Optic disc and retinal nerve fiber layer thickness descriptive analysis in megalopapilla.

PURPOSE

To evaluate the optic disc and retinal nerve fiber layer (RNFL) thickness in megalopapilla cases by confocal scanning laser ophthalmoscopy and Stratus optical coherence tomography (OCT). To assess the importance of these measurements in diagnosing megalopapilla.

METHODS

This study included 59 eyes (30 patients) diagnosed as megalopapilla. All subjects underwent a complete ophthalmic examination that included intraocular pressure and central corneal thickness measurements and standard automated perimetry using the Swedish Interactive Threshold Algorithm and the 24-2 program (Humphrey Field Analyzer; Carl Zeiss Meditec Inc., Dublin, CA). Confocal scanning laser ophthalmoscopy examinations were performed with the Heidelberg retina tomograph (HRTII; Heidelberg Engineering, Germany). Thickness of the RNFL around the optic disc was measured with Stratus OCT, version 4.0.1 (Stratus OCT; Carl Zeiss Meditec). A descriptive analysis was made using SPSS (version 12.0; SPSS Inc., Chicago, IL) statistical software.

RESULTS

The mean global optic disc area for all eyes with megalopapilla was 3.28±0.53 mm and was not statistically different among races (P≥0.159) or sex (P≥0.108). The average RNFL thickness was 102.5±12.68 μm. Pattern standard deviation was 3.8±2.4 and mean deviation was -1.22±2.65. Central corneal thickness mean value was 543±35.9 μm. Intraocular pressure (average from 3 measurements) ranged from 10.0 to 20.6 mm Hg (14.4±2.7).

CONCLUSIONS

In megalopapilla, the optic disc is abnormally large. The RNFL thickness is normal. These findings are essential for distinguishing megalopapilla from the optic glaucomatous neuropathy.