Corneal keloids exhibit similarities with skin keloids, likely stemming from excessive production of collagen by activated corneal fibroblasts [8, 9]. Unlike hypertrophic scars, which are confined to the area of the original injury, keloids have the potential to extend beyond the initial lesion, spreading across significant portions of the corneal surface, and they are frequently noted to recur [9]. While existing reports do not suggest a direct correlation between a predisposition for corneal keloid development and skin keloids [10], recent cases have reported corneal scarring after laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) in Caucasian patients with a history of skin keloid formation [11, 12]. Moreover, keloids have been documented following superficial keratectomy (SK) in patients without known risk factors [13]. However, they are significantly less common than skin keloids and are often associated with ocular trauma, a history of penetrating or non-penetrating surgery, or, in some cases, rare diseases such as Lowe’s syndrome and Rubinstein–Taybi syndrome [1, 14,15,16]. Corneal keloids have been reported more frequently in men [7]. In our case, the patient, a male, had a history of trauma necessitating a valve implant procedure, which led to endothelial failure, requiring endothelial transplantation.

Diagnosing corneal keloids can be challenging due to various terms used interchangeably, including corneal fibroma, myofibroma, and hypertrophic scars. Additionally, it can be easily mistaken for other conditions such as corneal dermoid tumors, ocular surface squamous neoplasia, Salzmann’s nodular degeneration, limbal dermoid, sclerocornea, Peters anomaly, myxomas, congenital glaucoma with corneal edema, metabolic diseases like mucopolysaccharidosis and mucolipidoses, and corneal inclusion cysts [4, 8, 10, 17, 18]. A definitive diagnosis of corneal keloids fundamentally requires a biopsy and histopathological examination, revealing dysplasia of the corneal epithelium and hyperplasia of collagen fibers [4,5,6, 13]. Bowman’s layer is usually disrupted or absent [7].

Pathogenesis of this uncommon ophthalmic disorder remains unclear. Trauma and intraocular surgeries are well-established predisposing factors for keloid development. It is well-established that keloids can manifest several months or even years following these surgeries. Additionally, any of these events, individually or in combination, might serve as the source of the keloid. There have been reports of congenital corneal keloids without a history of ocular injury or trauma, no history of chronic inflammation, or a family history of fibrovascular proliferative disease [1, 10]. This proliferation may induce an inflammatory response in the corneal stroma, serving as a stimulus for the expansion of the fibrotic process beyond the limits of the corneal injury, a characteristic feature of corneal keloids [13, 19]. In our case, a male patient had a history of trauma that required a valve implantation, leading to corneal decompensation necessitating endothelial transplantation. Although the keloid didn’t appear until 2 years after the endothelial transplant, and it is difficult to determine the exact cause. We hypothesize that fibroblasts were activated following the DSAEK and tube valve repositioning. However, the keloid might also result from the initial trauma and subsequent surgeries.

Successful management of corneal keloids involves various surgical techniques, including superficial keratectomy, lamellar excision, lamellar keratoplasty, or penetrating keratoplasty, with favorable outcomes reported in several studies [3]. Recurrence of corneal keloids post-superficial keratectomy, photorefractive keratectomy, and penetrating keratoplasty has been observed [3, 13, 20]. Recently, successful management of corneal keloids with deep anterior lamellar keratoplasty was reported, highlighting the importance of removing the entire stroma to prevent recurrent corneal stromal opacification. Additional treatments post-surgery may include the use of amniotic membrane, corticosteroids, mast cell stabilizers, cyclosporine, laser therapy, and cryotherapy [12, 21]. The choice of treatment depends on factors such as lesion depth, surface area, and surrounding corneal conditions, with penetrating keratoplasty being recommended in cases with extensive corneal damage and endothelial dysfunction. Additionally, sclerokeratoplasty has emerged as a successful alternative procedure, particularly in cases where conventional keratoplasty is not feasible due to extensive corneal damage. In our patient, we observed endothelial dysfunction following the SK, leading us to perform a PKP.

In summary, corneal keloids should be considered in cases of corneal lesions characterized by a dense, white, glistening, and bulging appearance, which may or may not be vascularized. These lesions often arise following surgical procedures, corneal insults, or trauma and can manifest months or even years after the initial injury. While surgical intervention is a common treatment approach, it carries an inherent risk of recurrence.