Is Pulse Synchronized Pneumotonometry More Reproducible than Routine Pneumotonometry and More in Agreement with Goldmann Applanation Tonometry?

Purpose

This study compared the variability of intraocular pressure (IOP) measurements taken with pulse synchronized pneumotonometry (PNT) and with routine PNT (without pulse synchronization) and evaluated the agreement between PNT and Goldmann applanation tonometry (GAT).

Methods

In this prospective study, 148 eyes from 78 patients were enrolled. Patients were randomized into two groups. In the first group (A), the sequence of measurements was pulse synchronized PNT, routine PNT, and GAT. In the second group (B), the sequence of measurements was routine PNT, pulse synchronized PNT, and GAT. The mean of three measurements was averaged for PNT and GAT. All the measurements were performed by the same investigator, who was masked to GAT measurements. The mean IOP measurements and intrapatient standard deviations among the three tonometers were compared using analysis of variance measurement. Bland & Altman plots were used to assess the agreement between PNT and GAT.

Results

The variability of IOP measurements taken with pulse synchronized PNT was significantly lower than with routine PNT in both groups (1.2±0.7 vs 1.3±0.7 mmHg in group A and 1.1±0.9 vs 1.3±1.0 mmHg in group B [p<0.001], respectively). PNT measurements with and without pulse synchronization were on average ±2 mmHg higher than GAT measurements in both groups (p<0.001). The 95% limits of agreement between PNT and GAT varied between −3.8 and 8.5 mmHg.

Conclusions

Pulse synchronized PNT gives more reproducible measurements than routine PNT. The agreement between PNT and GAT is poor. (Eur J Ophthalmol 2007; 17: 178–82)

Ocular Symptoms and Signs with Preserved and Preservative-Free Glaucoma Medications

PURPOSE

To compare the prevalence of side effects between eyedrops with or without preservatives, in terms of subjective symptoms and objective signs in patients with open-angle glaucoma.

METHODS

In a multicenter cross-sectional epidemiologic survey in four European countries, ophthalmologists in private practice enrolled 9658 nonconsecutive patients using preservative (P) or preservative-free (PF) beta-blocking eyedrops between June 1997 and December 2003. Subjective symptoms, conjunctival and palpebral signs, and superficial punctate keratitis were explored before and after a change in therapy. For statistical analysis, a Chi-square test was used to calculate the differences in the prevalence of symptoms and signs with or without preservatives.

RESULTS

A total of 74% of the patients used P, 12% PF, 10% a P-PF combination, and in 4% the type of medication was unknown. Each recorded symptom and all the palpebral, conjunctival, and corneal signs were significantly more frequent (p<0.0001) in the P-group than in the PF-group, such as pain or discomfort during instillation (48 vs 19%), foreign body sensation (42 vs 15%), stinging or burning (48 vs 20%), and dry eye sensation (35 vs 16%). A total of 68% of the patients had a sec-ond visit performed, of whom 63% (6083) had been evaluated on treatment difference. A significant decrease (p<0.0001) of all ocular symptoms and signs was observed in patients in whom the preserved eyedrops were diminished in number or altered into preservative free drops.

CONCLUSIONS

Compared to preserved eyedrops, preservative free eyedrops are significantly less associated with ocular symptoms and signs of irritation.

Anterior segment ischemia with rubeosis iridis after a circular buckling operation treated successfully with an intravitreal bevacizumab injection: a case report and review of the literature

PURPOSE

To report a case of anterior segment ischemia (ASI) with rubeosis iridis after circular buckling surgery in a highly-myopic patient which was successfully treated with a second intravitreal bevacizumab injection.

METHODS

Case report and review of the literature.

DISCUSSION

ASI is a rare but potentially serious complication of posterior segment surgery. Finally it leads to neovascular glaucoma as a result of rubeosis iridis. An encircling band can compromise anterior segment circulation in different ways: by manipulation or disinsertion of the recti muscles, by occlusion of the vortex veins through compression or by changes in the blood supply of iris and ciliary body. This patient developed rubeosis iridis secondary to ASI. There was a remarkable regression of rubeosis iridis one month after a second intravitreal bevacizumab injection. Other case reports of bevacizumab use in neovascular glaucoma have shown clinical improvements of these patients, with intraocular pressure control and reduction of the neovascularization process.

CONCLUSION

We describe a highly-myopic patient who developed ASI with rubeosis iridis after a circular buckling operation. Slit-lamp examination and gonioscopy can show very little rubeosis iridis and can be misleading. Iris fluorescein angiography is the most sensitive technique for evaluation of iris vessel abnormalities and is of considerable value in the early detection of rubeosis iridis. This report demonstrates the rapid resolution of rubeosis iridis on iris fluorescein angiography after a second intravitreal injection of bevacizumab. How long this regression will persist is unknown and repeated injections of bevacizumab may be necessary if rubeosis reappears.

The effect of phacoemulsification and combined phaco/glaucoma procedures on the intraocular pressure in open-angle glaucoma. A review of the literature

PURPOSE

This review article addresses the different aspects that influence the choice and sequence of surgical treatment in patients with coexisting open-angle glaucoma and cataract. The effect of phacoemulsification on the intraocular pressure (lOP) and on a preexisting bleb is discussed and phacotrabeculectomy and trabeculectomy are compared. Moreover, the most recent surgical pressure lowering techniques in combination with phacoemulsification are reviewed: iStent, Trabectome, Hydrus, Cypass and Canaloplasty.

METHODS

Medline database was used to search for relevant, recent articles.

CONCLUSION

A sustained IOP decrease of 1.5 mmHg can be expected after a phacoemulsification in patients with open-angle glaucoma. The higher the preoperative pressure, the greater the IOP lowering will be. A phacoemulsification on a trabeculectomized eye will often lead to reduced bleb function and an IOP rise of on average 2 mmHg after 12 months. Compared to a trabeculectomy, phaco-trabeculectomy will have a less IOP lowering effect and a higher complication rate. iStent and Trabectome combined with phacoemulsification can decrease the IOP with 3 to 5mmHg, with a low complication rate. The combination of Cypass and Hydrus with phaco-surgery may have a more significant IOP lowering effect but long term results are not yet published. Combining Canaloplasty with phacoemulsification is a more challenging surgery but if a tension suture can be placed, an IOP decrease around 10 mmHg might be expected.

Appraisal of optic disc stereo photos pre- and post-training session

PURPOSE

To determine whether the diagnostic accuracy of judging serial optic disc color stereo photographs for glaucomatous change by non-expert ophthalmologists changed after a training session.

METHODS

24 ophthalmologists in training at the University Hospitals Leuven classified 50 eyes with varying severity of glaucoma as stable or progressing based on the appraisal of serial optic disc stereo photographs. A comparison between the diagnostic accuracy of residents (n=18) and trainees (n=6) was made before and after a training session.

RESULTS

The mean agreement (kappa) with the reference standard before training was lower for the trainees than for the residents. The mean kappa before training was 0.37 for the residents and 0.29 for the trainees (p = 0.18). The mean agreement with the reference standard improved significantly after a training (from 0.29 to 0.56 [p = 0.031 for the trainees, and from 0.37 to 0.48 for the residents [p = 0.005]). The overall mean kappa was 0.35 pre-training and 0.50 post-training (p < 0.001).

CONCLUSIONS

The agreement and diagnostic accuracy of residents in training in appraising serial optic disc photos improved significantly after a training session.

Glaucoma medication during pregnancy and nursing

Risks that glaucoma medications pose to the fetus and neonate must be balanced against the risk of vision loss in the mother. There is no high level evidence for harmful effects on the fetus and neonate of medications used to treat glaucoma. All topical and systemic glaucoma medication should be avoided during the first trimester of pregnancy. Systemic carbonic anhydrase inhibitors, topical prostaglandin analogues and antimetabolites during surgery should be avoided absolutely. Some topical medications are deemed compatible with lactation by the American Academy of Pediatrics, however, caution should still be practiced.

Reversal of optic disc cupping with improvement of visual field and stereometric parameters after trabeculectomy in young adult patients (two case reports)

The authors report two cases of mid- to long-term reversal of optic disc cupping after trabeculectomy with mitomycine-C in young adult patients suffering from secondary glaucoma. The cup to disc ratio reversed from 0.80 and 0.60 to 0.65 and 0.40 respectively and remained unchanged until the last follow-up visit at 6 and 36 months respectively. Concomitantly, there was an improvement of the visual field and of the optic disc stereometric parameters on the Heidelberg Retina Tomograph.

The challenges of monitoring glaucoma progression

Diagnosing glaucoma progression is complex: it requires the precise assessment of functional loss and structural change compared with baseline measurements. Establishing reliable baseline data is essential in this process. Determining a functional baseline requires repeated visual field testing, while documentation of the optic disc appearance is needed for the acquisition of a structural baseline. The latter can be achieved using both clinical and imaging methods, which are complementary. Although imaging-based modalities to assess absolute and rate of progression are likely to prove more important in the future, more guidance is currently required for their use in clinical practice. Because the rate of progression provides important information about the risk of vision loss, guidelines recommend determining the rate of progression for each individual patient when planning management. Adherence issues must be addressed before changing the treatment strategy, since poor compliance can play a considerable role in many patients' disease progression. In conclusion, we must strive to improve the management of glaucoma to limit the impact disease progression has on the patient's quality of life.

Ahmed and Baerveldt glaucoma drainage implants: long-term results and factors influencing outcome

PURPOSE

To evaluate the clinical outcome of patients who received an Ahmed or Baerveldt implant for refractory glaucoma at the University Hospitals Leuven and to identify the factors which may influence the outcome.

METHODS

Retrospective study including 62 eyes with uncontrolled glaucoma, who underwent the implantation of a drainage device between January 2002 and December 2008. Criteria for complete success were an intraocular pressure (IOP) < or = 21 mmHg and > 5 mmHg, and a minimum 20% decrease in IOP compared to baseline, without additional medications at 2 consecutive visits after 3 months. Qualified success was defined as the same criteria with additional medications. If these criteria were not met, if additional glaucoma surgery was needed, or if the eye became phtitic, the case was classified as failure. Other outcome measurements were IOP reduction, additional glaucoma medications at the last follow-up, visual acuity, visual field, and complications.

RESULTS

Over a mean follow-up period of 25 +/- 21,91 months, the mean intraocular pressure decreased from 27,98 +/- 6,5 mmHg to 15,2 +/- 5,87 mmHg (mean drop of 45%) at the last visit. Overall success (i.e. with or without medication) was 67.3%. Visual acuity improved or remained unchanged in 52/62 (83,9%) of patients. Eight patients (12,9%) had complications with significant visual loss (at least two Snellen lines worse) and five patients (8,1%) needed further surgery due to complications. No significant outcome predictors could be established.

CONCLUSION

Ahmed and Baerveldt implants are a safe and effective procedure for lowering the IOP in the management of refractory glaucoma.

The iStent trabecular micro-bypass stent: a case series

PURPOSE

To evaluate the safety and effectiveness of a trabecular micro-bypass stent, the iStent (Glaukos, USA), for reduction of intraocular pressure in patients with open angle glaucoma.

METHODS

In this prospective case series, ten eyes of eight patients underwent a gonioscopically-guided implantation of an iStent. Six eyes underwent combined surgery: cataract surgery followed by iStent implantation, and the remaining four eyes underwent iStent implantation only. The primary outcome measure was intraocular pressure and the secondary outcome measures were the reduction in number of glaucoma medications, and the number of complications.

RESULTS

Mean intraocular pressure dropped from 19.6 mmHg preoperatively to 16.3 mmHg (range 12-27) after one month (p = 0.04), to 15.4 mmHg (range 8-23) after six months (p = 0.03) and 15.8 mmHg (range 9-25 mmHg) after one year (p = 0.03). There was a significant reduction in number of hypotensive medications between baseline and 12 months postoperatively from 2.7 to 1.7 medications. No vision-threatening complications were observed.

CONCLUSIONS

The Glaukos iStent trabecular micro-bypass implantation is a safe procedure that is not associated with complications traditionally associated with filtering surgery. This trabecular bypass results in significant mid-term reduction of intraocular pressure as well as the number of medications.

Acute visual field constriction in optic disc drusen: report of an unusual case

We describe a case of an acute symptomatic and non-progressive visual field constriction in one eye of a 19-year-old female with optic disc drusen. The fellow eye showed slowly progressive visual field defects. A limited or retrolaminar infarction of the optic nerve head seems a plausible cause of the acute visual field loss. The slow progression in the fellow eye is most probably due to mechanical compression by the drusen. The case is documented with Humphrey perimetry during a follow-up of 11 years and with Color Doppler Imaging (CDI) of the optic nerve.

Safe trabeculectomy technique: long term outcome

AIM

To assess the long term outcome of a new trabeculectomy technique.

METHODS

Trabeculectomy was performed using a fornix based conjunctival flap, an anterior chamber maintainer, a standardised punch technique, and a combination of adjustable and releasable sutures in 56 eyes of 53 patients. The main outcome measures were the postoperative intraocular pressure (IOP) and the frequency of early postoperative complications. The mean follow up time was 15.7 (range 12-21) months.

RESULTS

The mean preoperative and postoperative IOP at 12 months were 21.2 (SD 6) and 12.8 (3.0) mm Hg, respectively. All patients had an IOP of <21 mm Hg, 90.9% had an IOP <18 mm Hg, and 61.4% had an IOP <14 mm Hg. Postoperative complications were infrequent: flat anterior chamber (1.8%), bleb leakage (0%), or hypotony (1.5%) beyond 3 weeks, or choroidal detachment at any time point (8.9%).

CONCLUSIONS

This novel trabeculectomy method offers the possibility to tailor the IOP postoperatively with a minimum of postoperative complications and excellent IOP control at the long term follow up.

Argon versus selective laser trabeculoplasty

PURPOSE

To compare conventional argon laser trabeculoplasty (ALT) with selective laser trabeculoplasty (SLT) in terms of their efficiency in lowering the intra-ocular pressure.

METHODS

In this retrospective study, 56 eyes from 44 patients with primary open angle glaucoma, ocular hypertension, pseudo-exfoliative (PXF) or pigment dispersion glaucoma (PDG) were included. Patients underwent either ALT (n=18) or SLT (n=38). The intraocular pressure (IOP) was measured immediately prior to and 3 to 5 weeks after the theraPY.

RESULTS

At 3 to 5 weeks the lOP-reduction was 22.4% after ALT and 15.5% after SLT (p = 0.141). Of note, of the four patients with PDG 2 underwent ALT and 2 SLT. Remarkably, both patients who had had SLT showed a paradoxical rise in lOP after the procedure (+15.5%). When these patients were excluded from the analysis, a similar hypotensive efficacy was found between ALT (-19%) and SLT (-17.9%) (p = 0.836). A small additional study with lower energy levels (< 0.9 mJ) confirmed the paradoxical IOP rise in 6 patients with heavily pigmented angles (2 with PDG and 2 with PXF) (+19.2%). It occurred in the absence of steroid treatment and persisted until 12 weeks after treatment.

CONCLUSIONS

The short term efficacy of ALT and SLT was similar. In this study, the patients with PDG who underwent SLT showed a paradoxical rise in IOR This finding may indicate that even lower energies (0.4 to 0.6 mJ) are required when performing SLT in patients with heavily pigmented trabeculae.

Late-onset capsular bag distention syndrome after cataract surgery: 2 case-reports

Late capsular bag distension syndrome occurs most of the time with the accumulation of opaque milky fluid behind the IOL, without refractive change, like in one of our cases. The other case that we will describe had an accumulation of a clear fluid behind the IOL with an induced hyperopia. To the best of our knowledge, this is the first published report of capsular bag distension syndrome with a shift towards hyperopia. In both case the visual acuity and the initial refraction was restored after Nd:YAG posterior capsulotomy.

Needling-revision of failed filtering blebs

PURPOSE

To investigate the efficacy and safety of needling-revision of failed blebs after trabeculectomy.

METHODS

A retrospective chart review of 28 eyes of 28 patients who underwent a trabeculectomy with subsequent needling-revision between January 2002 and December 2003. The mean follow-up was 15 months after the first needling-revision. All interventions were conducted by the same surgeon. Absolute success was defined as an IOP <18 mmHg without medication or as an IOP reduction > 20% without medication if the preoperative IOP was < or = 21 mmHg. Relative success was defined as meeting these criteria with or without medication.

RESULTS

The mean interval between trabeculectomy and the first needling-revision was 5 months. Repeated needling-revision (up to 3 times) was performed as clinically necessary. In 90% of the needling-revisions 5-FU was used to prevent postoperative fibrosis. The mean +/- SD IOP before needling-revision and at the last follow-up was respectively 24.7 +/- 6 and 15.7 +/- 3 mmHg (p<0.001) Needling-revision was an absolute success in 39% (11/28) and a relative success in 68% (19/28). Minor complications attributed to needling-revision occurred in 32% including self reabsorbing subconjunctival bleeding (1), filamental (1) and punctate keratitis (1), transient choroidal effusion (3), wound leak (4) and hyphaema (2). Progression of cataract occurred in 1 patient. A serious complication occurred in 1 case (hypotony with persistent macular oedema).

CONCLUSIONS

Bleb needling-revision can prevent more invasive intervention in a significant number of patients with failed trabeculectomy blebs. Complications are similar to those seen after trabeculectomy.

Pachymetry before or after applanation tonometry: does it matter?

We examined prospectively 60 healthy volunteers to evaluate if the accuracy of central corneal thickness (CCT) measurement is influenced by Goldmann applanation tonometry (GAT) and vice versa. The sequence of the examinations in the right eye was CCT--GAT--CCT, in the left eye GAT--CCT--GAT and the measurements were done consecutively. Two tonometry and five pachymetry measurements were averaged each time. Pearson correlation coefficients and Bland-Altman plots were used to assess the correlation between the measurements. In the right eye the mean CCT measurement before and after GAT was 565.22 +/- 32.99 micro and 566.04 +/- 33.50 micro (p = 0.34, r = 0.98) respectively. In the left eye the mean GAT before and after pachymetry was 19.38 +/- 4.71 mmHg and 19.16 +/- 4.32 mmHg (p = 0.43, r = 0.86) respectively. The study suggests that the sequence of the two examinations doesn't matter.

Screening for vascular risk factors in glaucoma: the GVRF study

PURPOSE

To determine the prevalence of vascular risk factors (VRF) in patients with primary open-angle glaucoma (POAG), normal tension glaucoma (NTG), and ocular hypertension (OH), and to evaluate their influence in the progression of the disease.

METHODS

269 Belgian ophthalmologists were invited to participate in this cross-sectional prevalence study. Using a questionnaire the following parameters were analyzed in patients with POAG, NTG, and OH: age, intraocular pressure, refraction, visual field defect, vertical cup/disc ratio, medical therapy, and vascular risk factors. Progression of visual field was based on subjective analysis of minimum three reliable automated perimetries over a period of minimum three years.

RESULTS

4920 patients were enrolled in the study. 75% had POAG, 8% had NTG, and 17% had OH. The mean age was 67 years (40-99 y.). Fifty-three percent were female. There was a significant difference in the prevalence of no VRF vs. >1 VRF between the patients with OH and the patients with POAG/NTG (p < 0.01). Visual field progression was found in 34% of the patients with POAG and 46% of the patients with NTG. In the group with POAG the presence of at least 2 and at least 3 VRF increased the risk for visual field progression with respectively 16% and 42% compared to patients without VRF (p = respectively 0.03 and 0.002).

CONCLUSIONS

The prevalence of VRF is significantly higher in patients with POAG/NTG compared to patients with OH. The presence of VRF might increase the risk for progression of glaucomatous visual field defects.

Screening for glaucoma in a general population with the non-mydriatic fundus camera and the frequency doubling perimeter

PURPOSE

To evaluate the usefulness of non-mydriatic fundus camera (NMFu-camera) and frequency doubling perimeter (FDP) for detecting glaucoma in a general population.

METHODS

This prospective observational multicenter study consisted in screening for glaucoma in the populations of three Belgian cities. Intraocular pressure (IOP) was measured with non-contact pneumo-tonometer (NCT) and applanation tonometry (AT) if NCT IOP was > or = 17 mmHg. Visual field was screened with FDP (C-20-5) and digitized optic disc photographs (ODPs) were taken with NMFu-camera. FDP was considered abnormal if at least one defective point was found. ODPs were graded as normal or glaucomatous by consensus of three glaucoma specialists. Optic disc and visual field results were matched per eye. Subjects with known ocular hypertension and/or treated primary open angle glaucoma were excluded from the analysis.

RESULTS

A total of 1620 subjects were included in the study. Their mean age was 63.2 years. AT IOP was > 21 mmHg in 8.2%. A total of 98.1% of ODPs could be interpreted. Glaucomatous optic discs were detected in 3.5% of the subjects. In this group only 24% had an AT IOP > or = 22 mmHg. FDP was abnormal in 44.5%. The sensitivity and specificity of FDP to identify patients with an optic disc graded as glaucomatous were 58.6% and 64.3% respectively.

CONCLUSIONS

The combined use of the NMFu-camera and the FDP is a feasible method for an initial glaucoma mass screening. NMFu-camera may be a useful and quick method to screen for glaucomatous damage in a community. FDP in screening strategy was revealed to be not sensitive enough when setting the cut-off value at one defective test location. IOP measurements were confirmed to be a poor tool to detect glaucomatous damage.

Comparison of optical coherence reflectometry and ultrasound central corneal pachymetry

In 50 eyes of 25 patients we prospectively measured the central corneal thickness (CCT) comparing the OLCR (Optical Low Coherence Reflectometry) pachymeter with the contact ultrasound pachymeter. The OLCR system was mounted on to a Haag-Streit slit lamp. Every single measurement was the result of 5 scans. With the contact ultrasound Sonomed pachymeter we performed 5 separate measurements and calculated the mean. The correlation between the two measurements was excellent (r = 0.99). The mean standard deviation (SD) of the measurements taken with the non-contact OLCR pachymeter was significantly lower than with the contact ultrasound pachymeter, 0.49 microm and 4.71 microm respectively (p < 0.01). The variability of the CCT measurements taken with the non-contact OLCR pachymeter is significantly lower than the variability of the CCT measurements taken with the contact ultrasound pachymetry.

Miscalibration and severe complications after diode laser cyclophotocoagulation: two case reports

Because two similar transscleral cyclophotocoagulation diode lasers with identical power & duration settings induced significantly different postoperative inflammation, we wanted to compare the real output of both lasers. Using a Power/Energy Meter (Fieldmaster) we compared the output of the two lasers (the Iridis [Quantel Medical] and the Iris Medical [OcuLight SLx]) at different energy levels. At a setting of 600, 1000, 1400, 1700, 2000 and 2500 mW, the measured output for the Iridis and Iris Medical diode laser were respectively 685 and 400 mW, 970 and 650 mW, 1470 and 875 mW, 1700 and 1000 mW, and 1990 compared to 1000 mW. On the average the output of the Iridis laser was correct and the output of the Iris Medical laser was 40% lower than the setting. Overtreatment and severe complications occurred with the Iridis laser because the manufacturer recommended using wrong power settings based on the Iris Medical laser, which was undercalibrated. The calibration of cyclophotocoagulation diode lasers should be performed prior to use when changing to a new device and whenever over- or undertreatment is observed.

Short-term intra-individual variability in heidelberg retina tomograph II

We determined the short-term intra-individual variability for each parameter of the Heidelberg Retina Tomograph II (HRT II). Therefore we examined prospectively 20 healthy volunteers 3 times within 2 weeks. The variability was expressed as the coefficient of variation for each parameter. The short-term intra-individual variability in normal subjects was < or = 12% in all but 3 parameters. Rim Area was the least variable parameter (2 +/- 1%). Cup Volume had the highest variability (25 +/- 38%).

Reduction in IOP after clear corneal phacoemulsification in normal patients

A prospective study was performed to evaluate the changes in intraocular pressure (IOP) after clear corneal phacoemulsification in normal patients. The mean preoperative IOP of 30 patients was compared with the IOP at 1, 2, 3, and 5 months postoperatively. Lens extraction was associated with a reduction of IOP of 3.36 mmHg (SD +/- 2.33--p = 0.005) after 5 months.

Improvement of acquired pendular nystagmus by gabapentin: case report

Acquired Pendular Nystagmus (APN) may cause distressing visual symptoms in patients who are already suffering a severe general disease. Averbuch-Heller et al. conducted the first double-blind controlled study on treatment for APN. They showed that gabapentin substantially reduces pendular nystagmus and significantly increases visual acuity in the majority of patients. We present a patient with APN due to multiple sclerosis who suffered severe oscillopsy and reduction of visual acuity and who substantially benefited from a trial treatment with this agent.

Posterior uveitis: an under-recognized adverse effect of pamidronate: 2 case reports

Ocular adverse effects of pamidronic acid are rare but well documented. Pamidronate, an inhibitor of bone resorption used primarily in the management of tumor-induced hypercalcemia and Paget's disease, is reported to cause conjunctivitis, anterior uveitis, and infrequently episcleritis and scleritis. It is hypothesized that an allergic or immunologic phenomenon caused by drug-indued immune complex formation is at fault. The reason why the uvea is a target organ is unclear. The acute inflammatory response seems unrelated to the dose of the drug, the way of administration, or the activity of Paget's disease or malignancy. We report two cases of pamidronate-induced posterior uveitis, following the WHO Causality Assessment Guide of Suspected Adverse Reactions. Uveitis and scleritis have been reported in association with a variety of topical, intraocular, periocular, and systemic medications. Seven criteria were proposed to establish causality of adverse events by drugs. Only systemically administered biphosphonates meet all seven criteria. Where pamidronate is currently considered as the drug of choice in diverse strategies, the adverse ocular effects should be well known to physicians in order to make rapid diagnosis and stop the drug causing adverse reaction.

The long-term effect of diode laser cyclodestruction on intraocular pressure

We retrospectively reviewed the first 24 patients (26 eyes) who underwent ab externo diode laser cyclodestruction for refractory glaucoma and who had a follow-up of at least 10 months. We compared the intraocular pressure (IOP) and the number of antiglaucomatous medications used pre- and postoperatively. The mean follow-up period was 28 months (range 10 to 50 months). The mean IOP before and after treatment was respectively 30 +/- 12 mmHg and 22 +/- 12 mmHg (p < 0.05), a mean reduction of 29%. The average number of treatment sessions was 1.5 (range 1 to 5). An IOP < or = 21 mmHg was obtained in 65% of the cases; an IOP < or = 17 mmHg was achieved in 46% of the cases. The mean number of anti-glaucomatous medications used pre- and postoperatively was respectively 2.3 and 1.7 (p < 0.05). Only mild postoperative uveitis was observed; no eye developed phthisis bulbi. The study suggests that diode laser cyclodestruction is a safe procedure that can reduce the IOP in the long term in patients with refractory glaucoma.

Subconjunctival Loa Loa worm: case report

A 38-year old Ghanaian suddenly had the sensation of a foreign body in his right eye. Slit-lamp examination revealed a transparent worm underneath the conjunctiva. With topical anesthesia, the complete worm, 3.5 cm long, was removed surgically. A microbiological analysis at the Institute of Tropical Medicine confirmed the diagnosis of Loa Loa. Laboratory tests showed negative blood eosinophilia, positive blood film examination for microfilariae and positive results for filarial serology. The postoperative treatment consisted of progressive doses of di-ethyl-carbamazine (50-->100-->200 mg/d). A subconjunctival Loa Loa worm is rare in Belgium and usually occurs in immigrants or travellers returning from Tropical (Equatorial) West and Central Africa. Our patient visited Nigeria in 1985 and Ivory Coast in 1986. Those regions are highly endemic for Loa Loa.

Incidence of nd:Yag capsulotomy after lens implantation of an Acrylic IOL in one eye and a Silicone IOL in the other eye of the same patient: a preliminary study

We retrospectively reviewed the charts of 40 patients who underwent an uneventful phacoemulsification in both eyes and had an Acrylic IOL (AcrySof) implanted in one eye and a Silicone IOL (SI 30/S 140) in the other. A subset of 18 patients had a mean follow up of 1 1/2 year. In the Acrylic group 1 patient (5.5%) underwent a posterior Yag-capsulotomy. In the Silicone group 6 patients (30%) underwent a Yag-capsulotomy. (2 anterior--4 posterior) (p = 0.04) Acrylic IOL's were associated with a significantly reduced incidence rate of Yag-capsulotomy compared with silicone IOL's after 1 1/2 years.

[Chronic open angle glaucoma and cataract: when is it necessary to perform combined surgery?]

The combined surgical treatment of cataract and glaucoma has a long and controversial history (1). The guidelines proposed by the European Glaucoma Society facilitate however the therapeutic decisions (2). If the patient with open-angle glaucoma is stabilized with medical treatment it is often sufficient to operate the cataract alone and continue the medical treatment afterwards. If the patient is not stabilized or if the medical treatment is not well tolerated, it is suggested to perform a combined procedure. If visual functions are threatened by the glaucoma it is better to perform the filtering procedure first. We shall overview these options and elaborate on each surgical technique.

Primary graft failure caused by herpes simplex virus type 1

PURPOSE

To present a cluster of four patients with primary graft failure (PGF) who consecutively underwent a penetrating keratoplasty (PKP) during a period of 17 days in one institution. PKP was performed for reasons unrelated to herpes simplex infection. Herpes simplex virus type 1 (HSV-1) is presented as the possible cause of these PGFs.

METHODS

Viral culture of conjunctival swabs and of a bandage contact lens was performed on VERO, MRC-5, and Hep-2 cells. The four patients underwent subsequent regrafting. Polymerase chain reaction (PCR) for HSV-1 was carried out on aqueous humor and on a sample of iris and cornea with primers. Aqueous humor specimens were pretreated by boiling, and a qiagen extraction was performed according to the instructions of the manufacturer on biopsies of iris and cornea. Immunohistopathology was performed with polyclonal antibodies directed against HSV-1 and -2.

RESULTS

Culture of a conjunctival swab in three patients and culture of a bandage contact lens in the fourth patient were positive for HSV-1. In three of the four patients, PCR was positive for HSV-1 on aqueous humor and corneal graft tissue. PCR on iris tissue was positive in all patients. In three patients, culture for HSV-1 of aqueous humor and of iris tissue could not be carried out because of insufficient sample. Viral culture of the iris tissue in one patient and of the corneal graft in the four patients were negative. Immunohistopathologic examination was positive for HSV-1 in three cases.

CONCLUSION

These case reports strongly support the hypothesis that HSV-1 can be the cause of PGF.

The sensitivity and specificity of TOP, FDP and GDX in screening for early glaucoma

The purpose of this study was to evaluate the efficacy of three screening tests in detecting glaucoma in its early stage: the Tendency Oriented Perimetry (TOP) and Frequency Doubling Perimetry (FDP) visual field tests, and the Glaucoma Diagnostic (GDx) nerve fibre layer analyser. Eighteen patients with glaucoma who showed an early defect on HFA c 24-2 and twenty normals underwent the three tests. TOP showed a sensitivity of 94.4% and a specificity of 75%, FDP showed a sensitivity of 72.2% and a specificity of 100%, and GDx a sensitivity of 77.7% and a specificity of 60%.

Comparison of the effect of Healon vs. Viscoat on endothelial cell count after phacoemulsification and posterior chamber lens implantation

To evaluate the protective effect of 1% sodium hyaluronate (Healon) vs. a mixture of 4% chondroitin sulfate and 3% sodium hyaluronate (Viscoat) on the central corneal endothelium during surgery, we prospectively examined 20 eyes of 20 patients who underwent clear corneal phacoemulsification and implantation of an intracapsular posterior chamber intraocular lens (PC-IOL) with either Healon (10 eyes) or a combined use of Viscoat and Healon (10 eyes) as viscoelastic material. We compared the central endothelial cell counts, recorded by specular microscopy, preoperatively and 6 weeks postoperatively. Our results suggest that Viscoat offers no significant better endothelial cell protection during phacoemulsification than Healon.

The long-term effect of Yag laser posterior capsulotomy on intraocular pressure after combined glaucoma and cataract surgery

In order to evaluate the long-term effect of Yag laser posterior capsulotomy on intraocular pressure (IOP) after combined cataract and glaucoma surgery, we retrospectively studied 20 patients who underwent posterior capsulotomy after single-site combined phacoemulsification and trabeculectomy. We assessed mean IOP and number of glaucoma medications. The mean follow-up was 3 months (range 1 to 6 months). Mean IOP's remained almost unchanged, and were 13.9 +/- 2.7 before and 14.8 +/- 3 mmHg after capsulotomy (p = 0.115). The mean number of medications (0.4) remained unchanged. We conclude that Yag laser posterior capsulotomy does not significantly affect bleb function or glaucoma medication use in patients who underwent combined phacoemulsification and trabeculectomy.

Conventional retinal detachment surgery: technique, complications and results

A uniform conventional technique, modified by Dr. Zivojnovic, was performed on 104 consecutive patients with rhegmatogenous retinal detachments including pseudophakic eyes (23.1%) and cases with preoperative proliferative vitreoretinopathy (PVR) A-C2 (21.2%). A prospective study of 59 variables in 104 cases shows the risk factors influencing the results after a minimum follow-up (F.U.) according to multivariate analysis: preoperative detached macula, vitreous loss during previous cataract surgery and duration of detachment. The anatomic (94.2% reattachment after external surgery) and functional results (69.2% V.A. > or = 0.5) are discussed as well as the complications.

Management of a cracked Acrysof intraocular lens during implantation. Case report

The importance of a sufficiently large incision during soft intraocular lens (IOL) implantation is illustrated and highlighted by a single case study. In our patient, insufficient enlargement of the incision caused a crack in the optic of the Acrysof IOL. The IOL could, however, be left in place because of its excellent biocompatibility. Different management options are discussed.

Diode laser cyclophotocoagulation in refractory glaucoma

A retrospective analysis was made of the first 19 eyes of 19 patients with intractable glaucoma treated with contact diode cyclophotocoagulation. We assessed intraocular pressure (IOP) and number of glaucoma medications. The mean follow-up was 4 months (range 1 to 11 months). Mean IOP's decreased from 31.7 +/- 14.6 pre-diode treatment to 23.7 +/- 16.9 mmHg at the last follow-up visit after treatment (p = 0.02). The mean number of medications required decreased from 1.9 before to 1.3 after treatment (p = 0.03). The study suggests that diode cyclophotocoagulation is an effective and safe procedure in eyes with refractory glaucoma.

Costsaving in the operating room: the Procedure Pack

The concept of the Procedure Pack is very relevant in this era of managed care. By collecting more items in one pack, the hidden costs will be reduced and the pack will become relatively cheaper than the sum of every item. This paper compares the price of the Procedure Pack with the price of the separate items used for routine phaco-emulsification. The Procedure Pack is 2% more expensive, but the benefits by reducing the hidden costs are substantial and will be analyzed.

Target pressures in glaucoma

Despite exciting progress in the field of neuro-protection, lowering the intraocular pressure is still the only available option to treat glaucoma patients. The level to which the intraocular pressure should be lowered is different for each individual patient. The formula proposed to calculate the "target pressure" takes into account the pressure at which the glaucomatous damage presumably occurred (the "maximum pressure") and the risk of future damage. This target pressure should be re-evaluated periodically.

Interpretation of automated perimetry

This paper discusses basic principles of visual field interpretation. Only the two most popular perimeters, the Octopus and the Humphrey Field Analyzer, were considered. Choices of tests and strategies, software to assist interpretation (with emphasis on glaucoma progression), and future trends in visual field testing are covered.

Comparison of methods to evaluate the optic nerve head and nerve fiber layer for glaucomatous change

PURPOSE

To compare the rates of optic nerve damage in early human glaucoma as measured by four methods to evaluate change in the optic nerve and nerve fiber layer.

METHODS

Four techniques were used to detect progressive glaucomatous damage in a prospective, longitudinal study: (1) qualitative evaluation of stereoscopic color optic disk photographs, (2) qualitative evaluation of monochromatic nerve fiber layer photographs, (3) manual stereoplanimetric measurements of disk rim area, and (4) computerized measurement of peripapillary nerve fiber layer height. One eye of each patient with glaucoma or ocular hypertension was evaluated at the beginning and end of a follow-up period of not less than one year. The rates of structural change measured by these techniques and the rate of visual field change measured with threshold automated perimetry were determined.

RESULTS

We followed up 193 patients for a mean (+/- S.D.) of 3.3 +/- 1.0 years (range, one to six years). Twenty-nine (15%) of 193 eyes progressed by qualitative optic disk evaluation, 14 (7.2%) of 193 eyes progressed by qualitative nerve fiber layer evaluation, seven (3.6%) of 193 eyes progressed by stereoplanimetry, and 24 (13.2%) of 182 eyes progressed by measurement of nerve fiber layer height. Visual field deterioration was detected in 12 (5.2%) of 193 patients and correlated best with qualitative optic disk and nerve fiber layer evaluations. Evaluation by stereoplanimetry and nerve fiber layer height measurement detected change in eyes with primarily diffuse structural damage, a pattern not well detected by qualitative methods.

CONCLUSION

Both qualitative and quantitative methods of optic disk and nerve fiber layer evaluation contribute to the identification of progressive damage, depending on the stage of disease and the characteristics of optic nerve cupping.

An evaluation of clusters in the glaucomatous visual field

We used a statistical cluster analysis to analyze patterns of loss in 76 visual fields with typical glaucomatous defects to identify natural groupings of test locations in the visual field. Eleven clusters in the Octopus Program G1 (Interzeag, Inc., Northboro, Massachusetts) visual field were thus defined. In a separate population of 70 early glaucomatous and 70 age-matched normal visual fields, the local mean defects within these clusters and the global mean defect were calculated to assess their relative abilities to discriminate between the two groups. The 11 clustered mean defects collectively had a sensitivity of 90% and a specificity of 93%; the global mean defect had a sensitivity of 81% and a specificity of 91%. Additionally, we examined the long-term fluctuation clusters of test locations compared to the long-term fluctuation of individual test locations. Four hundred ten visual fields of 93 clinically stable eyes of 67 patients with glaucoma, as well as 210 visual fields of 105 eyes of 105 normal subjects were studied. In the stable glaucoma group, mean fluctuation of clustered test locations was 3.5 dB2, and mean fluctuation of individual test locations was 7.0 dB2. In the normal group, the respective values were 0.6 dB2 and 1.8 dB2. Cluster analysis was effective in detecting localized loss and in dampening long-term fluctuation. We studied the use of clusters in distinguishing normal from glaucomatous as well as stable from deteriorating visual fields.

Comparisons of methods to detect glaucomatous optic nerve damage

PURPOSE

Various techniques of optic disc and nerve fiber layer evaluation may be used to detect structural glaucomatous damage. The authors compared several qualitative and quantitative methods to determine their relative sensitivities and specificities to detect the presence of glaucomatous visual field loss.

METHODS

Fifty-one healthy eyes, 169 ocular hypertensive eyes with normal visual fields, and 132 glaucomatous eyes with early visual field defects were evaluated with qualitative and quantitative measures of structural damage to the optic nerve and nerve fiber layer. Qualitative evaluations were performed by three experienced masked observers who independently graded stereoscopic color disc and monochromatic nerve fiber layer photographs. Quantitative measurements of disc rim area and nerve fiber layer height were made with digitized image analysis of videographic images. Manual planimetric measurements of disc rim area were made from enlarged prints of stereoscopic optic disc photographs. Diagnostic precision was defined as the total proportion of correct diagnoses for the presence or absence of visual field loss.

RESULTS

The diagnostic precision of results of a quantitative disc examination (81%) was greater than those of a qualitative nerve fiber layer examination (75%). Quantitative nerve fiber height measurement had the highest sensitivity rate (73%) and results of the qualitative disc examination had the highest specificity rate (87%) of the methods tested.

CONCLUSION

The diagnostic precision of disc evaluation was superior to other methods, including nerve fiber layer examination, in correctly determining the presence of structural glaucomatous damage at the early visual field loss stage.

Wolfram syndrome: a clinical study of two cases

Two unrelated patients with two different images of Wolfram (or 'DIDMOAD') syndrome are presented: a 19-year old woman suffering from all the important features of this syndrome, and a 38-year old man showing two major characteristics but several minor abnormalities. This syndrome should be considered in young diabetic patients with unexplained visual loss or with polyuria and polydipsia in the presence of adequate blood sugar control. An early diagnosis is important to prevent unnecessary diagnostic investigations.

Fungal endophthalmitis: a report of two cases

Two patients with fungal endophthalmitis are presented. The first patient developed delayed-onset pseudophakic endophthalmitis. Candida glabrata was cultured from anterior chamber fluid. The second patient presented with a corneal ulcer and endophthalmitis. Candida albicans was isolated from the corneal scraping. The clinical features of these infections and specific treatment options are discussed.

Blindness following paranasal sinus surgery: a report of two cases

Two cases of blindness following paranasal sinus surgery are presented. The first patient, a 38-year old man, developed a delayed massive haemorrhage, after bilateral sphenoethmoidectomy. This hemorrhage could be stopped by electric cauterisation under endoscopical control. During this reintervention the patient developed total blindness of his right eye, and a restriction of the inferotemporal left visual field. The second patient, a 10-year old girl, developed, after bilateral spheno-ethmoidectomy for isolated sphenoiditis, total blindness of the left eye and paralysis of the ipsilateral extraocular muscles. According to the literature, blindness secondary to paranasal surgery is mainly due to retrobulbar hemorrhage. In the first case blindness was due to a direct cauterisation of the optic nerve, after perforation of the lamina papyracea. In the second case, blindness was probably due to a hemorrhage in the orbital apex.

Multifocal IOL implantation: 16 cases

We interpreted the clinical data from 16 eyes with a 3M multifocal implant and compared them with data from 16 monofocal implants with the same follow-up period. The multifocal implant has several disadvantages: a lower initial visual acuity, a higher frequency of posterior synechiae, and slightly more difficult ophthalmoscopy than with conventional lenses. The great advantage of the multifocal implant is the good near visual acuity without additional correction.