Comparison of central corneal thickness: ultrasound pachymetry versus slit-lamp optical coherence tomography, specular microscopy, and Orbscan.

BACKGROUND: Central corneal thickness (CCT) can be measured by using contact and non-contact methods. Ultrasound pachymetry (US pachymetry) is a contact method for measuring CCT and is perhaps the most commonly used method. However, non-contact methods like scanning slit topography (Orbscan II), slit-lamp optical coherence tomography (SL-OCT), and specular microscopy are also used. Not many studies have correlated the measurement of CCT with all four modalities. The purpose of this study was to compare and correlate the CCT measurements obtained by US pachymetry with SL-OCT, specular microscopy, and Orbscan. METHOD: This is a prospective, comparative study done in an institutional setting. Thirty-two eyes of 32 subjects with no known ocular disease and best-corrected visual acuity of 20/20 were enrolled. CCT measurements were obtained using SL-OCT, specular microscopy, scanning slit topography (Orbscan), and US pachymetry. Three measurements were made with each instrument by the same operator. Mean, standard deviation, and coefficient of variation were calculated for CCT measurements acquired by the four measurement devices. Bland-Altman plot was constructed to determine the agreements between the CCT measurements obtained by different equipment. RESULTS: The mean CCT was 548.16±48.68 µm by US pachymetry. In comparison, CCT averaged 546.36±44.17 µm by SL-OCT, 557.61±49.92 µm by specular microscopy, and 551.03±48.96 µm by Orbscan for all subjects. Measurements by the various modalities were strongly correlated. Correlations (r (2)) of CCT, as measured by US pachymetry compared with other modalities, were: SL-OCT (r (2)=0.98, P<0.0001), specular microscopy (r (2)=0.98, P<0.0001), and Orbscan (r (2)=0.96, P<0.0001). All modalities had a linear correlation with US pachymetry measurements. CONCLUSION: In subjects with healthy corneas, SL-OCT, specular microscopy, and Orbscan (with correction factor) can be used interchangeably with US pachymetry in certain clinical settings. The four modalities showed significant linear correlations with one another.

Small-incision, sutureless repair of subconjunctival fat prolapse.

PURPOSE: To present a new, small-incision, sutureless surgical technique for the repair of subconjunctival fat prolapse. METHODS: This is a retrospective interventional case series. Four eyes of 3 patients who presented with prolapsed subconjunctival fat were surgically repaired using a small-incision, sutureless technique with fibrin glue. No prolapsed subconjunctival fat was excised. RESULTS: The surgical treatment of prolapsed subconjunctival fat using a small-incision, sutureless technique with fibrin glue was successful in all 4 eyes. There have been no cases of recurrence of the prolapsed subconjunctival fat with a mean follow up of 31 months. CONCLUSIONS: Small-incision, sutureless repositioning of subconjunctival fat using fibrin glue is an effective new surgical technique for the management of prolapsed subconjunctival fat.

Multiple bilateral ocular metastases from malignant melanoma associated with blue nevi.

PURPOSE: Malignant melanoma associated with a blue nevus is a rare diagnosis. Additionally, only a handful of cases of malignant melanoma associated with blue nevi involving the ocular structures have been reported. We report a probable case of malignant melanoma associated with a blue nevus with metastasis to multiple bilateral ocular structures. METHODS: Observational case report. RESULTS: We report a case of a 27-year-old man with lymph node biopsy-proven malignant melanoma as well as a separate skin biopsy of a blue nevus, who developed multiple bilateral pigmented ocular lesions on the sclera, iris, trabecular meshwork, and choroid. CONCLUSIONS: Although ocular histopathologic evidence could not be obtained, our case likely represents a case of explosive widespread metastasis probably originating from a blue nevus of unknown location, which involved both eyes and adnexae.

Fundus autofluorescence and spectral domain optical coherence tomography in early detection of Plaquenil maculopathy.

PURPOSE: To report fundus autofluorescence (FAF) and spectral-domain optical coherence tomography (SD-OCT) findings in a patient with early hydroxychloroquine maculopathy. METHODS: A 50-year-old man presented with complaints of ring-like shadows in front of his eyes. He had been on hydroxychloroquine (Plaquenil) 400 mg orally twice daily for 10 years (5.14 mg/kg/day). Fundus examination revealed granular hypopigmentation in an arcuate pattern in the inferior parafoveal area bilaterally. The patient underwent further evaluation with SD-OCT and FAF imaging. Functional changes were assessed by microperimetry. RESULTS: Hypopigmented lesions on the fundus were autofluorescent and SD-OCT corresponding to this area revealed loss of inner segment-outer segment, suggesting loss of photoreceptor layer in the affected area with underling dysfunctional retinal pigment epithelium. CONCLUSIONS: Findings on SD-OCT and FAF imaging support the histopathologic findings described in cases of hydroxychloroquine maculopathy.