Corneal biomechanical changes after Descemet stripping automated endothelial keratoplasty, penetrating keratoplasty, and phacoemulsification.

PURPOSE: To evaluate corneal biomechanical changes after Descemet stripping automated endothelial keratoplasty (DSAEK), penetrating keratoplasty (PK), and phacoemulsification (PE). METHODS: This prospective study included 138 eyes which underwent PK (26 eyes), DSAEK (26 eyes), PE (57 eyes), and 29 normal eyes. Intraocular pressure (IOP) was measured by Goldmann applanation tonometer (GAT), and central corneal thickness (CCT) and axial length by ultrasound. The ocular response analyzer was used to measure corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann-related IOP (IOPg), and cornea-compensated IOP (IOPcc) preoperatively and 1, 3, and 6 months postoperatively. RESULTS: At baseline, PK group had the lowest CH and CRF. There was a significant increase in CH and CRF to normal values in PK (P = 0.015 and 0.006) and PE (P = 0.005 and 0.0001) groups over the study period. At 6 months, CH and CRF increased and reached normal values in the PK group; increased to a lower level than normal in the DSAEK group; and, after an initial reduction, increased to normal values in the PE group. At 6 months, DSAEK group had the lowest CH and CRF. There was a significant positive correlation between CRF and GAT (r = 0.281, P = 0.009), IOPg and GAT (r = 0.335, P = 0.001), and IOPcc and GAT (r = 0.282, P = 0.001). CH was negatively correlated with age (r = - 0.189, P = 0.04). CONCLUSION: Corneal biomechanical factors increase after DSAEK and PK. At post-operative month six, they reach normal values in PK group, but are lower than normal in DSAEK group.

Systemic oxygen therapy versus oral enalapril for treatment of diabetic macular ischemia: a randomized controlled trial.

The purpose of this study was to evaluate the structural and functional effects of systemic oxygen therapy and enalapril in patients with diabetic macular ischemia (DMI). This randomized clinical trial consisted of 105 eyes with DMI divided into three groups. Group I received systemic oxygen by face mask at a flow rate of 10 L/min; Group II received 5 mg enalapril daily; and Group III received placebo tablets for 3 months. Best-corrected visual acuity (BCVA), central macular thickness (CMT) measured by optical coherence tomography (OCT), extent of foveal avascular zone (FAZ) on fluorescein angiograms, and electroretinograms (ERG) were obtained at baseline and after 3 and 6 months. Overall, 102 patients completed the study. Baseline characteristics were not significantly different among groups. Significant improvement in BCVA and decrease in CMT and FAZ occurred at months 3 and 6 in oxygen group compared to deterioration in enalapril and control groups (All P values <0.001). ERG parameters were significantly better in oxygen group compared to enalapril group at months 3 and 6 and better than those in control group at month 3. Normobaric oxygen therapy for 3 months in DMI decreased CMT and FAZ and improved BCVA and ERG parameters. Enalapril did not show any favorable effect.

Capsulectomy Shunt Revision versus Repeat Shunt Implantation Following Ahmed Glaucoma Valve Failure in Refractory Glaucoma.

PURPOSE: To investigate the efficacy of capsulectomy shunt revision (CSR) compared with the implantation of a second Ahmed glaucoma valve (re-AGV) in glaucoma patients with failed shunts. DESIGN: Quasi-experimental study. SUBJECTS: Forty-six eyes with failed Ahmed glaucoma valves (AGVs) were included in the study; 25 underwent CSR, whereas 21 underwent re-AGV. METHODS: Patients were scheduled for CSR or re-AGV based on the appearance and accessibility of the existing AGV versus the feasibility for re-AGV in other quadrants. The CSR involved incision and dissection down to the thick fibrous capsule around the AGV plate, which was excised extensively. For re-AGV, the second shunt was implanted in the supranasal or infranasal quadrants. MAIN OUTCOME MEASURES: Surgical success, defined as intraocular pressure (IOP) > 5 mmHg, ≤ 21 mmHg, IOP reduction ≥ 20% from baseline, and no reoperation for glaucoma. Secondary outcome measures were IOP, number of glaucoma medications, and complications during a 12-month follow-up period. RESULTS: Mean IOP was significantly lower than preoperative values at all time points in both study groups (P < 0.001). Intraocular pressure decreased significantly from 28.3 ± 5.04 mmHg at baseline to 16.4 ± 2.4 mmHg at final follow-up in the capsulectomy group (P = 0.002). Corresponding IOP values for re-AGV were 30.99 ± 6.2 and 13.6 ± 3.8 mmHg, respectively (P = 0.001). Intraocular pressure in the CSR group was higher than re-AGV during the study (P = 0.003). The cumulative probability of success at 12 months was significantly higher in the re-AGV group (87.5% vs 53.3%, P = 0.002). There was no significant difference in the number of glaucoma medications and overall complications rate between the study groups. Wound leakage was the only complication more common in the CSR group (P = 0.012). CONCLUSION: In the eyes with a failed AGV, re-AGV and CSR are both effective. Implantation of a second shunt seems more effective than the surgical revision of an existing device; however, the latter procedure may be a viable option in selected cases. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

In Vivo Intraocular Lens Thickness Measurement and Power Estimation Using Optical Coherence Tomography.

Purpose: To estimate the power of an implanted intraocular lens (IOL) by measuring IOL thickness using anterior segment optical coherence tomography (AS-OCT) and to assess the repeatability of measurements. Methods: Ninety-seven eyes were studied one month after uneventful phacoemulsification within the bag Acrysof SA60AT IOL implantation (range +11 to +35). All eyes had postoperative refraction of ± 0.5 D of target refraction. AS-OCT was used to measure the central thickness of the IOL. Correlation between labelled IOL power and central IOL thickness as well as the measure of repeatability, for example, intraclass correlation coefficient (ICC), were evaluated. IOL thicknesses were also calculated using a formula and compared with AS-OCT derived measurements. Results: IOL thickness correlated significantly with labelled IOL power (R2 = 0.985, P < 0.001). The regression equation (IOL Power = [0.04 × IOL thickness in micron] - 7.56) indicates 25 microns of central IOL thickness change per 1D power change. Over the studied range, IOL power could be estimated with a precision of 0.85 ± 0.02 D (95% confidence interval: 0.83-0.94D). ICC for repeated measurements was 0.999. There was a significant correlation between calculated and measured (AS-OCT) IOL thickness (R2 = 0.984, P < 0.001). Conclusion: Central IOL thickness measurements with the AS-OCT are highly repeatable and closely correlated with the labelled IOL power, which can predict the IOL power with ± 0.85 D from the actual power. This method can be helpful in cases of postoperative IOL surprise.

Trabeculotomy Versus Combined Trabeculotomy-Trabeculectomy for Management of Primary Congenital Glaucoma.

PRCIS: Trabeculotomy (T) alone is as safe and effective as combined trabeculotomy-trabeculectomy (TT) in patients with primary congenital glaucoma (PCG) and requires significantly fewer examinations under anesthesia in the postoperative period. PURPOSE: The purpose of this study was to compare the outcomes of T and combined TT as the initial surgical procedure for patients with PCG. METHODS: In this retrospective study, medical records of patients who had undergone T or TT as the initial procedure for PCG were reviewed. The primary outcome measure was a surgical success, defined as 5≤ intraocular pressure (IOP) ≤21 mm Hg, IOP reduction of at least 20% with no need for further glaucoma surgery. Secondary outcome measures were the number of glaucoma medications and complications. RESULTS: A total of 134 eyes from 134 patients with a mean follow-up of 8±6.6 years were included consisting of 106 and 28 eyes, which had undergone T and TT, respectively. Success rates were comparable with both surgical procedures at 1, 2, 3, 4, and 5 years with no statistically significant difference. IOP was significantly decreased from 27.5±4.2 mm Hg preoperatively to 15.62±3.4 mm Hg at the 5-year follow-up visit in the T group and from 25.3±6.5 to 17.1±3.2 mm Hg in the TT group (P=0.1) there was no significant difference between the 2 groups in the number of glaucoma medications (P=0.2). Patients in the T group required significantly fewer examinations under anesthesia than the TT group (7.3±4.4 vs. 10.1±3.9, P=0.04). CONCLUSION: Trabeculotomy alone seems as effective as combined trabeculotomy-trabeculectomy and may significantly reduce exposure to anesthesia in primary congenital glaucoma patients.

The Influence of Near Vision Tasks on Intraocular Pressure in Normal Subjects and Glaucoma Patients.

Purpose: To investigate the effect of static accommodative tasks on intraocular pressure (IOP) of glaucomatous and normal eyes. Methods: Four groups of subjects categorized as primary open-angle glaucoma (POAG), primary angle-closure suspects (PACS), normal age-matched controls, and normal young adults (NYA; age < 40 years) were enrolled. The baseline IOPs were measured after the subjects were looking at a distant target for 15 min. Static accommodation was obtained by execution of near vision tasks (reading at 33 cm in daylight [300 lux] for 60 min). IOPs were measured at 15, 30, 45, and 60 min intervals while accommodating and then measured again after 15 min of relaxing accommodation while looking at a distant target. Results: One-hundred and eighteen eyes of 98 subjects were recruited. The study groups consisted of the following categories: 25 POAG (46 eyes), 24 PACS (47 eyes), 25 matched controls (50 eyes), and 24 NYA (48 eyes). Within all groups, the mean IOP decreased throughout the accommodation period at all time points. Maximum IOP reduction after accommodation was detected at the 30-min time among the POAG subjects, at the 45-min time in the PACS and matched control groups, and at 15 min after the relaxation of accommodation in the NYA group. IOP reduction levels showed no statistically significant difference among POAG, PACS, and the normal matched groups in their response to accommodation. However, NYA had significantly lower IOP and greater IOP reduction after the resting period (relaxation of accommodation). Conclusion: Static accommodative tasks can significantly reduce IOP in normal, POAG, and PACS individuals. Encouraging glaucoma patients to practice periodical near vision tasks could be viewed as an adjunctive measure for glaucoma management.

Oxygen therapy for diabetic macular ischemia: a pilot study.

PURPOSE: To evaluate the structural and functional effects of systemic oxygen therapy in patients with diabetic macular ischemia. METHODS: This interventional case series was performed on 20 eyes from 13 consecutive diabetic patients with macular ischemia. For each patient, baseline optical coherence tomography and electroretinography were obtained before and after administration of 100% oxygen by face mask at a flow rate of 10 L/minute for 1 hour. Central macular thickness and b-wave amplitude were measured before and after oxygen therapy. RESULTS: The patients included 9 women and 4 men with mean (SD) age of 63.38 (7.34) years. Central macular thickness decreased from 358.55 ± 96.27 µm before to 326.55 ± 84.11 µm after the oxygen therapy (P < 0.001). A reduction of >10% was observed in 55% of the eyes. In dark-adapted combined response electroretinography, the amplitude of b-wave increased from 227.76 ± 105.66 µV before to 264.35 ± 128.48 µV after the oxygen therapy (P < 0.001), representing a 16% increase. More than a 10% increase in b-wave amplitude occurred in 60% of the eyes. CONCLUSION: Oxygen therapy seems to have beneficial effects on the structural and functional changes of the retina in patients with diabetic macular ischemia. It may decrease central macular thickness and improve electrophysiologic function of the retina.

Intraocular Pressure and Corneal Biomechanical Changes after Water-Drinking Test in Glaucoma Patients.

PURPOSE: To evaluate intraocular pressure (IOP) and corneal biomechanical changes after water-drinking test (WDT) in glaucomatous and normal eyes using Ocular Response Analyzer (ORA). METHODS: This prospective study included 30 medically controlled, 30 surgically treated glaucoma patients and 30 normal individuals. Baseline measurements included central corneal thickness (CCT), ORA-derived corneal hysteresis (CH), corneal resistance factor (CRF), corneal-compensated IOP (IOPcc), and Goldmann-correlated IOP (IOPg). Measurements were repeated 15, 30, and 60 min after drinking 1000 mL of water. Changes in ORA parameters were compared among the groups. RESULTS: All groups showed a significant increase in IOPg and IOPcc at all test points. Peak IOP occurred at 15 min and decreased gradually over time but did not reach the baseline values at 60 min. The surgery group had significantly lower baseline IOPg and IOPcc (10.7 ± 3.1 and 12.8 ± 3.7 mmHg, P = 0.001 and 0.01), lower peak IOPg and IOPcc (14.4 ± 4.6 and 16.2 ± 4.6 mmHg, P = 0.003 and 0.034), and lower percent IOPg and IOPcc fluctuations (13 ± 5.6 and 15 ± 5.9, P = 0.0001 and 0.002), respectively, compared to the medical group. Baseline CH and its fluctuations were not significantly different among the groups. CH decreased to a trough corresponding to peak IOPcc. There was a significant negative correlation between IOPcc and CH (r = -0.609, P < 0.001). The medical group showed more CRF fluctuations compared to normal group.(P = 0.039). CONCLUSION: Surgically treated glaucomatous eyes show less IOP fluctuations and lower peak IOP after WDT compared to medically controlled and normal eyes.

Rate of visual field decay in glaucomatous eyes with acquired pits of the optic nerve.

BACKGROUND: To evaluate the relationship between the presence of an acquired pit of the optic nerve (APON) and the rate of visual field (VF) decay in primary open-angle glaucoma (POAG). METHODS: Consecutive patients with POAG were screened for APON by three glaucoma specialists. A control group of POAG eyes without APON were matched with the APON group for factors such as age, gender, baseline intraocular pressure and baseline mean deviation (MD). The pointwise rate of change (PRC) was used for pointwise comparisons between the two groups. MD rate, Visual Field Index (VFI) rate and Glaucoma Rate Index (GRI) were used for global rate comparisons. We compared the proportions of eyes progressing in the groups with event-based guided progression analysis (GPA), MD, VFI and GRI criteria. RESULTS: Mean (SD) PRC was faster in the APON group -1.00 (±2.57) %/year compared with the control group -0.25 (±2.19) %/year; p<0.001. MD rate (-0.22 (±0.27) dB/year vs 0.03 (±0.41) dB/year; p=0.009), VFI rate (-0.81 (±0.86) %/year vs -0.05 (±1.0) %/year; p=0.04) and GRI (-12.27 (±16.27) vs -3.75 (±10.6); p=0.052) were all faster in the APON group compared with controls. The proportion of progressing eyes with GPA, MD, VFI and GRI was not significantly different between the two groups (p>0.1). CONCLUSIONS: The presence of APON in patients with POAG is associated with focal, fast rates of VF decay. Identification of patients with APON should alert clinicians to the possibility of a fast rate of functional progression and to consider appropriately aggressive treatment of their glaucoma.

Intraocular Pressure Changes in the Contralateral Eye After Glaucoma Surgery.

PRCIS: Glaucoma surgery in 1 eye can result in significant intraocular pressure (IOP) elevation in the fellow eye in a significant percentage of subjects. This effect is more pronounced following glaucoma drainage device implantation and in subjects developing postoperative hypotony in the first eye. PURPOSE: The aim was to investigate the course and magnitude of IOP changes in contralateral eyes following glaucoma surgery. PATIENTS AND METHODS: We studied 131 glaucoma patients undergoing surgery. IOP changes in fellow eyes and the number of glaucoma medications were recorded for 6 months. Both normal and glaucomatous fellow eyes were included. Patients on preoperative acetazolamide were analyzed separately. IOP change ≥4 mm Hg or 20% increase from baseline values was considered significant. RESULTS: Baseline IOP in fellow eyes was 13.1±3.3 mm Hg which increased significantly at all-time points with a peak at 1 week (mean increase: 3.1±3.2 mm Hg) gradually decreasing up to 6 months (mean increase 0.9±2.1 mm Hg). The number of fellow eyes with clinically significant IOP elevation at 1 day, 1 week, and 1, 3. and 6 months was 47, 76, 47, 31, and 37 showing mean IOP rise of 4.5±2.3 (38.5%), 5.4±1.8 (48.5%), 4.8±1.6 (44.2%), 3.7±1.3 (36.5%), and 3.2±1.3 (32.6%) mm Hg, respectively. Medications were added to 18 fellow eyes (including 10 initially "normal" eyes) while 7 other fellow eyes required surgery.Significant IOP elevation in fellow eyes was associated with tube shunt surgery (P<0.008 at all-time points), a diagnosis of glaucoma following cataract surgery, IOP ≤5 mm Hg on the first postoperative day (P=0.002) and use of preoperative acetazolamide. CONCLUSION: Glaucoma surgery was associated with IOP elevation in fellow eyes in a significant number of subjects and suggests that IOP in the unoperated eye should also be checked at postoperative visits.

Progression in pediatric glaucoma: lessons learnt from 8 years' follow-up.

Background: Surgical procedures are used as 1 of the main treatment modalities for pediatric glaucoma, even though progression may occur. In this study, we aimed to investigate the risk factors affecting the progression of pediatric glaucoma. Methods: In this retrospective cohort study, we reviewed the medical records of patients diagnosed with pediatric glaucoma between April 2009 and March 2017. Pediatric glaucoma patients who underwent regular follow-up for at least 1 year were included. Demographics, intraocular pressure (IOP), central corneal thickness (CCT), axial length (AL), cup-to-disc ratio (C/D ratio), corneal diameter, type of glaucoma, age at time of diagnosis, and age at surgery were recorded. Progression was defined as an increase in AL > 2 mm, C/D ratio > 0.2, or corneal diameter > 1 mm during 1 year of follow-up. Results: Eighty-three eyes from 46 patients were included: 37 eyes (45%) with primary congenital glaucoma (PCG), 46 eyes (55%) with secondary glaucoma, and 27 of these 83 eyes (32.5%) showed progression. Progression was comparable between eyes with PCG and secondary glaucoma (PCG, 22%; secondary glaucoma, 41%; P = 0.152). Age at the time of diagnosis and age at the time of the first surgery were significantly lower in the eyes with progression (P = 0.046 and 0.012, respectively). The mean (standard deviation) of surgeries in progressed versus non-progressed eyes was 1.88 (1.1) versus 1 (0.8) (P = 0.015). The frequency of comorbid systemic disease was significantly higher in patients with glaucoma progression (P = 0.043). The progressed and non-progressed eyes were comparable in terms of other demographic characteristics and ocular parameters (all P > 0.05). Conclusions: Pediatric glaucoma patients who were younger at the time of diagnosis and the first glaucoma surgery and those with comorbid systemic disease are at higher risk of glaucoma progression. These findings are useful for clinicians when counseling parents of children with pediatric glaucoma about disease outcomes. However, future prospective studies with larger sample sizes and longer follow-up periods are needed to confirm our findings.

Effect of capsular tension ring implantation on predicted refractive error after cataract surgery in patients with pseudoexfoliation syndrome.

AIM: To investigate the effect of capsular tension ring (CTR) implantation on predicted refractive error after cataract surgery in patients with pseudoexfoliation (PEX) syndrome. METHODS: This double-blind randomized clinical trial was conducted on 60 patients with PEX syndrome referring to Imam Khomeini Hospital affiliated to Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran, for undergoing cataract surgery. The study population was divided into two groups, namely CTR group (n=30) and non-CTR group (control group; n=30). The refractive error and anterior chamber depth (ACD) were measured 1wk, 1mo, and 3mo after phacoemulsification (PE) surgery. RESULTS: The results indicated no statistically significant difference between the two groups in terms of predicted refractive error (obtained by subtracting preoperative predicted refractive error from actual postoperative refractive error) 1wk (P=0.47), 1mo (P=0.30), and 3mo (P=0.06) after the PE surgery. Regarding the CTR group, the changes of ACD was statistically significant 1 and 3mo after the PE surgery, compared to those obtained 1wk post-surgery (P=0.005). CONCLUSION: The CTR implantation in PEX cataractous patients without zonulysis has no statistically significant effect on the predicted refraction and ACD changes after PE. The predicted refraction error has a hyperopic shift in both groups. The results reveal the unnecessary of calculating modified IOL in CTR implantation.

Macular imaging with optical coherence tomography in glaucoma.

With the advent of spectral-domain optical coherence tomography, imaging of the posterior segment of the eye can be carried out rapidly at multiple anatomical locations, including the optic nerve head, circumpapillary retinal nerve fiber layer, and macula. There is now ample evidence to support the role of spectral-domain optical coherence tomography imaging of the macula for detection of early glaucoma. Macular spectral-domain optical coherence tomography measurements demonstrate high reproducibility, and evidence on its utility for detection of glaucoma progression is accumulating. We present a comprehensive review of macular spectral-domain optical coherence tomography imaging emerging as an essential diagnostic tool in glaucoma.

Modified Deep Sclerectomy for the Surgical Treatment of Glaucoma.

PURPOSE: To report the short-term outcomes of modified deep sclerectomy (MDS) in the management of open angle glaucoma. METHODS: This prospective, non-randomized, controlled study included 105 eyes (105 patients) with open angle glaucoma. Eyes were categorized as follows: trabeculectomy (30 eyes), MDS (27 eyes), phacotrabeculectomy (28 eyes), and phaco-MDS (20 eyes). The MDS technique involved removal of a third scleral flap to expose the suprachoroidal space and excision of a trabecular block. A two-site approach was used for combined surgeries. Main outcome measures included intraocular pressure (IOP), number of glaucoma medications, and complications. Treatment success was defined as an IOP of 6-15 mmHg and/or a 30% reduction in IOP. RESULTS: All groups showed significant decrease in IOP and number of medications (both P s < 0.001). The MDS group had a higher IOP (13.9 ± 3.8 vs. 12.4 ± 2.5 mmHg, P = 0.080) and required more medications (P = 0.001) than the trabeculectomy group at 1 year. The MDS group had a higher baseline IOP than the trabeculectomy group (P = 0.004) and both the groups showed similar IOP reductions (33.3% vs. 25.7%, P = 0.391). The phaco-MDS and phacotrabeculectomy groups had comparable IOP (13.3 ± 3.1 vs. 12.4 ± 3.1 mmHg, P = 0.354), number of medications (P = 0.594), and IOP reduction (P = 0.509) at 1-year follow-up visit. The trabeculectomy and phacotrabeculectomy groups developed more wound leaks (P = 0.043) and required more bleb needling during the early postoperative period (P < 0.001). CONCLUSION: The MDS technique seems to be slightly inferior to trabeculectomy, but when combined with phacoemulsification, is safer and results in similar IOP outcomes.

A Phenotype of Primary Open-angle Glaucoma With Systemic Vasospasm.

PURPOSE: Primary open-angle glaucoma (POAG) patients constitute a heterogenous group. Identification of phenotypic subtypes among these patients may provide a deeper understanding of the disease and aid associations with genotypes. We describe a phenotype of POAG patients associated with a constellation of systemic disorders; patients with this phenotype seem to be vulnerable to optic nerve damage at low intraocular pressures. MATERIALS AND METHODS: In this retrospective study, we evaluated the medical records of active Jules Stein Eye Institute glaucoma patients from January 1996 to 2017 and included subjects with POAG, acquired pits of the optic nerve (APON), and at least one of the following: systolic blood pressure persistently ≤100 mm Hg, history of migraine headaches or migraine variant, and the Raynaud syndrome. RESULTS: Of 87 patients (125 eyes) with APON, 37 patients (55 eyes) met the study criteria. In total, 34 patients were female (92%). The median age at the time of diagnosis was 55 years. Nineteen patients (73%) had low systolic blood pressures, same number had Raynaud syndrome, and 25 (68%) had a history of migraine. CONCLUSIONS: We describe a POAG subtype with APON and systemic vascular instability, predominantly female in their sixth decade of life who demonstrate progressive glaucomatous visual field damage at low intraocular pressure. We suggest that this clinical picture represents an important phenotype of POAG, and that identification and further study of it will help guide diagnosis and development of individualized treatments.

Oxygen therapy for severe corneal alkali burn in rabbits.

PURPOSE: To evaluate the efficacy of oxygen therapy in the treatment of severe corneal alkali injury in rabbits. METHODS: In a double-blind experiment, 28 white New Zealand rabbits were randomized into an oxygen treatment group (n = 14) and a control group (n = 14). Under general anesthesia, severe corneal alkali injuries were induced by application of 1 N sodium hydroxide to the right eye of each rabbit. The oxygen treatment group was treated with oxygen 100% at a flow of 5 L/min for 1 hour daily for 1 month. Daily photographs were taken of the rabbits' eyes, and the sizes of the epithelial defect in the 2 groups were compared. The principal endpoint was descemetocele and perforation of the cornea. The animals were euthanized at the end of the study or earlier if corneal perforation had occurred, and the corneas were excised and fixed in 10% neutral-buffered formalin for histologic examination. RESULTS: Experimentally induced severe eye burns gave similar opacity of the cornea in both groups. Three eyes in the oxygen group and 9 eyes in the control group developed descemetocele and perforation (P = 0.022). Mean time to beginning of ulceration was 13.45 days in the control group and 18.11 days in the oxygen treatment group (P = 0.032). There was no other significant difference between the 2 groups. CONCLUSIONS: Oxygen therapy at a flow of 5 L/min for 1 hour daily reduces the possibility of corneal perforation in rabbits and may delay ulceration of the cornea compared with the control group.

Structure-Function Relationships in Perimetric Glaucoma: Comparison of Minimum-Rim Width and Retinal Nerve Fiber Layer Parameters.

Purpose: To test the hypotheses that: (1) structure-function (SF) relationships between visual fields (VF) and Bruch's membrane opening-based minimum rim width (BMO-MRW) measurements are superior to those for peripapillary retinal nerve fiber layer (pRNFL) in perimetric glaucoma; (2) BMO-MRW measurements may extend the utility of structural measurement across the range of glaucoma severity; and (3) to estimate the influence of Bruch's membrane opening (BMO) size on BMO-MRW measurements. Methods: One hundred eight perimetric glaucoma eyes (68 patients) with good quality spectral-domain optical coherence tomography images of the optic disc and pRNFL, and reliable VF within 6 months were recruited. Relationship of global and sectoral BMO-MRW and pRNFL thickness with corresponding VF parameters and the influence of normalizing BMO-MRW (on BMO circumference, nBMO-MRW) on SF relationships were investigated. Broken-stick models were used to compare the point at which pRNFL and BMO-MRW parameters reached their measurement floor. Results: The median (interquartile range) of VF mean deviation was -5.9 (-12.6 to -3.6) dB. Spearman correlation coefficients between pRNFL, BMO-MRW, and nBMO-MRW measures and corresponding VF cluster average deviations ranged between 0.55 to 0.80, 0.35 to 0.66, and 0.38 to 0.65, respectively. Bruch's membrane opening-MRW parameters demonstrated weaker SF relationships compared with pRNFL globally and in temporal, temporal-superior, and nasal-inferior sectors (P < 0.03). Normalization of BMO-MRW did not significantly influence SF relationships. Conclusions: Structure-function relationships were somewhat weaker with BMO-MRW parameters compared with pRNFL in eyes with perimetric glaucoma. Bruch's membrane opening-MRW normalization did not significantly change SF relationships in this group of eyes with mild departures from average BMO size.

Vertical Macular Asymmetry Measures Derived From SD-OCT for Detection of Early Glaucoma.

Purpose: To test the hypothesis that vertical asymmetry in macular ganglion cell/inner plexiform layer (GCIPL) thickness can improve detection of early glaucoma. Methods: Sixty-nine normal eyes and 101 glaucoma eyes had macular imaging with spectral-domain optical coherence tomography (OCT; 200 × 200 cube). The resulting GCIPL thickness matrix was grouped into a 20 × 20 superpixel array and superior superpixels were compared to their inferior counterparts. A global asymmetry index (AI) was defined as the grand mean of the asymmetry ratios. To measure local asymmetry, the corresponding thickness measurements of three rows above and below the horizontal raphe were compared individually and in combinations. Global and local AIs were compared to the best-performing GCIPL thickness parameters with area under the receiver operating curves (AUC) and sensitivity/specificities. Results: Age or axial length did not influence AIs in normal subjects (P ≥ 0.08). Global and local AIs were significantly higher in the glaucoma group compared to normal eyes. Minimum (AUC = 0.962, 95% confidence interval [CI]: 0.936-0.989) and inferotemporal thickness (AUC = 0.944, 95% CI: 0.910-0.977; P = 0.122) performed best for detection of early glaucoma. The AUC for global AI was 0.851 (95% CI: 0.792-0.909) compared to 0.916 (95% CI: 0.874-0.958) for the best local AI. Combining minimum or inferotemporal GCIPL thickness and the best local AI led to higher partial AUCs (0.088 and 0.085, 90% specificity, P = 0.120 and 0.130, respectively) than GCIPL thickness measures. Conclusions: Macular vertical thickness asymmetry measures did not perform better than sectoral or minimum GCIPL thickness for detection of early glaucoma. Combining local asymmetry parameters with the best sectoral GCIPL thickness measures enhanced this task.

The relationship between central visual field sensitivity and macular ganglion cell/inner plexiform layer thickness in glaucoma.

AIMS: To explore the correlation of local macular ganglion cell/inner plexiform layer (GC/IPL) thickness measurements with sensitivity at individual test locations on the central 10-2 visual fields (VFs) in patients with glaucoma. METHODS: One hundred thirty-seven eyes of 125 patients with spectral domain optical coherence tomography (OCT) and 10-2 VFs were included. The exported thickness matrices (200×200) of GC/IPL measurements were centred on the fovea. Total deviation values at each test location were correlated with the 20 000 GC/IPL thickness measurements in the corresponding inferior or superior hemiretina, and areas of highest correlation were plotted. Macular structure-function relationships were also examined between six wedge-shaped GC/IPL sectors and the corresponding VF clusters. A multivariate model was built to identify the 10-2 VF test locations associated with each GC/IPL sector thickness. RESULTS: Average mean deviation on 10-2 VFs was -9.2±6.1 dB. The 10-2 VF test points demonstrated correlations with GC/IPL thickness in localised arcuate patterns mostly limited within the central 4.8×4.0 mm measurement ellipse (ρ=0.43-0.74, p<0.05 for all). Twenty-one test points of the 10-2 VF were the best predictors of sectoral GC/IPL thickness. Sectoral VF-OCT correlations were high (ρ=0.53-0.66, p<0.001) and did not significantly change after adjusting for retinal GC displacement (p>0.05). CONCLUSIONS: Macular OCT/VF relationships have localised arcuate characteristics in the central region of the macula. Given the overlapping nature of structure-function relationships, a smaller number of VF test locations may be used to summarise macular functional damage. TRIAL REGISTRATION NUMBER: NCT01742819.

Descemet's Membrane Detachment Management Following Trabeculectomy.

PURPOSE: To present a case of total Descemet's membrane detachment (DMD) after trabeculectomy and its surgical management. CASE REPORT: A 68-year-old woman presented with large DMD and corneal edema one day after trabeculectomy. Intracameral air injection on day 3 was not effective. Choroidal effusion complicated the clinical picture with Descemet's membrane (DM) touching the lens. Choroidal tap with air injection on day 6 resulted in DM attachment and totally clear cornea on the next day. However, on day 12 the same scenario was repeated with choroidal effusion, shallow anterior chamber (AC), and DM touching the lens. The third surgery included transconjunctival closure of the scleral flap with 10/0 nylon sutures, choroidal tap, and intracameral injection of 20% sulfur hexafluoride. After the third surgery, DM remained attached with clear cornea. Suture removal and needling bleb revision preserved bleb function. Lens opacity progressed, and the patient underwent uneventful cataract surgery 4 months later. CONCLUSION: Scleral flap closure using transconjunctival sutures can be used for DMD after trabeculectomy to make the eye a closed system. Surgical drainage of choroidal effusions should be considered to increase the AC depth.