Indian Journal of Ophthalmology - Case Reports

CASE REPORT
Year
: 2021  |  Volume : 1  |  Issue : 4  |  Page : 759--761

Orbital dermoid cyst combined with unilateral keratoconus: A case report


Zengying Wang1, Yifei Meng1, Lili Hao2, Sufang Qie1, Zhipeng Yan1,  
1 Department of Ophthalmology, The Third Hospital of Hebei Medical University, Shijiazhuang, Hebei Province, China
2 Department of Ophthalmology, The Fourth Hospital of Zhangjiakou, Zhangjia kou, Hebei Province, China

Correspondence Address:
Dr. Zhipeng Yan
Department of Ophthalmology, The Third Hospital of Hebei Medical University, 139 Ziqiang Road, Shijiazhuang, Hebei Province
China

Abstract

To report a rare case of an orbital dermoid cyst combined with unilateral keratoconus. A 19-year-old female presented with a painless, progressive upper eyelid swelling of the right eye accompanied by decreased visual acuity. Keratoconus of the right eye was confirmed by corneal topography. After surgery, the lesion mass proved to be a dermoid cyst on pathological examination. To the best of our knowledge, this is the first report to describe an orbital dermoid cyst combined with unilateral keratoconus. This case suggested that the keratoconus of the right eye may be a secondary manifestation of the mechanical pressure exerted by the orbital dermoid cyst.



How to cite this article:
Wang Z, Meng Y, Hao L, Qie S, Yan Z. Orbital dermoid cyst combined with unilateral keratoconus: A case report.Indian J Ophthalmol Case Rep 2021;1:759-761


How to cite this URL:
Wang Z, Meng Y, Hao L, Qie S, Yan Z. Orbital dermoid cyst combined with unilateral keratoconus: A case report. Indian J Ophthalmol Case Rep [serial online] 2021 [cited 2021 Dec 5 ];1:759-761
Available from: https://www.ijoreports.in/text.asp?2021/1/4/759/327739


Full Text



An orbital dermoid cyst is a developmental choristoma, which is formed by implanting epithelial ectoderm during the embryonic stage. The contents of the sac contain epithelium, hair, sebaceous glands, and sweat glands. The cyst is mostly located in the upper outer quadrant of the orbit and often causes the eyeball to shift downward or protrude.[1],[2] Keratoconus is mostly asymmetric, progressive disease, resulting in central and/or para-central thinning of the cornea, irregular astigmatism, and eventually severe vision loss. The etiology of keratoconus is complex. The currently recognized known risk factors include multiple genetic factors, environmental factors, and biochemical factors such as frequent eye rubbing and allergic conjunctivitis.[3],[4],[5] In this case, the patient was diagnosed with orbit dermoid cyst combined with keratoconus of the right eye. According to the clinical characters of this case, it is suggested that the occurrence of keratoconus is closely related to the compression caused by the orbital dermoid cyst. To the best of our knowledge, this is the first report of an orbital dermoid cyst combined with ipsilateral keratoconus. This study followed the Declaration of Helsinki and was approved by the Ethics Committee of the Hebei Medical University.

 Case Report



A 19-year-old female presented with a painless, slowly growing mass in the superotemporal area of the right orbit, which was soft and easily moveable. The patient described that the eyelid of the right eye was slowly swelling for 2 years. She felt the right eye was protruded and had blurred vision for 1 year. She also used to occasionally, but not often, rub her right eye due to eye fatigue. The basic information of this patient is as follows: The extent of the right eye proptosis was 2 mm by Hertel Exophthalmometry. Uncorrected visual acuity (UCVA) was 20/200 in the right eye and 20/60 in the left eye. The best-corrected distance visual acuity (BCVA) was 20/40 in the right eye and 20/20 in the left eye. Manifest refraction revealed + 3.5 spherical and − 4.5 cylinder at 97° in the right eye and − 1.5 spherical and − 0.25 cylinder at 145° in the left eye. The cornea showed mild thinning inferior to the pupil in the right eye under the slit lamp examination. There were no other signs of keratoconus. The ocular motility was normal. The fundus examination of both eyes was normal. Intraocular pressure (Goldmann applanation tonometry) was 12 mmHg in the right eye and 17 mmHg in the left eye. The corneal topography of the right eye (Pentacam HR) showed typical keratoconus characters, K1 = 44.5 D, K2 = 47.2 D, and Kmax = 50.0 D. Both the anterior and posterior elevation of the thinnest point was abnormally increased [Figure 1]a. The left eye showed normal corneal values. Corneal pachymetry measurements at the thinnest locations were 525 and 563 microns for the right and left eyes, respectively [Figure 1]a and [Figure 1]b. Next, the axial length (AL) was measured by Zeiss IOLMaster biometer (Carl Zeiss, Germany). AL of the right eye was shorter than that of the left eye (22.40 mm with 24.37 mm). The magnetic resonance imaging (MRI) scan revealed low intense lesion for T1-weight images and iso-to-hyperintense lesion for T2-weight images in the right orbit, which confirmed the characteristic component of the orbital dermoid cyst [Figure 1]c and [Figure 1]d. The patient underwent resection of the right orbital mass and lateral orbitotomy. The cyst was removed completely. Histopathological analysis showed a cyst lined by keratinized stratified squamous epithelium with keratin, skin appendages, and lipid debris in the lumen consistent with a dermoid cyst [Figure 1]e. The right eye proptosis was resolved completely and the same as the left eye by Hertel 1 month after surgery. UCVA and BCVA of both the eyes were the same as that before surgery. Manifest refraction revealed + 3.25 spherical and − 3.5 cylinder at 90° in the right eye and − 1.25 spherical in the left eye. The corneal topography revealed that the cornea curvature remained unchanged compared with that of the first visit [Figure 1]f.{Figure 1}

 Discussion



Generally, keratoconus is a non-inflammatory bilateral ectasia of the cornea. The known risk factors include multiple genetic factors, environmental, and biochemical factors such as eye rubbing and allergic conjunctivitis.[3],[4] There are a few published case reports of orbital tumors combined with unilateral keratoconus. Hornblass and Sabates (1980) reported that a 38-year-old man had a 35-year history of a slowly progressive eyelid cavernous hemangioma combined with keratoconus.[6] Vasilios Liarakos and D Ioannis Mavrikakis reported that a 22-year-old man had orbital fibrous dysplasia combined with keratoconus.[7] However, the exact mechanism between their relationship remained poorly understood.

A dermoid cyst is not an uncommon orbital tumor, accounting for 3–9% of all orbital masses.[8] Although it is an embryonic development disease, some patients do not get onset until adulthood. In this case, the reduced vision occurred 1 year after the right eye proptosis and got worse during the time. There is reason to believe that unilateral keratoconus of the right eye may be induced by the compression of the orbital dermoid cyst in this case. Basically, the reported frequency of unilateral keratoconus ranges between 0.5 and 4%,[9] which is related to biomechanical stress that includes eye rubbing or chronic pressure causing irreversible biomechanical weakening in patients. Adrien Mazharian et al.[10] evaluated sleeping position in patients with unilateral or high astigmatism keratoconus (UHAKC) by multivariate analysis. They concluded that keratoconus appears to be more common in patients who sleep on their stomach which results in a compression of the globe, subsequently, this ocular compression could increase the activity of inflammatory mediators, which lead to the biochemical changes and stromal thinning in keratoconus. Inflammation is currently considered by some researchers to play a role in the pathogenesis of keratoconus.[5] Although there was no family history of keratoconus, the habits of eye rubbing, allergic conjunctivitis, and system diseases, in this case, it is quite possible that the “occasional eye rubbing” combined with the prolonged and stronger impact of dermoid cyst applied on the cornea resulted in a permanent thinning and deformation of the cornea.

 Conclusion



To the best of our knowledge, there are no reports that describe the orbit dermoid cyst combined with unilateral keratoconus published so far. This case report suggested that in the case of exophthalmos caused by an orbital dermoid cyst, corneal topography and related examinations were necessary for examining the possibility of keratoconus. An association between a dermoid cyst and unilateral keratoconus needs to be emphasized for the eye specialist. Meanwhile, it would also be interesting to note if the unilateral keratoconus stabilized after removal of the presumed mechanical pressure or if this could be a case of bilateral asymmetrical keratoconus with presentation delayed in the other eye. This may become self-evident on a longer follow-up.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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