Natural course of intraocular pressure after cataract extraction and the effect of intracameral carbachol

Comparison of the Effect of Sodium Hyaluronate (Ophthalin®) and Hydroxypropylmethylcellulose (HPMC-Ophtal®) on Corneal Endothelium, Central Corneal Thickness, and Intraocular Pressure after Phacoemulsification

PURPOSE

To prospectively evaluate the effects of 2% hydroxypropyl-methylcellulose (HPMC-Ophtal) and sodium hyaluronate 1% (Ophthalin) on intraocular pressure, corneal thickness, and endothelial cell loss in small incision cataract surgery with implant.

METHODS

A total of 110 patients undergoing routine phacoemulsification with implant received either 2% hydroxypropyl methylcellulose or sodium hyaluronate 1% as ophthalmic viscosurgical device. Pre- and postoperative slitlamp examination, intraocular pressure measurement (preoperatively and at 1-4 hours, 1 day, and 7 days postoperatively), ultrasonic pachymetry (preoperatively and at 1 week, 4-6 weeks, and 12 weeks post operatively), and corneal endothelial cell count (preoperatively and 12 weeks postoperatively) were performed. Data were analyzed using two-way analysis of variance.

RESULTS

All measurements were comparable between the two groups preoperatively. Intraocular pressure was significantly lower in the Ophthalin group at 1 day post operatively, while no significant difference was found between the two groups on the 1-4 hours and 7 days examination. The central corneal thickness was not significantly different between the two groups at any postoperative visit . However, the mean cell density demonstrated a significant fall of 11.76% for Ophthalin and 4.27% for HPMC-Ophtal at 12 weeks post-operatively, the difference between the two being significant (p=0.009).

CONCLUSIONS

2% Hydroxypropyl methylcellulose, compared with sodium hyaluronate 1%, is superior in protecting the corneal endothelial cells, has the same effect on central corneal thickness, and is associated with slightly higher intraocular pressure 1 day post operatively. It compares favorably with sodium hyaluronate 1% and can be used as an effective and cheaper alternative in routine small incision cataract surgery with implant.

A comparative study of postoperative intraocular pressure changes in small incision vs conventional extracapsular cataract surgery

AIMS

To compare short- and long-term IOP changes in small incision cataract surgery (SICS) vs conventional extracapsular cataract surgery (CECS).

METHODS

A total of 232 eyes of as many patients undergoing cataract surgery were randomized to SICS or CECS. Sixteen eyes had to be excluded out of the study. IOP was recorded preoperatively and postoperatively on day 1, 2, and 7; and then after 1, 3, and 6 months. Only 160 eyes remained under 6-month follow-up, out of which 48 had CECS and remaining 112, SICS. Results were analysed statistically (repeated measure ANOVA, multiple comparisons).

RESULTS

A significantly higher IOP was observed on day 1, 2, and 7 in both types of surgeries as compared to mean preoperative IOP. Variation in rise was more pronounced in CECS (nearly twofold) than in SICS (P<0.05). Maximum decrease in IOP occurred during the first week and it was more rapid in SICS than CECS. At 3 months, IOP was significantly higher than baseline in CECS but significantly lower in SICS. From 3 to 6 months, there was no further decrease in IOP in either type of surgery.

CONCLUSIONS

IOP rises significantly on day one in CECS and SICS and thereafter comes down slightly by day 2 and rapidly by day 7. IOP rise is more pronounced in CECS than in SICS. After 1 week to 3 months, IOP decline is very gradual and thereafter ceases to decrease.

Oral versus topical carbonic anhydrase inhibitors in ocular hypertension after scleral tunnel cataract surgery

Purpose:

To compare the effect of oral acetazolamide and topical 2% dorzolamide in prevention of ocular hypertension after scleral tunnel cataract surgery.

Setting:

Ophthalmic department, Sana’a University, Yemen Sana’a from March 2007 to October 2007.

Methods:

This prospective double-blind, randomized study included 150 eyes undergoing scleral tunnel cataract surgery with hard posterior chamber intraocular implantation. Methylcellulose was used as the viscoelastic in all surgery cases. Patients were assigned to one of three groups: group 1: topical gentamicin eye drops (control; n = 52); group 2: systemic acetazolamide 250 mg (n = 45); and group 3: topical 2% dorzolamide (n = 53). Acetazolamide patients received one 250 mg tablet, one hour before surgery, then half a tablet every eight hours. A topical dorzolamide 2% or gentamicin was applied in one drop one hour before surgery then every eight hours, for three days postoperatively. Intraocular pressures (IOP) were measured by Goldman applanation tonometry one hour preoperatively and 16, 24, and 48 hours postoperatively.

Results:

At 16 hours, IOP between the three groups increased significantly with a statistically significant p-value of 0.008, but the mean IOP of acetazolamide patients was less than other groups. IOP nearly returned to the normal level 24 and 48 hours postoperatively, but this was not statistically significant (p = 0.452 and 0.138, respectively).

Conclusion:

Acetazolamide offers better IOP control than topical dorzolamide 2% in preventing ocular hypertension after scleral tunnel cataract surgery.

Relationship of immediate intraocular pressure rise to phaco-tip ergonomics and energy dissipation

PURPOSE

To evaluate the rise in intraocular pressure (IOP) after phacoemulsification using a straight microtip or a Kelman microtip and its relationship to phaco energy delivered to the eye.

SETTING

Iladevi Cataract & IOL Research Center, Ahmedabad, India.

METHODS

This prospective randomized study comprised 48 consecutive age- and sex-matched patients with senile cataract. Inclusion criteria included older than 45 years and presence of any type of cataract from grade I to III. The patients were divided into 2 groups: straight microtip and Kelman microtip. Each group comprised 13 men and 11 women. The mean age was 58.29 years +/- 6.46 (SD) in the straight microtip group and 60.05 +/- 8.45 years in the Kelman microtip group. The IOP was measured preoperatively and postoperatively with a pneumotonometer and applanation tonometer. One surgeon performed all operations using a standardized surgical technique and topical anesthesia. The intraoperative mean phaco power and ultrasound (US) time were noted. The effective phaco time (EPT), percentage of IOP rise, and wound-site thermal injury (mild, moderate, or severe) were calculated. The correlation between the EPT and percentage of rise in IOP was evaluated using correlation coefficients and the paired t test.

RESULTS

The mean preoperative IOP was 13.73 +/- 2.89 mm Hg in the straight microtip group and 15.14 +/- 2.60 mm Hg in the Kelman microtip group. The mean US time was 239.4 +/- 1.61 seconds and 238.2 +/- 1.48 seconds, respectively. The mean phaco power was 17.37% +/- 3.28% in the straight microtip group and 17.10% +/- 5.26% in the Kelman microtip group and the mean EPT, 39.06 +/- 2.28 seconds and 40.08 +/- 0.24 seconds, respectively (P =.412). The mean rise in IOP was 111.60% +/- 37.83% in the straight microtip group and 91.29% +/- 31.85% in the Kelman microtip group. The difference between groups was significant (P<.05). The correlation coefficient between the EPT and percentage of IOP rise was significant in both groups: 0.3823, straight microtip group (P<.05); 0.514, Kelman microtip group (P<.01). Wound-site thermal injury was noted in 3 patients in the straight microtip group and 1 patient in the Kelman microtip group.

CONCLUSIONS

Although the amount of phaco energy dissipated in the eye was the same between the 2 groups, the percentage of IOP rise was greater with the straight microtip. The rise in IOP was correlated with the dissipated phaco energy.

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.

Revisiting early postoperative follow-up after phacoemulsification

PURPOSE

To determine whether postoperative evaluation of routine phacoemulsification can be safely and effectively performed on the day of surgery and 4 days postoperatively and evaluate the incidence and management of early intraocular pressure (IOP) elevations 3 to 7 hours postoperatively in patients with or without glaucoma.

SETTING

Community-based hospital.

METHODS

This retrospective series comprised 465 consecutive patients who had phacoemulsification and intraocular lens implantation. All patients had postoperative follow-up on the day of surgery (3 to 7 hours postoperatively) and at 4 days. Patients were classified into 2 groups: nonglaucoma (NG), 396 patients; and glaucoma (GL), 69 patients. The main outcome measures were the incidence and management of postoperative complications including IOP spikes, wound leaks, uveitis, and endophthalmitis.

RESULTS

Three to 7 hours postoperatively, 73 NG (18.4%) and 32 GL (46.4%) patients had IOP elevations greater than 28 mm Hg, a significant change from baseline (P <.0001). Fourteen NG (3.6%) and 13 GL (18.8%) patients had IOP elevations greater than 40 mm Hg (P <.0001). Significant IOP elevations were effectively managed with a paracentesis with or without short-term antiglaucoma medications on the day of surgery, with 75 NG (18.9%) and 39 GL (56.5%) patients requiring IOP intervention. There were no IOP elevations greater than 21 mm Hg on the next day or at 4 days. There were no complications that were missed at the same-day evaluation that may have been identified at the 1-day postoperative visit.

CONCLUSIONS

The results indicate that after routine phacoemulsification, patients can be safely and effectively reviewed on the day of surgery and 4 days postoperatively to identify and manage early postoperative IOP spikes. A significant number of patients, particularly those with preexisting glaucoma, had potentially harmful IOP spikes 3 to 7 hours postoperatively.

Intraindividual comparison of the effects of a fixed dorzolamide-timolol combination and latanoprost on intraocular pressure after small incision cataract surgery

To compare the effect of a fixed dorzolamide-timolol combination with that of latanoprost on intraocular pressure (IOP) after small incision cataract surgery. Department of Ophthalmology, University of Vienna, Vienna, Austria. This prospective randomized study comprised 60 eyes of 30 patients scheduled for small incision cataract surgery in both eyes. The patients were randomly assigned to receive 1 drop of a fixed dorzolamide-timolol combination or latanoprost immediately after cataract surgery in the first eye. The second eye received the other antiglaucomatous agent. Cataract surgery was performed under sodium hyaluronate 1% with a temporal 3.5 mm sutureless posterior limbal incision, phacoemulsification, and implantation of a foldable intraocular lens. The IOP was measured preoperatively as well as 6 and 20 to 24 hours and 1 week postoperatively. Six hours after surgery, the mean IOP decreased by -0.8 mm Hg +/- 3.2 (SD) (P =.184) in the dorzolamide-timolol group and increased by 3.6 mm Hg +/- 3.5 (P <.001) in the latanoprost group. Twenty to 24 hours after surgery, the mean IOP decreased by -2.8 +/- 2.4 mm Hg (P <.001) in the dorzolamide-timolol group and increased by 0.6 +/- 3.5 mm Hg (P =.353) in the latanoprost group. The differences between groups were significant at 6 hours (P <.001) and 20 to 24 hours (P <.001). The fixed dorzolamide-timolol combination was more effective than latanoprost in reducing IOP after small incision cataract surgery. Only the fixed dorzolamide-timolol combination prevented a postoperative IOP increase and occasional IOP spikes of 30 mm Hg or higher.

Randomised fellow eye comparison of the effectiveness of dorzolamide and apraclonidine on intraocular pressure following phacoemulsification cataract surgery

PURPOSE

To compare the effectiveness of 2% dorzolamide and 0.5% apraclonidine on intraocular pressure (IOP) following phacoemulsification cataract surgery.

METHODS

This prospective, randomised study comprised 54 eyes of 27 consecutive patients with age-related cataract scheduled for cataract surgery in both eyes. In each patient the eye with the higher degree of cataract was randomly assigned to receive one drop of either dorzolamide or apraclonidine immediately after surgery. The fellow eye was operated on later and received the other treatment. Cataract surgery was performed with a superior 6.0 mm sutureless frown incision, phacoemulsification and implantation of a three-piece PMMA intraocular lens. The IOP was measured pre-operatively as well as 6 h and 20-24 h and 1 week post-operatively.

RESULTS

The mean pre-operative IOP was not significantly different between the groups (dorzolamide group, 14.9 +/- 2.3 mmHg; apraclonidine group, 14.6 +/- 2.5 mmHg; p = 0.450). At 6 h post-operatively, the mean IOP was significantly lower in the dorzolamide than in the apraclonidine group (15.6 +/- 3.9 mmHg vs 18.0 +/- 4.0 mmHg; p < 0.001). An IOP increase of more than 5 mmHg at 6 h post-operatively occurred in 3 (12%) eyes in the dorzolamide group and in 9 (36%) eyes in the apraclonidine group (p = 0.034). At 20-24 h post-operatively and at 1 week post-operatively no difference was found between the groups.

CONCLUSIONS

2% Dorzolamide is more effective than 0.5% apraclonidine in preventing the early post-operative IOP increase following phacoemulsification cataract surgery.

Intraocular pressure after small incision cataract surgery with Healon5 and Viscoat

PURPOSE

To evaluate the effect of Healon5 (sodium hyaluronate) and Viscoat (sodium chondroitin sulfate-sodium hyaluronate) on intraocular pressure (IOP) after bilateral small incision cataract surgery.

SETTING

Department of Ophthalmology, University of Vienna, Vienna, Austria.

METHODS

This prospective randomized study comprised 70 eyes of 35 consecutive patients with age-related cataract in both eyes scheduled for bilateral small incision cataract surgery. The patients were randomly assigned to receive Healon5 or Viscoat during cataract surgery in the first eye. The second eye received the other viscoelastic substance. Cataract surgery was performed in an identical fashion in both eyes, with a temporal 3.5 mm sutureless posterior limbal incision, phacoemulsification, and implantation of a foldable silicone intraocular lens. The IOP was measured preoperatively and 6 hours, 20 to 24 hours, and 1 week postoperatively.

RESULTS

At 6 hours after surgery, the mean IOP increased by 5.2 mm Hg +/- 5.3 (SD) in the Healon5 group (P < .0001) and by 10.1 +/- 8.7 mm Hg in the Viscoat group (P < .0001). The increase was significantly higher in the Viscoat group than in the Healon5 group (P = .0016). Intraocular pressure spikes of 30 mm Hg or more occurred in 2 eyes in the Healon5 group and in 10 eyes in the Viscoat group (P = .0112). Twenty to 24 hours and 1 week postoperatively, the mean IOP in the 2 groups was not statistically different.

CONCLUSIONS

Viscoat caused a significantly higher IOP increase and significantly more IOP spikes than Healon5 in the early period after small incision cataract surgery.

Effect of dorzolamide and latanoprost on intraocular pressure after small incision cataract surgery

PURPOSE

To evaluate the effect of dorzolamide 2% and latanoprost 0.005% on intraocular pressure (IOP) after small incision cataract surgery.

SETTING

Department of Ophthalmology, University of Vienna, Vienna, Austria.

METHODS

This prospective study comprised 102 eyes of 102 consecutive patients scheduled for small incision cataract surgery. The patients were assigned preoperatively to 1 of 3 groups of 34 each: dorzolamide, latanoprost, and control (no treatment). One drop of the assigned medication was instilled immediately after surgery. Intraocular pressure was measured preoperatively and 6 and 20 to 24 hours postoperatively.

RESULTS

Six hours after surgery, the mean increase in IOP was 1.9 mm Hg +/- 3.9 (SD) in the dorzolamide group (P = .004 versus control), 2.2 +/- 3.0 mm Hg in the latanoprost group (P = .005 versus control), and 4.8 +/- 5.2 mm Hg in the control group. Twenty to 24 hours postoperatively, IOP decreased a mean of -0.9 +/- 3.5 mm Hg in the dorzolamide group (P = .012 versus control) and increased a mean of 0.3 +/- 3.6 mm Hg in the latanoprost group (P = 0.24 versus control) and 1.3 +/- 4.2 mm Hg in the control group. One eye in the dorzolamide group, 1 eye in the latanoprost group, and 4 eyes in the control group had an IOP of 30 mm Hg or higher 6 hours postoperatively.

CONCLUSION

Six hours postoperatively, dorzolamide and latanoprost were effective in reducing the IOP increase after small incision cataract surgery; however, at 20 to 24 hours, only dorzolamide was effective. Neither drug prevented IOP spikes of 30 mm Hg or higher.

Effect of intracameral carbachol on intraocular pressure following clear corneal phacoemulsification

PURPOSE

To investigate the effect of 0.01% carbachol on early intraocular pressure (IOP) after cataract extraction with phacoemulsification.

METHODS

Fifty-one patients who underwent cataract extraction with phacoemulsification and intraocular lens implantation were prospectively randomly assigned to one of two groups. Twenty-seven patients were given 0.5 ml carbachol intracamerally (carbachol group); the other 24 patients were given the same amount of balanced salt solution intracamerally (control group). IOPs were measured by Goldmann applantation tonometry on the day before surgery, and at 8 h, 24 h and 7 days post-operatively.

RESULTS

There was no difference between the mean IOPs of the groups pre-operatively (p > 0.5). All the mean post-operative IOP values of the carbachol group were lower than those of the control group. At 8 and 24 h post-operatively the mean IOP was 12.4 +/- 3.4 mmHg and 13.1 +/- 4.5 mmHg respectively in the carbachol group, 19.4 +/- 6.4 mmHg and 17.2 +/- 4.2 mmHg respectively in the control group. The differences were significant (p < 0.04 and p < 0.05). There was no significant difference between the values at 7 days post-operatively (p > 0.8). An IOP greater than 25 mmHg was recorded at 8 h and 24 h post-operatively in 8 (33%) and 4 (17%) of the control group and in 1 (4%) and 1 (4%) of the carbachol group. All the IOPs were 20 mmHg or lower in both groups at 7 days post-operatively.

CONCLUSION

Patients treated with intracameral carbachol following uncomplicated clear corneal phacoemulsification and posterior chamber intraocular lens implantation demonstrate lower early post-operative IOP.

Intraocular pressure trends after supranormal pressurization to aid closure of sutureless cataract wounds

PURPOSE

To measure intraocular pressure (IOP) immediately and 25 minutes after small sutureless cataract surgery to estimate the duration of any elevation and to evaluate the relationship between supranormal pressurization and an elevated IOP 24 hours postoperatively.

SETTING

Routine outpatient cataract surgery at a tertiary referral center.

METHODS

Thirty-six consecutive eyes that had uneventful phacoemulsification cataract extraction were studied in a prospective fashion. Supranormal pressurization was attempted in all cases. Surgery was performed through a 3.5 mm scleral wound.

RESULTS

Mean IOP dropped from 38.8 mm Hg +/- 11.4 (SD) to 19.8 +/- 5.3 mm Hg 25 minutes after the surgery (P < .0001). A subgroup of patients (n = 6) whose IOP was greater than 24 mm Hg 24 hours postoperatively had a pressure drop from 36.8 +/- 12.3 mm Hg to 23.2 +/- 6.2 mm Hg 25 minutes postoperatively (P = .051). In this subgroup, the mean 24 hour IOP then rose to 30.8 +/- 5.2 mm Hg (P = .043). Another subgroup of patients (n = 7) whose IOP was greater than 24 mm Hg at 25 minutes had a pressure drop from 46.3 +/- 8.5 mm Hg to 27.9 +/- 2.4 mm Hg (P = .0014), falling to 21.7 +/- 6.6 mm Hg at 24 hours (P = .018).

CONCLUSION

These findings demonstrate the rapid decline of IOP after supranormal pressurization at the conclusion of cataract surgery. In addition, supranormal pressurization did not seem to contribute to IOP elevation at 24 hours.

Surgery for cataracts

The advent of phacoemulsification has substantially improved the success rate of cataract surgery in dogs, whereas the development of artificial lens implantation has equally improved postoperative visual acuity. In this chapter information pertaining to the etiology, diagnosis, and management of canine cataracts is provided for the general practitioner. More detailed information on phacoemulsification and artificial lens implantation is provided for residents in training or practicing ophthalmologists that may be converting from extracapsular extraction.

Comparison of the effect of four viscoelastic agents on early postoperative intraocular pressure

PURPOSE

To compare the effect of four commercially available viscoelastic agents on postoperative intraocular pressure (IOP).

SETTING

Four outpatient sites.

METHODS

Sixty-nine patients having routine extracapsular cataract extraction were enrolled in the study; 54 were available for a 3 month follow-up examination. The four viscoelastic agents were Amvisc, Amvisc Plus, Healon, and Viscoat. Intraocular pressure was measured preoperatively and at 2, 3, 4, 5, 6, 8, 10, 12, and 24 hours and 3 months postoperatively. Pachymetry and endothelial cell counts were performed preoperatively and 3 months postoperatively.

RESULTS

Mean postoperative IOP and IOP changes from baseline did not differ among the four treatment groups at any time. However, when mean maximal IOP was compared, the Healon group demonstrated the highest IOP increases (P = .0033). There was also a significant difference (P = .0015) among the treatment groups in the mean maximum postoperative change from baseline; the Healon group exhibited the largest mean change in IOP. At 3 months postoperatively, IOP values and pachymetry were normal for all treatment groups and were not statistically different among groups, indicating the four agents provided similar degree of endothelial protection and IOP stability.

CONCLUSION

These results suggest that IOP increases occur in varying degrees and at varying times in the early postoperative period after cataract surgery using a viscoelastic agent.

Viscoelastic-related glaucomas

The routine surgical use of viscoelastic substances has revolutionized many anterior segment procedures. All of the currently available agents may be responsible for causing or exacerbating a transient, but occasionally significant, postoperative IOP elevation. In spite of differences in physical properties such as molecular weight, concentration, and viscosity, none of the various viscoelastics has consistently shown a decreased likelihood of producing ocular hypertension. Moreover, any newly introduced product must be evaluated carefully for this potential complication. Lavage of viscomaterial from the anterior chamber and administration of ocular antihypertensives may be helpful in averting or controlling the increased IOP. The surgeon should be cognizant of any pre-existing optic nerve damage and adjust the aggressiveness of postoperative glaucoma therapy accordingly. In the future, the development of new substances or simultaneous use of degrading enzymes may reduce or eliminate the incidence of viscoelastic-induced ocular hypertension.

Is measuring intraocular pressure necessary on the first post-operative day following uncomplicated cataract surgery?

A prospective study was undertaken to assess whether the level of intraocular pressure (IOP) on the first day after cataract surgery could be estimated by clinical examination only, thereby removing the need for applanation tonometry. A total of 70 patients underwent uncomplicated extracapsular cataract extraction and intraocular lens implantation. The following day a Consultant, Registrar and Senior House Officer were asked to identify those patients with significantly raised IOP (> 27 mmHg) using slit lamp examination only. A fourth examiner, masked to the assessments of the three observers, measured the IOP using the Goldmann applanation tonometer. Pressures of > 27 mmHg by Goldmann tonometry were found in 10 patients (14%) of which 8 (80%) were missed by all three ophthalmologists. Formal measurement of IOP appears a necessary part of the post-operative assessment after uncomplicated cataract surgery.