Twelve hour reproducibility of choroidal blood flow parameters in healthy subjects.

AIMS/BACKGROUND: To investigate the reproducibility and potential diurnal variation of choroidal blood flow parameters in healthy subjects over a period of 12 hours. METHODS: The choroidal blood flow parameters of 16 healthy non-smoking subjects were measured at five time points during the day (8:00, 11:00, 14:00, 17:00, and 20:00). Outcome parameters were pulsatile ocular blood flow as assessed by pneumotonometry, fundus pulsation amplitude as assessed by laser interferometry, blood velocities in the opthalmic and posterior ciliary arteries as assessed by colour Doppler imaging, and choroidal blood flow, volume, and velocity as assessed by fundus camera based laser Doppler flowmetry. The coefficient of variation and the maximum change from baseline in an individual were calculated for each outcome parameter. RESULTS: None of the techniques used found a diurnal variation in choroidal blood flow. Coefficients of variation were within 2.9% and 13.6% for all outcome parameters. The maximum change from baseline in an individual was much higher, ranging from 11.2% to 58.8%. CONCLUSIONS: These data indicate that in healthy subjects the selected techniques provide adequate reproducibility to be used in clinical studies. Variability may, however, be considerably higher in older subjects or subjects with ocular disease. The higher individual differences in flow parameter readings limit the use of the techniques in clinical practice. To overcome problems with measurement validity, a clinical trial should include as many choroidal blood flow outcome parameters as possible to check for consistency.

Effect of endothelin and BQ123 on ocular blood flow parameters in healthy subjects.

PURPOSE: To characterize the role of the endothelin system in the blood flow control of the optic nerve head and of the choroid in humans. METHODS: Two studies were performed in healthy subjects. Study 1 was a randomized, placebo-controlled, double-masked, balanced, two-way crossover design and study 2 a three way-way crossover design. In study 1 twelve healthy male subjects received endothelin (ET)-1 in stepwise increasing doses of 1.25, 2.5, and 5 ng/kg x min (each infusion step occurred over 20 minutes) coinfused with BQ123 (60 microg/kg x min) or placebo on two different study days. In study 2 twelve healthy male subjects received two doses of BQ123 (60 or 120 microg/kg x min over 60 minutes) or placebo on three different study days. Measurements of optic nerve head blood flow (ONHBF) and choroidal blood flow (ChBF) were performed with laser Doppler flowmetry in both studies. In study 2 mean flow velocity (MFV) of the ophthalmic artery was assessed with Doppler sonography. RESULTS: In study 1, ET-1 significantly decreased ONHBF (-22.8% +/- 4.3% at 5 ng/kg x min, P = 0.003 versus baseline) and ChBF (-21.7% +/- 3.2% at 5 ng/kg x min, P = 0.0001 versus baseline). The effect of the highest administered dose of exogenous ET-1 on ONHBF was significantly attenuated (P = 0.04, ANOVA) by coinfusion of BQ123. Effects of exogenous ET-1 on blood flow (2.5 ng/kg x min ET-1 or higher) also were attenuated in the choroid by coinfusion of BQ123 (ChBF: P = 0.03, ANOVA). In study 2, both dosages of BQ123 significantly increased MFV in the ophthalmic artery (60 microg/kg x min, 12.5% +/- 7.3%; 120 microg/kg x min, 17.2% +/- 9.2%, versus baseline; P = 0.001), but did not change blood flow in the ONH or the choroid. CONCLUSIONS: BQ123 antagonizes the effects of exogenously administered ET-1 on blood flow in the ONH and the choroid. The data indicate, however, that ET-1 does not substantially contribute to the regulation of basal vascular tone in these tissues.

Effect of topical brimonidine on intraocular pressure after small incision cataract surgery.

PURPOSE: To evaluate the effect of brimonidine 0.2% on intraocular pressure (IOP) after small incision cataract surgery. SETTING: Department of Ophthalmology, University of Vienna, Vienna, Austria. METHODS: This prospective randomized study comprised 80 eyes of 40 patients scheduled for small incision cataract surgery in both eyes. In each patient, 1 eye was randomly assigned to receive 1 drop of brimonidine 0.2% or no treatment (control) immediately after surgery. The fellow eye received the other assigned treatment. All patients had standardized surgery by the same surgeon with sodium hyaluronate 1%, 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. RESULTS: Six hours after surgery, the mean increase in IOP was 4.7 mm Hg +/- 6.1 (SD) in the brimonidine group and 4.6 +/- 5.3 mm Hg in the control group. In each group, 17 eyes (43%) had an IOP increase of 5 mm Hg or more. Twenty to 24 hours after surgery, the mean increase in IOP was 1.5 +/- 4.2 mm Hg in the brimonidine group and 1.6 +/- 4.4 mm Hg in the control group. There were no statistically significant between-group differences at any measurement. CONCLUSIONS: In both groups, IOP significantly increased 6 hours and 20 to 24 hours after small incision cataract surgery. Brimonidine 0.2% failed to reduce the IOP increase observed after small incision cataract surgery.

Posterior continuous curvilinear capsulorhexis with hydrogel and silicone intraocular lens implantation: development of capsulorhexis size and capsule opacification.

PURPOSE: To evaluate the influence of primary posterior continuous curvilinear capsulorhexis (PCCC) on capsule opacification development and capsular bag changes within the first year after cataract surgery with 2 intraocular lenses (IOLs) of comparable design but different material. SETTING: Department of Ophthalmology, University of Vienna, Medical School, Vienna, Austria. METHODS: Thirty-seven patients with age-related cataract had bilateral small incision cataract surgery with a PCCC performed after capsular tension ring insertion. One eye was randomly assigned to receive a hydrogel IOL and the other eye, a silicone IOL. Standardized digital retroillumination photographs were taken 1 day, 1 week, and 1, 3, 6, and 12 months after surgery to evaluate changes in the dimensions of the anterior and posterior capsulorhexis opening area and the presence of anterior and posterior capsule opacification. RESULTS: The area of the anterior continuous curvilinear capsulorhexis (ACCC) opening was significantly reduced during the first 6 postoperative months. The shrinkage was more pronounced (-25%) in the silicone IOL group than in the hydrogel IOL group. Ten percent of eyes with a silicone IOL had marked shrinkage of the ACCC. The area of the PCCC did not change in eyes with a hydrogel IOL but was larger (+20%) in eyes with a silicone IOL. Anterior ongrowth was observed in 60% in the hydrogel group and in no eye in the silicone group. Anterior capsule fibrosis was observed in 90% in the silicone group and in 20% in the hydrogel group. Total closure of the PCCC was not observed within the first year, but posterior ongrowth was observed in 40% in the hydrogel group and 10% in the silicone group. CONCLUSIONS: Anterior capsulorhexis shrinkage with concomitant posterior capsulorhexis enlargement was observed in eyes with a silicone IOL. The hydrogel IOL induced more ongrowth on the anterior and posterior IOL surfaces, whereas the silicone IOL induced more anterior capsule fibrosis. Total closure of the PCCC was not observed within the first year after surgery.

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.

Cellular reaction on the anterior surface of 4 types of intraocular lenses.

PURPOSE: To assess the cellular reaction on the anterior surface of 4 types of foldable intraocular lenses (IOLs). SETTING: Department of Ophthalmology, University Hospital of Vienna, Vienna, Austria. METHODS: One hundred eyes scheduled for cataract surgery were prospectively randomized into 4 groups of 25 eyes each using random number tables. Group 1 received a Hydroview IOL (Bausch & Lomb), Group 2 an AcrySof IOL (Alcon), Group 3 a MemoryLens IOL (ORC), and Group 4 a CeeOn 920 IOL (Pharmacia). Patients were examined 1, 3, 7, 30, 90, and 180 days postoperatively. Postoperative biomicroscopic examinations were done with a slitlamp, and a specular microscope was used to document the presence of cell deposits and identify areas with the highest density of cells. RESULTS: The local tissue response revealed 2 patterns: a nonspecific foreign-body reaction to the IOL (small round, fibroblast-like, epithelioid, and giant cells) and a lens epithelial cell (LEC) reaction. The highest incidence of LECs was in the Hydroview group, in which LECs were present on 81.8% of lenses 180 days postoperatively. During the first postoperative days, small round and fibroblast-like cells were found on all IOLs. From 7 days on, the incidence and density of these cells were less severe in the Hydroview and CeeOn 920 groups. After several weeks, epithelioid cells and foreign-body giant cells were seen on some IOLs. These cells appeared more often on AcrySof, MemoryLens, and CeeOn IOLs. CONCLUSION: This study found IOL-related differences in cellular reaction after cataract surgery. The incidence of a nonspecific foreign-body reaction to 4 IOLs is consistent with the results of previous studies. The incidence of LECs was highest in the Hydroview group and lowest in the AcrySof group. The CeeOn 920 group had the lowest incidence of all types of cells.

Morphological appearance and size of contact zones of piggyback intraocular lenses.

PURPOSE: To characterize the morphology, size, and change in size of the contact zone of piggyback intraocular lenses (IOLs) of different materials and optic designs. SETTING: Department of Ophthalmology, Vienna General Hospital, Vienna, Austria. METHODS: In a prospective study, 9 eyes of 7 patients received piggyback IOLs of the following materials: poly(methyl methacrylate) (PMMA), acrylic, hydrogel, and silicone. The contact zone between the anterior and posterior IOLs was photodocumented from 1 day to 1 year after surgery using specular microscopy. The contact zone area was measured. RESULTS: A contact zone was present with all IOL materials studied. The area of contact, however, differed significantly. With PMMA IOLs, the contact zone was small and surrounded by Newton rings, indicating the tiny gap between the IOLs. With IOLs of soft material, such as silicone and hydrogel, it was larger than with PMMA IOLs and had a slightly irregular shape. With foldable acrylic IOLs, it was regular, round, and slightly larger than with the soft materials. The contact area enlarged primarily during the first 3 months after surgery. After 1 year, 2 eyes with acrylic piggyback IOLs had a membrane formation around the contact zone and 2 eyes developed Elschnig pearls between the IOLs. CONCLUSION: In piggyback IOL eyes, the shape and size of the contact zone were strongly dependent on the IOL material and optic design. Contact area enlargement seemed to be induced by capsule shrinkage. Fibrous membrane formation around the contact zone and Elschnig pearl formation between the piggyback IOLs were long-term complications of this technique.

Intraocular pressure rise after small incision cataract surgery: a randomised intraindividual comparison of two dispersive viscoelastic agents.

AIM: To evaluate the effects of the dispersive viscoelastic agents Ocucoat (hydroxypropyl methylcellulose 2%) and Viscoat (sodium chondroitin sulphate 4%-sodium hyaluronate 3%) on postoperative intraocular pressure (IOP) after bilateral small incision cataract surgery. METHODS: This prospective, randomised study comprised 80 eyes of 40 consecutive patients with age related cataract in both eyes scheduled for bilateral small incision cataract surgery. The patients were randomly assigned to receive Ocucoat or Viscoat during cataract surgery of the first eye. The second eye was operated later and received the other viscoelastic agent. Cataract surgery was performed with a temporal 3.2 mm sutureless posterior limbal incision, phacoemulsification, and implantation of a foldable silicone intraocular lens. The IOP was measured preoperatively as well as 6 hours, 20-24 hours, and 1 week postoperatively. RESULTS: At 6 hours after surgery the mean IOP increased by 4.6 (SD 5.1) mm Hg in the Ocucoat group (p<0.001) and by 8.6 (8.1) mm Hg in the Viscoat group (p<0.001). The increase was significantly higher in the Viscoat group than in the Ocucoat group (p=0.004). Intraocular pressure spikes of 30 mm Hg or more occurred in two eyes in the Ocucoat and in nine eyes in the Viscoat group (p=0.023); 20-24 hours and 1 week postoperatively the mean IOP was not statistically different. CONCLUSION: These findings indicate that Viscoat causes a significantly higher IOP increase and significantly more IOP spikes than Ocucoat in the early period after small incision cataract surgery.

Effect of tropicamide on aqueous flare before and after cataract surgery.

PURPOSE: To examine the effect of tropicamide on flare intensity under phakic and pseudophakic conditions and to differentiate between the possible mechanisms of action of tropicamide on aqueous flare. SETTING: Department of Ophthalmology, Vienna General Hospital, University of Vienna, Vienna, Austria. METHODS: In this prospective study, aqueous flare was measured with the laser flare-cell meter in 20 eyes of 20 patients with age-related cataract enrolled for cataract surgery. Measurements were performed before and 30, 90, and 180 minutes after pupil dilation with tropicamide 0.5%. This measurement was performed in the phakic eye on the day before surgery and in the pseudophakic eye on postoperative days 1, 3, 7, and 28. RESULTS: After tropicamide instillation, aqueous flare decreased preoperatively and on all postoperative days. There was a continuous flare decrease until 3 hours after instillation, reaching a maximum decrease of about 30%. Pupil diameter reached its maximum after 30 minutes. CONCLUSION: Tropicamide significantly decreased aqueous flare, seemingly by pharmacological means, not volumetric changes. The time between drug application and measurement should be kept constant.

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.

Long-term disorders of the blood-aqueous barrier after small-incision cataract surgery.

PURPOSE: To determine the long-term function of the blood-aqueous barrier after small-incision cataract surgery with implantation of a foldable intraocular lens. METHODS: The blood-aqueous barrier function in 74 eyes of 62 patients who underwent cataract surgery was examined using a laser flare-cell meter. The measurements were performed pre-operatively and post-operatively between 12 and 35 months after surgery. For statistical analysis a linear regression was used. The study was designed as a single cohort study, with comparison of pre- and post-operative values. RESULTS: Highly statistically significant differences (p < 0.0001) were found between pre-operative flare values and those measured at the final visit. The linear regression model showed significantly higher flare values post-operatively compared with those measured pre-operatively. Other variables such as incision technique, sex, operation time, phaco time and systemic disease had no influence on this outcome. CONCLUSION: The results suggest that there is persistent blood-aqueous barrier dysregulation even several years after cataract surgery.

Course of postoperative inflammation after implantation of 4 types of foldable intraocular lenses.

PURPOSE: To compare the course of postoperative inflammation after small incision cataract surgery with implantation of 4 types of foldable intraocular lenses (IOLs). SETTING: Department of Ophthalmology, University Hospital of Vienna, Austria. METHODS: One hundred twenty eyes were prospectively randomized to receive a foldable silicone (Pharmacia 920), hydrogel (Bausch & Lomb Hydroview), methyl methacrylate/hydroxyethyl methacrylate (Mentor MemoryLens), or acrylic (Alcon AcrySof) IOL. All surgery was performed by the same experienced surgeon using a standardized surgical protocol: clear corneal incision, capsulorhexis, phacoemulsification, and in-the-bag implantation of the IOL. All patients received standardized postoperative medication and follow-up. Postoperative inflammation was evaluated by measuring aqueous flare preoperatively and 1, 3, 7, 14, 28, 90, and 180 days after surgery using the Kowa 1000 laser flare-cell meter. RESULTS: Except on the first day after surgery, when the AcrySof group had higher flare values than the other groups (P = .0265), no significant differences were found up to 6 months. Re-establishment of the blood-aqueous barrier was similar in eyes with the AcrySof, Hydroview, and MemoryLens IOLs; the course of postoperative inflammation was different in eyes with the silicone IOL. CONCLUSION: Comparison of postoperative flare values after implantation of 4 foldable IOLs showed no clinically relevant differences in the course of postoperative inflammation.

Effect of cooled intraocular irrigating solution on the blood-aqueous barrier after cataract surgery.

PURPOSE: To evaluate the effect of cooled intraocular irrigating solution during phacoemulsification on postoperative blood-aqueous barrier (BAB) disturbance. SETTING: Department of Ophthalmology, University of Vienna, Austria. METHODS: In a prospective, randomized clinical study, 40 eyes with senile cataract had phacoemulsification with irrigating solutions cooled to approximately 10 degrees C (n = 20) or at room temperature (n = 20). Surgical procedure and postoperative therapy were otherwise identical in both groups. Postoperative BAB disturbance was assessed with the laser flare-cell meter on days 1, 3, 7, 14, and 28. RESULTS: Anterior chamber flare was significantly lower in the group with cooled irrigating solution on postoperative day 1. There was no significant between-group difference in flare on any other postoperative day. CONCLUSION: Cooled intraocular irrigating solution reduced immediate postoperative inflammation compared with irrigating solution at room temperature. However, this effect was of short duration.

Inflammation after phacoemulsification in patients with type 2 diabetes mellitus without retinopathy: prospective study.

PURPOSE: To evaluate inflammation after clear corneal incision (CCI) cataract surgery in patients with noninsulin-dependent diabetes mellitus and no retinopathy. METHODS: Forty patients with diabetes and 40 age-matched controls had standardized temporal CCI cataract surgery with implantation of a foldable intraocular lens. Anterior chamber flare was evaluated in an undilated eye with a laser flare-cell meter preoperatively and 1, 3, 7, 14, and 28 days postoperatively. RESULTS: In both groups, flare and cell values increased on the first postoperative day and successively decreased on the following days. Flare had not recovered to preoperative values by day 28. At no time was there a significant mean difference in cell and flare between the 2 groups. CONCLUSION: It does not appear necessary to alter the postoperative therapeutic regimen in patients with type 2 diabetes mellitus and no retinopathy.

Postoperative inflammation after clear corneal and sclerocorneal incisions.

PURPOSE: To compare two standard small incision techniques for cataract surgery--clear corneal incision and sclerocorneal incision--with regard to postoperative disturbance of the blood-aqueous barrier (BAB). SETTING: Department of Ophthalmology, University of Vienna, Austria. METHODS: This prospective comparative study comprised 108 eyes with senile cataract. A clear corneal tunnel incision was made in 53 eyes and a sclerocorneal incision with tunnel preparation in 55. All other surgical procedures and postoperative medication were standardized. Postoperative BAB disruption was measured with a laser flare-cell meter (Kowa FC 1000) in an undilated pupil on 1, 3, 7, 14, 28, 60, and 90 days postoperatively. The values were compared using a two-sided t-test. RESULTS: In both groups, flare and cell values were highest on the first postoperative day. They gradually declined but without recovery of preoperative flare values on day 28. At no time was there a noticeable between-group difference in mean cell and flare values except for flare at day 14 (P = .04). CONCLUSION: Postoperative trauma, measured by the BAB disturbance, was equally low after clear corneal and sclerocorneal incisions.