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

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

PurposeTo test the hypothesis that vertical asymmetry in macular ganglion cell/inner plexiform layer (GCIPL) thickness can improve detection of early glaucoma.MethodsSixty-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.ResultsAge 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.ConclusionsMacular 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

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

Modified descemet′s stripping automated endothelial keratoplasty for congenital hereditary endothelial dystrophy

A 19-year-old male with congenital hereditary endothelial dystrophy (CHED) presented with severe bilateral corneal clouding precluding any view of the intraocular structures. He underwent modified Descemet′s stripping automated endothelial keratoplasty (DSAEK) technique including a suture pull-through technique to prevent lens damage. Surgery resulted in progressive clearing of the cornea and decreased corneal thickness. Visual acuity increased from hand motions preoperatively to counting fingers at 4 m after 4 months. DSAEK can be successfully performed in phakic eyes with CHED as an alternative to penetrating keratoplasty. It has the advantage of less wound problems and better preservation of globe integrity especially in children

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 ofdiagnosis, 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

Scheimpflug Imaging Criteria for Identifying Eyes at High Risk of Acute Angle Closure

Purpose: To compare anterior segment and ocular biometric parameters in unaffected fellow eyes of patients with a previous attack of acute angle closure (AAC), primary angle closure suspect (PACS) eyes, and normal eyes; and to identify eyes at high risk of AAC among primary angle closure suspects. Methods: In this case-control study, 16 unaffected fellow eyes of patients with a previous attack of AAC (group I), 20 PACS eyes (group II) and 18 normal eyes (group III) underwent Pentacam and A-scan echography. Results: Mean anterior chamber volume was 72±18, 77±18 and 176±44 μl in groups I, II, and III, respectively (P0.05). Conclusion: Eyes with anterior chamber volume ≤100 μl, depth ≤2.1 mm and angle ≤26° may be considered at high risk for developing AAC. These criteria could be helpful for making decisions regarding prophylactic laser peripheral iridotomy

Normobaric Oxygen Therapy for Scleral Ischemia or Melt

Purpose: To investigate the efficacy of normobaric oxygen (NBO) therapy for treatment of scleral ischemia or melt. Methods: This prospective interventional case series includes 9 eyes of 8 patients with scleral ischemia or melt of diverse etiologies. Following the failure of conventional medical and/or surgical therapy to improve ischemia or upon clinical deterioration, NBO was initiated. All patients received 100% NBO at flow rate of 10 liters/minute by face mask for 1 hour, twice daily until complete vascularization of ischemic areas. Main outcome measures were improvement of scleral ischemia and healing of conjunctival epithelial defects. Results: NBO therapy led to epithelialization and vascularization of the ischemic sclera in all eyes; the repair process began 3-4 days after NBO had been initiated and was completed in 18.1±4.7 (range, 10-25) days. All patients remained stable over a 9-month follow-up period. Conclusion: NBO therapy seems effective for treatment of scleral ischemia or melt, and hence can be considered as a non-invasive alternative to surgical intervention in these conditions

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.

PurposePrimary 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 methodsIn 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.ResultsOf 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.ConclusionsWe 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