Symptomatic Eyes Research Articles

Enhanced Visual Acuity and Image Perception Following Correction of Highly Aberrated Eyes Using an Adaptive Optics Visual Simulator

To evaluate the changes in visual acuity and visual perception generated by correcting higher order aberrations in highly aberrated eyes using a large-stroke adaptive optics visual simulator. A crx1 Adaptive Optics Visual Simulator (Imagine Eyes) was used to correct and modify the wavefront aberrations in 12 keratoconic eyes and 8 symptomatic postoperative refractive surgery (LASIK) eyes. After measuring ocular aberrations, the device was programmed to compensate for the eye's wavefront error from the second order to the fifth order (6-mm pupil). Visual acuity was assessed through the adaptive optics system using computer-generated ETDRS opto-types and the Freiburg Visual Acuity and Contrast Test. Mean higher order aberration root-mean-square (RMS) errors in the keratoconus and symptomatic LASIK eyes were 1.88+/-0.99 microm and 1.62+/-0.79 microm (6-mm pupil), respectively. The visual simulator correction of the higher order aberrations present in the keratoconus eyes improved their visual acuity by a mean of 2 lines when compared to their best spherocylinder correction (mean decimal visual acuity with spherocylindrical correction was 0.31+/-0.18 and improved to 0.44+/-0.23 with higher order aberration correction). In the symptomatic LASIK eyes, the mean decimal visual acuity with spherocylindrical correction improved from 0.54+/-0.16 to 0.71+/-0.13 with higher order aberration correction. The visual perception of ETDRS letters was improved when correcting higher order aberrations. The adaptive optics visual simulator can effectively measure and compensate for higher order aberrations (second to fifth order), which are associated with diminished visual acuity and perception in highly aberrated eyes. The adaptive optics technology may be of clinical benefit when counseling patients with highly aberrated eyes regarding their maximum subjective potential for vision correction.

Correlation of Aberrometry, Contrast Sensitivity, and Subjective Symptoms With Quality of Vision After LASIK

To compare which parameter category (wavefront data, psychophysical data, or subjective symptoms) predicts best subjective quality of vision after LASIK. Twenty-eight eyes (15 patients) were included. Twenty-three eyes (12 patients) underwent uneventful LASIK; 5 eyes (3 patients) were symptomatic eyes treated with myopic LASIK elsewhere. Mean preoperative spherical equivalent refraction was -4.79+/-1.92 diopters (D) (range: -1.63 to -7.13 D); mean patient age was 36.6+/-7.4 years (range: 18 to 48 years). All examinations were performed 1 month postoperatively. The wavefront error was described with Zernike polynomials (6-mm pupil). Psychophysical tests included high-contrast visual acuity and contrast sensitivity with and without glare at 167 cd/m(-2), 1.67 cd/m(-2), and 0.167 cd/m(-2) with best spectacle correction. Correspondingly, overall subjective quality of vision and frequency of visual symptoms (glare, halos, starbursts, ghosting, blur) were assessed for three lighting conditions (photopic, high-mesopic, and low-mesopic) using a questionnaire with a visual analog scale. For each parameter category and each lighting condition, a multiple stepwise backwards regression model with the overall quality of vision item value as dependent was applied. Under all lighting conditions, subjective symptom scores predicted subjective quality of vision best (adjusted R2=0.83-0.92) with blur as the main predictor throughout all conditions. Psychophysical tests did not significantly predict postoperative subjective quality of vision. The adjusted R2 for the Zernike coefficients was highest for low-mesopic (0.56) and lowest for photopic conditions (0.31). Different parameter categories for the description of optical quality did not predict subjective quality of vision after LASIK equally. Subjective symptom scores had the highest predictability, whereas psychophysical tests with spectacle correction had no predictability. The latter probably do not reflect all dimensions of subjective quality of vision.

Do visual evoked potentials give relevant information to the neuro-ophthalmological examination in optic nerve lesions?

The visual evoked potentials (VEPs) and neuro-ophthalmological examinations of 134 patients were compared. The VEPs were abnormal in 95% of the eyes with optic neuritis. Defective color vision was found in 99%, visual field defects in 88%, decreased vision in 66% and an afferent pupillary defect in 55%. 29 patients with optic neuritis were followed up with repeated tests. VEPs and color vision recovered more slowly than visual acuity and visual field. Abnormal VEPs were observed in 68% of 50 MS patients. An analysis of symptomatic and asymptomatic eyes showed that testing of color vision, visual field and red-free ophthalmoscopy were equally as useful diagnostic tools as VEPs. 4 (8%) of the MS patients had abnormal VEPs despite a normal neuro-ophthalmological examination; 94% of MS patients with symptoms and 47% of MS patients without visual symptoms had abnormal VEPs. VEPs were pathological in 59% of 24 patients with traumatic or compressive optic nerve diseases or optic atrophies of unknown etiology. The neuro-ophthalmological examination was more sensitive than VEPs in the diagnosis of these disorders. A neuro-ophthalmological examination is in most cases sufficient to diagnose optic nerve lesions. VEPs are of diagnostic aid especially in mild optic nerve lesions.

Comparison of Zernike and Fourier Wavefront Reconstruction Algorithms in Representing Corneal Aberration of Normal and Abnormal Eyes

Purpose To investigate the accuracy of Zernike and Fourier reconstruction algorithms in describing simulated wavefront data from corneal topography of normal and abnormal eyes. Methods Corneal topography (Orbscan IIz) was collected on 87 normal, 27 keratoconus, 9 penetrating keratoplasty (PKP), and 20 postoperative LASIK symptomatic eyes over a 6-mm pupil. Raw data from slit images were converted into elevation maps, which were then resampled at resolutions of 100, 300, and 500 µm. Differences in elevation between adjacent pixels were used to generate simulated wavefront slope data. Both conventional Zernike and iterative Fourier algorithms were used to reconstruct the elevation map from the same slope information. The difference between the reconstructed and original maps was used to evaluate reconstruction performance, quantified by the residual root-meansquare (RMS) error. Results When using the Zernike-based method, residual RMS error decreased substantially as the number of modes used in the reconstruction increased up to approximately the 10th order. Both Zernike and Fourier algorithms performed best when reconstructing simulated wavefronts from normal eyes and worst with PKP eyes. Using a large number of Zernike modes to reconstruct simulated wavefronts of low spatial resolution lead to inaccurate reconstructions. The Fourier method had better reconstruction reliability in the center of the pupil than peripherally. Only 2nd through 5th order Zernike modes were required to produce less residual RMS error than the Fourier method. Conclusions For all conditions tested, the Zernike method outperformed the Fourier method when representing simulated wavefront data from topography maps. Even 2nd through 5th order Zernike polynomials were enough to outperform the Fourier method in all populations. Up to 9th order Zernike modes may be required to accurately describe the simulated wavefronts in some abnormal eyes. [ J Refract Surg . 2008;24:582–590.]

Corneal wavefront–guided enhancement for high levels of corneal coma aberration after laser in situ keratomileusis

To evaluate the improvement in visual and optical performance after corneal wavefront-guided laser in situ keratomileusis (LASIK) enhancement in patients with high levels of corneal coma aberration and complaints about quality of vision. Vissum-Instituto Oftalmológico de Alicante, Alicante, Spain. Corneal wavefront-guided LASIK enhancement was performed in 34 symptomatic eyes of 29 patients aged 26 to 64 years with previous LASIK surgery and a significant level of primary coma aberration. The ablation design was calculated using ORK-CAM software (Schwind eye-tech-solutions). The follow-up period was 6 months. Changes in refraction, corneal aberrometry, and subjective symptoms were analyzed. At 6 months, the mean efficacy index was 0.88 +/- 0.12 and the mean safety index, 1.03 +/- 0.16. The reduction in sphere and cylinder at 1 month was statistically significant (P<.01). Of all eyes, 97.06% had a spherical equivalent within +/-1.00 diopter. At 1 month, statistically significant changes were observed: total (P = .01), and primary coma root mean square reduction (P<.01), and negativization of the primary spherical aberration coefficient (P<.01). At 6 months, patient perception of halos and glare was reduced or eliminated in a high percentage of cases. Corneal wavefront-guided enhancements with the ORK-CAM system are a useful tool for the correction of the second order refractive errors and for the reduction of the corneal primary coma induced by previous keratorefractive procedures.

Wavefront-guided Treatment of Symptomatic Eyes Using the LADAR6000 Excimer Laser

To evaluate the clinical results of wavefront-guided customized treatment of eyes that underwent previous keratorefractive surgery with clinically significant visual symptoms related to the presence of higher order aberrations, with or without defocus/astigmatism. Twenty-eight consecutive eyes of 19 symptomatic patients underwent wavefront-guided custom photorefractive keratectomy (PRK with mitomycin C) to correct low and high order aberrations, using the LADAR-Vision platform. All eyes had manifest refractive spherical equivalent (MRSE) error from 0.00 to -4.25 diopters (D), and high order aberrations root-mean-square (RMS) values >0.80 microm for a 6.0-mm measurement diameter (mean: 1.18 microm). Eyes were examined at 1, 3, and 6 months postoperatively. Uncorrected (UCVA) and best spectacle-corrected visual acuity (BSCVA), MRSE, wavefront measurement of high order aberrations, and patient subjective evaluation were the parameters used to assess the treatment. Six months after treatment, all 28 eyes had an improvement in UCVA compared to preoperative values. Seventeen (60.7%) eyes gained lines of BSCVA (1 to 3 lines) whereas 1 eye lost 1 line. Although the amount of positive defocus was intentionally and empirically undercorrected in this study, MRSE was slightly hyperopic (mean +0.65 D, range: -0.25 to +1.75 D). All eyes showed a reduction in pre-existing high order aberrations, with a mean reduction of 47% (0.62 microm). Spherical aberration reduced the most (mean 60%), coma was reduced by a mean 29%, and all other terms were reduced by a mean 42% compared to preoperative values. Subjectively, all patients but 1 (both eyes treated) noticed a reduction in their pre-existing visual symptoms. Overall, the treatment was considered satisfactory by the patients in terms of visual quality gain. This series of consecutive treatments of symptomatic eyes indicates wavefront-guided custom ablation is an effective surgical option to reduce visually impairing high order aberrations and related visual symptoms. To avoid the resulting hyperopic shift, some significant nomogram adjustments are necessary, most often when pre-existing positive spherical aberration is present.

Potential Complications of Ocular Surgery in Patients with Coexistent Keratoconus and Fuchs’ Endothelial Dystrophy

To describe the potential complications of cataract and refractive surgery in patients with Fuchs' endothelial dystrophy (FED) and keratoconus. Retrospective case series. Eight patients with FED and keratoconus in a large university group practice. We reviewed the clinical and topographic findings of 8 patients (15 eyes) with FED and keratoconus. Clinical examination, corneal topography, specular microscopy were done, and sequential central corneal thickness (CCT) was obtained. Follow-up ranged from 1 month to 6 years. Findings of keratoconus and FED in preoperative evaluation. Five patients had concomitant cataracts; 3 had refractive errors and sought surgical correction. Cataract surgery was performed on 3 of 5 patients (5 eyes). LASIK was performed on one eye of 3 patients. Of 5 eyes that underwent cataract extraction, 4 had blurry vision after surgery. The interval between the surgical procedure and onset of symptoms ranged from 1 month to 4 years. The causes of decreased vision after cataract surgery were corneal edema and/or corneal ectasia. The CCT readings ranged from 426 to 824 microm. One of 4 symptomatic eyes underwent penetrating keratoplasty. The CCTs of 3 patients (6 eyes) who presented with refractive error ranged from 507 to 565 microm. One eye had undergone an attempted LASIK procedure resulting in a lost cap. Corneal topography and specular microscopy showed the coexistence of keratoconus and FED, and the patients were advised against having LASIK surgery. Corneal thinning caused by keratoconus and concurrent increase in corneal thickness caused by FED may combine to normalize the corneal pachymetry readings; disease severity may be underestimated, which may lead to unexpected postoperative visual outcomes. Routine use of preoperative topography and specular microscopy may help to avert potential surgical complications.

Topography-guided Treatment of Irregular Astigmatism With the WaveLight Excimer Laser

To evaluate the feasibility, safety, and predictability of correcting high irregular astigmatism in symptomatic eyes with the use of topography-guided photoablation. In a prospective, non-comparative case series, 16 consecutive symptomatic eyes of 11 patients with small hyperopic and myopic excimer laser optical zones, decentered and irregular ablation after corneal graft, and corneal scars were operated. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest and cycloplegic refraction, and corneal topography, with asphericity and regularity, were analyzed. LASIK (n = 10) and photorefractive keratectomy (n = 6) were performed using the ALLEGRETTO WAVE excimer laser and T-CAT software (Topography-guided Customized Ablation Treatment; WaveLight Laser Technologie AG, Erlangen, Germany). In the LASIK group, UCVA improved from 0.81 +/- 0.68 IogMAR (20/130) (range: 0.2 to 2.0) to 0.29 +/- 0.21 logMAR (20/39) (range: 0.1 to 0.7) at 6 months. In the PRK group, mean UCVA improved from 0.89 +/- 0.87 IogMAR (20/157) (range: 0.1 to 2.0) to 0.42 +/- 0.35 logMAR (20/53) (range: 0.1 to 1.0) at 6 months. Best spectacle-corrected visual acuity did not change significantly in either group. One PRK patient lost one line of BSCVA. Refractive cylinder for the LASIK group improved from -2.53 +/- 1.71 diopters (D) (range: -0.75 to -5.75 D) to -1.28 +/- 0.99 D (range: 0 to -2.50 D) at 6 months. Refractive cylinder in the PRK group improved from -2.21 +/- 2.11 D (range: -0.25 to -5.50 D) to -1.10 +/- 0.42 D (range: -0.50 to -1.50 D). Index of surface irregularity showed a decrease from 60 +/- 12 (range: 46 to 89) to 50 +/- 9 (range: 32 to 63) at 6 months in the LASIK group whereas no significant change was noted in the PRK group. Subjective symptoms, such as glare, halos, ghost images, starbursts, and monocular diplopia, were not present postoperatively. Topography-guided LASIK and PRK resulted in a significant reduction of refractive cylinder and increase of UCVA, without a significant loss of BSCVA.

Wavefront-guided Enhancements Using the WaveLight Excimer Laser in Symptomatic Eyes Previously Treated With LASIK

To describe our clinical experience in wavefront-guided LASIK enhancements using the WaveLight ALLEGRETTO system (WaveLight Technologie AG, Erlangen, Germany) for symptomatic eyes previously treated with standard LASIK. Twenty-six eyes of 20 patients with residual myopia, hyperopia, or mixed astigmatism and/or night vision symptoms after primary standard LASIK were considered for wavefront-guided customized retreatment using the WaveLight ALLEGRETTO WAVE 200 Hz excimer laser system (model 106). Preoperative best spectacle-corrected visual acuity (BSCVA), uncorrected visual acuity, topography with the ALLEGRETTO Topolyzer, wavefront analysis using the ALLEGRETTO WAVE Tscherning Analyzer, and contrast sensitivity were compared to postoperative (enhancement) measurements. Twenty-two of the original 26 eyes underwent wavefront-guided enhancement, 4 were excluded because they did not meet wavefront-guided treatment inclusion guidelines of this study. Mean follow-up was 8 months (range: 6 to 13 months, standard deviation [SD] 2). All patients were within +/- 0.50 diopters (manifest refraction) of intended postoperative refraction. The mean preoperative BSCVA improved from 20/25 (SD +/- 0.12) to 20/18 (SD +/- 0.1) postoperatively. All patients gained at least one line of BSCVA, and a maximum of three lines. There was no loss of BSCVA in any patient. The total amount of high order aberrations (RMSH) decreased from an average of 1.04 (SD +/- 0.22) to 0.46 (SD +/- 0.14) microm. Patients also had a mean improvement in low contrast sensitivity of 59%. Based on this small series, customized wavefront-guided enhancements using the WaveLight ALLEGRETTO system in patients who underwent previous LASIK appear to be safe and effective in correcting residual refractive error, reducing high order aberrations, and improving visual symptoms when reliable and reproducible measurements are achieved.

Vitrectomy for Stage 1 Macular Holes Identified by Optical Coherence Tomography

To describe a series of patients with decreased vision secondary to stage 1 macular hole confirmed by optical coherence tomography (OCT) that failed to spontaneously resolve with observation. To determine whether current surgical techniques can prevent progression to a full-thickness macular hole and lead to improved visual acuity. Retrospective, comparative case series presenting patient demographics, duration of symptoms, timing of surgery, preoperative and postoperative vision, and clinical outcome based on examination and OCT. Five eyes of five patients with stage 1 macular holes identified on OCT required surgical repair. All eyes showed anatomic closure and lack of progression to a full-thickness hole confirmed by OCT after one procedure. Mean preoperative visual acuity was 20/102 (range, 20/50 to 20/200) and mean postoperative visual acuity was 20/52 (range, 20/25 to 20/200). Average improvement for all five eyes was 3 Snellen lines, with four of the five (80%) improving 5 lines each. In symptomatic eyes with stage 1 macular holes that fail to spontaneously resolve with observation, vitrectomy with intraocular gas tamponade may prevent progression to a full-thickness hole and lead to improved visual acuity.

A New Night Vision Disturbances Parameter and Contrast Sensitivity as Indicators of Success in Wavefront-guided Enhancement

To determine the level of success of wavefront-guided repair of night vision disturbances after conventional (Munnerlyn) myopic LASIK using a new parameter to describe higher order aberrations, and to compare the improvements to matched myopic LASIK controls who were symptom-free. We developed a single parameter metric to represent raw spherical aberration (RAWS) to functionally describe the cumulative spherical aberration for an eye over a range of physiological pupil sizes. To derive the RAWS parameter, spherical aberration is plotted over pupil analysis zones from 3000 to 6000 microm. The RAWS parameter (unit = microm2) is then equal to the area under the plot. Sixteen eyes treated for night vision disturbances by wavefront-guided repair were each compared to the mean of four matched control eyes (total 64 eyes) treated by aspheric myopic ablation and without night vision disturbances. Contrast sensitivity and RAWs parameter for spherical aberration were determined for each of the repair eyes and control eyes before and after surgery. Following wavefront-guided repair, 76% of eyes were subjectively reported to have night vision disturbances improved by at least 80%. The percentage of eyes within normal contrast range increased from 25% to 80% following wavefront-guided repair (P < .05). For the control eyes, LASIK increased RAWS by 126% (RAWS was 122 microm2 preoperatively and 276 microm2 postoperatively). For the night vision disturbances repair eye group, RAWS at presentation was 104% (563 microm2) above the respective postoperative RAWS control eyes. Following wavefront-guided repair, RAWS was decreased (P < .05) to only 49% (410 microm2) above the postoperative control group. The RAWS parameter enabled a single digit descriptor of overall higher order aberrations for an eye over the principal physiological pupil range. By comparing RAWS parameter changes in wavefront-guided repair eyes to matched postoperative asymptomatic eyes, we were able to determine the magnitude of the deficit in the symptomatic eyes and the relative efficacy of wavefront-guided repair.

Topography-guided Custom Retreatments in 27 Symptomatic Eyes

To evaluate the use of topography-guided ablations for refractive irregularities induced by previous surgery. This prospective, non-comparative trial comprised 27 symptomatic eyes with a history of LASIK for myopia that underwent topography-guided treatment with the ALLEGRETTO WAVE system. Pre- and postoperative refraction, uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), corneal asphericity (Q value), low contrast sensitivity, and patient's subjective assessment of improvement were measured. Preoperative data were sphere -0.84 +/- 1.37 diopters (D), cylinder -1.55 +/- 0.78 D, UCVA 20/49 +/- 0.22, BSCVA 20/32 +/- 0.15, and Q value 1.46 +/- 0.79. Postoperative data at mean 6-month follow-up were: sphere -0.61 +/- 0.81 D, cylinder -0.53 +/- 0.58 D, UCVA 20/25 +/- 0.21 (P < .01), BSCVA 20/21 +/- 0.14 (P < .001), and Q value 1.07 +/- 0.89. Contrast sensitivity scores improved by 70%. No loss of BSCVA occurred in any patient. Topography-guided treatments may be effective in correcting the quality of vision. It should be viewed as a possible two-step procedure due to spherical adjustment that may change refraction unpredictably.

Use of Orbital Color Doppler Imaging for Detecting Internal Carotid Artery Stenosis in Patients with Amaurosis Fugax

Purpose: To determine whether orbital color Doppler imaging (CDI) can be used to detect internal carotid artery stenosis (ICAS) in patients with amaurosis fugax (AF). Methods: Twenty patients with AF (20 symptomatic eyes) and 14 normal controls (14 randomly selected eyes) were studied. The AF patients were divided by magnetic resonance angiography or carotid arteriography into those without ICAS (Group 1, n = 14), and those with ICAS (Group 2, n = 6). The peak systolic velocities (PSV) and end diastolic velocities (EDV) of the ophthalmic artery (OA) and the central retinal artery (CRA) were determined by orbital CDI, and the values were compared between the three groups. Results: There were no significant differences in the PSV and EDV of the CRA between the three groups. However, the PSV and EDV of the OA were significantly lower in Group 2 than in the other two groups. From the distribution of PSV-OA and EDV-OA in AF patients, Group 2 could be separated from Group 1 by the PSV-OA value of 10 cm/s. Conclusions: The PSV-OA of 10 cm/s can be used to identify AF patients with ICAS. It is concluded that orbital CDI is a valuable method for detecting ICAS in AF patients.

External beam radiotherapy of choroidal metastases – final results of a prospective study of the German Cancer Society (ARO 95-08)

Purpose: In 1994 a prospective study of the ‘Arbeitsgemeinschaft Radiologische Onkologie’ of the German Cancer Society was initiated to examine the results of a standardized radiation therapy for choroidal metastases with 40 Gy. Recommendations in the literature vary from 21 to 50 Gy of total dose and from 2 to 5 Gy per single fraction. To date, no larger series treated with both a standardized technique and dose has been reported. Patients and methods: Between 1994 and 1998, 56 patients were enrolled and 50 patients with 65 involved eyes were available for analysis. Thirty-five patients (70%) had unilateral and 15 patients (30%) had bilateral choroidal metastases. Fifty eyes (77%) were symptomatic and 15 eyes (23%) were asymptomatic. Thirty-one patients (62%) had breast cancer and 13 patients (26%) lung cancer as the primary tumor. Patients were treated with 40 Gy in 20 fractions with bilateral asymmetric fields for bilateral or a unilateral field for unilateral choroidal metastasis. Seventeen patients had additional chemotherapy after radiotherapy for general tumor progression. Results: With a median follow-up of 5.8 months (1–44 months) 41 out of 50 patients were dead. The median survival of all patients was 7 months and for patients with breast cancer 10 months. Of the 50 symptomatic eyes visual acuity increased for two or more lines in 36% (18/50), was stabilized in 50% (25/50 eyes), and decreased in 14% (7/50). No patient with asymptomatic metastasis ( n=15 eyes) developed ocular symptoms during follow-up. No patient with unilateral tumor and unilateral irradiation developed contralateral metastasis. Severe side effects, possibly related to tumor progression, occurred in three eyes (5%). Conclusion: Radiation therapy with 40 Gy is an effective and safe palliative treatment for symptomatic and asymptomatic choroidal metastases to preserve vision in the majority of the patients. A unilateral field for unilateral metastasis seems to be sufficient to prevent contralateral disease. Side effects of radiotherapy are acceptable: 50% of patients developed a mild skin erythema and conjunctivitis (RTOG I). Late side effects were seen in three eyes (5%).

Extracranial Cerebrovascular Revascularization for Chronic Ocular Ischemia

We investigated the demographics, presentation, and outcome of patients undergoing cerebrovascular reconstruction for chronic ocular ischemia (COI) at a single institution through a review of 17 patients over a 9-year period. A total of 558 extracranial cerebrovascular reconstructions were performed during the period of study. Seventeen patients (3%) suffered symptoms of COI. There were 19 symptomatic eyes and 15 asymptomatic eyes. Two patients suffered bilateral symptoms. Eighteen (95%) symptomatic eyes experienced rapidly degenerating global visual acuity, and one suffered bright-light amaurosis. Concomitant ocular pathology was present in 10 (59%) patients, consisting of glaucoma (n = 4), cataracts (n = 4), diabetic retinopathy (n = 3), and macular degeneration (n = 1). Symptomatic eyes were found to have significantly worse ipsilateral internal carotid artery (p = 0.004), external carotid artery (p = 0.002), aortic arch branch disease (p = 0.04), and vertebral artery disease (p = 0.04). All 17 reconstructions treated ipsilateral disease. Twelve patients (70.6%) had significant bilateral disease at the time of operation. Three patients underwent staged contralateral reconstruction. Following revascularization, subjective visual improvement or stabilization occurred in 16 patients (94%). A single patient worsened after developing acute narrow angle glaucoma in the perioperative period. Worse cerebrovascular disease is present ipsilateral to symptomatic eyes. When revascularization is performed, arrest of progression or improvement of symptoms occurs in most patients.

In vitro susceptibilities to topical antibiotics of bacteria isolated from the surface of clinically symptomatic eyes. Egger SF, Ruckhofer J, Alzner E, Hell M, Hitzl W, Huber-Spitzy V, Grabner G. Ophthalmic Res 2001;33:117–120.

In vitro susceptibilities to topical antibiotics of bacteria isolated from the surface of clinically symptomatic eyes. Egger SF, Ruckhofer J, Alzner E, Hell M, Hitzl W, Huber-Spitzy V, Grabner G. Ophthalmic Res 2001;33:117–120.

Survival ofSerratia marcescensin the Presence of Complement

Serratia marcescens has been isolated from a variety of ocular infections and/or infammation. In order to survive in the eye, strains must be able to resist host defence systems. Complement has been shown to have an increased concentration and to be active during sleep. Not only is the complement system involved in host defence, but its activation can also produce in ammation. The aim of the present study was to examine the ability of ocular isolates of S. marcescens to withstand complement attack, activate complement and to examine the mechanisms used for evasion of this host defence system. The majority of isolates tested (4/6) were resistant to complement attack. These isolates were able to activate both complement pathways, as detected by enzyme-linked immunosorbent assays (ELISA) and western blotting assays. Components detected included C4, Factor B, C3 and C5. Possible mechanisms of resistance were elucidated including quantity of lipopolysaccharide (LPS) on the cell surface, ability to bind lactoferrin, types of complement components deposited onto the surfaces of strains, and the amount and location of C3 bound on the surface, as determined by transmission electron microscopy. Complement-resistant strains generated iC3b, bound more lactoferrin (1.7 ± 0.6 for resistant cells compared with 0.4 ± 0.2 for complement-sensitive cells, relative values), and had larger amounts of extractable endotoxin (216.8 ± 88.8 µ g/ml for resistant strains and 36.0 ± 48.4 µ g/ml for sensitive strains). Although there was no direct correlation between the ability to resist and activate complement and the isolation of strains from symptomatic or asymptomatic eyes, the resistance of strains to complement may allow these strains to remain in the eye and the activation of complement may contribute to the in ammatory response seen during infection or ocular infammation. Keywords: Serratia marcescens , complement, host defence, tear ?film.

In vitro Susceptibilities to Topical Antibiotics of Bacteria Isolated from the Surface of Clinically Symptomatic Eyes

Background: The permanent change of resistance patterns of bacteria causing ocular infections makes repeat susceptibility testings against the most recent clinical isolates mandatory. The aim of the present study was to assess the in vitro susceptibility of ocular bacterial isolates of clinically symptomatic eyes admitted to the outpatient clinic of the eye department of a large central hospital to commonly used topical antibiotics. Methods: Ocular isolates (n = 454) were tested for their susceptibility to ofloxacin, ciprofloxacin, norfloxacin, gentamicin, tobramycin, meomycin, bacitracin, erythromycin, tetracycline and chloramphenicol. Results: All three tested fluoroquinolones were found to be very effective against gram-negative organisms but demonstrated some weakness against certain strains of gram-positive germs, in particular coagulase-negative staphylococci and Streptococcus viridans. These germs, however, were very susceptible to bacitracin and chloramphenicol. The relative overall in vitro efficacy was (in decreasing order): chloramphenicol, ciprofloxacin, ofloxacin, norfloxacin, bacitracin, tetracycline, neomycin, erythromycin, tobramycin and gentamicin. Conclusion: Chloramphenicol had the highest overall in vitro efficacy, but has potential lethal side effects. The fluoroquinolones were highly effective, especially being superior to the aminoglycosides tested, but no single antibiotic provided 100% coverage against all of the bacterial isolates that were tested.

Radiotherapy of Choroidal Metastases in Patients with Disseminated Cancer

Background: >Choroidal metastasis is the most common ocular tumor, in most cases related to breast and lung cancer. Radiotherapy (RT) mostly is the therapy of choice. However, there is a lack of data about the results of uniformly, prospective treated patients. Patients and Methods: Between November 1994 and September 1997, 37 patients with 49 metastatic eyes were enrolled into the study. 25 patients (68%) had unilateral and 12 patients (32%) had bilateral metastases. 21 patients had breast cancer as primary tumor, 12 patients lung cancer, and 4 patients other tumors. 3 patients were excluded from analysis, 34 patients with 46 involved eyes were available for analysis. 29 of those patients had symptomatic metastases, 5 patients had asymptomatic choroidal metastases. RT was performed with bi- or unilateral asymmetric fields, total dose was 40 Gy with a single dose of 2 Gy, 5 fractions per week. 12 patients (35%) had a chemotherapy following RT due to diagnosis of general tumor progression. Endpoints of the study were visual acuity (VA), local tumor control, survival, and side effects. Results: The median follow up was 6 months, 22 out of 34 patients died of metastatic disease. In 17 of symptomatic eyes (53%) an increase of VA and in 11 of symptomatic eyes (34%) a ‘no change’ was achieved. The local tumor control rate after 18 months was 83%. One patient with asymptomatic metastasis (1/14 eyes) developed symptoms until death. The median survival time was 15 months. Altogether, in 2 patients late side effects (6%) were observed (1 patients with bilateral retinopathy, 1 patient with optic nerve atrophy). Conclusions: RT with 40 Gy is highly effective in the treatment of symptomatic and asymptomatic choroidal metastases, VA was stable or improved in almost 90% of treated eyes. The rate of side effects is low.

Foveal outer retinal function in eyes with unexplained visual symptoms or acuity loss.

To determine whether foveal outer retinal dysfunction is common in eyes with unexplained visual symptoms or acuity loss. Prospective study. Seventy-three eyes of 44 consecutive patients with unexplained visual symptoms or acuity loss, 39 eyes of 39 control subjects, and 12 eyes of 7 patients with known maculopathy. Foveal cone electroretinography (ERG) and letter recognition perimetry. Foveal cone ERG data. Abnormal foveal cone ERG data were recorded in 35 (48%) of 73 eyes (23 [52%] of 44 patients). Among these 35 eyes, amplitude was lower than in normal controls (P<.001) and was correlated with visual acuity and the number of letter recognition perimetry errors (P<.05 for both). The latter was higher in eyes with abnormal retinal responses than in symptomatic eyes with normal responses (P<.01). However, initial symptoms, visual acuity, and macular appearance did not differentiate between these 2 groups. Foveal cone ERG test vs retest data showed consistent results. Foveal outer retinal dysfunction is a common underlying mechanism of previously unexplained visual symptoms or acuity loss. Foveal cone ERG testing should be considered early in the evaluation of eyes with this presentation.