Prevalence of human papillomavirus in eyelid carcinoma among Koreans: a clinicopathological study.

BACKGROUND: Human papillomavirus (HPV) has been detected in eyelid sebaceous gland carcinoma (SGC) and squamous cell carcinoma (SCC), and detection rates greatly varied across studies. This study aimed to investigate the presence of HPV in eyelid SGC and SCC among Koreans and its correlation with clinicopathological characteristics. METHODS: Surgically resected eyelid samples diagnosed as SGC or SCC from January 1999 to June 2011 were identified from the pathology database of three referral centres in Korea. Clinicopathological information including origin (skin vs. tarsal conjunctiva) and treatment outcomes were retrospectively reviewed. Immunohistochemistry (IHC) for p16, HPV DNA in situ hybridisation (ISH), and polymerase chain reaction-based DNA microarray were performed in paraffin-embedded tissue sections. RESULTS: Our cohort included 34 SGC and 12 SCC cases with Asian ethnicity. HPV was detected in 4 SGC and 6 SCC by DNA microarray, while 2 SCC (16.7%) showed positivity in ISH. SCC of tarsal conjunctival origin was significantly more common in HPV-positive SCC than in HPV-negative SCC (5 of 6 vs. 0 of 6, P = 0.015, Fisher's exact test). Among samples showing positive staining in p16 IHC, HPV positivity rates were 0.0% (0/19) in SGC and 100% (3/3) in SCC. There was no significant difference in overall and local recurrence rate in eyelid SGC and SCC according to the HPV status (P > 0.99). CONCLUSIONS: HPV was found in a subset of eyelid SGC and SCC among Koreans and might be aetiologically related to SCC of tarsal conjunctival origin. Overexpression of p16 is considered to be inappropriate as an indicator of HPV infection in eyelid SGC. Further investigation is required to elucidate the transmission route and pathogenic roles of HPV.

Differentiating malignant and benign eyelid lesions using deep learning.

Artificial intelligence as a screening tool for eyelid lesions will be helpful for early diagnosis of eyelid malignancies and proper decision-making. This study aimed to evaluate the performance of a deep learning model in differentiating eyelid lesions using clinical eyelid photographs in comparison with human ophthalmologists. We included 4954 photographs from 928 patients in this retrospective cross-sectional study. Images were classified into three categories: malignant lesion, benign lesion, and no lesion. Two pre-trained convolutional neural network (CNN) models, DenseNet-161 and EfficientNetV2-M architectures, were fine-tuned to classify images into three or two (malignant versus benign) categories. For a ternary classification, the mean diagnostic accuracies of the CNNs were 82.1% and 83.0% using DenseNet-161 and EfficientNetV2-M, respectively, which were inferior to those of the nine clinicians (87.0-89.5%). For the binary classification, the mean accuracies were 87.5% and 92.5% using DenseNet-161 and EfficientNetV2-M models, which was similar to that of the clinicians (85.8-90.0%). The mean AUC of the two CNN models was 0.908 and 0.950, respectively. Gradient-weighted class activation map successfully highlighted the eyelid tumors on clinical photographs. Deep learning models showed a promising performance in discriminating malignant versus benign eyelid lesions on clinical photographs, reaching the level of human observers.

Ophthalmic manifestations and visual outcomes of granulomatosis with polyangiitis: a retrospective multicentre study in Korea.

OBJECTIVES: To analyse the ophthalmic manifestations and treatment outcomes of Korean patients with granulomatosis with polyangiitis (GPA). METHODS: One hundred twenty patients diagnosed with GPA by rheumatologists from January 1984 to March 2019 at three referral centres were retrospectively reviewed. Patients with ophthalmic symptoms were examined by ophthalmologists and underwent orbital imaging. Ophthalmic manifestations were divided into ocular involvement and ocular adnexal involvement. Multivariable logistic regression was used to examine the factors related to ocular, ocular adnexal, and optic nerve involvement. Visual improvement was defined as a best-corrected visual acuity gain of ≥2 Snellen lines, accompanied by improvements in optic nerve function. RESULTS: Ophthalmic manifestations were observed in 50 patients (41.7%) during the median follow-up period of 6.7 years. Proteinase 3-anti-neutrophil cytoplasmic antibody (PR3-ANCA) positivity (odds ratio 3.19, 95% confidence interval 1.18-8.60) was an independent risk factor for ocular involvement, while sinonasal involvement (21.94, 2.54-189.69) and brain involvement (5.38, 1.50-19.31) were independent risk factors for ocular adnexal involvement. Antinuclear antibody (ANA) positivity was associated with optic nerve involvement (12.8, 1.80-90.5). Visual improvement occurred in 5 of 14 patients with optic nerve involvement, all of whom received intravenous (IV) immunosuppressive treatments beyond oral steroids within 2 months of visual impairment. CONCLUSIONS: Ophthalmic involvement is common in Korean GPA patients and should be considered in the presence of PR3-ANCA, sinonasal or brain involvement. Patients with positive ANA have an increased risk of optic nerve involvement, and early IV immunosuppressive treatments beyond oral steroids are necessary to improve the visual outcome.

Twenty-Year Retrospective Study of Post-Enucleation Chemotherapy in High-Risk Patients with Unilateral Retinoblastoma.

Primary enucleation is a life-saving treatment for advanced intraocular retinoblastoma, particularly in patients with poor visual potential and functional contralateral eyes. This single-center study presents the treatment outcomes of patients with unilateral retinoblastoma who received primary enucleation and adjuvant chemotherapy with cyclophosphamide, vincristine, doxorubicin, and intrathecal methotrexate (CVDM) between 2000 and 2020. Twenty patients were enrolled in the study. The median age at diagnosis was 26 months (range, 1-45). Eighteen patients (90%) were in group E and two (10%) were in group D, according to the intraocular classification of retinoblastoma guidelines. Excluding one patient with an inadequate specimen, 19 patients (95%) had optic nerve involvement (ONI) at least up to the lamina cribrosa. Eight patients (40%) had choroidal invasion in addition to ONI. Two patients (10%) were surgical resection margin positive. The overall and event-free survival rates were 100% and 95%, respectively, for a median follow-up duration of 102.24 months (range 24.2-202.9). There were no relapses or deaths due to any cause, but one patient developed secondary rhabdomyosarcoma 99.6 months after chemotherapy. Treatment was well tolerated, with minimal hematotoxicity and hepatotoxicity. CVDM as a post-enucleation chemotherapy for advanced intraocular retinoblastoma has excellent outcomes with tolerable toxicity. However, in line with updated treatment trends, further risk stratification and lowering the treatment intensity should be considered. Continued long-term follow-up is required to further determine late effects.

Quantitative analysis of morphological and functional alterations of the meibomian glands in eyes with marginal entropion.

PURPOSE: To quantitatively analyze morphological and functional alterations of the meibomian glands in eyes with marginal entropion and their changes after surgery. METHODS: Sixty eyes of 52 patients with marginal entropion and underwent meibography and interferometer were included. One-hundred and seventeen age- and sex-matched eyes with minimal to mild meibomian gland dysfunction (MGD) were recruited as control eyes. Meibomian gland loss (MGL) and lipid layer thickness (LLT) were compared between eyes with marginal entropion and control eyes. Subgroup analysis was performed according to the extent of entropion. MGL and average LLT at 1 and 5 months after surgery were compared with those of 20 eyes with marginal entropion followed without surgery. RESULTS: In eyes with marginal entropion, MGL was higher (27.7% vs. 12.8%, P = 0.014), and average LLT was thinner (64 nm vs. 86 nm, P = 0.005) than those in control eyes. MGL was higher in eyes with more extensive entropion (> 2/3 eyelid width) than in eyes with less extensive entropion (≤ 1/3 eyelid width) (40.5% vs. 13.2%, P = 0.001). Average LLT increased after surgery (97 nm at 1 month, P = 0.003; 75 nm at 5 months, P = 0.319), and thicker than that of eyes followed without surgery (97 nm vs. 66 nm, P = 0.046). MGLs after surgery remained unchanged from the preoperative MGL (all P > 0.7). CONCLUSION: Marginal entropion is associated with morphological and functional alterations of the meibomian glands. Functional improvement after entropion repair suggests that marginal entropion could cause or exacerbate MGD. Further studies are required to establish the role of entropion repair in managing MGD.

The effects of using spacer grafts on lower-eyelid retraction surgery in patients with facial nerve palsy.

PURPOSE: To evaluate the effects of the concomitant use of spacer grafts in lateral tarsal strip surgery in patients with facial nerve palsy-related lower-eyelid retraction. METHODS: Patients who underwent lateral tarsal strip surgery to correct facial nerve palsy-related lower-eyelid retraction were retrospectively reviewed. Postoperative decreases in marginal reflex distance-2 values at 1, 2 and 6 months were measured along with the effects of spacer grafts. RESULTS: Forty-five patients (28 males) were included (mean age: 59.56 years). Mean preoperative marginal reflex distance-2 was 6.87 ± 1.34 mm. Twenty patients underwent lateral tarsal strip surgery only (lateral tarsal strip-only); 25 patients underwent lateral tarsal strip surgery using spacer grafts (lateral tarsal strip + graft). Median (interquartile range) follow-up duration was 12.0 (6.0-23.0) months. Retraction was significantly improved and maintained at 1, 2 and 6 months postoperatively in all patients (mean marginal reflex distance-2: 3.78 ± 1.06 mm, 4.30 ± 1.23 mm and 4.72 ± 1.11 mm, respectively). Surgical outcomes were significantly better in the lateral tarsal strip + graft than in the lateral tarsal strip-only group (Δmarginal reflex distance-2: 3.92 vs. 2.05 mm at 1 month, p < 0.001; 3.38 vs. 1.61 mm at 2 months, p = 0.001; 2.88 vs. 1.69 at 6 months, p = 0.042). Subgroup analyses by spacer graft type revealed no significant differences. CONCLUSION: The concomitant use of spacer material in lateral tarsal strip surgery yielded better surgical outcomes than lateral tarsal strip surgery alone. The use of spacer grafts should be considered for correcting severe facial nerve palsy-related lower-eyelid retraction.

The effect of lacrimal drainage abnormality on the surgical outcomes of congenital lacrimal fistula and vice versa.

PURPOSE: To evaluate the various surgical modalities of congenital lacrimal fistula and assess the mutual effect of lacrimal fistula and lacrimal drainage abnormality on the individual surgical outcomes. METHODS: In this retrospective cohort and case-control study, 74 eyes from 63 patients with lacrimal fistula who underwent surgical management between 2000 and 2015 at three medical centers were enrolled. The data collected included sex, age, preoperative symptoms, presence of concurrent lacrimal drainage abnormality, surgical methods, and surgical outcomes. The main outcome measures were treatment outcomes based on lacrimal drainage patency and symptom improvement, surgical outcome of fistulectomy according to the presence of lacrimal drainage abnormality, and surgical outcome of lacrimal drainage abnormality according to the presence of fistula. RESULTS: The mean age at the time of surgery was 9.2 (SD, ±8.8) years and the mean follow-up duration was 14.4 (SD, ±19.5) months. All eyes (37/37) with fistula without lacrimal drainage abnormality demonstrated surgical success after simple fistulectomy. Patients with concurrent lacrimal drainage abnormalities showed more frequent surgical failure than those with fistula alone (p = 0.009). However, the presence of fistula did not affect the outcomes of surgery for lacrimal drainage abnormality (p = 0.179). CONCLUSION: Simple fistulectomy is sufficient for sole asymptomatic or pauci-symptomatic lacrimal fistula. Symptomatic fistula as well as those accompanied with lacrimal drainage abnormality underwent fistulectomy and lacrimal drainage system surgery. Patients with accompanying lacrimal drainage system abnormalities showed less favorable outcomes. Meticulous preoperative examination of the lacrimal drainage system is critical for surgical planning and prognosis prediction.

Outcomes of enucleation and porous polyethylene orbital implant insertion in patients with paediatric retinoblastoma: a long-term follow-up study.

BACKGROUND/AIMS: To report the long-term outcomes of enucleation and insertion of porous polyethylene (PP) orbital implant according to the evolving surgical techniques and implant in patients with paediatric retinoblastoma . METHODS: Patients with paediatric retinoblastoma who underwent enucleation and PP implant insertion from December 1998 to December 2014 were retrospectively reviewed and divided into four groups: group A, classic enucleation +PP implant; group B, enucleation +PP implant +anterior closure of the posterior Tenon's (ACPT) capsule; group C, enucleation +PP implant +free orbital fat graft +ACPT and group D, enucleation +smooth surface tunnel PP implant +ACPT. Survival analysis of implant exposure and eyelid malpositions was performed. RESULTS: One hundred and ninety-eight eyes of 196 patients were included. The median follow-up period was 13.0 years (range, 5.0-21.1). A 20 mm implant was inserted for 149 eyes (75.3%). The 10-year exposure-free survival probabilities were 44.6% in group A, 96.4% in group B, 97.4% in group C and 97.7% in group D. ACPT was associated with significant reduction in implant exposure (p<0.001). The most common eyelid malposition was upper eyelid ptosis (24.2%). The eyelid malposition-free survival probability did not differ among the four groups. However, the insertion of a 20 mm implant was associated with significant reduction in upper eyelid ptosis and lower eyelid entropion (p=0.004 and 0.038, respectively). CONCLUSIONS: The long-term postenucleation implant exposure was rare after PP implant insertion and ACPT, even with a 20 mm-diameter implant. A larger implant can be beneficial in long-term prevention of eyelid malposition.

Change in the eye position under general anesthesia in children with intermittent exotropia.

PURPOSE: To evaluate the eye position in subjects with intermittent exotropia and normal subjects under general anesthesia (GA) using the strabismus photo analyzer. METHODS: This retrospective case-control study included 78 subjects with intermittent exotropia and 25 normal control subjects who underwent epiblepharon surgery. Eye position under GA was assessed using the strabismus photo analyzer, based on eye models generated from corneal lights and limbus in pre- and post-anesthesia images. Eye positions under GA in the control and intermittent exotropia groups were compared. Preoperative angle of deviation was also compared with amount of change in eye position under GA in the intermittent exotropia group. RESULTS: Eye position under GA was more divergent in subjects with intermittent exotropia than in controls (P = 0.008). The amount of change in eye position under GA was correlated with the preoperative angle of deviation (r2 = 0.47; P < 0.001). In small preoperative exodeviations, the change in eye position was primarily more divergent, whereas in large exodeviations, a convergent tendency-less exotropic compared with the preoperative angle of exodeviation-was observed. CONCLUSIONS: In subjects with small preoperative exodeviations, there was a tendency for eye position to become more divergent after GA; in those with large exodeviations, there was less exotropia after GA.

Non-specific orbital inflammation: Current understanding and unmet needs.

Non-specific orbital inflammation (NSOI) is a noninfectious inflammatory condition of the orbit. Although it is generally considered the most common diagnosis derived from an orbital biopsy, it is a diagnosis of exclusion, meaning that the diagnosis requires exclusion of a systemic process or another identifiable etiology of orbital inflammation. The clinical diagnosis of NSOI is ill-defined, but it is typically characterized by acute orbital signs and symptoms, including pain, proptosis, periorbital edema, chemosis, diplopia, and less commonly visual disturbance. NSOI poses a diagnostic and therapeutic challenge: The clinical presentations and histological findings are heterogeneous, and there are no specific diagnostic criteria or treatment guidelines. The etiology and pathogenesis of NSOI are poorly understood. Here we recapitulate our current clinical understanding of NSOI, with an emphasis on the most recent findings on clinical characteristics, imaging findings, and treatment outcomes. Furthermore, gene expression profiling of NSOI and its implications are presented and discussed.

Effect of Congenital Lower Eyelid Epiblepharon Surgery on Asymmetric Margin Reflex Distance 1.

Objectives: To investigate the characteristics of margin reflex distance 1 (MRD1) asymmetry in congenital lower eyelid epiblepharon and its resolution after surgical correction of epiblepharon.Methods: Among patients who underwent lower eyelid epiblepharon surgery from November 2015 to September 2017, patients with a preoperative MRD1 difference of more than 1.0 mm between the two eyes according to medical photographs were defined as having MRD1 asymmetry. A postoperative MRD1 difference of less than 1.0 mm between the two eyes was regarded as MRD1 asymmetry resolution. The preoperative MRD1 difference was compared between subgroups with resolved or sustained MRD1 asymmetry. Astigmatism and amblyopia were also assessed.Results: Among 432 patients, MRD1 asymmetry was observed in 24 patients (5.6%). MRD1 was always lower in the side with more extensive epiblepharon. At 6 months after surgery, the mean MRD1 difference between the two eyes was significantly decreased (1.8 ± 0.7 mm to 0.5 ± 0.8 mm, p < .001, paired t-test) and MRD1 asymmetry resolution occurred in 19 patients (79%). In the resolved MRD1 asymmetry group, the preoperative MRD1 difference was 2.0 mm or less and was significantly smaller than that in the sustained MRD1 asymmetry group (p = .010, Mann-Whitney U test). Six patients had preoperative aniso-astigmatism ≥ 1.50 D. Unilateral amblyopia presented in nine patients (38%) and improved within 1 year postoperatively.Conclusions: MRD1 asymmetry can be resolved after epiblepharon surgery, especially when the preoperative MRD1 difference is 2.0 mm or less. Unilateral amblyopia was frequent, but the treatment outcome was good.

Geometric Profiling of Corneal Limbal Dermoids for the Prediction of Surgical Outcomes.

PURPOSE: To search for novel geometric parameters for corneal limbal dermoids that enable the prediction of clinical and surgical outcomes. METHODS: We reviewed the medical records and anterior segment photographs of 85 eyes of 85 patients with corneal limbal dermoids that had been surgically excised. Patients were assigned to the following 4 cohorts (multiple assignments allowed): postoperative visual acuity (cohort 1, n = 65), amblyopia (cohort 2, n = 67), postoperative scar formation (cohort 3, n = 51), and preoperative spontaneous progression of dermoids (cohort 4, n = 39). For geometric profiling, 11 geometric parameters of lesions, including orientation, angular width, and 9 ratio parameters, were preoperatively defined in each patient based on the digital anterior-segment photographs. Each geometric parameter and demographic variable were analyzed for correlation with postoperative outcomes (cohorts 1-3) and preoperative spontaneous dermoid progression (cohort 4). RESULTS: The mean patient age at surgery was 6.0 ± 6.3 years. Among the geometric and demographic parameters analyzed, the invaded angular axis of dermoid to corneal diameter ratio had the highest r coefficient (r = 0.728) in cohort 1 and best stratified patients in cohort 2 (cutoff > 0.48) and cohort 3 (cutoff > 0.56). No parameters were correlated with spontaneous dermoid progression in cohort 4. CONCLUSIONS: We devised geometric parameters to evaluate corneal limbal dermoids before surgery for the prediction of surgical outcomes. The invaded angular axis of dermoid to corneal diameter ratio value was the most significant factor associated with postoperative visual acuity, amblyopia development, and postoperative scarring.

CT and MR imaging findings of ocular adnexal mucosa-associated lymphoid tissue lymphoma associated with IgG4-related disease: multi-institutional case series.

AIM: To report CT and MR imaging findings of ocular adnexal mucosa-associated lymphoid tissue lymphoma associated with IgG4-related disease (IgG4-MALT lymphoma), a rare but clinically important complication of ocular adnexal IgG4-related disease. METHODS: We retrospectively reviewed all cases of histologically confirmed ocular adnexal IgG4-related disease at three tertiary and one secondary referral centers, between February 2003 and December 2016. Seven cases of histopathologically diagnosed IgG4-MALT lymphoma were identified. CT and MR images were analyzed by consensus of two experienced head and neck radiologists. RESULTS: Lacrimal glands were the main site of involvement in all seven patients. The lesions typically showed well-demarcated margins, iso- to hyperattenuation on precontrast CT, T2 hypo- to isointensity, T1 isointensity, and homogenous internal architecture with homogenous enhancement pattern. Lesions were mostly hyperdense and isointense to normal extraocular muscles on postcontrast CT and MR images, respectively. CONCLUSION: Unlike in typical ocular adnexal IgG4-related disease, T2 isointensity and hyperattenuation on precontrast CT images were noted in some IgG4-MALT lymphoma cases. Although the findings may be nonspecific, the possibility of accompanying MALT lymphoma may need to be considered, when ocular adnexal lesions in patients clinically suspected of having IgG4-related disease are refractory to glucocorticoids and show T2 isointensity and hyperattenuation on precontrast CT for the optimal management of the patients. However, this is a case series of a very rare complication of ocular adnexal IgG4-related disease, and thus caution is warranted to generalize the conclusion.

Long-term results of maintenance of lacrimal silicone stent in patients with functional epiphora after external dacryocystorhinostomy.

PURPOSE: To evaluate long-term outcomes of maintenance of lacrimal silicone stent for the management of functional epiphora after anatomically patent external dacryocystorhinostomy (DCR). METHODS: We retrospectively reviewed the medical records of 101 eyes of 75 patients who were diagnosed to have functional epiphora after external DCR from 2005 to 2014. Functional epiphora was defined as epiphora that persisted or recurred even after patent DCR confirmed by a lacrimal irrigation test. Secondary silicone intubation was indicated when the patients wanted a further intervention. The stent was intended to be kept in situ unless there was a stent-related complication or the patient wanted removal. RESULTS: In total, 34 of 75 patients (45.3%, 52 eyes) who agreed to the intervention underwent secondary silicone intubation. The success rates at 1, 3, and 5 years after surgery were 96.2%, 75.5%, and 70.2%, respectively. At the final follow-up (mean 72.7 ± 26.4 months), 32 (61.5%) eyes chose to retain the silicone tube: silicone stent was well maintained without epiphora and complications once inserted in 18 eyes (34.6%), whereas tube replacement was needed in 14 eyes (26.9%) because of nasal crust or whitish plaque formation on the tube surface. In 13 cases (25.0%), silicone stent was removed because of tube-related complications, and the most common complication was canaliculitis (n = 8, 15.4%). CONCLUSIONS: Secondary intubation and maintenance of the stent is an effective and simple procedure for functional epiphora. The main obstacle to long-term maintenance is tube-associated canaliculitis.

Conjunctival pigmented lesion: Clinicopathological analysis of 85 cases in Korean population.

To evaluate histopathological characteristics of conjunctival pigmented lesions and analyze clinical features related to histologic classification in Asian population, we analyzed medical records, anterior segment photographs, and histological specimen of 85 eyes who had undergone biopsy for pigmented conjunctival lesions at Seoul National University Hospital between 1999 and 2018. Compound nevus was the most common type of conjunctival pigmented lesions (67.1%), followed by conjunctival melanocytic intraepithelial neoplasia (primary acquired melanosis)(11.8%), subepithelial nevus (8.2%), and malignant melanoma (MM)(7.1%). Patients with compound nevus were younger than those with non-compound nevus (22.1 ± 17.0 vs 39.9 ± 18.8 years, p < 0.001), while patients with MM were older than those without melanoma (55.7 ± 18.2 vs 25.8 ± 18.0 years, p = 0.001). The lesion in compound nevus tended to be more frequently located on the temporal conjunctiva than that in the non-compound nevus group (54.4% vs 32.1%, p = 0.053), and feeder vessels were associated with most of compound nevus (98.2% vs 78.6% of non-compound nevus, p = 0.005). The lesion in MM was larger, involved multiple quadrants, and had extrabulbar location than lesions without melanoma (p < 0.001, p < 0.001, and p = 0.002, respectively). Together, the results would help clinicians to distinguish benign conjunctival pigmentations from malignant counterparts in clinical practice without biopsy.

Conservative management of congenital dacryocystocele: resolution and complications.

OBJECTIVE: To investigate the clinical outcomes of initial conservative management in infants with congenital dacryocystocele. DESIGN: Retrospective case series. PARTICIPANTS: A total of 30 congenital dacryocystoceles of 28 Korean infants treated between January 2006 and December 2015. METHODS: All patients were managed conservatively with lacrimal sac massage. Clinical courses and outcomes of the patients were retrospectively reviewed, and rates of resolution of dacryocystoceles and development of dacryocystitis were analyzed. RESULTS: In 27 cases of dacryocystoceles without infection, spontaneous resolution was achieved without any complication in 20 of 27 (74.1%) cases after conservative treatment. The mean duration of treatment was 27.5 days. Lacrimal probing was needed in 5 (18.5%) dacryocystoceles that persisted despite lacrimal sac massage for more than 1 month. Infectious dacryocystitis developed in 2 of 27 (7.4%) cases. Three dacryocystoceles were infected at presentation. Overall, 5 dacryocystoceles were complicated with infection and those cases received prompt systemic antibiotics treatment. External incision and drainage of the lacrimal sac was needed in 3 dacryocystoceles, and all cases were finally resolved without any additional procedures. CONCLUSIONS: In this case series, most of the uninfected dacryocystoceles could be successfully managed with conservative treatment alone. In cases with infection, systemic antibiotics were essential and external drainage was sometimes required, but these cases could be conservatively managed after the remission of infection.