Keith H. Baratz

The effect of corneal light scatter on vision after descemet stripping with endothelial keratoplasty

OBJECTIVE To establish an association between corneal light scatter and vision after Descemet stripping with endothelial keratoplasty (DSEK). METHODS Twenty eyes of patients with Fuchs endothelial dystrophy were examined before and at 1, 3, and 6 months after DSEK in a prospective study. Main outcome measures were high-contrast best-corrected visual acuity, intraocular forward light scatter, and corneal backscatter. RESULTS One eye was excluded because of endothelial graft failure within 1 month. Best-corrected visual acuity improved at 3 months after DSEK (mean [standard deviation], 0.31 [0.20] logarithm of the minimum angle of resolution [logMAR]; Snellen equivalent, 20/41) relative to before DSEK (0.46 [0.26] logMAR; Snellen equivalent, 20/58; P = .03). Posterior corneal backscatter decreased 1 month after DSEK (P < .001), but backscatter from the anterior, middle, and posterior cornea did not return to normal by 6 months (P < or = .02). At 6 months, best-corrected visual acuity correlated with recipient age (r = 0.84, P < .001) and with intraocular forward light scatter (r = 0.67, P < .001); forward light scatter also correlated with recipient age (r = 0.67, P < .001). CONCLUSIONS Six months after DSEK, corneal light scatter remained greater in eyes with Fuchs endothelial dystrophy than in normal eyes and correlated with recipient age and visual acuity. Recipient age might be the best preoperative predictor of vision after DSEK.

Incidence, recurrence, and outcomes of herpes simplex virus eye disease in Olmsted County, Minnesota, 1976-2007: the effect of oral antiviral prophylaxis.

OBJECTIVES To provide an estimate of the incidence of herpes simplex virus (HSV) eye disease in a community-based cohort, and to investigate the effect of prophylactic oral antiviral therapy on HSV recurrences and outcomes. METHODS All Olmsted County, Minnesota, residents diagnosed with ocular HSV from 1976 through 2007 were retrospectively reviewed. The frequency of recurrences and adverse outcomes, such as vision loss or need for surgery, were compared between untreated patients and those treated prophylactically with oral antiviral medication. RESULTS Three hundred ninety-four patients with ocular HSV were identified, yielding an annual incidence of 11.8 per 100,000 people (95% confidence interval [CI], 10.6-13.0). No trends in incidence or adverse outcomes were identified during the 32-year period. Oral antiviral therapy was prescribed in 175 patients. Patients were 9.4 times more likely (95% CI, 5.0-17.9) to have a recurrence of epithelial keratitis, 8.4 times more likely (95% CI, 5.2-13.7) to have a recurrence of stromal keratitis, and 34.5 times more likely (95% CI, 10.8-111.1) to have a recurrence of blepharitis or conjunctivitis if not being treated prophylactically at the time of the recurrence. Twenty patients experienced adverse outcomes, and 17 (85%) were not being treated with oral antiviral medications immediately preceding the adverse event. CONCLUSIONS Oral antiviral prophylaxis was associated with a decreased risk of recurrence of epithelial keratitis, stromal keratitis, conjunctivitis, and blepharitis due to HSV. Patients with adverse outcomes due to ocular HSV were usually not being treated with oral antiviral prophylaxis.

Corneal haze determined by confocal microscopy 2 years after descemet stripping with endothelial keratoplasty for fuchs corneal dystrophy

OBJECTIVE To quantify corneal light scatter and its relationship to vision after Descemet stripping with endothelial keratoplasty (DSEK). METHODS Eyes with Fuchs corneal dystrophy were examined before and 1, 3, 6, 12, and 24 months after DSEK. Outcome measures were high- and low-contrast visual acuity, contrast sensitivity, and forward light scatter. Corneal reflectivity (backscatter), expressed in scatter units (SU), was quantified using in vivo confocal microscopy. RESULTS Comparing 49 study eyes with 35 normal eyes, the mean (SD) corneal subepithelial layer was more reflective than normal before (2325 [613] vs 1208 [287] SU, P<.001) and through 24 months after DSEK (1760 [432] SU, P<.001). Interface reflectivity remained higher than in normal stroma through 24 months (1228 [287] vs 827 [188] SU, P<.001). At 1 year, forward light scatter correlated with subepithelial reflectivity (r=0.28, P=.01) but not interface reflectivity. Recipient age was correlated with improvement in subepithelial reflectivity at 12 months (r=–0.41, P=.01, 34 eyes) and 24 months (r=–0.36, P=.02, 26 eyes) after DSEK, and the improvement of subepithelial haze in eyes of participants aged 62 years or younger was correlated with improvement in forward light scatter at 12 months (r=0.52, P=.008) and 24 months (r=0.62, P=.004). CONCLUSIONS In Fuchs corneal dystrophy, the corneal subepithelial region is a more important source of forward light scatter than the DSEK interface. Subepithelial haze improves more in younger patients and is associated with improvement in forward light scatter. CLINICAL RELEVANCE Visual function after DSEK is affected by residual haze in the anterior host cornea more so than the surgical interface. Haze, which likely is experienced as glare disability, improves after surgical intervention but improves more in younger patients.

Decreased corneal sensitivity and abnormal corneal nerves in Fuchs endothelial dystrophy.

Purpose: To determine corneal sensitivity and evaluate corneal nerves before and after keratoplasty for Fuchs endothelial dystrophy. Methods: Central corneal sensitivity, measured by using a Cochet–Bonnet esthesiometer in 69 eyes before and after different keratoplasty procedures for Fuchs dystrophy, was compared with that of 35 age-matched normal corneas. Corneal nerves were qualitatively examined by confocal microscopy in 42 eyes before and after Descemet stripping endothelial keratoplasty (DSEK). Results: Corneal sensitivity in Fuchs dystrophy (4.61 ± 1.42 cm) was lower than that of age-matched controls (5.74 ± 0.48 cm, P < 0.001). Sensitivity decreased by 1 month after DSEK (2.98 ± 2.01 cm, P < 0.001), returned to preoperative sensitivity by 24 months (4.50 ± 1.63 cm, n = 33, P = 0.99), but remained lower than controls at 36 months (4.50 ± 1.48 cm, n = 15, P < 0.001). Sensitivity at 36 months after penetrating keratoplasty (1.46 ± 1.98 cm) remained decreased compared with preoperative sensitivity (P < 0.001). Subbasal nerves appeared sparse with abnormal branching before and through 36 months after DSEK. Sensitivity was lower in corneas without visible subbasal nerves by confocal microscopy at 12 months after DSEK (P < 0.005) than in corneas with visible nerves. Stromal nerves were frequently tortuous and formed loops in Fuchs dystrophy, and this appearance persisted in some eyes at 36 months after DSEK. Conclusion: Corneal sensitivity is decreased in Fuchs dystrophy compared with normal and remains subnormal even at 3 years after endothelial keratoplasty. Decreased sensitivity is likely to be related to loss of subbasal nerves and abnormal nerve morphology, which persist after endothelial keratoplasty.

Acyclovir-resistant Herpes Simplex Virus Keratouveitis after Penetrating Keratoplasty

PURPOSE A case of acyclovir-resistant herpes simplex virus keratouveitis after penetrating keratoplasty is reported. METHODS Resistance to acyclovir was evident clinically and was confirmed by in vitro susceptibility testing. The susceptibility of the herpes simplex isolates to acyclovir and foscarnet was determined by a dye uptake assay that measured cytopathic effect, and thymidine kinase activity was measured by a plaque autoradiography technique. RESULTS The viral isolate from postoperative day 22 was susceptible to acyclovir and foscarnet, and showed normal thymidine kinase activity. Isolates from postoperative days 29 and 32 (coinciding with deterioration in clinical appearance) were resistant to acyclovir, susceptible to foscarnet, and deficient in thymidine kinase activity. CONCLUSION Practitioners should be aware of the potential for the emergence of resistance in this setting; prophylaxis and rational alternate therapies are discussed.

Periorbital and Ocular Necrobiotic Xanthogranuloma Leading to Perforation

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Gene expression in the corneal endothelium of Fuchs endothelial corneal dystrophy patients with and without expansion of a trinucleotide repeat in TCF4

Fuchs Endothelial Corneal Dystrophy (FECD) is a late onset, autosomal dominant eye disease that can lead to loss of vision. Expansion of a CTG trinucleotide repeat in the third intron of the transcription factor 4 (TCF4) gene is highly associated with FECD. However, only about 75% of FECD patients in the northern European population possess an expansion of this repeat. The remaining FECD cases appear to be associated with variants in other genes. To better understand the pathophysiology of this disease, we compared gene expression profiles of corneal endothelium from FECD patients with an expanded trinucleotide repeat (RE+) to those that do not have a repeat expansion (RE-). Comparative analysis of these two cohorts showed widespread RNA mis-splicing in RE+, but not in RE- samples. Quantitatively, we identified 39 genes in which expression was significantly different between RE+ and RE- samples. Examination of the mutation profiles in the RE- samples did not find any mutations in genes previously associated with FECD, but did reveal one sample with a rare variant of laminin subunit gamma 1 (LAMC1) and three samples with rare variants in the gene coding for the mitochondrial protein peripheral-type benzodiazepine receptor-associated protein 1 (TSPOAP1).

Rapid Measurement of Selected Tear Proteins in Health and Disease Using the Touch Tear Microassay System

Measurement of tear fluid immunoglobulins has been restricted to investigational studies due to the complexity of testing methods, yet many studies have demonstrated association of elevated tear IgE with allergic disease of the external eye1–7. The methods of testing have also been hampered by need for a relatively large volume of tear fluid and the attendant induced reflex tearing at the time of collection resulting in artefactually low values of IgE. The Touch Tear Microassay System was designed to adapt solid-phase ELISA testing with sensitive reflectometric determination of color density reaction during the measurement of protein levels in very small volume tear samples (2 µl). The present clinical study attempted to quantitate levels of IgE, IgG and C-reactive protein in normal patients and patients with external ocular signs and symptoms due to allergic and infectious disease using the Touch Tear Microassay System.