Proteolytic Degradation and Inflammation Play Critical Roles in Polypoidal Choroidal Vasculopathy

Polypoidal choroidal vasculopathy (PCV) is a common subtype of wet age-related macular degeneration in Asian populations, whereas choroidal neovascularization is the typical subtype in Western populations. The cause of PCV is unknown. By comparing the phenotype of a PCV mouse model expressing protease high temperature requirement factor A1 (HTRA1) in retinal pigment epithelium with transgenic mice expressing the inactive HTRA1S328A, we showed that HTRA1-mediated degradation of elastin in choroidal vessels is critical for the development of PCV, which exhibited destructive extracellular matrix remodeling and vascular smooth muscle cell loss. Compared with weak PCV, severe PCV exhibited prominent immune complex deposition, complement activation, and infiltration of inflammatory cells, suggesting inflammation plays a key role in PCV progression. More important, we validated these findings in human PCV specimens. Intravitreal delivery of an HTRA1 inhibitor (DPMFKLboroV) was effective (36% lesion reduction; P = 0.009) in preventing PCV initiation but ineffective in treating existing lesions. Anti-inflammatory glucocorticoid was effective in preventing PCV progression but ineffective in preventing PCV initiation. These results suggest that PCV pathogenesis occurs through two stages. The initiation stage is mediated by proteolytic degradation of extracellular matrix proteins attributable to increased HTRA1 activity, whereas the progression stage is driven by inflammatory cascades. This study provides a basis for understanding the differences between PCV and choroidal neovascularization, and helps guide the design of effective therapies for PCV.

Macular capillary plexuses after macular hole surgery: an optical coherence tomography angiography study

AIMS

To investigate the structural changes of the superficial capillary plexuses (SCP) and deep capillary plexuses (DCP) using optical coherence tomography (OCT) angiography (OCTA) in patients with idiopathic macular hole (MH) after surgery, determine the factors related to changes of macular capillary plexuses and evaluate its association with postoperative visual outcomes.

METHODS

Thirty-three patients with unilateral MH who were followed for ≥6 months after surgery were included. Ophthalmologic evaluations included best corrected visual acuity (BCVA) and spectral-domain OCT before surgery and 6 months postsurgery. En face OCTA images were obtained for both eyes at 6 months postsurgery, and the postoperative foveal avascular zone (FAZ) area and parafoveal vascular density were identified.

RESULTS

Compared with fellow eyes, eyes after MH surgery had a smaller FAZ area in both SCP and DCP (p<0.05 for all). The FAZ area was positively correlated with postoperative foveal thickness of the whole, inner and outer layers (p<0.05 for all). In the parafoveal region, eyes after MH surgery had a tendency to have lower parafoveal vascular density, particularly in DCP (p=0.019). The parafoveal vascular density in DCP was positively correlated with retinal thickness of the whole, inner and outer layers (p<0.05 for all). Correlations between BCVA and FAZ area in both SCP and DCP were significant 6 months after MH surgery (p<0.05 for all).

CONCLUSION

Assessment of macular capillary plexuses using OCTA may be useful for monitoring retinal structural and functional changes in MH.

Feline-transmitted Staphylococcal hyicus endophthalmitis after clear lens extraction: a case report

Background

Postoperative endophthalmitis is a dreaded postsurgery complication which may lead to legal blindness. In addition to typical risk factors, some minor episodes may also lead to the occurrence of endophthalmitis. The purpose of the current study was to report a case of acute postoperative endophthalmitis caused by Staphylococcus hyicus in a patient with a contact history of felines.

Case presentation

A 58-year-old Taiwanese female who had a history of contact with felines due to her occupation had received clear lens extraction surgery of the left eye on July 10, 2015. One day after the surgery, the best-corrected visual acuity (BCVA) of the left eye was 20/40, which rapidly deteriorated to light perception with hypopyon formation. She was admitted for acute postoperative endophthalmitis and received antibiotic therapy with topical levofloxacin instillation and intravitreal vancomycin plus amikacin injection. Trans pars plana vitrectomy (TPPV) was then performed 1 day after admission. The specimen obtained from the vitreous and anterior chambers yielded the growth of S. hyicus. The patient was discharged with BCVA measured by counting fingers. Another TPPV was arranged for the persistent vitreous opacity on October 20, 2015, and the BCVA recovered to 20/32 at the last visit.

Conclusion

To our knowledge, this is the first case of acute postoperative endophthalmitis caused by S. hyicus due to feline contact. Unusual pathogens in the environment and personal hygiene status should be validated preoperatively to prevent the development of postoperative endophthalmitis.

Bacterial and Fungal Endophthalmitis

Endophthalmitis is a severe eye infection that may result in permanent loss of useful vision in the affected eye. Most cases are exogenous and occur as a complication of cataract surgery, an intravitreal injection, or penetrating ocular trauma. Endogenous endophthalmitis results from hematogenous seeding of the eye by bacteria or fungi, but bacteremia or fungemia may be transient and patients may present without symptoms of systemic infection. Nearly all endophthalmitis patients present with decreased vision, and some also have eye pain. Eye examination usually reveals a hypopyon and intraocular inflammation. Diagnosis is clinical, supported by cultures of the vitreous and/or aqueous or by blood cultures in some endogenous cases. Molecular diagnostic techniques have been used in research laboratories for pathogen identification in endophthalmitis and offer the possibility of rapid diagnosis, including in culture-negative cases. Intravitreal injection of antibiotics is the most important component of treatment; some cases also benefit from surgical debridement of the vitreous by a vitrectomy. The visual outcome depends partly on the pathogen: coagulase-negative staphylococcal endophthalmitis has a better prognosis than does streptococcal endophthalmitis, for example. Endophthalmitis is a medical emergency, and prompt diagnosis and treatment are essential for saving vision.

Metastatic endophthalmitis and thyroid abscess complicating Klebsiella pneumoniae liver abscess

The thyroid is resistant to infection due to its anatomical and physiological characteristics. We present a rare case of invasive liver abscess with metastatic thyroid abscess and endogenous endophthalmitis in a previously healthy 55-year-old female patient without diabetes or other medical illness. This report raises an important question of the virulence of Klebsiella pneumoniae as an increasingly common causative agent of liver abscess.

Vascular Displacement in Idiopathic Macular Hole after Single-layered Inverted Internal Limiting Membrane Flap Surgery

Purpose

To compare vascular displacement in the macula after surgical closure of idiopathic macular hole (MH) after single-layered inverted internal limiting membrane (ILM) flap technique and conventional ILM removal.

Methods

This retrospective study included patients who underwent either vitrectomy and ILM removal only or vitrectomy with single-layered inverted ILM flap for idiopathic MH larger than 400 µm from 2012 to 2015. A customized program compared the positions of the retinal vessels in the macula between preoperative and postoperative photographs. En face images of 6 × 6 mm optical coherence tomography volume scans were registered to calculate the scale. Retinal vessel displacement was measured as a vector value by comparing its location in 16 sectors of a grid partitioned into eight sectors in two rings (inner, 2 to 4 mm; outer, 4 to 6 mm). The distance and angle of displacement were calculated as an average vector and were compared between the two groups for whole sectors, inner ring, outer ring, and for each sector.

Results

Twenty patients were included in the ILM flap group and 22 in the ILM removal group. There were no statistical differences between the groups for baseline characteristics. The average displacement in the ILM flap group and the ILM removal group was 56.6 µm at −3.4° and 64.9 µm at −2.7°, respectively, for the whole sectors (p = 0.900), 76.1 µm at −1.1° and 87.3 µm at −0.9° for the inner ring (p = 0.980), and 37.4 µm at −8.2° and 42.7 µm at −6.3° for the outer ring (p = 0.314). There was no statistical difference in the displacement of each of the sectors.

Conclusions

Postoperative topographic changes showed no significant differences between the ILM flap and the ILM removal group for idiopathic MH. The single-layered ILM flap technique did not appear to cause additional displacement of the retinal vessels in the macula.

The effect of vitreomacular and cataract surgery on oxygen saturation in retinal vessels

PURPOSE

To evaluate the effects of vitreomacular and cataract surgery on retinal oximetry in vitreomacular disease.

PATIENTS AND METHODS

Thirty-eight eyes with epiretinal membrane (ERM) and 15 with idiopathic macular hole (MH) underwent 25 gauge pars plana vitrectomy combined with cataract surgery and intraocular lens implantation. Retinal oximetry was performed using the Oxymap T1 before, 1 month, and 6 months after surgery. Oxymap T1 simultaneously captures monochrome images of the fundus at two different wavelengths of light. Built-in Oxymap Analyzer software measures the oxygen saturation and vessel diameter.

RESULTS

Mean arterial oxygen saturation significantly increased from 96.8%±6.2% to 100.2%±5.8% at 1 month and to 99.6%±5.8% at 6 months after surgery (P<0.01). Mean venous oxygen saturation also significantly increased from 54.6%±7.5% to 61.2%±6.4% at 1 month and to 62.6%±5.9% at 6 months after surgery (P<0.01). Mean arteriovenous (A-V) difference decreased from 42.2%±6.6% to 39.0%±7.8% at 1 month and to 37.0%±6.9% at 6 months after surgery (P<0.01). The ERM and MH groups showed similar changes in retinal oxygen saturation. However, there were no significant changes in the caliber of major retinal vessels after surgery (from 125.2±15.2 μm to 124.0±15.4 μm in artery, from 168.7±14.6 μm to 169.8±14.6 μm in vein).

CONCLUSION

Oxymap T1 was able to measure the increase in oxygen saturation in retinal arteries and veins, which led to a decrease in the A-V difference in oxygen saturation after vitrectomy combined with cataract surgery.

Exogenous Streptococcus pneumoniae Endophthalmitis in Diabetic Rabbits

Diabetics are at increased risk for eye infections including bacterial endophthalmitis. It is unclear whether the severity of endophthalmitis is greater in these patients due to confounding factors such as pre-existing ocular diseases in some but not others. Therefore, we tested the hypothesis that disease severity and/or bacterial loads would be significantly higher in a Type I diabetic rabbit model of Streptococcus pneumoniae endophthalmitis. Rabbits were treated with alloxan to destroy pancreatic islet cells, or mock-treated with vehicle, and maintained for 10 days before intravitreal infection with S. pneumoniae E353. Clinical scoring of the eyes was performed 24 and 48 hours after infection, followed by euthanasia and vitreous harvest to quantitate bacterial loads. There were no significant differences in clinical scores (P ≥ 0.440) or bacterial loads (P = 0.736), however, 4/12 (33%) of the diabetic rabbits became bacteremic. This finding not only indicates a breakdown in the blood-ocular barrier, but also prompts further investigation into the exploitation of the diabetic eye by the streptococci.

Relationship between anesthesia and postoperative endophthalmitis: A retrospective study

Previous study showed that patients under general anesthesia (GA) had nasopharyngeal secretions on the face at the end of ocular surgery, especially in propofol-based total intravenous anesthesia (TIVA), it might induce postoperative endophthalmitis. Therefore, we conducted a retrospective study to compare the incidence of endophthalmitis after ocular surgery under topical, inhalation anesthesia, and propofol-based TIVA in our medical center from 2011 to 2015.A total of 21,032 patients were included, and we evaluated epidemiologic factors, systemic diseases, other ocular pathologic characteristics, complications during the surgery, technique of ocular surgery, method of antibiotic prophylaxis, vitreous culture, and vision outcome in these patients.Fifteen endophthalmitis cases among 21,032 operations reported, equaling an incidence of 0.071%. The incidence rates under topical, inhalation anesthesia, and propofol-based TIVA were 0.083%, 0.039%, and 0%, respectively (P = 0.39). Moreover, the risk of endophthalmitis under GA (0.024%) was significantly lower than topical anesthesia (0.083%) (P < 0.001). We also found that elder was the risk factor for endophthalmitis following ocular surgery.In conclusion, propofol-based TIVA or inhalation anesthesia did not increase the risk of endophthalmitis after ocular surgery. Thus, GA was not a risk factor for postoperative endophthalmitis. By contrast, elder was the risk factor for postoperative endophthalmitis.

Visual Outcomes and Prognostic Factors after Pars Plana Vitrectomy for Traumatic Endophthalmitis

Purpose. To evaluate visual outcomes and identify prognostic factors after pars plana vitrectomy (PPV) surgery for traumatic endophthalmitis. Methods. Medical records of 121 consecutive patients (121 eyes) diagnosed with traumatic endophthalmitis that had undergone pars plana vitrectomy were retrospectively reviewed. Results. 121 patients, aged from 6 to 71 years, all underwent PPV surgery. 113 cases had improved best corrected visual acuity (BCVA) after surgery and 60% of them obtained BCVA better than fingers counting (FC). Good final visual prognosis was significantly associated with time between trauma and initial treatment less than 12 hrs (40% versus 98%; P < 0.001), time between trauma and PPV treatment less than 24 hrs (62% versus 98%; P < 0.001), laceration length less than 10 mm (63% versus 96%; P < 0.001), and presenting VA better than LP (42% versus 96%; P < 0.001), while gender, type of laceration, presence of IOFB or retinal detachment, and the use of silicone oil tamponade were not significant factors resulting in better BCVA. Bacteria were identified in 43.8% of specimens and most of the microorganisms were identified as nonvirulent ones. Conclusions. Pars plana vitrectomy surgery was preferred as a primary treatment option for traumatic endophthalmitis. A good final visual prognosis was significantly associated with timely treatment, prompt vitrectomy surgery, shorter length of laceration, and better presenting visual acuity.

Climate and season: the effects on ophthalmic diseases

Seasonal changes and climate have a significant impact on human health. Diseases influenced by temperature and climate conditions are likely to undergo dynamic pattern shifts with consequent impact on human health. A number of infectious and non-infectious ophthalmic diseases are influenced by temperature and seasonality. Awareness of this is important from public and global health perspective in addition to resource allocation strategies. We examine the evidence for a seasonal pattern to ophthalmic diseases and assess the possible impact of climate change.

High-frequency aflibercept injections in persistent neovascular age-related macular degeneration

PURPOSE

To report the 1-year outcomes of every-4-weeks (Q4W) as-needed aflibercept treatment in resistant neovascular age-related macular degeneration (nAMD) patients who had been treated and failed prior bevacizumab or ranibizumab injections, and who also responded poorly to every-8-weeks (Q8W) aflibercept treatment.

METHODS

Forty-three eyes of 39 patients with persistent nAMD despite monthly bevacizumab and/or ranibizumab injections and who were switched to Q8W 2-mg aflibercept injections, but showed persistence of fluid were included. Patients were treated with as-needed Q4W aflibercept injections with monthly monitoring. Maximum retinal thickness (MRT), central macular thickness (CMT), maximum pigment epithelial detachment height (PED) and best-corrected visual acuity (BCVA) were assessed and compared to baseline when high-frequency aflibercept was initiated.

RESULTS

A mean of 8 (interquartile range, 4-11) Q4W injections were given during the follow-up. MRT and CMT significantly decreased at all follow-up visits (p < 0.05); however, there was no significant change in maximum PED height (p > 0.05) at any visit. Mean BCVA was 0.38 ± 0.28 (logMAR) (≈20/63, Snellen) at baseline, and 0.4 ± 0.34 (logMAR) (≈20/76, Snellen) at 1 year (p = 0.76). Seventy-two percent of eyes maintained a final BCVA of 20/63 or better. Twelve eyes (28 %) had some subretinal scar tissue formation and 5 eyes (11.6 %) had evidence of atrophy at 1 year.

CONCLUSION

A stepwise algorithm with Q4W as-needed aflibercept treatment led to anatomic improvement in previously treated eyes which failed other therapies, including aflibercept every 8 weeks. Lack of visual improvement may be due to a ceiling effect as our eyes generally had good visual acuity.

Post-cataract surgery endophthalmitis: Brief literature review

PURPOSE

To investigate recent evidence in prophylaxis and management of post-cataract surgery endophthalmitis.

METHODS

We conducted a literature search using Pubmed database for post cataract surgery endophthalmitis, and relevant articles were selected from original English papers published since 2015.

RESULTS

Forty-nine articles were published regarding post-cataract surgery endophthalmitis from January 2015 to February 2016. A low incidence of post-cataract surgery endophthalmitis has been reported. A growing number of articles are focusing on preventing endophthalmitis using intracameral antibiotics.

CONCLUSION

Based on the current evidence, intracameral antibiotics seems to be effective in preventing endophthalmitis after cataract surgery.