Barbara Link

Salzmann's nodular degeneration of the cornea: a review and case series.

Salzmanns nodular degeneration is a rare, noninflammatory, slowly progressive, degenerative condition. Bluish-white nodules raised above the surface of the cornea characterize it. It has usually developed in corneas with a history of phlyctenulosis, trachoma, vernal keratoconjunctivitis, measles, scarlet fever, and various other viral diseases. However, today the majority of cases have been seen without recognized previous keratitis. It is composed of dense irregularly arranged collagen tissue with hyalinization between epithelium and Bowmans layer or beyond. Manual removal, phototherapeutic keratectomy (PTK) with or without the use of topical mitomycin-C, lamellar or penetrating keratoplasty have been used in the treatment of this disease. Salzmanns nodular degeneration does not seem to consist of one clinical entity. In some cases, elevated and pannus-like tissue can be separated easily from the corneal surface leaving Bowmans layer almost untouched. In these eyes, subsequent PTK may be necessary to smooth the surface. Recurrences are rare in these eyes. In contrast, some eyes (often with major peripheral vascularization) are left with deep defects in Bowmans layer and superficial stroma after difficult mechanical removal of nodules. In these eyes, multiple masking/laser ablation procedures are mandatory to acquire a homogenous surface. In our experience, the required laser ablation depth is significantly greater and the best-corrected visual acuity to be expected is reduced in contrast to the eyes with easy removal of the nodules. In these eyes recurrences seem to occur more frequently after treatment. Of 35 eyes documented to have Salzmanns nodular degeneration during the last 15 years in our department, 22 needed PTK treatment. Visual acuity increased from 0.4 to 0.7 on average. As a routine, laser ablation should be combined with previous conventional removal of nodules and excessive pannus tissue. By doing so, lamellar and penetrating keratoplasty techniques are hardly ever required in those eyes.

Rod and S-cone driven ERG signals at high retinal illuminances

The purpose of the present study was to investigate whether L- and M-cone driven responses can be influenced by concomitant modulation in the rods or the S-cones. In addition, it was studied whether a change in the state of adaptation in L- or M-cones can have a different influence on ERG data when simultaneously the mean number of photoisomerizations in either rods or S-cones is altered. It was found that rods and/or S-cones cannot be neglected when measuring L- or M-cone driven ERGs.

Carcinoma-associated retinopathy-an electrophysiological and immunohistochemical correlation.

Purpose: To correlate the clinical, electrophysiological, and immunohistochemical findings in patients suffering from carcinoma-associated retinopathy. Methods: Four patients with visual loss were included in this retrospective, observational consecutive case series. Electrophysiology and immunohistochemical analysis were performed to confirm the diagnosis of carcinoma-associated retinopathy. Results: Immunohistochemistry revealed a marked interindividual variability of antibody reactions against different retinal cell layers of individual patients. The electrophysiological changes corresponded to the respective immunohistochemical findings. Conclusion: Carcinoma-associated retinopathy is a heterogeneous disease, caused by different antiretinal antibodies and leading to different electrophysiological abnormalities. Diagnosis should not be delayed as undetected and thus untreated malignancy can be the cause.

Solid corneal dermoids and subconjunctival lipodermoids: impact of differentiated surgical therapy on the functional long-term outcome.

Purpose: The functional long-term outcome after differentiated surgical therapy of solid corneal dermoids and subconjunctival lipodermoids with special regard to determinants for amblyopia will be assessed. Methods: Forty-six consecutive patients undergoing surgery for solid epibulbar dermoids, subconjunctival lipodermoids, or both were included. Visual acuity, refraction, keratometry, and degree of amblyopia were determined. Surgical therapy for corneal dermoids consisted of lamellar sclerokeratectomy, lamellar keratoplasty, corneoscleroplasty, and lamellar removal with autologous episcleral transplant. Surgical therapy for lipodermoids consisted of excision and reduction of the volume of the tumor. Follow-up examination was performed on average 4.5 years after surgical intervention. Results: A significant correlation between tumor volume and preoperative visual acuity could be observed in patients with solid corneal dermoids not occluding the optical axis. Visual acuity improved significantly from 0.21 ± 0.4 to 0.35 ± 0.4 after surgery of corneal dermoids. Most eyes had concomitant hyperopia. Postoperative visual acuity correlated positively with preoperative visual acuity (P = 0.0001). After tumor excision, hyperopia and astigmatism were not reduced significantly on average. Nineteen of 47 patients suffered from amblyopia. Amblyopia was more often observed in patients with preoperative hyperopia ≥2 diopters and astigmatism >2 diopters. Visual acuity, refraction, and astigmatism were not changed significantly by surgery in patients with subconjunctival lipodermoids. Conclusions: Epibulbar dermoids require differentiated surgical therapy. Amblyopia is a major threat of solid corneal dermoids. The incidence of amblyopia seems to depend on preoperative occlusion of the optical axis and preoperative degree of hyperopia and astigmatism.

Long-term reproducibility of screening for glaucoma with FDT-perimetry.

PurposeAim of this study was to evaluate the long-term reproducibility of frequency doubling technology (FDT) screening procedures. MethodsLongitudinal data of 433 eyes of 294 patients with no progression of glaucomatous optic disc atrophy were retrospectively analyzed: 62 control eyes, 184 ocular hypertensive eyes, 104 preperimetric, and 83 perimetric open-angle glaucoma eyes. All subjects had annual tests with the FDT perimeter and a standardized ophthalmologic examination (ie, conventional perimetry, optic disc inspection, tonometry, lens opacity measurement for exclusion of cataract). The present analysis used a published overall screening score with case-wise recalculation of missed localized probability levels. We analyzed long-term variability by correlation analysis, sign tests, and limits of agreement (LoA) as introduced by Altman and Bland. All subjects had at least 2 annual tests. Three hundred twenty-six eyes had 2 annual tests with the C-20 procedure and at least 1 test with the N-30 protocol another year later. One hundred thirty-five eyes had 1 C-20 and 2 annual tests with the N-30 protocol. ResultsAnalyses of repeated measurements revealed a significant learning effect (P<0.001, LoA: −4, 17) between the first and second examination but no significant difference between the second and following tests with the C-20 protocol (P>0.6, LoA: ±9). In addition, there was no significant difference between second C-20 and N-30 tests (P>0.5, LoA: −12, 6). ConclusionsThe study demonstrates the variability of FDT tests over several years. Longitudinal FDT-results in a clinical study showed a higher reproducibility if the first test was discarded. Reproducibility of screening with the N-30 protocol is comparable to the C-20 procedure if an overall score is considered.