Acute ganglion cell loss during rapid visual recovery in optic neuritis.

PURPOSE: To report dynamic changes in the retinal ganglion cell layer (GCL) and visual function in acute and chronic optic neuritis (ON). METHODS: Sixteen eyes (15 patients) with acute ON were followed for 3.5 to 31 months (average, 10.2). The best-corrected visual acuity (BCVA) and thickness of the GCL plus the inner plexiform layer (GCL+IPL) were measured 4 to 13 times between baseline and the final visit using the ganglion cell analysis software in the Cirrus HD-OCT [high-definition optical coherence tomography] instrument. Goldmann perimetry was performed at baseline and at the final visit. RESULTS: The thickness of the GCL+IPL at baseline was within normal limits in the affected (80.4 ± 4.9 microns) and unaffected fellow eyes (80.5 ± 5.0 microns). Rapid thinning to 69 ± 7.3 microns occurred during month 1 in the affected eyes, slowing during month 2, and then reaching a minimum level (63.6 ± 8.7 microns). In contrast, BCVA was lowest (mean ± standard deviation logarithm of the minimum angle of resolution, -1.29 ± 0.96) in 11 eyes at baseline, increased markedly to -0.15 ± 0.37 during month 1, and reached a maximum level (-0.18 ± 0.19) during month 2 and (-0.02 ± 0.23) at the final visit. The BCVA in the other five eyes fluctuated during month 1, increased markedly during month 2, and then reached a maximum plateau (-0.07 ± 0.20). The patterns of visual field defects at baseline were varied, and were determinants of BCVA. The visual field largely recovered in 11 eyes, but small central scotomas in four eyes and an enlarged blind spot in one eye remained at the final visit. Eyes with the least GCL+IPL thinning at month 1 or 2 had the least depression in the final deviation map. CONCLUSIONS: In acute ON, the progression toward irreversible ganglion cell loss occurs rapidly during months 1 and 2. In contrast, visual function recovers rapidly during the same period. Remodeling of the neural network may occur between the photoreceptors and the reduced numbers of ganglion cells during the first months of ON. The small number of residual ganglion cells appears to compensate for the initial visual dysfunction.

Intravitreal gas injection without vitrectomy for macular detachment associated with an optic disk pit.

PURPOSE: To evaluate the clinical outcomes after gas tamponade without vitrectomy for retinal detachment associated with an optic disk pit using optical coherence tomography. METHODS: Intravitreal gas injection was performed on 8 consecutive patients (mean age, 35.0 years; range, 15-74 years) with unilateral macular detachment associated with an optic disk pit. A 0.3-mL injection of 100% sulfur hexafluoride 6 gas was carried out without an anterior chamber tap. Patients treated with gas injection were instructed to remain facedown for 5 days. RESULTS: Complete retinal reattachment after only gas tamponade was achieved in four out of eight eyes. The mean number of gas injections was 1.8. The mean best-corrected visual acuity before and after the treatment with gas tamponade was approximately 30/100 and 20/20, respectively. The period required for reattachment after final gas treatment was 12 months. There were no incidences of recurrence after complete reattachment by gas tamponade in any of the cases during the 94-month average follow-up period (range, 64-132 months). CONCLUSION: Gas tamponade appears to be an effective alternative method for macular detachment associated with an optic disk pit, even though the mechanisms of optic disk pit maculopathy are still unknown.

Topical voriconazole therapy of Purpureocillium lilacinum keratitis that occurred in disposable soft contact lens wearers.

The objective of this study was to describe 2 cases of keratitis caused by Purpureocillium lilacinum (formerly Paecilomyces lilacinus) that occurred in disposable contact lens users, which were successfully treated with topical voriconazole. Case 1 was a healthy 44-year-old woman, who wore weekly disposable contact lenses and had developed a superficial corneal infection in her right eye. For diagnosis, corneal scraping and molecular identification of the cultured pathogen were performed. A corneal smear revealed the presence of fungi. The pathogen was identified as P. lilacinum by traditional morphological identification of fungal culture, and this identification was confirmed by DNA sequencing of the ribosomal internal transcribed spacer (ITS) sequence. Therapy with topical fluconazole, topical pimaricin (natamycin), and oral itraconazole were ineffective. Topical voriconazole showed a significant effect, and the keratitis was successfully treated. Case 2 was a 43-year-old woman with bilateral recurrent peripheral corneal ulcers by meibomian gland dysfunction, who used therapeutic bandage contact lenses on her left eye. However, a corneal abscess with hypopyon occurred in the eye after 3 months. The microbial smear examination showed the presence of fungi and the fungal culture, and the DNA sequence of ITS region revealed that the causative agent was P. lilacinum. The susceptibility testing against antifungal agents showed that voriconazole was effective. The lesion improved gradually by topical voriconazole. As a conclusion, P. lilacinum keratitis can occur in disposable soft contact lens wearer. Early and accurate detection of the pathogenic organism is essential. Topical voriconazole was effective against P. lilacinum keratitis.