The effect of orally administered glycerol on anterior chamber depth during cataract surgery in eyes with narrow anterior chambers.

PURPOSE: Cataract surgery on eyes with shallow anterior chambers may be demanding. Glycerol intake prior to surgery has been a well-known method in an effort to increase anterior chamber depth. It is used since it is thought that glycerol as an osmotic agent causes the vitreous body to shrink, pulling back the iris and thereby deepening the anterior chamber - making the surgery easier. Our controlled clinical trial tests this hypothesis and investigates the effect of glycerol on anterior chamber depth (ACD), intraocular pressure (IOP), corneal thickness (CCT), pupil diameter change after viscodilation (PD), operating time and perioperative complications. METHODS: We performed a controlled clinical trial. All patients underwent cataract surgery on both eyes with at least 7 days apart. Preoperatively the patient was given glycerol orally when the right eye was operated - when the left eye was operated, nothing was given. In this way, each patient was serving as its own control. Measurements of ACD, IOP and CCT were performed before and after glycerol intake, pupillary diameter was measured before and after viscoelastics during the operation, and operating time and surgical complications were noted. RESULTS: The study included 22 patients with bilateral cataract and anterior chambers depth <2.5 mm. Glycerol caused the anterior chamber to increase by 0.022 mm (p < 0.05), and IOP was lowered by 5.1 mmHg compared to the control group (p < 0.05). However, exposure to glycerol showed no effect on CCT, pupillary dilation of viscoelastics, operating time or surgical complications. CONCLUSION: Glycerol increases anterior chamber depth and lowers intraocular pressure significantly. These changes had no significant impact on operating time nor on the complication rate, suggesting that these changes are too subtle to have a clinical impact on the cataract procedure.

Corneal endothelial cell changes after cataract surgery in patients on systemic sympathetic α-1a antagonist medication (tamsulosin).

PURPOSE: The purpose of this study was to assess the incidence of intraoperative floppy iris syndrome (IFIS) and the morphology of the corneal endothelium after cataract extraction in Caucasian male patients exposed to the α-1a adrenergic receptor antagonist tamsulosin. METHODS: In a clinical prospective study, 23 male patients (23 eyes) treated with tamsulosin due to benign prostatic hyperplasia and 25 male patients (25 eyes) with no tamsulosin treatment had cataract surgery. The divide-and-conquer technique was used with the Infinity OZil(®) machine. A combination of Healon and Healon5 was used in all patients, but the use of additional Vision Blue, iris retractors or intracameral phenylephrine in the tamsulosin group was at the discretion of the surgeon. The endothelial cell density, variation in endothelial cell size (CV), percentage of hexagonal cells and central corneal thickness (CCT) were recorded at baseline and at 3 months postoperatively. RESULTS: In the tamsulosin-treated group, 19 of 23 eyes (83%) developed IFIS, compared with no IFIS in the control group. Compared with the control group, the tamsulosin group showed significantly less dilatation at the start of the operation, significant miosis during surgery and significantly greater corneal endothelial cell loss 3 months postoperatively (12% versus 3%; p< 0.001). CONCLUSION: Intraoperative floppy iris syndrome during cataract surgery is significantly associated with tamsulosin-treated male patients. Patients on tamsulosin showed less preoperative dilatation, significant miosis during surgery, and had significantly greater postoperative endothelial cell loss compared with nontreated patients despite recommended precautions.

A comparative study of trabeculectomy and the new clear-cornea filtering procedure, intrastromal diathermal keratostomy (IDK).

PURPOSE: For the first time to compare the 1-year success rates of trabeculectomy and the new clear-cornea filtering procedure, intrastromal diathermal keratostomy (IDK). METHODS: Prospective clinical observational study including 99 consecutively operated eyes (69 patients) with well-established primary open-angle glaucoma referred for filtering operation. We compared the change in intraocular pressure (IOP), number of anti-glaucomatous medication, complications and reoperations after 1 year. Seventy-four eyes were operated with trabeculectomy, and 25 with IDK. Complete success was defined as IOP ≤ 18 mmHg, IOP lowered ≥ 30%, no medication and no reoperation. Qualified success was defined as IOP ≤ 18 mmHg, and IOP lowered ≥ 30% with or without medication or reoperation. RESULTS: Intraocular pressure pre- and postoperatively in the trabeculectomy group was 25.3 and 14.1 mmHg versus 23.8 and 15.8 mmHg in the IDK group. The number of medications pre- and postoperatively in the trabeculectomy group was 3.1 and 0.5 versus 3.2 and 1.3 in the IDK group. Forty-four (59%) of the eyes in the trabeculectomy group met the complete success criteria compared with 5 (20%) in the IDK group (p < 0.01). Sixty-eight (92%) in the trabeculectomy group and 16 (64%) in the IDK fulfilled the qualified success criteria (p < 0.01). CONCLUSION: Both the complete and qualified 1-year success rates of IDK are significantly lower compared with the success rates of trabeculectomy. The IDK does not reduce the IOP as much as the procedure of trabeculectomy, and it carries a higher frequency of reoperations and more medication postoperatively. Thus, our prospective data do not support the procedure of IDK as 'the gold standard' for filtering surgery in patients with open-angle glaucoma.

Corneal endothelial cell changes associated with cataract surgery in patients with type 2 diabetes mellitus.

PURPOSE: To investigate the corneal endothelial cell density and morphology in patients with and without diabetes after phacoemulsification with intraocular lens implantation. METHODS: A clinical prospective study including 30 patients with type 2 diabetes and 30 control patients without diabetes scheduled to undergo cataract surgery. No difference in preoperative age was observed between the 2 groups (P = 0.90). Sample size was based on a power calculation (power 0.90; P = 0.05). The patients without diabetes had a casual blood glucose test performed to disclose undetected diabetes. The patients with diabetes had a serum glycosylated hemoglobin (HbA1c) test performed to reveal the glycemic control. The endothelial cell density, variation in endothelial cell size (CV), percentage of hexagonal cells, and central corneal thickness (CCT) were recorded at baseline and at 3 months postoperatively. RESULTS: The mean decrease in endothelial cell density at 3 months in the diabetic group was 154 cells per square millimeter (6.2%) and 42 cells per square millimeter (1.4%) in the control group. The difference in cell loss between the 2 groups was significant (P = 0.04). A significant decrease in the percentage of hexagonal cells was also seen in the diabetic group (P = 0.01). There was no statistically significant change in CV or CCT. Visual acuity increased significantly and equally in the 2 groups. CONCLUSIONS: The present study reveals a significantly greater loss of corneal endothelial cells in a diabetic group under good glycemic control, compared with nondiabetic group 3 months after phacoemulsification. The morphological changes in the endothelial cells in patients with well-controlled diabetes were not reflected in impaired function as judged by CCT.

Randomized and double-blinded pilot clinical study of the safety and anti-diabetic efficacy of the Rauvolfia-Citrus tea, as used in Nigerian traditional medicine.

AIM OF THE STUDY: The aim of this randomized and double blinded pilot clinical trial was to investigate the anti-diabetic efficacy of the Rauvolfia-Citrus (RC) tea in humans. We have earlier shown that a combination of calorie-restriction and chronic administration of the RC tea to the genetic diabetic (BKS-db) mice resulted in the normalization of blood sugar, reduction in lipid accumulated in the mice eyes and prevention of the degeneration of the otherwise brittle BKS-db pancreas. The tea is made by boiling foliage of Rauvolfia vomitoria and fruits of Citrus aurantium and is used to treat diabetes in Nigerian folk medicine. MATERIALS AND METHODS: The RC tea was produced using the Nigerian traditional recipe and tested in the traditional dosage on 23 Danish type 2 diabetes (T2D) patients. The participants were divided into two equivalent groups after stratification by sex, age and BMI, in a 4-month double-blinded, placebo-controlled and randomized clinical trial. Most of the study subjects (19/23) were using oral anti-diabetic agents (OADs). Mean disease duration was 6±4.6 years, mean age was 64±7 years and mean BMI was 28.7±3.8 kg/m(2). Prior to starting the treatment, the participants received individual dietician consultations. RESULTS: At the end of the 4-month treatment period, the treated group showed an 11% decrease in 2-h postprandial plasma glucose relative to the 3% increase in the placebo group (p=0.004). The improvement in blood glucose clearance with RC tea treatment was reflected in a 6% reduction in HbA(1c) (p=0.02) and in a 10% reduction in fasting plasma glucose (p=0.02), when comparing the post 4-month treatment to pre-treatment baseline values. Though the basal levels of phosphorylated acetyl CoA carboxylase enzyme in skeletal muscle were significantly reduced in the treated group (p=0.04), as compared to the placebo, only the pattern of reductions in the tissue fatty acids (FAs) differed in the two groups. While all types of FAs were reduced in placebo, only saturated (SFA) and monounsaturated (MUFA) FAs were reduced with treatment. Interestingly, a modest increase in the polyunsaturated FAs fraction was observed in the RC treated group. In addition, the reduction in SFA and MUFA with RC tea treatment came solely from the triglyceride fractions, as there was an increase in the skeletal muscle phospholipids. CONCLUSIONS: Chronic administration of the RC tea to overweight T2D on OADs caused significant improvements in markers of glycaemic control and modifications to the fatty acid profile of skeletal muscle, without adverse effects or hypoglycaemia. Further exploration of the anti-diabetic effects of the RC tea is warranted.

Intraoperative floppy iris syndrome (IFIS): a practical approach to medical and surgical considerations in cataract extractions.

Intraoperative floppy iris syndrome (IFIS) during cataract surgery is characterized by iris fluttering, iris prolapse towards the incisions, and a progressive pupillary constriction leading to high rates of complications. The syndrome has been reported following the treatment of benign prostatic hyperplasia with α-1(a) adrenergic receptor inhibitors, especially tamsulosin. The present paper describes the syndrome and discusses its pharmacological background. Several techniques to prevent and to deal with the syndrome are presented.

Corneal endothelial cell loss after mitomycin C-augmented trabeculectomy.

PURPOSE: To determine the effect on the corneal endothelium of mitomycin C (MMC)-augmented trabeculectomy 3 and 12 months after surgery. PATIENTS AND METHODS: In a prospective, observational clinical study, 14 eyes of 14 patients with well-established open angle glaucoma were followed for 12 months after MMC-augmented trabeculectomy. We measured the endothelial cell density, the variation in mean cell size, the percentage of hexagonal cells, and the central corneal thickness at baseline and 3 and 12 months postoperatively. RESULTS: The mean endothelial cell density was 2525 [standard deviation (SD) 457] cells/mm(2) before surgery and 2332 (SD 643) cells/mm(2) and 2283 (SD 597) cells/mm(2) at 3 and 12 months after surgery, respectively, representing a cell loss of 9.5% (P=0.052) and 10.0% (P=0.027). The cell loss from 3 to 12 months was nonsignificant (P=0.40). After 12 months of follow-up, the variation in mean cell size and the percentage of hexagonal cells had not yet stabilized around the preoperative values. CONCLUSIONS: Our results show that significant cell loss occurs during or immediately after MMC-augmented trabeculectomy. However, no progressive cell loss was observed from 3 to 12 months, demonstrating that MMC has no prolonged toxic effect on the corneal endothelium. From 3 to12 months after MMC-augmented trabeculectomy, active endothelial adaptations were taking place.

Endothelial cell damage after cataract surgery: divide-and-conquer versus phaco-chop technique.

PURPOSE: To compare endothelial cell damage during cataract surgery performed using the divide-and-conquer or phaco-chop nuclear fracturing technique. SETTINGS: Department of Ophthalmology, Frederiksberg University Hospital, Frederiksberg, Denmark. METHODS: In a prospective study, 60 eyes of 60 patients were randomly assigned to 1 of 2 groups (30 eyes each group) based on the phacoemulsification technique used: phaco chop or divide and conquer. During surgery, phaco time, phaco power, irrigation volume, and grade of nuclear firmness were recorded. The endothelial cell density, variation in endothelial cell size, percentage of hexagonal cells, and central corneal thickness (CCT) were recorded at baseline and 3 and 12 months postoperatively. Sample size was based on a power calculation (power 0.90, P = .05, clinically important difference = 300 cells/mm2). RESULTS: Significantly less phaco power was used during phaco-chop surgery than during divide-and-conquer surgery. Postoperatively, both groups had a significant but equal decrease in cell density. There were no statistically significant changes in variation in endothelial cell size, percentage of hexagonal cells, or CCT. Visual acuity increased significantly and equally in the 2 groups. Higher endothelial cell loss was significantly correlated with shorter axial length. CONCLUSIONS: It has been suggested that the phaco-chop technique is less harmful to the corneal endothelium than the divide-and-conquer technique because it uses less phaco power. The findings did not support this hypothesis as similar and low cell loss was observed in the 2 groups.

The influence of viscoelastic substances on the corneal endothelial cell population during cataract surgery: a prospective study of cohesive and dispersive viscoelastics.

PURPOSE: To compare the ability of cohesive and dispersive ophthalmic viscoelastic devices (OVDs) to protect the corneal endothelium following in-the-bag phacoemulsification with implantation of a foldable posterior chamber intraocular lens (IOL). METHODS: In a prospective single-masked randomized study, 60 eyes of 60 cataract patients were assigned to three groups of 20 patients each, according to which OVD was used: Celoftal, Vitrax or Healon. The corneal response to surgery was evaluated by measuring the endothelial cell loss, the variation in mean cell area of the endothelial cells (CV), the frequency of hexagonal cells, and the central corneal thickness. Data were recorded preoperatively and 3 months postoperatively. RESULTS: Preoperatively, no significant difference was observed in cell count, CV, hexagonal pattern or pachymetry among groups. Postoperatively, all three groups had a significant decrease in cell count, but the decrease was significantly less in the Vitrax group (6.97%) than in the Celoftal (18.03%) and Healon groups (18.46%). No changes in CV, hexagonality or corneal thickness were observed within any of the three groups or among the groups. There was an equal and significant increase in visual acuity. CONCLUSIONS: Phacoemulsification with implantation of a posterior chamber lens is known to affect the density and morphology of corneal endothelial cells. Viscoelastics facilitate cataract surgery and protect the corneal endothelium during the procedure. Choosing a dispersive hyaluronate OVD during the phaco procedure may allow for protection of the endothelial cells while suppressing the formation of free radicals. This may be the reason for the superior protective effect on the corneal endothelial cells of Vitrax compared with Celoftal and Healon.

Visual functional outcomes of cataract surgery in the United States, Canada, Denmark, and Spain: report of the International Cataract Surgery Outcomes Study.

PURPOSE: To compare functional outcomes after cataract surgery performed at 4 sites in 4 countries that have been described as having significant differences in the organization of care and patterns of clinical practice. SETTING: Multicenter cohort study from the United States, Canada, Denmark, and Spain. METHODS: Clinical data and patient interview data were collected preoperatively and 4 months postoperatively. Functional outcomes were assessed by the Visual Function Index (VF-14), a self-reported measure of visual function. Scores on the VF-14 range from 0 (maximum impairment) to 100 (no impairment). RESULTS: Unilateral surgery was performed in 1073 patients. In this subgroup, the odds of achieving an optimal functional outcome (VF-14 score > or =95) were similar among sites after controlling for differences in case mix. Bilateral surgery was performed in 211 patients. A postoperative visual acuity of 0.50 or better in both eyes was reported in 155 patients. However, 37% of these patients reported visual function impairment (VF-14 score <95). CONCLUSIONS: A previously identified variation in treatment modalities among the 4 sites did not have a significant effect on the odds of achieving an optimal functional outcome. In addition to visual acuity measurements, the VF-14 index provides information on functional outcomes that is useful, especially in studies assessing the benefits of cataract surgery in a public health care setting.