Display content if form field is filled - Do not display if field is empty
Oh yes, I recommend some DRYing principles here.  Don't ask php to do the same thing over and over for the same result in a loop -- execute those tasks, just once, before entering the loop.

Rather than repeating whole portions of mark up only to change a few values, create a lookup array of the social networks that you want to cycle through and only replace those values in a reusable piece of the dom.

The social variables are always going to be "set", because they are unconditionally declared when get_field() is called.  There is no point in isset().

If there are any qualifying socials, then the parent &lt;div&gt; will enclose all qualifying &lt;a&gt;-tagged-wrapped &lt;img&gt;s.

This ALSO makes it easy for you to scale your application.  In case you ever want to add more socials in the future, just add a new element to $socials (assuming all of the other data is consistent) and you won't need to touch any part of the processing code.

Code: (Demo)

$socials = ['facebook', 'twitter', 'instagram'];
$templateDirectory = get_template_directory_uri();
foreach ($socials as $social) {
    $socialHref = trim(get_field($social, 'option'));
    if (strlen($socialHref)) {
        $socialLinks[] = sprintf(
            '&lt;a class="social-link ie9" href="%s" target="_blank" rel="noopener"&gt;
                 &lt;img src="%s/svg/%s.svg" alt="%s Icon"&gt;
            &lt;/a&gt;',
            $socialHref, $templateDirectory, $social, ucfirst($social)
        );
    }
}
if (isset($socialLinks)) {
    echo '&lt;div class="social-media--icons"&gt;' , implode(' ', $socialLinks) , '&lt;/div&gt;';
}


Output:

&lt;div class="social-media--icons"&gt;
    &lt;a class="social-link ie9" href="blah-facebook-blah" target="_blank" rel="noopener"&gt;&lt;img src="https://example.com/svg/facebook.svg" alt="Facebook Icon"&gt;&lt;/a&gt;
    &lt;a class="social-link ie9" href="blah-twitter-blah" target="_blank" rel="noopener"&gt;&lt;img src="https://example.com/svg/twitter.svg" alt="Twitter Icon"&gt;&lt;/a&gt;
    &lt;a class="social-link ie9" href="blah-instagram-blah" target="_blank" rel="noopener"&gt;&lt;img src="https://example.com/svg/instagram.svg" alt="Instagram Icon"&gt;&lt;/a&gt;
&lt;/div&gt;