Purpose: The aim of this study is to compare the hysteresis and corneal resistance factor (CRF) in normal tension glaucoma (NTG), primary open angle glaucoma (POAG) and ocular hypertension (OHT) ...eyes measured by the ocular response analyser (ORA).
Methods: This is a prospective, cross‐sectional and comparative clinical trial. The setting was a teaching hospital in Birmingham, England. Patients: 216 eyes with POAG, 68 eyes with NTG and 199 eyes with OHT. Observational procedures: Goldmann applanation tonometry and intraocular pressure (IOP), hysteresis and CRF measured by ORA and central corneal thickness (CCT) by ultrasonic pachymetery. The main outcome measures were IOP, CCT, hysteresis and CRF.
Results: The hysteresis in NTG, POAG and OHT eyes was 9.0 ± 1.9, 9.9 ± 2.1 and 10.2 ± 2.0 mmHg; CRF was 9.1 ± 2.2, 10.6 ± 2.0 and 12.0 ± 2.0 mmHg; IOP by Goldmann applanation tonometry and ORA was 14.7 ± 2.8 and 15.3 ± 4.2 mmHg, 16.7 ± 4.0 and 16.9 ± 4.6 mmHg and 20.5 ± 4.1 and 20.0 ± 4.5 mmHg; CCT was 526.5 ± 42.2, 537.0 ± 36.0 and 563.4 ± 35.9 µm, respectively. The difference for CRF, IOP and CCT for NTG, POAG and OHT eyes was statistically significant.
Conclusion: Hysteresis and CRF were highest in OHT eyes. These factors may prove to be useful measurements of ocular rigidity and may help to understand role of the corneal rigidity in monitoring the progress of conditions such as NTG, POAG and OHT.
Limbal stem cell deficiency (LSCD) is a disease resulting from the loss or dysfunction of epithelial stem cells, which seriously impairs sight. Autologous limbal stem cell transplantation is ...effective in unilateral or partial bilateral disease but not applicable in total bilateral disease. An allogeneic source of transplantable cells for use in total bilateral disease can be obtained from culture of donated cadaveric corneal tissue. We performed a controlled multicenter study to examine the feasibility, safety, and efficacy of allogeneic corneal epithelial stem cells in the treatment of bilateral LSCD. Patients were randomized to receive corneal epithelial stem cells cultured on amniotic membrane (AM): investigational medicinal product (IMP) or control AM only. Patients received systemic immunosuppression. Primary endpoints were safety and visual acuity, secondary endpoint was change in composite ocular surface score (OSS). Sixteen patients were treated and 13 patients completed all assessments. Safety was demonstrated and 9/13 patients had improved visual acuity scores at the end of the trial, with no significant differences between IMP and control groups. Patients in the IMP arm demonstrated significant, sustained improvement in OSS, whereas those in the control arm did not. Serum cytokine levels were measured during and after the period of immune suppression and we identified strongly elevated levels of CXCL8 in the serum of patients with aniridia, which persisted throughout the trial. This first randomized control trial of allogeneic corneal epithelial stem cells in severe bilateral LSCD demonstrates the feasibility and safety of this approach. Stem Cells Translational Medicine 2019;8:323–331
Patients with severe ocular surface disorder received transplants of amniotic membrane with (black bars) or without (gray bars) cadaveric‐donor‐derived cultured limbal stem cells. All patients received immune suppression. Only patients who received transplants containing limbal stem cells showed sustained significant improvements (reductions) in combined ocular surface scores (5 factors scored 0–3 where 0 is a normal eye score).
To compare hysteresis, a novel measure of ocular rigidity (viscoelasticity) in normal and keratoconic eyes.
The study consisted of 207 normal and 93 keratoconic eyes. Eyes were diagnosed as ...keratoconic based on clinical examination and corneal topography. The hysteresis was measured by the Ocular Response Analyzer (ORA; Reichert Ophthalmic Instruments, Buffalo, NY). The data were recorded by Generation 3 software for the ORA. Central corneal thickness (CCT) was measured with a handheld ultrasonic pachymeter in the midpupillary axis.
The mean hysteresis was 10.7 +/- 2.0 (SD) mm Hg (range, 6.1-17.6) in normal eyes compared with 9.6 +/- 2.2 mm Hg (range, 4.7-16.7) in keratoconic eyes. The difference was statistically significant (P < 0.0001, unpaired t-test). Mean CCT in the normal and keratoconic eyes was 545.0 +/- 36.4 microm (range, 471-650) and 491.8 +/- 54.7 microm (range, 341-611), respectively; the difference was significant (P < 0.0001, unpaired t-test).
Hysteresis was significantly higher in normal than in keratoconic eyes. It may be a useful measurement in addition to CCT, when assessing ocular rigidity, and may be of particular importance when trying to correct intraocular measurements for increased or decreased ocular rigidity. Long-term studies of change in hysteresis may provide information on the progression of keratoconus.
Abstract Objective: To report the outcomes of anterior stromal micropuncture (ASP) combined with amniotic membrane transplantation (AMT) in the management of painful bullous keratopathy (BK) with ...poor visual potential, and to assess amniotic membrane (Am) retention. Design: Case series, retrospective review. Participants: Twelve eyes of 12 patients with BK causing intractable pain or discomfort and poor visual potential, treated between March 2006 and October 2008 at Gartnavel General Hospital, Glasgow. Methods: Epithelial debridement was followed by ASP and the amniotic membrane was stabilized with a purse-string 10/0 nylon corneal suture and a bandage contact lens. During a mean follow-up of 67 weeks (range, 27–139 weeks), pain relief, epithelial healing, visual changes, confocal microscopy, and appearance of new bullae were evaluated. Success was defined as complete resolution or significant improvement in pain. Results: Twelve eyes of 12 patients, mean age 61 years (range, 40-88 years), were identified. Corneal epithelial healing was complete in 11 eyes 1 month postoperatively. Pain and conjunctival inflammation resolved in 11 patients (91.67%) and improved from severe to mild in the remaining patient. Incorporation of the AMT was observed on slit-lamp biomicroscopy in all eyes and was confirmed using confocal microscopy at final follow-up. Conclusions: ASP combined with AMT is safe and effective, alleviates pain and discomfort, reduces ocular inflammation, and promotes epithelial healing and resolution of bullae in patients with BK with poor visual potential. There was long-term evidence of amniotic membrane graft retention in all eyes after the procedure, suggesting that ASP may improve the long-term retention rate of AM.
The aim of this study was to measure ocular hysteresis and corneal resistance factor (CRF), novel methods of analysing ocular rigidity/elasticity and to determine the relationship between central ...corneal thickness (CCT), hysteresis and CRF in normal subjects.
Prospective, cross-sectional, clinical trial.
The study included 207 normal eyes.
Hysteresis and CRF were measured by the ocular response analyser. The CCT was measured using a hand held ultrasonic pachymeter.
Ocular hysteresis and CRF in normal patients and their relationship with CCT.
The mean hysteresis was 10.7
±
2.0
mmHg standard deviation (S.D.) (range 6.1–17.6
mmHg); the mean CRF was 10.3
±
2.0 (range 5.7–17.1
mmHg). The mean CCT was 545.0
±
36.4
μm (471–650
μm). The relationship between hysteresis and CCT; CRF and CCT; CRF and hysteresis were significant (
p
<
0.0001).
This study demonstrated that corneal hysteresis increased with increasing CCT, however, the correlation was moderate. It would appear that CCT, hysteresis and CRF may measure different biomechanical aspects of ocular rigidity and are likely to be useful additional measurement to CCT in the assessment of ocular rigidity when measuring intraocular pressure (IOP). This may be of particular importance when trying to correct IOP measurements for increased or decreased ocular rigidity.
Corneal oedema following cataract surgery during the immediate postoperative period is a common clinical problem, often due to endothelial injury due to multi-factorial mechanisms. Descemet's ...membrane detachment (DMD) is an underrecognized cause of postoperative corneal oedema. The understanding of the pathogenic mechanisms of DMD is still evolving. We report a case of DMD in a 64-year-old female presenting with immediate postoperative corneal oedema, diagnosed and monitored using anterior segment optical coherence tomography (AS OCT). Various mechanisms have been proposed for surgically induced DMD. We believe that hydration of surgical wounds at the end of surgery can inadvertently cause DMD, if DMD has not been recognized previously. Surgeons should be alert to this cause of DMD when hydrating surgical wounds.
Highlights • Collagen cross-linking is an existing treatment modality that strengthens corneal tissue and causes changes in corneal cellular activity with a resultant re-ordering of corneal ...structure. • Corneal graft wounds t Please check the hierarchy of the section headings. ake a long time to heal. • We observed a statistically significant increase in adhesion between tissues in mock corneal grafts treated with collagen cross-linking.
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