Effect of central corneal thickness and corneal hysteresis on tonometry as measured by dynamic contour tonometry, ocular response analyzer, and Goldmann tonometry in glaucomatous eyes.

PURPOSE: The dynamic contour tonometer (DCT; Pascal tonometer) and the Ocular Response Analyzer (ORA) are novel tonometers designed to measure intraocular pressure (IOP) independent of corneal properties and central corneal thickness (CCT), respectively. We wanted to compare the corneal compensated IOP (IOPcc) as measured by ORA with IOP values measured by DCT and Goldmann applanation tonometry (GAT) with respect to IOP readings and the influence of corneal hysteresis (CH) and CCT in glaucoma patients. PATIENTS AND METHODS: In a study of 94 glaucomatous eyes, IOP measurements by ORA, DCT, and GAT were compared, and the effects of CCT and CH were analyzed. All measurements were taken by 1 of the authors only. RESULTS: The Mean CCT was 550+/-44 mum and mean CH 10.24+/-3.3 mm Hg. The mean value for IOPcc was 17.94+/-5.9 mm Hg, 15.14+/-3.7 mm Hg for DCT, and 14.3+/-4.3 mm Hg for GAT. The mean difference was 3.65+/-3.85 mm Hg between IOPcc and GAT and 2.80+/-4.9 mm Hg between IOPcc and DCT (P<0.001) and -0.85+/-3.3 mm Hg between GAT and DCT (P=0.015). None of the methods was related to CCT. In contrast, CH was highly statistically significant related to IOPcc (P<0.0001), whereas GAT and DCT showed only weak relation to CH (P=0.05). CONCLUSIONS: IOP measurements with the ORA are significantly higher than DCT or GAT with no apparent linear correction factor. To date, we cannot estimate the impact of differences in CH in relation to IOP and its measurement.

Changes in corneal hysteresis after clear corneal cataract surgery.

PURPOSE: To assess the changes in corneal hysteresis (CH) as measured by the Ocular Response Analyzer (ORA; Reichert Ophthalmic Instruments, Buffalo, New York, USA) to describe the influence of clear corneal cataract surgery on corneal viscoelastic properties and intraocular pressure (IOP) measured by noncontact tonometry (NCT) and Goldmann applanation tonometry (GAT). DESIGN: Retrospective, interventional, comparative study. METHODS: One hundred and one eyes of 101 consecutive patients who underwent routine clear corneal cataract surgery were evaluated. CH, NCT, and central corneal thickness (CCT) were measured by ORA before surgery and at postoperative day 1. A control group of 48 pseudophakic eyes (surgery >3 months previously) was included. RESULTS: CCT increased from 556.82 +/- 32.5 microm before surgery to 580.26 +/- 45.5 microm after surgery (P < .001; control, 555.16 +/- 42.33 microm). Mean CH decreased from 10.35 +/- 2.5 mm Hg before surgery to 9.20 +/- 1.9 mm Hg after surgery (P < .001; control, 10.47 +/- 1.63 mm Hg). NCT values rose from 17.85 +/- 3.8 mm Hg before surgery to 20.10 +/- 6.3 mm Hg after surgery. GAT values were 14.85 +/- 2.8 mm Hg before surgery and 15.24 +/- 4.1 mm Hg after surgery (P = .52). There was no significant difference of CCT or CH between the preoperative values and the values of the control group (CCT, P = .986; CH, P = .166), in contrast to the difference between postoperative values and the values of the control group (CCT, P = .005; CH, P = .031). CONCLUSIONS: At day 1 after clear corneal cataract surgery, CH is diminished, whereas CCT is increased significantly. Postoperative corneal edema leads to a change of corneal viscoelastic properties, resulting in a lower damping capacity of the cornea. It is supposed that GAT and NCT measurements are significantly different because of postoperative changes in viscoelastic properties of the cornea.

Six-year follow-up of laser in situ keratomileusis for moderate and extreme myopia using a first-generation excimer laser and microkeratome.

PURPOSE: To evaluate objectively and subjectively the long-term outcome of laser in situ keratomileusis (LASIK) in patients with high and very high myopia. SETTING: Department of Ophthalmology, Philipps University, Marburg, Germany. METHODS: Thirty-three eyes of 19 patients were followed for a mean of 76 months (range 50 to 84 months) after primary LASIK using the Keratom I excimer laser (Schwind) and the ALK microkeratome (Chiron). Refraction, glare, pachymetry, corneal topography, and tear-film secretion and stability were measured. At the last examination, patients also answered a 14-item questionnaire. RESULTS: Preoperatively, the mean spherical equivalent was -13.65 diopters (D). At 1 year, it was -0.25 D and after 6 years, -0.88 D. Fifteen percent of eyes lost > or =2 lines of best spectacle-corrected visual acuity (BSCVA), and 9% gained > or =2 Snellen lines. At the end of the study, 46% of eyes were within +/-1.0 D of the attempted corrected and 88% were within +/-3.0 D. There were 5 microkeratome-associated complications; 3 resulted in loss of BSCVA. The latest pachymetry showed a mean corneal thickness of 498.5 microm (range 396 to 552 microm). There were no cases of keratectasia. Seventy-five percent of patients noted an increase in their quality of life. Seventy-one percent were satisfied with their postoperative visual acuity; however, 75% noticed glare and halos at night. CONCLUSIONS: Laser in situ keratomileusis correction of very high myopia did not cause keratectasia in the long term provided the corneal thickness was respected. A flap thickness setting of 130 microm with a first-generation microkeratome resulted in a high number of cut failures. Most patients were happy with the results despite a modest level of accuracy and glare.

Pituitary function test and endocrine status in patient with cirrhosis of the liver before and after hepatic transplantation.

OBJECTIVE: Hormonal alterations caused by chronic liver disease are well described. In contrast, the reversibility of peripheral hormonal changes after orthotopic liver transplantation (OLT) has only partially been analyzed since the establishment of OLT as treatment of chronic hepatic failure. In addition it is not finally verified if chronic liver failure and especially hepatic encephalopathy also affect pituitary function. We therefore performed extensive endocrine studies including a global pituitary stimulation test before and after liver transplantation. METHODS: 22 patients with chronic alcoholic and non alcoholic liver failure were included in this prospective study. Basal hormone values (ACTH, cortisol, FSH, GH, IGF-I, LH, oestradiol, PRL, thyroid hormones and testosterone) were measured before and up to 5 years after OLT. Furthermore all patients underwent pituitary function tests with application of GRF, TRH, GnRH, and CRF before, 3 weeks and 3 months after OLT. RESULTS: Estradiol, LH and FSH increased significantly in postmenopausal and only slightly in premenopausal female patients after OLT. Total testosterone revealed no marked changes and was normal before and up to five years after OLT in male patients. After stimulation with GnRH the LH response in females and the FSH response in males was significantly higher three months after OLT than pretransplant. LH response in males and FSH response in females was only slightly higher after OLT. Peripheral IGF-I was low and growth hormone was elevated in all patients prior OLT. Growth hormone declined significantly three months afterwards. The response to GRF was highest prior OLT and decreased afterwards. Prolactin values were normal prior and post OLT. After stimulation with TRH prolactin values in male patients were significantly higher before OLT than afterwards. CONCLUSION: In the observed relatively small number of patients gross pituitary function in chronic liver failure remained intact, whereas slight alterations in several axis were found. These pituitary alterations are presumably only partially caused by feedback mechanisms. Both a normalisation of peripheral endocrine parameters and pituitary function were achieved by OLT despite significant alterations pretransplant.

[Extracapsular cataract surgery with posterior chamber lens implantation in patients with diabetes mellitus - retrospective study on 145 patients]. / Extrakapsuläre Kataraktoperation mittels Kernexpression mit Hinterkammerlinsenimplantation bei Patienten mit Diabetes mellitus - eine retrospektive Studie an 145 Patienten.

BACKGROUND: The purpose of this paper is to investigate whether cataract surgery in patients with diabetes mellitus influences the progression of diabetic retinopathy, diabetic macular oedema and anterior segment complications. PATIENTS AND METHODS: 145 consecutive patients with type-II-diabetes mellitus underwent an extracapsular cataract surgery with implantation of a posterior chamber lens. 88 patients (119 eyes have been operated) could be followed up for an average of 19 months and 58 patients (88 eyes have been operated) could be followed up for an average of 38 months. Evaluation of the data included the preoperative retinal findings, intraoperative and early postoperative complications and problems, the progression of diabetic fundus changes, the progression of visual acuity and late complications. RESULTS: Insufficient pupil dilatation (25.2 %) was the most frequent intraoperative complication. Among early postoperative complications anterior segment inflammation was most frequent (10.1 %). During the follow-up period the diabetic retinopathy in the operated eyes showed a progression which was statistically not different from that in the non-operated eyes. After an average of 19 months the diabetic retinopathy deteriorated in 22.7 % of the operated eyes and in 17.5 % of the non-operated eyes. After an average of 38 months the diabetic retinopathy deteriorated in additional 12.5 % of the operated and 11.1 % of the not-operated eyes. A diabetic macular oedema was present after an average of 19 months in 6.8 % of the operated 119 eyes and after an average of 38 months in 6.7 % of the operated 88 eyes. In the non-operated partner-eyes no diabetic macular edema developed during the follow-up period. The main late-complication during the whole follow-up period was the development of a capsular fibrosis in 52.3 % of the operated eyes. Postoperative visual acuity at the end of the first follow-up period (average 19 months) was >/= 0.5 in 85.7 % of the operated eyes and at the end of the second follow-up period (average 38 months) in 81.8 % of the operated eyes. CONCLUSION: Extracapsular cataract surgery in patients with diabetes mellitus is a procedure with good results, of high reliability and a slightly higher rate of complications than in non-diabetic patients. Extracapsular cataract surgery does not give rise to progression of diabetic retinopathy.