<?php if ( is_singular() && get_the_author_meta( 'description' ) ) : ?>
<div class="vt-post-author">
    <div class="row">
        <div class="col-md-2">
            <div class="author-img"><?php echo get_avatar( get_the_author_meta('email'), '90' ); ?></div>
        </div>
        <div class="col-md-9">
        	<div class="author-content">
                <h4 class="author-title"><?php the_author_posts_link(); ?></h4>
        		<p><?php the_author_meta('description'); ?></p>
        	</div>
        </div>
    </div>
</div>
<?php endif; ?>