This study revealed that surgical outcomes of evisceration or enucleation with primary implant placement by resident trainees in patients with fulminant endophthalmitis or panophthalmitis were satisfactory, with a low rate of implant exposure or extrusion and residual infection and a high rate of successful prosthesis fitting. In patients with panophthalmitis, evisceration was significantly associated with a higher frequency of implant exposure or extrusion than enucleation. The predictive factors affecting implant exposure or extrusion were Pseudomonas aeruginosa infection and not receiving intravitreal antimicrobial drugs before the eye removal procedure.
The management of medically refractory endophthalmitis or panophthalmitis is evisceration or enucleation to eradicate the infection. However, surgical choices, timing and types of implant placement remain controversial. A discussion among international experts was performed in 2005; however, there was no consensus .
The advantages of evisceration are less operative time in addition to less disruption of orbital tissues  but may increase the risk of sympathetic ophthalmia [11, 12]. Evisceration is also thought to have higher extrusion rates due to the residual nidus in the sclera. Wills Eye Hospital found that the implant extrusion rate in eviscerated sockets was 22%, compared with 6% after enucleation . Primary orbital implantation at the time of evisceration or enucleation, in cases of endophthalmitis, was previously believed to have a higher risk of implant extrusion. In 1988, Shore et al  performed delayed wound closure in 3 patients who had successful outcomes, but 1 patient underwent primary closure, which developed wound dehiscence and implant extrusion at 6 weeks postoperatively. However, there are many advantages of primary implant placement, including decreasing both the risks and expenses of two separate surgeries and early initiation of rehabilitation . Primary orbital implantation has been performed recently in cases of endophthalmitis or panophthalmitis, with satisfactory outcomes and an acceptable rate of complications [6–9]. A retrospective nonrandomized comparative interventional case series was conducted by Tripathy et al in 2015  to compare the outcome of evisceration with primary orbital implants in blind eyes, with and without fulminant infection, and there was no statistically significant difference in major complications between the two groups.
In 2017, Fu et al  conducted a survey among American Society of Ophthalmic Plastic and Reconstructive Surgery (ASOPRS) surgeons to assess practice patterns in the treatment of endophthalmitis and found that 72% preferred evisceration, while 28% preferred enucleation. If infection extended to orbital tissues, 59% preferred enucleation versus 27% who preferred evisceration. Primary implant placement was performed by 65% in enucleation and 58% in evisceration.
In 2007, Tawfik et al  studied the outcomes of evisceration with primary implant placement in 52 endophthalmitis patients and 15 panophthalmitis patients; implant extrusion occurred in 2 patients (3%), and successful prosthesis fitting was achieved by 62 patients (92%). In our study, implant extrusion was found in 2 patients with endophthalmitis and 2 patients with panophthalmitis. The extrusion rate was 6%, slightly more than that in a previous study . This might be due to the higher proportion of panophthalmitis patients, which consisted of 55% with panophthalmitis in our study versus 22% with panophthalmitis in a previous study . Additionally, we recruited only patients who underwent surgery by resident trainees. Thus, these comparable outcomes were satisfactory.
From this study, the rate of implant exposure or extrusion in patients with panophthalmitis was 67% in the evisceration group compared with 9% in the enucleation group. Hence, enucleation is recommended in cases of panophthalmitis. Diagnosis as endophthalmitis or panophthalmitis was not associated with surgical outcomes in our study, which might be due to a tendency to perform enucleation in patients with panophthalmitis.
Porous implant placement has been discussed in terms of concerns about the potential seeding of infection within a vascularized implant and subsequent extrusion. In this study, bovine hydroxyapatite and porous polyethylene were used as the primary implants in 1 patient each, and the result of prosthesis fitting of 2 patients who had porous implant placement was successful, without major complications. In accordance with the study by Park et al , they assessed the results of evisceration with primary porous implant placement in 29 eyes with endophthalmitis, and only 2 eyes developed implant exposure or infection.
In cases of ocular infection by virulent organisms, such as Bacillus species and Pseudomonas aeruginosa, scleral abscess, scleral melting, and perforation frequently develop, and these have a poor response to topical and systemic antibiotics [17, 18]. Previous studies suggested enucleation in these cases because the integrity of the sclera might not be strong enough to support an orbital implant, especially in diabetes mellitus and immunocompromised hosts [6, 7, 19]. Accordingly, this study demonstrated that implant exposure or extrusion more commonly developed in eyes infected by Pseudomonas aeruginosa than in eyes infected by other organisms. Therefore, the preoperative diagnosis was Pseudomonas aeruginosa infection, and secondary implant placement may need to be considered.
Various routes of antibiotic administration are used in endophthalmitis, and intravitreal injection is the main treatment because drugs are directly delivered into the infected part of the eye [1, 20]. In contrast with systemic medication, penetration into the ocular posterior segment is limited by the blood-retinal barrier [21, 22]. This study also showed the benefit of intravitreal antibiotics as lower rates of implant exposure or extrusion after enucleation or evisceration in cases of endophthalmitis or panophthalmitis. It is feasible that intravitreal injection can control some part of organism growth and reduce scleral invasion or orbital tissue infection.
Bee et al  reported that preoperative white blood cell counts of more than 9500 cells/microliter were associated with a higher risk of implant exposure, whereas in our study, implant exposure or extrusion was not significantly different in patients with either high or normal white blood cell counts.
The strengths of this study consisted of the following. First, long-term surgical outcomes were able to be assessed due to the long follow-up period (mean: almost 5 years), which was long enough to demonstrate late postoperative complications and the retention of implants. Second, this was the first study to demonstrate the results of evisceration or enucleation performed by resident trainees in patients with fulminant endophthalmitis or panophthalmitis. However, there were some limitations in this study, including the lack of evaluation of patient satisfaction after prosthesis fitting, a high loss of follow-up rate and incomplete data, due to this being a retrospective study. This information of our study encouraged the surgeons to perform enucleation in patients with panophthalmitis to prevent implant exposure or extrusion. Additionally, the resident trainees had the competency to perform the eye removal procedure in severe eye infection. However, the comparison of surgical results and complications of the eye removal procedure in this disease in ophthalmology consultants and resident trainees must be evaluated prospectively. The assessment of surgical outcome in terms of cosmesis and satisfaction of prostheses is suggested.
In conclusion, evisceration or enucleation with primary implant placement can be performed by resident trainees in patients with endophthalmitis or panophthalmitis with an acceptable rate of implant exposure or extrusion. Pseudomonas aeruginosa infection and not receiving intravitreal injection before eye removal may be risk factors for postoperative implant exposure or extrusion; secondary implant placement may be considered in these situations. In patients with panophthalmitis, enucleation was preferred due to the lower rate of implant exposure or extrusion.