Orbital exenteration is the surgical procedure of choice for malignancies of ocular and adnexal origin with local orbital extension. Although it is a highly disfiguring surgery, a significant number of patients undergo this procedure, especially in low-middle-income countries. To the best of our knowledge, the current study spanning a period of 20 years, is one of the largest series from Southeast Asia. on orbital exenterations published from a single centre till date Previously a study published in 1995 by Gunalp et al from Turkey reported clinical and pathological data on a set of 429 cases over 30 years.8 Another study by Martel A et al from national data base, PMSI (Programme de Médicalisation des Systèmes d’Information), France reported the nationwide incidence of orbital exenteration from 2006-17 with 1057 orbital exenteration data collected.9
In an earlier study reported from our centre in 2004, clinical profile of orbital exenterations in adult patients was reported overall in 26 cases for a study period of 10 years.10 The current study shows an increase in the number of exenterations being performed compared to 1990s. However, in terms of the percentage of all tumor related surgeries performed at our centre, the ratio of exenteration to the total tumor related surgeries has shown a declining trend. The substantial number of exenterations noted in the current study could be due to an improved referral and better access to care of eye and adnexal tumors patients in general as compared to the previous time. A declining trend in percentage of cases requiring exenteration probably points to improved awareness and early referral to the tertiary care centre. However, the overall number of exenterations being performed in low middle income countries is still high as compared to Europe and North America.11,12,13
The indication for exenteration in the majority is malignancy; however, in a smaller percentage, it is undertaken to treat non-malignant disease as well. Bartley et al. represented their experience at Mayo Clinic with 102 patients of exenteration, over 20 years. Ninety eight percent (100/102) of their patients had malignancies and 2% patients were exenterated for benign aetiologies (mucormycosis and post-burn facial deformity).14 Levin et al and Mohr and Esser also reported malignancy as indication in 93.9% (93/99) cases and 96.1% (74/77) cases respectively.15,16 Martel A et al also reported malignancies (n = 755; 92.0%) as the most common indication of orbital exenteration followed by infectious diseases (n = 16; 1.9%).13 In the current study also, majority of cases requiring exenteration were of malignant disease.
In the current study, secondary tumors were more common indication for exenteration than primary orbital tumors. This is similar to that reported by Bartley and co-workers. The authors reported 19 different neoplasms, with BCC, SCC, and melanomas accounting for 70% of malignancies. Paranasal sinus/nasal cavity, eyelid and eye tumors were the three most frequent sites of secondary tumors in their series, accounting for 28%, 26% and 15% of the total orbital tumors respectively.14 Levin and Dutton reported 33% (32/97) of their patients were exenterated for squamous cell carcinomas mostly originating from paranasal sinuses (n = 13) or skin (n = 12), and 18.5% of patients (18/97) were melanomas, arising mostly from the conjunctiva (n = 10).16
At our centre, sino-orbital fungal infections and malignancies are managed by otolaryngology surgeons, and hence fungal infections or malignancies requiring orbital exenteration are underreported in the current study. Keeping this in mind, our results correlate with those reported by Bartley et al, Levin et al with eyelid being the most common site and SCC being the most common histologic subtype of malignancy requiring exenteration, respectively. However, this is in contrast to the study by Shields et al. where conjunctiva neoplasm was reported as most common cause for exenteration.17 In our study, a greater percentage of exenterations were done for ocular surface melanoma than ocular surface SCC.
In previous study published from India, Pushker et al reported eyelid tumors as the most common tumors requiring orbital exenteration.10 Out of the 26 patients of orbital exenteration reported over a 10-year study period, the authors reported SCC and SGC of the eyelids (n = 6 each) as the most common indications for exenteration followed by conjunctival melanoma (n = 5). In another study by Maheswari et al from western India, authors reported 15 orbital exenterations over a 10-year period with sebaceous gland carcinoma (SGC) of the eyelid (26%) to be the most common indication.18 Similarly, Kaur et al. from northern India reported sebaceous gland carcinoma of the eyelid with an orbital extension as the commonest indication in their series of twenty-five exenterations.19 However, in the current study, we noted eyelid SCC to be the most common tumor requiring exenteration.
Also, the majority of SCC were well differentiated. This shift in the histological profile of eyelid malignancies requiring exenterations may probably be explained by a more locally indolent/ recurrent nature of SCC that are often managed by inadequate resection especially those arising from the conjunctival epithelium or possibly due to a higher fatality in cases with SGC. The mean duration of symptoms in the SCC group was larger than that on SGC in our study, indicating a more locally indolent course of SCC.
Overall, based on the type of tumor, squamous cell carcinoma of ocular suface and eyelid was the largest in the series requiring exenteration (n = 108/352; 30.68%). There may be an overlap of the diagnosis as one may evolve into the other. Though the previous studies from southeast Asia, give a near equal prevalence of eyelid squamous, sebaceous, and basal cell carcinoma, we found that number of cases that underwent exenteration due to SCC (n = 94) was more than double than that by SGC (n = 40).20 We wonder if this could be explained by a more fatal nature of SGC as compared to SCC.
There is a definite decreasing trend in the number of retinoblastoma-related exenterations in the last 10 years. With the advent of chemotherapy in the late 90s, and it’s implementation in practice in developing countries in the first decade of 20th century, exenteration has become limited to cases of locally advance/ extraocular retinoblastoma not responding to neoadjuvant chemotherapy. This change in treatment modality led to significantly reduced tumor burden and thereby avoided any unnecessary surgery. Similar trend was also noted by Hayyam Kiratli & İrem Koç, with a decrease in exenterations noted after 2006.21
Three hundred fifty-two cases of exenterations have been performed between 2001 and 2020 in our institution. This reflects, that even now, a significant number of cases need to undergo such a debilitating procedure like exenteration. Early diagnosis can avoid exenterations in these patients. Exenteration in many of these cases probably resulted from a neglect by economically deprived patients or due to inadequate surgical resection and poor post-operative follow-up. This reflects the need of improving awareness of both the patients and ophthalmologists treating the tumor in early stages of the disease.
The current study is limited by its retrospective design. As some cases were performed about 20 years ago detailed information availability was lacking in those cases. Therefore, it is difficult to carry out prospective study on exenteration; also as it is not a common surgical procedure.
In conclusion, the current study shows that the absolute number of exenterations performed at the centre have increased even though the percentage of exenterations performed out of all tumor-related surgeries for eye, adnexal structures and orbit has shown a decrease. The most common indication for orbital exenterations in ophthalmic practice remains secondary orbital invasion by eyelid malignancy in adults and retinoblastoma in children. Eyelid SCC is the leading cause of orbital exenteration in the current times. In a socio-economically challenged society, there is a need of creating more awareness among ophthalmologists regarding early diagnosis and referral, and adherence to standardized protocols of management to prevent the loss of seeing eyes.