ICD-10-CM > H00-H59 > H43-H44 > H44 > H44.4 > H44.42 H44.42 Hypotony of eye due to ocular fistula Non-Billable/Non-Specific Codes H44.421Hypotony of right eye due to ocular fistulaH44.422Hypotony of left eye due to ocular fistulaH44.423Hypotony of eye due to ocular fistula, bilateralH44.429Hypotony of unspecified eye due to ocular fistula