Microforceps-Assisted Transscleral Fixation of Intraocular Lens.

PURPOSE: We present a novel technique for intraocular lens (IOL) fixation. The technique can be used on single-piece acrylic IOLs and can manage the patients who are either aphakia or with a dislocated IOL. METHODS: One end of Gore-Tex suture is tied into the optic-haptic junction of the IOL. Another end is fixated in the scleral wall. The single sclerotomy and double sclerotomies settings can be applied to different situations. RESULTS: Twelve eyes received this procedure. After a follow-up period of up to 20 months, the IOLs were well centered. CONCLUSION: The technique is a reliable method for scleral fixation of IOLs, which can be applied on the widely used single-piece acrylic IOLs. In our experience, it is reproducible and rarely cause complications.

Orbital and conjunctival nontuberculous mycobacteria infection.

A 64-year-old female developed refractory red-eye with itching and watery discharge 2 weeks after being injured by a comb in the left eye. It presented as diffuse pinkish thickening of the bulbar conjunctiva. Biopsy and histological examinations revealed granulomatous inflammation with microgranuloma. Acid-fast-positive bacilli were found within the tissue, which was identified by culture 5 weeks later as Mycobacterium Abscessus. The orbital computed tomography with contrast medium showed irregular enhancement with an ill-defined margin along the inferior sclera. Due to symptomatic and recurrent bulbar conjunctival thickening and abscess-like lesion formations, wide excision of the conjunctival and orbital granuloma with amniotic membrane transplantation was performed twice. Conjunctiva inflammation subsided after the surgical treatment was combined with 4 months of topical and parenteral antimycobacterial treatment. The presentation, diagnosis, and treatment of ocular nontuberculous mycobacterial (NTM) infection will be discussed in this article. NTM can cause infections of all adnexal and ocular tissues in patients with ocular trauma or surgical history. The pathological findings were granulomatous inflammation without true caseating. Periocular cutaneous, adnexal, and orbital NTM infections remain rare and require surgical debridement and long-term parenteral antibiotic therapy.

Necessity of Local Modification for Deep Learning Algorithms to Predict Diabetic Retinopathy.

Deep learning (DL) algorithms are used to diagnose diabetic retinopathy (DR). However, most of these algorithms have been trained using global data or data from patients of a single region. Using different model architectures (e.g., Inception-v3, ResNet101, and DenseNet121), we assessed the necessity of modifying the algorithms for universal society screening. We used the open-source dataset from the Kaggle Diabetic Retinopathy Detection competition to develop a model for the detection of DR severity. We used a local dataset from Taipei City Hospital to verify the necessity of model localization and validated the three aforementioned models with local datasets. The experimental results revealed that Inception-v3 outperformed ResNet101 and DenseNet121 with a foreign global dataset, whereas DenseNet121 outperformed Inception-v3 and ResNet101 with the local dataset. The quadratic weighted kappa score (κ) was used to evaluate the model performance. All models had 5-8% higher κ for the local dataset than for the foreign dataset. Confusion matrix analysis revealed that, compared with the local ophthalmologists' diagnoses, the severity predicted by the three models was overestimated. Thus, DL algorithms using artificial intelligence based on global data must be locally modified to ensure the applicability of a well-trained model to make diagnoses in clinical environments.

PLGA nanoparticles containing Lingzhi extracts rescue corneal epithelial cells from oxidative damage.

Oxidative stress-related ocular surface epithelial damage can be initiated by ambient oxygen, UV radiation, and chemical burns. The oxidative damage to cornea can lead to inflammation and even vision loss. Lingzhi (Ganoderma lucidum) is a Chinese herbal drug and has been shown to prevent chronic diseases in clinical practices and has been proven to possess anti-oxidative and anti-inflammatory properties. In the study, we prepared poly (lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) as a sustained drug release system of Lingzhi (LZH) to improve bioavailability. The particle size of developed NPs containing LZH (LZH-NPs) was ~184 nm with narrow size distribution. The results of cellular uptake revealed that using NPs as a drug delivery system could significantly increases the intracellular retention time. The results of the cell viability and chemiluminescence assay revealed that 5 µg/ml of LZH-NPs might be the threshold concentration for cultivation of corneal epithelial cells. After treating LZH-NPs in oxidative damaged cells, the results showed that the inflammation-related gene expression and DNA fragmentation level were both significantly decreased. Post-treatment of LZH-NPs in damaged corneal epithelial cells could increase the cell survival rate. In the rabbit corneal alkali burn model, topical instillation of LZH-NPs could promote corneal wound healing and decrease the inflammation. These results suggest that LZH-NPs may have the potential to treat ocular surface diseases caused by oxidative stress.

Dermis-fat graft as treatment of early implant exposure in a postpenetrating keratoplasty patient with nontraumatic eyeball rupture.

Orbital implant exposure may be the most common complication after evisceration surgery with orbital implantation. Management of implant exposure is a vital issue for oculoplastic surgeons. We present the case of a patient with nontraumatic eyeball rupture receiving dermis-fat graft after early implant exposure. The present case with multiple penetrating keratoplasty history underwent emergent evisceration and silicon sphere implantation due to nontraumatic eyeball rupture with severe uvea prolapse. The surrounding corneal tissue of the rupture aperture was almost unidentified before the operation. Deep superior sulcus syndrome and orbital implant exposure developed 2 months after the operation; hence, orbital reconstruction and dermis-fat graft transplantation were performed. Orbital reconstruction and orbital implant exposure management are discussed in the content.

The presence and impact of herpes virus DNA in recipient cornea and aqueous humor on graft survival following penetrating keratoplasty.

BACKGROUND/PURPOSE: Reactivation of herpes viruses poses threat to corneal graft survival. This study evaluated the presence of herpes simplex virus type 1 (HSV-1), HSV type 2 (HSV-2), and cytomegalovirus (CMV) DNA in recipient corneas and the aqueous humor of patients undergoing penetrating keratoplasty (PKP), and the impact on graft survival. METHODS: This retrospective study reviewed 90 eyes of 71 patients underwent PKP between 2008 and 2016. Cornea and aqueous humor samples were sent for polymerase chain reaction (PCR) testing for viral DNA. The main outcomes were PCR results and graft survival. RESULTS: Recipient corneas tested positive for HSV-1 in 47 eyes (52.2%), for HSV-2 in 24 eyes (26.7%), and for CMV in seven eyes (7.8%). Aqueous humor tested positive for HSV-1 in 44 eyes (48.9%), for HSV-2 in 25 eyes (27.8%), and for CMV in eight eyes (8.9%). The presence of aqueous HSV-1 DNA was associated with higher risk of graft failure (p = 0.005), whereas corneal HSV-1 DNA was not. The presence of HSV-2 DNA had no significant impact on graft survival. Aqueous CMV DNA was associated with higher risk of graft failure in univariate model, but not in multivariate model. CONCLUSION: There were high positive rates of HSV-1, HSV-2, and CMV DNA in recipient corneas and aqueous humor at the time of PKP, even among patients not suspected of latent viral infection. The presence of aqueous HSV-1 DNA was associated with higher risk of graft failure.

Intraocular pressure monitoring by rebound tonometry in children with myopia.

BACKGROUND/PURPOSE: Topical atropine treatment is generally accepted to retard the progression of myopia, but it is associated with side effects such as photophobia and elevation of intraocular pressure (IOP). IOP measurements in children are challenging. The traditional applanation tonometry by direct contact with the cornea will require patient's cooperation. The rebound tonometer, using a dynamic electromechanical method for measuring IOP, shows good correlation with traditional tonometry. The purpose of this study is to evaluate the IOP of myopic children under atropine treatment using rebound tonometer and to compare the characteristics between rebound tonometry and applanation tonometry. METHODS: This study is a prospective study measuring IOP by rebound tonometer in myopic children under regular low-dose atropine treatment. We recruited children with refraction error showing myopia over -0.5 D with 0.15%, 0.3%, or 0.5% atropine eye drops use every night or every other night for myopia control. Children with treatment duration of atropine <1 month were excluded from the study. IOP measurements were performed by applanation tonometer (Tono-Pen XL, Reichert) and rebound tonometer (ICARE). The reliability of rebound tonometer was analyzed with percentage. Comparison of IOP between rebound tonometer and applanation tonometry was presented. RESULTS: The rebound tonometry was well tolerated by all participants and caused no complaints, discomfort, or adverse events. Totally 42 myopic eyes of 42 subjects were included in the study. The average age of these participants was 10 years old, range from 5 to 16. Median = 10 years old. The average IOP of the right eye by rebound tonometer was 17.4 ± 3 mmHg, and 17.1 ± 3 mmHg by applanation tonometry. Nearly 19%, 33%, and 24% of difference of IOP readings between rebound tonometer and Tono-Pen applanation are within 0 mmHg, 1 mmHg, and 1-2 mmHg, respectively. CONCLUSIONS: Rebound tonometry has good correlation with applanation tonometry and 76.1% of differences between two tonometers are <2 mmHg. The advantage of drop-free rebound tonometry has made it easier to obtain IOP readings in myopia children under atropine treatment.

Intraocular lens opacification after Descemet's stripping automated endothelial keratoplasty.

Compared with conventional penetrating keratoplasty, Descemet's stripping automated endothelial keratoplasty (DSAEK) more effectively maintain global integrity and rapid vision rehabilitation with less ocular surface disorders in patients with endothelial dysfunction. Here, we report a case of a 76-year-old woman who experienced opacification of a hydrophilic intraocular lens (IOL) approximately 10 months after DSAEK. The patient with no history of systemic disease developed pseudophakic bullous keratopathy in the right eye 2 years after undergoing cataract surgery. The best-corrected visual acuity (BCVA) of the right eye was Snellen 0.01 when presented to our hospital. DSAEK was arranged and performed smoothly. However, the graft detached over the upper part of the cornea on postoperative day 1. Thus, rebubbling was performed immediately. After the procedure, the graft was well attached, and the cornea became clear gradually. The BCVA returned to Snellen 0.6. However, progressive opacification over the anterior surface of the IOL was observed 10 months postoperatively. Vision deteriorated to 0.5 with various refractive errors during 2-year follow-up. IOL exchange may be considered if the vision is getting worse. IOL opacification may result from a direct contact between the IOL surface and exogenous air, particularly in a hydrophilic IOL, and can be a rare but significant complication after DSAEK. Clinicians planning to perform DSAEK should consider the composition of the IOL, the amount of intracameral air, duration of air filling, and high intraocular pressure.

Herpetic keratouveitis mixed with bilateral Pseudomonas corneal ulcers in vitamin A deficiency.

A 56-year-old woman complained of blurred vision and pain in her right eye for several days. Slit lamp examination revealed a large epithelial defect and disciform stromal edema with ring infiltration in her right cornea. Unfortunately, hypopyon and purulent discharge subsequently developed in both eyes. Herpetic keratouveitis and a superimposed pseudomonas infection were diagnosed. A systemic review on the patient showed malnutrition due to her dietary preference and vegetarianism. After the infection was controlled, bilateral epithelial defects persisted for a long time. We performed amniotic membrane transplantation on both eyes and the clinical status improved with administration of vitamin and protein supplements. Although rare in Taiwan, vitamin A deficiency should be kept in mind when conjunctival and corneal xerosis occurred. Vitamin A supplements are suggested because of the increased susceptibility to infection in patients with this clinical status.

Applications of biomaterials in corneal wound healing.

Disease affecting the cornea is a common cause of blindness worldwide. To date, the amniotic membrane (AM) is the most widely used clinical method for cornea regeneration. However, donor-dependent differences in the AM may result in variable clinical outcomes. To overcome this issue, biomaterials are currently under investigation for corneal regeneration in vitro and in vivo. In this article, we highlight the recent advances in hydrogels, bioengineered prosthetic devices, contact lenses, and drug delivery systems for corneal regeneration. In clinical studies, the therapeutic effects of biomaterials, including fibrin and collagen-based hydrogels and silicone contact lenses, have been demonstrated in damaged cornea. The combination of cells and biomaterials may provide potential treatment in corneal wound healing in the future.

Attenuation of the pulmonary chemoreflex following acute cervical spinal cord injury.

Bronchopulmonary C fibers are the primary chemosensitive afferents in the lung. The activation of bronchopulmonary C fibers evokes the pulmonary chemoreflex, which is characterized by apnea, hypotension, and bradycardia and is a critical reflex that modulates cardiorespiratory responses under physiological and pathological conditions. The present study was designed to investigate whether the pulmonary chemoreflex is altered following acute cervical spinal injury. A unilateral hemisection (Hx) or laminectomy (uninjured) in the second cervical spinal cord was performed in adult male Sprague-Dawley rats. The pulmonary chemoreflex induced by intrajugular capsaicin administration was evaluated by measuring respiratory airflow in spontaneously breathing rats and phrenic nerve activity in mechanically ventilated rats. Capsaicin treatment evoked a cessation of respiratory airflow and phrenic bursting in uninjured animals, but not in C2Hx animals. To clarify whether the attenuation of the pulmonary chemoreflex in C2Hx animals is restricted to capsaicin-induced stimuli, or generally applied to other stimuli that excite bronchopulmonary C fibers, another bronchopulmonary C-fiber stimulant (phenylbiguanide) was used to evoke the pulmonary chemoreflex in spontaneously breathing rats. We observed that phenylbiguanide-induced apnea was also blunted in C2Hx animals, suggesting that the respiratory response induced by bronchopulmonary C-fiber activation was attenuated following acute cervical spinal Hx. The blunted inhibitory respiratory response may represent a compensatory respiratory plasticity to preserve the breathing capacity and may also reduce the capability of preventing inhaled irritants in this injured condition.

Respiratory motor outputs following unilateral midcervical spinal cord injury in the adult rat.

The present study was designed to investigate the impact of midcervical spinal cord injury on respiratory outputs and compare respiratory recovery following high- vs. midcervical spinal injury. A unilateral hemisection (Hx) in the spinal cord at C2 or C4 was performed in adult rats. Respiratory behaviors of unanesthetized animals were measured at normoxic baseline and hypercapnia by whole body plethysmography at 1 day and 1, 2, 4, and 8 wk after spinal injury. C2Hx and C4Hx induced a similar rapid shallow breathing pattern at 1 day postinjury. The respiratory frequency of C4Hx animals gradually returned to normal, but the tidal volume from 1 to 8 wk postinjury remained lower than that of the control animals. Linear regression analyses indicated that the tidal volume recovery was greater in the C4Hx animals than in the C2Hx animals at the baseline, but not at hypercapnia. The bilateral phrenic nerve activity was recorded in anesthetized animals under different respiratory drives at 8-9 wk postinjury. The phrenic burst amplitude ipsilateral to the lesion reduced following both high- and midcervical Hx; however, the ability to increase activity was lower in the C4Hx animals than in the C2Hx animals. When the data were normalized by the maximal inspiratory effort during asphyxia, the phrenic burst amplitude enhanced in the C4Hx animals, but reduced in the C2Hx animals compared with the control animals. These results suggest that respiratory deficits are evident following midcervical Hx, and that respiratory recovery and neuroplasticity of phrenic outputs are different following high- vs. midcervical spinal injury.

Diagnosis of microsporidial keratitis with in vivo confocal microscopy.

As a rare cause of microbial keratitis, microsporidial keratitis (MK) is first described in a patient with acquired immunodeficiency syndrome. As increased use of topical steroid creates a localized immunosuppressive environment of the eyes, MK occurs more commonly than expected in immunocompetent patients nowadays. Owing to initial insidious growth of pathogens and nonspecific ocular symptoms of infected patients, its frequent misdiagnosis has posed a major clinical challenge in recent decades. Without appropriate treatments, MK can progress deeply into corneal stroma, anterior and posterior segments, subsequently deteriorating vision severely and ultimately requiring corneal transplant. Related risk factors for the occurrence of MK in immunocompetent individuals include contact lens wear, topical steroid use, previous corneal trauma, and a history of laser refractive surgery. The conventional standard of MK diagnosis is based on a tissue biopsy by superficial corneal scrapping. In vivo confocal laser scanning microscopy can obtain images through the cornea in a plane paralleling to the vertical axis. This approach provides an effective method of identifying tissue layers that correspond to corneal histologic structures. This current study investigates the efficacy of \textit{in vivo} confocal laser scanning microscopy in diagnosing MK in immunocompetent patients. The clinical presentations of enrolled patients, including features of slit lamp biomicroscopy and the histopathological results of corneal scrapping, were described. In these patients, the confocal microscopy identified multiple small intracellular hyper-reflective dots in the cytoplasm of corneal epithelial cells and stromal keratocytes. Additionally, the confocal microscopic images clearly revealed the enhanced cytoplasm of cell with intracellular round hyper-reflective dots. The size and morphology of hyper-reflective dots were compatible with the spores of microsporidia found in corneal tissue. Moreover, vision recovered after topical use of antimicrobial medicine. This observation suggests that in vivo confocal laser scanning microscopy provides a rapid, non-invasive, and high resolution scheme for diagnosing MK. In addition to diminishing the risk of secondary infection from epithelial defect created by superficial debridement, this approach facilitates early diagnosis and appropriate treatments. Furthermore, from a series of images taken during the clinical courses, this method is highly promising for use in monitoring treatment effects and identifying the recurrence of MK.

Transient changes of intraocular pressure and anterior segment configuration after diagnostic mydriasis with 1% tropicamide in children.

BACKGROUND: This study investigated the association of transient changes in intraocular pressure (IOP) with changes in the anterior chamber configuration in children after diagnostic mydriasis with 1% tropicamide. METHODS: In this prospective case-control study, 163 hospital clinic-based samples of unrelated children with or without myopia were enrolled. Complete ophthalmological examinations, including visual acuities, cycloplegic refraction, slitlamp examination, fundus examination, IOP, axial length measurement and Pentacam examination were performed. RESULTS: Lens thickness in emmetropic children was significantly greater than in myopic children of both genders, both before and after mydriasis. In a comparison of the biometric differences before and after mydriasis, IOP was not different, but the lens thickness after mydriasis was significantly less in myopic and emmetropic children of both genders. The mean anterior chamber angle, anterior chamber depth and anterior chamber volume significantly increased after mydriasis in myopic and emmetropic children of both genders. These parameters were not related to the changes of IOP under multiple regression analysis. There were no statistically significant differences between groups in either biometric parameters or anterior chamber configurations. CONCLUSION: While the present findings do not show a significant change in IOP following mydriasis, there was wide inter-individual variation, with some children showing an increase in IOP of up to 8.0 mmHg and some showing a decrease of a similar amount. This variation suggests that IOP should be monitored when mydriatics or cycloplegics are used in children.

Reverse effect of mammalian hypocalcemic cortisol in fish: cortisol stimulates Ca2+ uptake via glucocorticoid receptor-mediated vitamin D3 metabolism.

Cortisol was reported to downregulate body-fluid Ca(2+) levels in mammals but was proposed to show hypercalcemic effects in teleostean fish. Fish, unlike terrestrial vertebrates, obtain Ca(2+) from the environment mainly via the gills and skin rather than by dietary means, and have to regulate the Ca(2+) uptake functions to cope with fluctuating Ca(2+) levels in aquatic environments. Cortisol was previously found to regulate Ca(2+) uptake in fish; however, the molecular mechanism behind this is largely unclear. Zebrafish were used as a model to explore this issue. Acclimation to low-Ca(2+) fresh water stimulated Ca(2+) influx and expression of epithelial calcium channel (ecac), 11ß-hydroxylase and the glucocorticoid receptor (gr). Exogenous cortisol increased Ca(2+) influx and the expressions of ecac and hydroxysteroid 11-beta dehydrogenase 2 (hsd11b2), but downregulated 11ß-hydroxylase and the gr with no effects on other Ca(2+) transporters or the mineralocorticoid receptor (mr). Morpholino knockdown of the GR, but not the MR, was found to impair zebrafish Ca(2+) uptake function by inhibiting the ecac expression. To further explore the regulatory mechanism of cortisol in Ca(2+) uptake, the involvement of vitamin D(3) was analyzed. Cortisol stimulated expressions of vitamin D-25hydroxylase (cyp27a1), cyp27a1 like (cyp27a1l), 1α-OHase (cyp27b1) at 3 dpf through GR, the first time to demonstrate the relationship between cortisol and vitamin D(3) in fish. In conclusion, cortisol stimulates ecac expression to enhance Ca(2+) uptake functions, and this control pathway is suggested to be mediated by the GR. Lastly, cortisol also could mediate vitamin D(3) signaling to stimulate Ca(2+) uptake in zebrafish.

Recurrent cytomegalovirus corneal endotheliitis after penetrating keratoplasty.

PURPOSE: To report a case of recurrent cytomegalovirus (CMV) corneal endotheliitis after penetrating keratoplasty. METHODS: Penetrating keratoplasty (PK) was performed in a 49-year-old man with bullous keratopathy. Pigmented keratic precipitates (KPs) were found in the corneal endothelium of the graft 13 days after surgery, with the subsequent appearance of coin-shaped lesions. Confocal microscopy was performed on the corneal endothelium. Aqueous humor was analyzed for viral DNA by polymerase chain reaction (PCR). RESULTS: CMV DNA was detected from the excised corneal button, and aqueous humor revealed positive results for CMV and HSV1 by PCR. Confocal microscopy showed large corneal endothelial cells, consistent with the typical owl's eye morphology of CMV endotheliitis. After systemic ganciclovir was administered, the pigmented KPs and coin-shaped lesions gradually decreased. CONCLUSIONS: Stress from surgery and corticosteroid usage can revitalize CMV activity. PCR and confocal microscopy are valuable for the diagnosis of CMV corneal endotheliitis.

Validity of the keratometric index: evaluation by the Pentacam rotating Scheimpflug camera.

PURPOSE: To determine the keratometric index based on actual measurements of the anterior and posterior corneal surfaces using a rotating Scheimpflug camera (Pentacam, Oculus) and evaluate the accuracy of this keratometric index in estimating total and posterior corneal powers. SETTING: Departments of Ophthalmology, Taipei Medical University Hospital and Taipei City Hospital, Taipei, Taiwan. METHODS: The right eye of 221 subjects was measured with the Pentacam system. The radius of the best-fit sphere for the anterior corneal surface (rant) and posterior corneal surface (rpost), mean radius of simulated keratometry (rsimK), and central corneal thickness were obtained. The ratio of rant to rpost (AP ratio) and keratometric index were calculated in each eye. RESULTS: The means for rant, rpost, rsimK, and AP ratio were 7.75 mm +/- 0.28 (SD), 6.34 +/- 0.28 mm, 7.75 +/- 0.27 mm, and 1.223 +/- 0.034 mm, respectively. These parameters were normally distributed. The mean calculated keratometric index (Ncal) was 1.3281 +/- 0.0018. Using the keratometric indices of 1.3281 (Ncal), 1.3315 (Gullstrand schematic eye), and 1.3375 (conventional), the mean arithmetic and absolute estimation errors for the total corneal power were, 0.00 +/- 0.24 diopter (D) and 0.17 +/- 0.17 D, 0.43 +/- 0.23 D and 0.45 +/- 0.21 D, and 1.21 +/- 0.24 D and 1.21 +/- 0.24 D, respectively. The total corneal power was predicted to within +/-0.50 D of the actual value in 95.0%, 60.2%, and 0.9% of eyes, respectively. The mean arithmetic and absolute estimation errors for the posterior corneal power using an AP ratio of 1.223 (this study) or 1.132 (Gullstrand schematic eye) were 0.00 +/- 0.17 D and 0.13 +/- 0.12 D and 0.47 +/- 0.18 D and 0.47 +/- 0.17 D, respectively. The posterior corneal power was estimated to within +/-0.50 D of the actual value in 97.7% and 60.2% of eyes, respectively. CONCLUSION: Using the Pentacam-derived keratometric index improved the prediction accuracies of total and posterior corneal powers.

The combination of peripheral nerve grafts and acidic fibroblast growth factor enhances arginase I and polyamine spermine expression in transected rat spinal cords.

Treatment with a combination of peripheral nerve grafts and acidic fibroblast growth factor improves hind limb locomotor function after spinal cord transection. This study examined the effect of treatment on expression of arginase I (Arg I) and polyamines. Arg I expression was low in the spinal cords of normal rats but increased following spinal injury. Only fully repaired spinal cords expressed higher Arg I levels 6-14 days following repair. In 10-day repaired spinal cords, high Arg I immunoreactivity was detected in motoneurons and alternatively activated macrophages in the graft area and graft-stump edges, and high levels of the polyamine spermine were expressed by macrophages within the intercostal nerve graft. Thus, in addition to enhancing the expression of Arg I and spermine in repaired spinal cords, our treatment may recruit activated macrophages and create a more favorable environment for axonal regrowth.

Sudden death caused by dissecting thoracic aortic aneurysm in a patient with autosomal dominant polycystic kidney disease.

Among the fatal vascular complications associated with autosomal dominant polycystic disease (ADPKD), ruptured intracerebral aneurysm and ruptured abdominal aortic aneurysm are widely known. However, there are few reports on the dissecting thoracic aortic aneurysm as a fatal complication of ADPKD. We report a case of a 58-year-old man with a history of ADPKD who presented to the emergency department with out-of-hospital cardiac arrest. Immediate cardiopulmonary resuscitation restored a spontaneous circulation successfully and subsequent image study revealed a type I dissecting thoracic aortic aneurysm. Emergency aortic grafting was performed--but he died from postoperative haemorrhage. The surgical specimen of the aorta showed cystic medial necrosis. This rare case emphasizes the need to consider such a diagnosis in a patient with ADPKD who presents to the emergency department with sudden cardiac arrest. In addition, the histological finding indicates the aetiological role of a collagen defect in addition to chronic hypertension in the pathogenesis of aortic dissection in ADPKD patients.