively to 23.36 +/- 10.80 mm Hg at 15 minutes (P<.001), 33.82 +/- 11.74 mm Hg at 30 minutes (P=.005), 35.00 +/- 6.53 mm Hg at 45 minutes (P=.015), and 38.50 +/- 2.51 mm Hg at 60 minutes (P=.041).

CONCLUSIONS

Marked IOP spikes developed in eyes without glaucoma or ocular hypertension after uneventful phacoemulsification. Anterior chamber decompression immediately lowered IOP, but the effect was transient.

Avoiding complications in combined phacotrabeculectomy

Combined phacoemulsification and trabeculectomy offers the advantage of relieving both cataract and increased intraocular pressure in one surgical sitting. The procedure however entails greater risks than either alone. An approach to minimize these risks is described.

Intraocular pressure after bilateral cataract surgery using Healon, Healon5, and Healon GV

PURPOSE

To determine whether there is a difference in frequency or severity of postoperative intraocular pressure (IOP) spikes after bilateral phacoemulsification with complete ophthalmic viscosurgical device (OVD) removal when Healon5 (sodium hyaluronate 2.3%), Healon (sodium hyaluronate 1%), or Healon GV (sodium hyaluronate 1.4%) is used.

SETTING

York Finch Eye Associates and Humber River Regional Hospital, Toronto, Ontario, Canada.

METHODS

Bilateral cataract surgery was performed in 99 patients; 50 were randomly assigned to receive Healon5 in 1 eye and Healon GV in the fellow eye and 49, Healon in 1 eye and Healon GV in the fellow eye. The IOP was measured preoperatively as well as 5 and 24 hours and 7 days postoperatively. The mean IOP and standard deviation at each time interval were calculated for each OVD. The results were compared among the OVDs using Student t tests for each time at which IOP was assessed.

RESULTS

There were no significant differences in postoperative IOP spikes among the Healon5, Healon, and Healon GV groups; however, patients receiving lower viscosity OVDs had a lower mean IOP at 24 hours. All groups had increased IOP at 5 and 24 hours and reduced IOP at 7 days.

CONCLUSIONS

Within a family of molecularly similar OVDs, lower viscosity OVDs appear to cause slightly lower mean elevations in IOP in normal patients at 24 hours. However, if the OVD is removed, postoperative IOP spikes above 21 mm Hg appear related more to patient factors (eg, predisposition in glaucoma patients) and surgically induced trauma than to the specific long-chain non-cross-linked hyaluronan OVD used.

Timolol gel versus acetazolamide in the prophylaxis of ocular hypertension after phacoemulsification

PURPOSE

To compare postoperative intraocular pressure (IOP) after administration of acetazolamide and timolol following phacoemulsification and intraocular lens implantation.

SETTING

Ophthalmic Consultants of Long Island, Rockville Centre, New York, USA.

METHODS

Sixty patients were included in a prospective, randomized, masked trial. The patients received either two doses of oral, sustained-release acetazolamide (Diamox Sequels) or a single dose of topical timolol 0.5% gel (Timoptic XE). Intraocular pressure was measured by Goldmann applanation tonometry preoperatively and 1 day postoperatively.

RESULTS

Mean preoperative IOP was 16.4 mm Hg. One day postoperatively, it was 19.5 mm Hg in the oral acetazolamide group and 15.9 mm Hg in the timolol gel group. One patient in the acetazolamide group developed significant adverse reactions.

CONCLUSION

Prophylactic use of topical timolol 0.5% gel for viscoelastic-induced ocular hypertension after cataract extraction appears to offer better IOP control than oral acetazolamide and has potentially fewer adverse systemic effects.