Sevoflurane and propofol decrease intraocular pressure equally during non-ophthalmic surgery and recovery

BACKGROUND

To provide good control of intraocular pressure (IOP) during anaesthesia and surgery, we conducted a study comparing the effects on IOP during maintenance and recovery of sevoflurane vs propofol anaesthesia in 33 patients (ASA I-II) undergoing elective non- ophthalmic surgery.

METHODS

Anaesthesia was induced with propofol 2 mg kg(-1), fentanyl 2 micro g kg(-1) and vecuronium 0.1 mg kg(-1). Patients were allocated randomly to receive either propofol 4-8 mg kg(-1) h(-1) (group P; n=16) or 1.5-2.5 vol% sevoflurane (group S; n=17) for maintenance of anaesthesia. Fentanyl 2-4 micro g kg(-1) was added if necessary. The lungs were ventilated with 50% air in oxygen. Blood pressure, heart rate, oxygen saturation and end-tidal carbon dioxide were measured before and throughout anaesthesia and in the recovery room. IOP was determined with applanation tonometry (Perkins) by one ophthalmologist blinded to the anaesthetic technique.

RESULTS

There was a significant decrease in IOP after induction and during maintenance of anaesthesia in both groups. No significant differences in IOP between the two groups was found.

CONCLUSION

Sevoflurane maintains the IOP at an equally reduced level compared with propofol.

Effect of different doses of cisatracurium on intraocular pressure in sedated patients

BACKGROUND AND OBJECTIVE

The aim was to examine the course of intraocular pressure after relaxation with different doses of cisatracurium.

METHODS

The investigation was carried out as a prospective, randomized double-blind study in a crossover design in 30 postoperative patients with stable haemodynamic and respiratory function (ASA I and II). To exclude any disrupting factors, patients remained intubated and continuously sedated. Twenty patients received an intubation dose (2 x ED95) of cisatracurium (0.1 mg kg(-1)) compared with atracurium (0.5 mg kg(-1)). In a second series, 10 patients were given an effective dose, ED95 (0.05 mg kg(-1)), and a repeat dose (0.02 mg kg(-1)) of cisatracurium. The intraocular pressure was determined before (T0) as well as 1 (T1), 5 (T5), 10 (T10), 15 (T15), 20 (T20) and 45 (T45) min after bolus administration.

RESULTS

Intraocular pressure decreased after an intubation dose of either cisatracurium or atracurium, and reached a minimum after 10 min (6.7 +/- 2.2 and 7.9 +/- 2.1 mmHg, respectively). There was no significant difference between either muscle relaxant (P = 0.27). When lower doses of cisatracurium (0.05 and 0.02 mg kg(-1)) were applied, the intraocular pressure also decreased, albeit to a lesser extent and with a delayed onset (8.4 +/- 1.9 mmHg after 10 min, 9.9 +/- 3.4 mmHg after 15 min). There was no significant difference between dosages (p = 0.44).

CONCLUSIONS

Cisatracurium is a useful drug in patients when a decrease of intraocular pressure is wanted and where muscle relaxation is necessary and acceptable.

Midterm visual outcome and progression of diabetic retinopathy following cataract surgery. Midterm outcome of cataract surgery in diabetes

OBJECTIVE

To assess the influence of cataract surgery on progression of diabetic retinopathy and visual acuity.

METHODS

37 patient eyes with mild to moderate diabetic retinopathy at baseline underwent phacoemulsification and intraocular posterior chamber lens implantation. They were examined 3.3 +/- (SD) 0.7 years after surgery.

RESULTS

83.8% of the eyes showed a better final visual acuity, and 67.6% achieved a final visual acuity of 0.5 or better. The retinopathy remained unchanged in 83.8% and progressed in 16.2% of the eyes. No eye progressed to proliferative retinopathy.

CONCLUSION

Phacoemulsification and implantation of a posterior chamber intraocular lens is a safe procedure for patients with mild to moderate diabetic retinopathy.

The clinical use of viscoelastic artificial tears and sodium chloride in dry-eye syndrome

This study was performed to test viscoelastic artificial tears (VAT) based on both subjective and clinical parameters in patients with keratoconjunctivitis sicca (KCS). Twenty-eight patients were evaluated in a randomized double-blind study. Sodium hyaluronate was used in two different concentrations (0.4%, 0.25%) and in combination with chondroitin sulfate. Each preparation was used for one week preceded by another weekly cycle using a sodium chloride solution. Before and after each cycle, clinical examinations were performed: tear film break-up time, Schirmer's test, lipid-layer thickness and fluorescein staining. Patients kept a record of the drop-frequency, subjective response and side effects. After the study, they were asked to give a rating of the various preparations. The severity of KCS was expressed based on a sicca score and correlated with response to viscoelastic treatment. Both the subjective and the clinical parameters revealed no statistically significant differences between the various viscoelastic agents or between the viscoelastics and the sodium chloride solutions. Severe side effects did not occur. There was a positive correlation of response to viscoelastic treatment with severe KCS (+ 0.36) but not with mild KCS (-0.07). The VAT seems to be indicated in severe cases of dry-eye syndrome. Sodium chloride solutions may be a useful short-term alternative to other tear formulations.

Ocular blood flow in patients infected with human immunodeficiency virus

PURPOSE

Alterations of ocular blood flow may play a role in the pathophysiology of human immunodeficiency virus (HIV) related retinal microvasculopathy. In this study ocular blood flow was investigated in patients with HIV infection.

DESIGN

In a prospective, cross-sectional study ocular blood flow was measured in 37 eyes of consecutive HIV- infected persons and compared with the data of age-matched healthy controls. This sample size was calculated based on an alpha-error of 0.5 and a beta-error of 0.8.

METHODS

Macular white blood cell flow, fundus pulsation amplitude, and blood flow velocities in the retrobulbar vessels were measured with blue field entoptic technique, laser interferometry, and Doppler sonography, respectively. Immunologic and ophthalmologic status was evaluated from each patient.

RESULTS

Mean CD4+ cell count of the HIV-infected persons was 206.8 +/- 145.6 cells/mm(3). In five patients HIV-related retinopathy was observed. A significant reduction in leukocyte density was seen in HIV infected persons (82.2 +/- 23.4) as compared with the control group (102.0 +/- 28.4; P =.019). The resistive index in the central retinal artery was higher in HIV infected patients (0.77 +/- 0.05) as compared with the controls (0.74 +/- 0.04; P =.04). The other hemodynamic parameters were not different between groups. No correlation of flow parameters and CD4+ cell count or HIV-related retinopathy was observed.

CONCLUSIONS

Decreased macular leukocyte density was detected in HIV infected persons. Our study suggests that abnormal retinal hemodynamics in individuals infected with HIV may be involved in the pathogenesis of HIV-related microvasculopathy.

Tolosa Hunt Syndrome--intractable pain treatment with acupuncture?

PURPOSE

The Tolosa Hunt Syndrome (THS) is a painful granular inflammation of the cerebral vessels followed by pain and disorders of the extrabulbar muscles. The therapy consists of corticosteroids and analgetics. There was a 70 year old woman who suffered from painful paresis of the abducent and oculomotor nerves following an infection with Borrelia Burgdorferi--but without ocular symptoms. The treatment with corticosteroids reduced the palsy but she complained of excessively painful attacks in the region of the first branch of the trigeminal nerve. Opiold analgetic therapy did not bring about any relief. Acupuncture is an irritative method with a physical effect on the nervous system: its pain-reducing effect is caused by the activation of transmitters like endorphins in thalamus and brain stem. Knowing this effect, the THS patient, after informed consent, was treated with acupuncture. To measure the extent of pain, a visual analog scale (0: no pain - 10: maximum pain) was used. Acupuncture was performed according to the empirical rules of the Traditional Chinese Medicine (TCM), during a period of 10 weeks and 12 weeks. There was a significant pain relief after acupuncture from VAS 10 to VAS 5. The effect vanished during the next four months. After a second series of 12 sessions pain reduction was reported from VAS 10 to 4. One year after the last Tolosa Hunt Syndrome - intractable pain pain strength ranged between VAS 4 - 6. Therefore acupuncture seems to be a good additional method for reduction of intractable pain.

Inflammation after phacoemulsification in diabetic retinopathy. Foldable acrylic versus heparin-surface-modified poly(methyl methacrylate) intraocular lenses

PURPOSE

To evaluate inflammation after cataract surgery in patients with nonproliferative diabetic retinopathy (NPDR) and compare results with 2 intraocular lenses (IOLs): a foldable hydrophobic acrylic and a heparin-surface-modified (HSM) poly(methyl methacrylate) (PMMA).

SETTING

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

METHODS

Patients with NPDR were randomized for implantation of an HSM PMMA IOL (811C, Pharmacia) through a 6.0 mm sclerocorneal incision (30 patients) or a foldable hydrophobic acrylic IOL (AcrySof, Alcon) through a 4.0 mm sclerocorneal incision (32 patients). Both IOLs had 6.0 mm optics. All patients were treated according to a standardized protocol. The degree of flare in the anterior chamber was measured with the Kowa 1000 laser flare-cell meter 1 day preoperatively and 1 day, 1 week, and 1 and 3 months postoperatively.

RESULTS

In both IOL groups, flare was highest on the first postoperative day and decreased to preoperative levels by 3 months after surgery. There was no statistically significant difference in relative flare values between the 2 groups.

CONCLUSION

There was no difference in postoperative inflammation in eyes with a foldable hydrophobic acrylic IOL implanted through a small incision and those with a rigid HSM PMMA IOL. Postoperative inflammation results indicate that the lenses are equally suitable for the use in patients with diabetic retinopathy.

Evaluation of cytomegalovirus retinitis management. Outcome of four years of cytomegalovirus therapy

Cytomegalovirus (CMV) is the most common pathogen of opportunistic viral infections in patients with the acquired immunodeficiency syndrome. In this study, we assessed the therapeutic outcome of our treatment regimen of CMV retinitis by analysing retrospectively 33 consecutive patients. The clinical utility of CMV cultures from blood, urine and throat specimens obtained at the time of diagnosis was additionally evaluated. Treatment started with ganciclovir (GCV) therapy. In case of relapsing retinitis, re-induction therapy was initiated, and if unsuccessful, the patient was switched to foscarnet. Patients developing resistant retinitis despite foscarnet therapy were offered a GCV-foscarnet combination therapy. Under primary GCV therapy, the median first stable interval of the whole group was 202 days (mean 238 days). Twenty-five out of 33 CMV retinitis patients (76%) responded to initial GCV therapy. Eleven of these patients showed relapsing retinitis that could be stabilised in 3 patients solely with combination therapy. Eight patients did not respond to primary GCV therapy. Three of them improved with foscarnet, but 3 patients did not respond to either treatment. In 18 (56%) out of 32 patients, CMV cultures yielded positive results. Considering our series, we may conclude that in the majority of patients primary or secondary viral resistance can be overcome by dose increase, switching to the alternative drug or a combination therapy.

Intravitreal injection of tissue plasminogen activator and gas in subretinal hemorrhage caused by age-related macular degeneration

PURPOSE

To assess the efficacy and safety of intravitreal injection of recombinant tissue plasminogen activator and sulfur hexafluoride gas for displacement of subretinal hemorrhages in patients with age-related macular degeneration.

METHODS

The authors injected 25 microg of recombinant tissue plasminogen activator and 0.5 mL sulfur hexafluoride gas intravitreally in 11 patients with subretinal hemorrhages of less than 3 weeks duration. Anatomic and functional results were evaluated.

RESULTS

Displacement of subretinal blood was successful within the first week after surgery in 10 of 11 patients. This was accompanied by visual improvement in eight patients. After 1 year, visual acuity was better than before surgery in five patients. Diagnosis of a choroidal neovascularization by fluorescein angiography was possible in all patients, and was treated with laser photocoagulation in five. The authors observed no adverse effects of treatment.

CONCLUSION

Recombinant tissue plasminogen activator and gas effectively displace subretinal blood in patients with age-related macular degeneration. Randomized studies are necessary to prove the benefit of this simple and safe method in patients with subretinal hemorrhage due to age-related macular degeneration.

Phacotrabeculectomy with a small-optic PMMA implant: two-year functional and morphological results

PURPOSE

Previous studies have documented good pressure control with combined cataract and filtering surgery. However, relatively high incidences of iridocapsular synechiae (ICS) and cell precipitates on the optic (CPO) were found. Corneal valve incisions preclude intraoperative chamber flattening and iris injury or prolapse. Rigid one-piece PMMA lenses with a small optic maintain a pronounced optic-iris clearance. In a prospective series, the effect of this approach was studied with special regard to the morphological results.

METHODS

A temporary corneal lip was created in the clear cornea beneath the scleral flap to serve as a temporary valve during cataract extraction. The lip was then widened and a rigid one-piece 5-mm PMMA lens implanted. Lip and trabeculum were finally excised en bloc at a width of 3 mm. Two years' functional and morphological results were evaluated.

RESULTS

Fifty-four eyes were available for evaluation. After the mean follow-up of 21 months, mean IOP had dropped from 21.6+/-3 mm Hg preoperatively to 13.9+/-2.4 mm Hg, with a mean pressure reduction of 7.7+/-3.4 mm Hg. IOP was 18 mm Hg or less in all cases. The mean medication index dropped from 2.7 to 1.0. Eyes with a preoperative IOP of 21 mm Hg or more showed a significantly greater IOP reduction than eyes with an IOP of 20 mm Hg or less (-9.2+/-3.0 vs. -6.1+/-2.9 mm Hg, p = 0.0003). Intraoperatively, the temporary valve effectively prevented chamber flattening and iris injury or prolapse. Postoperatively, 9 eyes or 6% showed hyphemas, 1 undergoing lavage. Two eyes developed a capsular hematoma, 1 requiring YAG capsulotomy. Ten eyes or 19% developed mild and 2 eyes severe but transient fibrin exudation following hypotony or iridoplasty. One eye showed grade I anterior chamber flattening, 1 developed a ciliolenticular block requiring surgery. Postoperative pressure spikes of 30-35 mm Hg were noted in 4 eyes. Three eyes showed prolonged hypotony associated with transient choroidal effusion. A pronounced optic-iris clearance was found in 87% of the eyes. Iris-optic touch developed in 1 eye with prolonged postoperative anterior chamber flattening and in 3 of the 4 eyes that had undergone intraoperative iridoplasty. Three of the latter developed extensive ICS followed by CPO. The mean optic-iris distance was 1.2 mm and the anterior chamber depth 4.2 mm.

CONCLUSION

Apart from effectively lowering IOP, the surgical approach used significantly reduced the incidence of ICS and CPO.

Is there a correlation between the severity of diabetic retinopathy and keratoconjunctivitis sicca?

PURPOSE

Patients with diabetic retinopathy (DRP) seldom report symptoms of ocular surface irritation, but evaluations of dryness are pathologic. This study was designed to evaluate the correlation between the severity of DRP and dry eyes.

METHODS

We included 144 eyes of 72 patients. Severity of retinopathy was graded according to the Early Treatment Diabetic Retinopathy Study. The examinations for dry eyes included Schirmer's test, break-up time, lipid layer thickness, fluorescein and rose bengal staining of the cornea, impression cytology, and a questionnaire. A sicca severity score was calculated using a point system of the results of these tests. Patients were divided into three groups: postpanretinal laser coagulation (PPL), postcentral laser coagulation (PCL), and those with no laser treatment (0-L). For statistics, we used the correlation coefficient to determine relationships and the unpaired Student t test for statistical difference.

RESULTS

The correlation (c) of keratoconjunctivitis sicca (KCS) and DRP after laser treatment was c = 0.24 and after central laser treatment was c = 0.22; the correlation without laser treatment was 0.54. The best correlation is 1 or -1, the worst was 0. The score of those patients with mild to moderate retinopathy was compared to that of patients with severe to proliferative disease. There was a significant statistical difference in the sicca severity score between both groups, (p < 0.006. Student t test).

CONCLUSION

KCS represents another manifestation of diabetes mellitus and its severity--measured by a many-membered score--correlates with the severity of the DRP.

Ocular haemodynamics and colour contrast sensitivity in patients with type 1 diabetes

BACKGROUND

There is evidence that altered ocular blood flow is involved in the development and progression of diabetic retinopathy. However, the nature of these perfusion abnormalities is still a matter of controversy. Ocular haemodynamics were characterised with two recently introduced methods.

METHODS

The cross sectional study was performed in 59 patients with type 1 diabetes with a diabetes duration between 12 and 17 years and an age less than 32 years and a group of 25 age matched healthy controls. Scanning laser Doppler flowmetry and laser interferometric measurement of fundus pulsation amplitude were used to assess retinal and pulsatile choroidal blood flow, respectively. In addition, colour contrast sensitivity along the tritan axis was determined.

RESULTS

Fundus pulsation amplitude, but not retinal blood flow, increased with the progression of diabetic retinopathy. Retinal blood flow was influenced by plasma glucose levels (r = 0.32), whereas fundus pulsation amplitude was associated with HbA(1c) (r = 0.30). In addition, a negative correlation between the colour contrast sensitivity along the tritan axis and retinal blood flow was observed.

CONCLUSIONS

The present study indicates that pulsatile choroidal blood flow increases with the progression of diabetic retinopathy. Increased retinal blood flow appears to be related to loss of colour sensitivity in patents with type 1 diabetes.

[Etiology of non-penetrating corneal injuries]

BACKGROUND

Non-penetrating injuries of the cornea are frequent. Complications like corneal infiltrations, or corneal ulcera, may follow.

MATERIAL AND METHODS

This prospective study included 144 patients with non-penetrating corneal injuries. Records contained epidemiological data, field of activity, profession, cause of the injury, and stress during the trauma.

RESULTS

97% of the patients were men, 78% of the injuries occurred during working hours, 41% of the patients were from metal working professions, 73% of the accidents happened with grinding machines and drilling machines. Only 6.9% of patients weared adequate glasses. The cause of trauma was deflection and working without glasses. In 32% of patients stress played a role in the cause of injuries.

CONCLUSIONS

Most of the corneal, non penetrating injuries happened during the working hours by deflection, and by neglecting safety glasses. With the use of safety glasses the number of corneal non-penetrating injuries could definitely be reduced.

[Effect of acupuncture in keratoconjunctivitis sicca]

BACKGROUND

Conjunctivitis sicca is a chronic disease of the ocular surface. The substitution of tear deficiency with artificial tears is not satisfying in many patients. In a series of patients successfully treated with acupuncture we observed very different effects on each patient. In this study we evaluate the correlation between the effect of acupuncture and the etiology of the dry eyes treated.

PATIENTS AND METHODS

102 patients (87 women, 15 men) with dry-eye syndrome have been needed 10 sessions, once per week, for 30 minutes. We recorded causal factors according to the traditional chinese medicine (TCM): external and internal factors. External factors were: toxic, allergic, drug-induced, ocular surface inflammation and infection, contact lens and generally external irritations. Internal factors were disorders of hormones, immune system, psychic, and vitamin-A deficiency. Ophthalmologic observation included the slit-lamp examination, Schirmers test II, break-up time of tear film (BUT) and a drop-frequency protocol--before and 1 week after acupuncture treatment.

RESULTS

There was a statistically significant difference (p < 0.001) in Schirmers test, BUT and drop frequency between before and after acupuncture. There was no significant difference between internal and external factors, but the effect on external induced sicca was better. The best effect of acupuncture was found in external factors after inflammation and in patients with imbalance of the autonomic nervous system, the least effects in Sjögren Syndrome. The effect was better in younger then in patients over 50 years.

CONCLUSION

The study demonstrate, according DeLa Fuye that the best effect of acupuncture is seen on functionally disorders.

Penetration and decay of meropenem into the human aqueous humor and vitreous

The aim of this study was to determine the penetration of intravenously administered meropenem into the human aqueous humor and vitreous. Thirty patients about to undergo cataract surgery and fourteen patients about to undergo vitrectomy received a 2 g dose of meropenem before surgery. Specimens of aqueous humor or vitreous and blood were obtained intraoperatively and analyzed by high performance liquid chromatography (HPLC). The study was designed as a non-randomized prospective trial. Thirty min to 12 hr after administration, mean aqueous humor levels of 13.4 and 1.1 mg/l and vitreous levels between 8.94 and 1.08 mg/l were found, respectively. The peak concentrations are distinctly above the in vitro measured minimum inhibitory concentration of meropenem for 90% (MIC90) of almost all relevant gram-positive and gram-negative organisms, including Pseudomonas aeruginosa and Enterobacteriaceae. With regard to its broad spectrum, high antibacterial activity, and good penetration into ocular fluids, meropenem seems to be an alternative to currently used systemic drugs. Its usefulness in perioperative prophylaxis, as initial therapy after perforating or penetrating injuries, or in the therapy of bacterial endophthalmitis has yet to be proved.

Control of cytomegalovirus retinitis after combination antiretroviral therapy

PURPOSE

To report on AIDS patients having combination antiretroviral therapy whose cytomegalovirus (CMV) retinitis remained inactive after discontinuation of anti-CMV maintenance therapy.

METHODS

We describe the course of CMV-retinitis in 3 patients with AIDS after initiation of combination antiretroviral therapy.

RESULTS

After cessation of anti-CMV therapy no relapse of CMV-retinitis has been observed for up to 18 months. Two of the patients developed new CMV-retinitis in the first months after initiation of combination therapy, nevertheless after further improvement of immunological parameters retinitis remained stable without anti-CMV therapy.

CONCLUSION

The sustained immunological effects of combination therapy are possibly sufficient enough to provide protection against CMV-retinitis.

Reduction of intraocular pressure in a glaucoma patient undergoing hormone replacement therapy

OBJECTIVES

To show the reducing effect of estrogens and progestins on the elevated intraocular pressure (IOP) in the case of a 56-year-old woman showing typical climacteric complaints, who was admitted to the menopause outpatient unit. She also suffered from a primary open-angle glaucoma treated with betaophtiole eye drops with intraocular pressures of 16-20 mmHg under this local therapy.

METHODS

IOP patterns were monitored by means of standardised daily pressure profiles four times a day before as well as 4 and 12 weeks after the beginning of hormone replacement therapy (HRT). The local glaucoma therapy remained unchanged.

RESULTS

During HRT, IOP levels were reduced from 16-20 mmHg before therapy to 12-15 mmHg at week 4 and to 13-15 mmHg at week 12 after the beginning of HRT.

CONCLUSION

The finding of a close chronological relationship between the onset of menopause and the development of a glaucoma is a potentially new indication for HRT.

Dual beam optical coherence tomography: signal identification for ophthalmologic diagnosis

The dual beam version of optical coherence topography can be used for noninvasive, high-resolution imaging of the human eye fundus, enabling in vivo visualization of retinal morphology as well as accurate quantification of the thickness profiles of its layers. Interferometric fundus signals-optical A-scans-and retinal tomograms of patients with glaucoma, diabetic retinopathy, and age-related macular degeneration are compared with those of healthy, normal subjects to elucidate the origin of the signal peaks detected and to investigate and interpret the retinal microstructures contained in the cross-sectional images. © 1998 Society of Photo-Optical Instrumentation Engineers.