Late ophthalmological complications after total body irradiation in non-human primates.

PURPOSE: To investigate the long-term effects of total body irradiation (TBI) on the incidence and time course of ocular complications. MATERIALS AND METHODS: Rhesus monkeys treated with TBI photon doses up to 8.5 Gy and proton doses up to 7.5 Gy were studied at intervals up to 25 years post-irradiation. They were compared with control groups with a similar age distribution. Cataract formation and ocular fundus lesions were scored according to a standardized protocol. Fluorescein angiography and histopathology was performed in selected animals. RESULTS: Cataract formation occurred after a latent period of 3-5 years. Significant cataract induction was observed for photon-doses of 8 and 8.5 Gy and beyond 20 years after proton irradiation. The severity of the lesions represents significant impairment of vision and would require cataract surgery if similar results occurred in human bone marrow transplant patients. Fluorescein angiography demonstrated a normal pattern of retinal vessels in 13 out of 14 animals (93%) from the irradiated group and in eight out of nine animals (89%) from the control group. No additional lesions apart from age-related degenerative changes could be demonstrated. Histological evaluation revealed no radiation-associated vasculopathy. CONCLUSIONS: Radiation alone for doses up to 8.5 Gy of photons does not carry a potential risk for fundus pathology, whereas clinically important cataract induction should be anticipated within 5 years after photon doses of 8.0 and 8.5 Gy and proton doses in excess of 2.5 Gy.

The effect of 1% apraclonidine on intraocular pressure after cataract surgery.

BACKGROUND AND OBJECTIVE: To measure the effect of 1% apraclonidine hydrochloride eyedrops on intraocular pressure (IOP) after cataract surgery. The effects of two different dosage regimens, once before surgery or once before and after surgery, were studied. PATIENTS AND METHODS: Patients scheduled for extracapsular cataract extraction and artificial lens implantation were randomly assigned to three groups: group A had a placebo treatment (n = 18), group B had one drop of 1% apraclonidine 1 hour before surgery (n = 16), and group C had one drop of 1% apraclonidine 1 hour before surgery and 1 drop at the end of surgery (n = 17). Two percent hydroxy-propyl-methyl-cellulose was used as the viscoelastic substance. The preoperative IOP and the IOP 6 hours postoperatively in each patient were compared. The paired Student's t test was used to compare IOP before and after surgery. The study design was a randomly assigned, double-masked controlled clinical trial. RESULTS: In group A (placebo) and group B (apraclonidine before surgery), there was a significant increase in IOP (mean IOP increase 11.2 +/- 9.9 mm Hg SD, range -4 to 32, P = .00017, and 9.4 +/- 7.4 mm Hg SD, range -3 to 24, P = .00014, respectively). In group C (apraclonidine 1 hour before and immediately after surgery), the increase in IOP was not significant (mean IOP increase 5.1 +/- 11.5 mm Hg SD, range -10 to 28, P = .084). A postoperative IOP of more than 40 mm Hg applanation tension was reached by two patients in group A, one patient in group B, and two patients in group C. CONCLUSION: Although 1% apraclonidine eye-drops instilled 1 hour before and immediately after extracapsular cataract extraction with artificial lens implantation may help prevent a statistically significant increase in IOP after the operation, 2 of the 17 patients still had IOPs greater than 40 mm Hg 6 hours postoperatively. Apraclonidine applied only before surgery did not prevent a statistically significant increase in IOP.

Decreased basal tear turnover in patients with untreated primary open-angle glaucoma.

PURPOSE: To detect whether untreated primary open-angle glaucoma or ocular hypertension is associated with an impaired basal tear turnover. METHODS: Basal tear turnover was determined by fluorophotometry in 18 patients with newly detected, untreated primary open-angle glaucoma and 29 patients with untreated ocular hypertension. The results were compared with those of 27 age-matched control subjects. RESULTS: The basal tear turnover in glaucoma patients (mean +/- S.D., 11.4 +/- 3.1%/min) was 22% lower than in patients with ocular hypertension (14.7 +/- 3.0%/min; P = .0007) and 27% lower than in control subjects (15.7 +/- 5.3%/min; P = .001). Tear turnover of patients with ocular hypertension did not differ significantly from that of control subjects (P = .4). The basal tear turnover values were found to decrease with increasing vertical or horizontal cup/disk ratios (P = .004 and P = .008, respectively). CONCLUSIONS: Primary open-angle glaucoma, but not ocular hypertension, was found to be associated with an impaired basal tear turnover. Dry eye complaints may originate from decreased basal tear turnover as a result of glaucoma drug therapy as well as from primary open-angle glaucoma itself.

Is glaucoma associated with an increased risk of cataract?

AIMS: The risk of developing cataract in patients with untreated glaucoma or with ocular hypertension was evaluated by comparing the values of lenticular autofluorescence and light transmission in 16 patients with primary open angle glaucoma and 22 patients with ocular hypertension with those of 24 healthy controls. METHODS: Increase of lenticular autofluorescence and decrease of transmission values in comparison with controls were considered to be precursors of cataract. The values of both variables were determined by fluorophotometry. Each value was normalised for age by dividing it by the value for a healthy control of the same age. RESULTS: The mean age normalised autofluorescence and transmission values of all patients did not differ significantly from those of the controls (difference < 5%; p = 0.6 and p = 0.2, respectively). Also the mean age normalised autofluorescence and transmission values between glaucoma and ocular hypertension patients did not differ significantly (p = 0.8 and p = 0.9, respectively). CONCLUSION: The study indicates that untreated primary open angle glaucoma or untreated ocular hypertension do not seem to increase significantly the risk of developing cataract.

Recurrent herpetic keratitis in penetrating keratoplasty.

In a retrospective study we evaluated 49 consecutive penetrating keratoplasties for herpes simplex keratitis. Mean follow-up was 44.2 months. Survival analysis with Kaplan-Meier curve showed an overall survival rate (clear graft) of 88% at one year, 76% at two years and 72% at four years postoperatively. Survival analysis showed a recurrence-free survival rate of 72% at one year, 59% at two years and 51% at four years postoperatively. Of the 13 non-primary graft failures, 9 happened in eyes with an HSV recurrence. Recurrence of HSV infection occurred in 18 (39%) eyes at an average of 12.6 months after surgery (range 0.3-46). Five (28%) of the recurrences occurred within two months after the start of steroid treatment for rejection. Nine (50%) of the recurrences cases resulted in a clouded graft at the end of follow-up. 73% of the eyes with a clear graft had a VA of 0.25 or better. We conclude from these data that a recurrence of a herpetic infection following corneal transplantation is the main reason for graft failure in this group.

The effect of high-intensity focused ultrasound on intraocular pressure in therapy-resistant glaucoma 3-4 months and 1 year after treatment.

The effect of therapeutic ultrasound for the treatment of refractory glaucoma was evaluated in 44 patients by comparing average IOP curves measured before and 3-4 months after treatment. The insonification regime was standardized and the glaucoma medication in each individual patient was unchanged during IOP curve measurements. The average IOP decrease 3-4 months after insonification was 42.2% +/- SD 31.9. In 23 patients who were followed for at least one year the average IOP 3-4 months after treatment was compared with the average IOP 1 year after treatment. In this group average IOP 3-4 months after treatment was 25.3 mmHg +/- SD 16.4 and average IOP 1 year after treatment was 24.1 mmHg +/- SD 15.9. The correlation coefficient between IOP 3-4 months after treatment and IOP 1 year after treatment was 0.79 (P < 0.0001).

Epithelial permeability in corneal grafts by fluorophotometry.

The epithelial permeability to fluorescein of 27 clear corneal grafts in 23 patients was determined by fluorophotometry at greater than 1 year after penetrating keratoplasty (PKP) so as to study the recovery of corneal epithelial function. The mean epithelial permeability of the corneal grafts did not differ significantly from that of normal corneas (0.042 +/- 0.016 and 0.038 +/- 0.017 nm/s, respectively; P greater than 0.3). Multiple linear regression analysis showed that permeability correlated with recipient age but not with donor age (permeability increase, 0.00054 nm/s per year; r = 0.6, P less than 0.005 and r = 0.1, P greater than 0.5, respectively). These results indicate that corneal grafts can regain a normal epithelial barrier function and that recovery of epithelial function is better in young than in old recipients.

Effect of indomethacin and prednisolone on the disruption of the blood-aqueous barrier after hyperthermia on the rabbit eye by focused ultrasound.

In 24 rabbits both eyes were treated in the perilimbic area with hyperthermia by focussed ultrasound at a frequency of 4.65 MHz. The intra-ocular pressure (IOP) decreased significantly in all eyes. The effect of pre-treatment with indomethacin and prednisolone on the inflammatory response induced by the insonification was assessed by determination of protein in the aqueous humour 2 h after ultrasound treatment. Local pre-treatment with indomethacin but not with prednisolone was followed by less increase in protein concentration of the aqueous humour as compared to placebo-treated controls. The IOP was not influenced significantly by the drug pre-treatments.

The effect of therapeutic ultrasound on the average of multiple intraocular pressures throughout the day in therapy-resistant glaucoma.

The effect of therapeutic ultrasound was evaluated in 17 patients with therapy-resistant glaucoma by comparing average intraocular pressure (IOP) curves measured before and 3-4 months after insonification. The insonification regimen was standardized; the medication was identical during both pressure curve measurements. The average IOP decrease was 44% +/- 24 SD (range, 73% decrease to 6% increase). In 82% of the patients the IOP decrease was more than 34%. There was no correlation between the percentage of IOP decrease and the average IOP before insonification (correlation coefficient, 0.21; P = 0.41).

Corneal transmission in whole human eyes.

The transmission of blue-green argon laser light (lambda = 488 nm and lambda = 514.5 nm) through clear healthy corneae was measured by means of a photodiode implanted into whole human donor eyes. The mean corneal transmission in seven eyes (donor age: 32-84 y) was 93.2 +/- 3.2% S.D., range 87-98%. The time between death and measurement ranged from 3.5 to 16 hr. These results indicate that hardly any correction for light loss in a healthy cornea is required in fluorophotometric results obtained with the use of fluorescein (lambda max.exc. = 489 nm, lambda max.em. = 514 nm).

Orbital decompression and motility disturbances in endocrine ophthalmopathy.

The changes in ocular motility in 15 patients with endocrine ophthalmopathy before and after orbital decompression according to Ogura-Walsh are discussed. The conclusion is that decompression of the orbita gives rise to a considerable risk of development or increase of limitations of ocular movements, with diplopia as a result.

The lens and PUVA therapy.

A study was made of patients, who were receiving PUVA therapy for psoriasis, to see if lens abnormalities occurred which could be due to the PUVA treatment. In a group of 42 patients there was only one eye of one patient, in which a very slight opacity was found which might possibly have developed during the therapy.

Atenolol 4% eyedrops in glaucoma simplex.

The single-dose response to local administration of atenolol 4% is compared in normal eyes and 3 groups of eyes with glaucoma simplex. The reduction in intraocular pressure is seen to be greater in eyes with glaucoma than in normal eyes. The usefulness of atenolol 4%, whether or not combined with other local therapy, seems to be limited by tachyphylaxis.