There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

PURPOSE\nTo measure macular choroidal thickness in normal eyes at different points using enhanced depth imaging (EDI) optical coherence tomography (OCT) and to evaluate the association of choroidal thickness and age.\n\n\nDESIGN\nRetrospective, observational case series.\n\n\nMETHODS\nEDI OCT images were obtained in patients without significant retinal or choroidal pathologic features. The images were obtained by positioning a spectral-domain OCT device close enough to the eye to acquire an inverted image. Seven sections were obtained within a 5 x 30-degree area centered at the fovea, with 100 scans averaged for each section. The choroid was measured from the outer border of the retinal pigment epithelium to the inner scleral border at 500-microm intervals of a horizontal section from 3 mm temporal to the fovea to 3 mm nasal to the fovea. Statistical analysis was performed to evaluate variations of choroidal thickness at each location and to correlate choroidal thickness and patient age.\n\n\nRESULTS\nThe mean age of the 30 patients (54 eyes) was 50.4 years (range, 19 to 85 years), and 14 patients (46.7%) were female. The choroid was thickest underneath the fovea (mean, 287 microm; standard deviation, +/- 76 microm). Choroidal thickness decreased rapidly in the nasal direction and averaged 145 microm (+/- 57 microm) at 3 mm nasal to the fovea. Increasing age was correlated significantly with decreasing choroidal thickness at all points measured. Regression analysis suggested that the subfoveal choroidal thickness decreased by 15.6 microm for each decade of life.\n\n\nCONCLUSIONS\nChoroidal thickness seems to vary topographically within the posterior pole. The thickness of the choroid showed a negative correlation with age. The decrease in the thickness of the choroid may play a role in the pathophysiologic features of various age-related ocular conditions.

Enhanced Depth Imaging Optical Coherence Tomography of the Choroid in Normal Eyes

The ability to form biofilms in a variety of environments is a common trait of bacteria, and may represent one of the earliest defenses against predation. Biofilms are multicellular communities usually held together by a polymeric matrix, ranging from capsular material to cell lysate. In a structure that imposes diffusion limits, environmental microgradients arise to which individual bacteria adapt their physiologies, resulting in the gamut of physiological diversity. Additionally, the proximity of cells within the biofilm creates the opportunity for coordinated behaviors through cell–cell communication using diffusible signals, the most well documented being quorum sensing. Biofilms form on abiotic or biotic surfaces, and because of that are associated with a large proportion of human infections. Biofilm formation imposes a limitation on the uses and design of ocular devices, such as intraocular lenses, posterior contact lenses, scleral buckles, conjunctival plugs, lacrimal intubation devices and orbital implants. In the absence of abiotic materials, biofilms have been observed on the capsule, and in the corneal stroma. As the evidence for the involvement of microbial biofilms in many ocular infections has become compelling, developing new strategies to prevent their formation or to eradicate them at the site of infection, has become a priority.

https://dash.harvard.edu/bitstream/handle/1/16121069/4384075.pdf?sequence=1

Biofilms in Infections of the Eye

PURPOSE
To measure macular choroidal thickness (CT) in highly myopic eyes using enhanced depth imaging optical coherence tomography (OCT).


DESIGN
Retrospective, observational case series.


METHODS
Enhanced depth imaging OCT images were obtained in highly myopic eyes (> or =6 diopters [D]). Images of CT were obtained by positioning a spectral-domain OCT device close enough to the eye to acquire an inverted image. CT was measured from the outer border of the retinal pigment epithelium to the inner scleral border at 1000-mum intervals of a horizontal section from 3 mm temporal to the fovea to 3 mm nasal to the fovea. Statistical analysis was performed to evaluate CT at each location and to correlate CT with age and refractive error.


RESULTS
The mean age of the 31 patients (55 eyes) was 59.7 years (+/- 17.6 years; range, 24 to 90 years), and the mean refractive error was -11.9 D (+/- 3.7 D). The mean subfoveal CT was 93.2 microm (+/- 62.5 microm) and was correlated negatively with age (P = .006), refractive error (P < .001), and history of choroidal neovascularization (P = .013). Regression analysis suggested that subfoveal CT decreased by 12.7 mum for each decade of life and by 8.7 microm for each D of myopia.


CONCLUSIONS
The choroid in highly myopic eyes is very thin and undergoes further thinning with increasing age and degree of myopia. Abnormalities of the choroid may play a role in the pathogenesis of myopic degeneration.

Enhanced Depth Imaging Optical Coherence Tomography of Choroid in Highly Myopic Eyes

Background
A dacryocystorhinostomy (DCR) procedure aims to restore drainage of tears by bypassing a blockage in the nasolacrimal duct, through the creation of a bony ostium that allows communication between the lacrimal sac and the nasal cavity. It can be performed using endonasal or external approaches. The comparative success rates of these two approaches have not yet been established and this review aims to evaluate the relevant up-to-date research.

Objectives
The primary aim of this review is to compare the success rates of endonasal DCR with that of external DCR. The secondary aim is to compare the complication rates between the two procedures.

Search methods
We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2016, Issue 8), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to 22 August 2016), Embase (January 1980 to 22 August 2016), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to 22 August 2016), Web of Science Conference Proceedings Citation Index- Science (CPCI-S) (January 1990 to 22 August 2016), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 22 August 2016. We requested or examined relevant conference proceedings for appropriate trials.

Selection criteria
We included all randomised controlled trials (RCTs) comparing endonasal and external DCRs.

Data collection and analysis
Two review authors independently assessed studies for eligibility and extracted data on reported outcomes. We attempted to contact investigators to clarify the methodological quality of the studies. We graded the certainty of the evidence using GRADE.

Main results
We included two trials in this review. One trial from Finland compared laser-assisted endonasal DCR with external DCR, and one trial from India compared mechanical endonasal DCR (using punch forceps) with external DCR. The trials were poorly reported and it was difficult to judge the extent to which bias had been avoided.

Anatomic success was defined as the demonstration of a patent lacrimal passage on syringing, or endoscopic visualisation of fluorescein dye at the nasal opening of the anastomoses after a period of at least six months following surgery. Subjective success was defined as the resolution of symptoms of watering following surgery after a period of at least six months. Both included trials used anatomic patency demonstrated by irrigation as a measure of anatomic success. Different effects were seen in these two trials (I2 = 76%). People receiving laser-assisted endonasal DCR were less likely to have a successful operation compared with external DCR (63% versus 91%; risk ratio (RR) 0.69, 95% confidence intervals (CI) 0.52 to 0.92; 64 participants). There was little or no difference in success comparing mechanical endonasal DCR and external DCR (90% in both groups; RR 1.00, CI 0.81 to 1.23; 40 participants). We judged this evidence on success to be very low-certainty, downgrading for risk of bias, imprecision and inconsistency. The trial from Finland also assessed subjective improvement in symptoms following surgery. Resolution of symptoms of watering in outdoor conditions was reported by 84% of the participants in the external DCR group and 59% of those in the laser-assisted endonasal DCR group (RR 0.70, CI 0.51 to 0.97; 64 participants, low-certainty evidence).

There were no cases of intraoperative bleeding in any participant in the trial that compared laser-assisted endonasal DCR to external DCR. This was in contrast to the trial comparing mechanical endonasal DCR to external DCR in which 45% of participants in both groups experienced intraoperative bleeding (RR 1.00, 95% CI 0.50 to 1.98; 40 participants). We judged this evidence on intraoperative bleeding to be very low-certainty, downgrading for risk of bias, imprecision and inconsistency.

There were only two cases of postoperative bleeding, both in the external DCR group (RR 0.33, 95% CI 0.04 to 3.10; participants = 104; studies = 2). There were only two cases of wound infection/gaping, again both in the external DCR group (RR 0.20, CI 0.01 to 3.92; participants = 40; studies = 1). We judged this evidence on complications to be very low-certainty, downgrading one level for risk of bias and two levels for imprecision due to the very low number of cases.

Authors' conclusions
There is uncertainty as to the relative effects of endonasal and external DCR. Differences in effect seen in the two trials included in this review may be due to variations in the endonasal technique, but may also be due to other differences between the trials. Future larger RCTs are required to further assess the success and complication rates of endonasal and external DCR. Different techniques of endonasal DCR should also be assessed, as the choice of endonasal technique can influence the outcome. Strict outcome criteria should be adopted to assess functional and anatomical outcomes with a minimal follow-up of six months.

/pdf/endonasal-versus-external-dacryocystorhinostomy-for-1626gxtn6b.pdf

Endonasal versus external dacryocystorhinostomy for nasolacrimal duct obstruction

PURPOSE To analyze the clinical outcomes of external (EX-), endoscopic (EN-), and transcanalicular multidiode laser (TC-) with dacryocystorhinostomy (DCR). METHODS Ninety-two patients with primary acquired nasolacrimal duct obstruction were enrolled (divided into EX-DCR [n = 33], EN-DCR [n = 30], and TC-DCR groups [n = 29]) in this prospective study. Primary outcome measures were the anatomical and functional success of operations at the last control examination. Secondary outcome measures were the ostium size, surgical time, and complications. RESULTS The difference in mean surgical time among the 3 groups was statistically significant (p < 0.0001). External DCR required the longest surgical time (46.6 ± 15.3 minutes), while TC-DCR was the shortest (20.3 ± 7.7 minutes). There were no significant differences between the groups regarding anatomical (81.8%, 75.9%, and 76.7% in EX-, EN-, and TC-DCR groups, respectively; p = 0.824) and functional success rates (81.8%, 72.4%, and 73.3% in EX-, EN-, and TC-DCR groups, respectively; p = 0.626). Final ostium size was the largest with EX-DCR (33.7 ± 17.4 mm) and smallest with EN-DCR (19.0 ± 8.9 mm; p = 0.001). The complication rate was similar in all groups. The most common complications were the formation of granulation tissue (16.3%) and intranasal synechiae (9.8%), all of which led to surgical failure and were more frequent in the EN- and TC-DCR groups. CONCLUSIONS External DCR, EN-DCR, and TC-DCR had similar success and complication rates in patients with primary acquired nasolacrimal duct obstruction. External DCR resulted in the largest ostium size. Transcanalicular DCR appeared to be effective with the shortest surgical time.

Prospective comparison of 3 dacryocystorhinostomy surgeries: external versus endoscopic versus transcanalicular multidiode laser.

Purpose. To investigate whether platelet morphology or function is altered in patients with diabetic retinopathy (DR). Methods. This prospective study enrolled 85 healthy controls (HCs) (group 1) and 262 patients with Type 2 diabetes mellitus (T2DM). Patients were subclassified into three groups according to ocular findings: no DR (group 2; n = 88); nonproliferative DR (group 3; n = 88), and proliferative DR (group 4; n = 86). Mean platelet volume (MPV), platelet distribution width (PDW), platelet large cell ratio (PLCR), plateletcrit (PCT) values, and platelet count were measured in the studied groups. Results. MPV, PDW, and PLCR levels were significantly altered in groups 2-4 compared with HCs (p 0.05). Conclusion. Our findings suggest an association between mean platelet indices (MPI) (i.e., MPV, PDW, and PLCR) and DR stage. Therefore, MPI could be a beneficial prognostic marker of DR in patients with T2DM.

/pdf/relationship-between-altered-platelet-morphological-1353hrvilr.pdf

Relationship between Altered Platelet Morphological Parameters and Retinopathy in Patients with Type 2 Diabetes Mellitus

AIM To compare bacterial biofilm colonization in lacrimal stents following external dacryocystorhinostomy (EX-DCR), endoscopic dacryocystorhinostomy (EN-DCR), and transcanalicular dacryocystorhinostomy (TC-DCR) with multidiode laser. METHODS This prospective study included 30 consecutive patients with nasolacrimal duct obstruction who underwent EXT-, EN-, or TC-DCR. Thirty removed lacrimal stent fragments and conjunctival samples were cultured. The lacrimal stent biofilms were examined by scanning electron microscopy (SEM). RESULTS Eleven (36.7%) of the 30 lacrimal stent cultures were positive for aerobic bacteria (most commonly Staphylococcus epidermidis and Pseudomonas aeruginosa). However anaerobic bacteria and fungi were not identified in the lacrimal stent cultures. Twenty-seven (90%) patients had biofilm-positive lacrimal stents. The conjunctival culture positivity after the DCR, biofilm positivity on stents, the grade of biofilm colonization, and the presence of mucus and coccoid and rod-shaped organisms did not significantly differ between any of the groups (P>0.05). However, a significant difference was found when the SEM results were compared to the results of the lacrimal stent and conjunctival cultures (P<0.001). CONCLUSION Type of dacryocystorhinostomy (DCR) surgery did not affect the biofilm colonization of the lacrimal stents. SEM also appears to be more precise than microbiological culture for evaluating the presence of biofilms on lacrimal stents.

Comparison of scanning electron microscopy findings regarding biofilm colonization with microbiological results in nasolacrimal stents for external, endoscopic and transcanalicular dacryocystorhinostomy.

To evaluate changes in central macula thickness (CMT), subfoveal choroid thickness (SCT), and intraocular pressure (IOP) before and after neodymium:yttrium–aluminum–garnet (Nd:YAG) laser capsulotomy. 42 eyes of 42 patients who underwent Nd:YAG laser capsulotomy were included in this prospective study. CMT, SCT, and IOP were evaluated preoperatively and at postoperative week 1 and postoperative months 1, 3, 6, and 12. CMT was 238.1 ± 27.6 μm (mean ± SD) preoperatively, then 239.7 ± 29.8, 241.3 ± 28.7, 242.7 ± 27.2, 238.8 ± 23.7, and 238.3 ± 21.7 μm at postoperative week 1 and months 1, 3, 6, and 12, respectively. SCT was 263.3 ± 21.6 μm preoperatively, and 265.5 ± 24.8, 266.2 ± 25.7, 267.1 ± 26.3, 269.1 ± 24.2, and 269.9 ± 21.4 μm at postoperative week 1 and months 1, 3, 6, and 12, respectively. There were no significant differences between preoperative and postoperative results for CMT, SCT, or IOP (all p > 0.05). Although there were slight changes in choroid thickness in the long term, treatment of posterior capsule opacification with a low-energy Nd:YAG laser is a safe procedure that increases visual acuity without creating a significant increase in IOP, CMT, and SCT.

Long-term changes in subfoveal choroidal thickness and central macula thickness after Nd:YAG laser capsulotomy

Purpose: To compare the conjunctival, lacrimal sac, and nasal flora cultures and conjunctival normalization time following external (EX-), endoscopic (EN-), and transcanalicular multidiode laser (TC-) dacryocystorhinostomy (DCR) and to evaluate the relationship between culture positivity and surgical success. We further performed antibiotic sensitivity analyses for lacrimal sac culture samples. Methods: A total of 90 patients with primary acquired nasolacrimal duct obstruction were recruited and divided into EX-DCR (n=32), EN-DCR (n=28), and TC-DCR (n=30) groups. Conjunctival, nasal, and lacrimal sac cultures and antibiograms were analyzed. Results: In all three groups, coagulase-negative Staphylococcus (CNS) was predominantly isolated preoperatively from the conjunctiva, nose, and lacrimal sac and postoperatively from the conjunctiva. Preoperative and postoperative conjunctival culture positivity rates were similar between all the groups (p>0.05). A statistically significant difference in the growth rate of culture in the lacrimal sac was observed between the three groups (p=0.001). CNS and Staphylococcus aureus cultures were predominantly sensitive to linezolid, teicoplanin, tigecycline, vancomycin, and mupirocin. Conjunctival normalization times were similar between the three groups (p>0.05). Anatomical and functional success rates were not found to be significantly correlated with preoperative conjunctival and lacrimal sac culture positivity (p>0.05). Conclusions: Similar rates of preoperative and 1-week postoperative conjunctival culture positivity were observed in all the groups; a significantly lower bacterial growth rate was observed in postoperative conjunctival cultures. CNS was the most commonly isolated organism. Bacterial growth rates in the lacrimal sac samples were significantly higher in the EN-DCR group. Bacterial growth rates obtained preoperatively from the conjunctival and lacrimal sac culture samples were not correlated with DCR success.

/pdf/bacteriological-profile-in-conjunctival-lacrimal-sac-and-2po9mtj58q.pdf

Bacteriological profile in conjunctival, lacrimal sac, and nasal specimens and conjunctival normalization time following external, endoscopic, and transcanalicular multidiode laser dacryocystorhinostomy

Tolga Yilmaz

Papers

Prospective comparison of 3 dacryocystorhinostomy surgeries: external versus endoscopic versus transcanalicular multidiode laser.

Relationship between Altered Platelet Morphological Parameters and Retinopathy in Patients with Type 2 Diabetes Mellitus

Comparison of scanning electron microscopy findings regarding biofilm colonization with microbiological results in nasolacrimal stents for external, endoscopic and transcanalicular dacryocystorhinostomy.

Long-term changes in subfoveal choroidal thickness and central macula thickness after Nd:YAG laser capsulotomy

Bacteriological profile in conjunctival, lacrimal sac, and nasal specimens and conjunctival normalization time following external, endoscopic, and transcanalicular multidiode laser dacryocystorhinostomy