Aby Jacob - Academia.edu (original) (raw)

Papers by Aby Jacob

British Journal of Ophthalmology, Apr 1, 2003

Aim: To report progression of primary angle closure suspects (PACS) to primary angle closure (PAC... more Aim: To report progression of primary angle closure suspects (PACS) to primary angle closure (PAC) at the 5 year follow up of a population based sample. Methods: 82 of 118 PACS who could be contacted and 110 randomly selected normals from a population based survey in 1995 were invited for a follow up examination in 2000. Progression to PAC was based on the development of raised IOP or synechiae in a PACS. Results: 50 of the 82 PACS contacted were examined. 11 (22%; 95% CI 9.8 to 34.2) developed PAC (seven synechial and four appositional); all were bilateral PACS. Two of 50 people previously diagnosed as PACS were reclassified as normal. One person among the 110 normals progressed to PAC. The relative risk of progression among PACS was 24 (95% CI 3.2 to 182.4). There was no significant difference in axial length, anterior chamber depth, or lens thickness between those who progressed and those who did not. None of the patients developed optic disc or field damage attributable to angle closure. One angle closure suspect was diagnosed to have normotensive glaucoma. Conclusion: In this population based study of PACS the 5 year incidence of PAC was 22%; none developed functional damage. Bilateral PACS was a clinical risk factor for progression.

Diagnostics

Purpose: to assess the tomographic retinal layers’ thickness in eyes affected by branch retinal a... more Purpose: to assess the tomographic retinal layers’ thickness in eyes affected by branch retinal artery occlusion (BRAO) and to compare it to those of patients affected by primary open angle glaucoma (POAG). Methods: retrospective review of 27 patients; 16 with BRAO (16 eyes) and 11 with POAG (20 eyes) were identified among those who received SD-OCT scans, including analysis of macular retinal nerve fiber layer (mRNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), neuroretinal rim (NRR), circumpapillary RNFL at 3.5 mm and hemisphere asymmetry (HA). Results: the total IPL and INL thinning difference between the two groups was statistically significant (p = 0.0067 and p < 0.0001, respectively). The HA difference for the total macular thinning, mRNFL, GCL, IPL and INL (p < 0.0001) was also statistically significant. The analysis of the average total retinal thinning, total mRNFL and GCL thinning showed no statistically significant difference b...

Cureus

Background Deep sclerectomy (DS) is a non-penetrating surgical procedure for glaucoma, reducing t... more Background Deep sclerectomy (DS) is a non-penetrating surgical procedure for glaucoma, reducing the resistance to aqueous outflow and lowering intraocular pressure while maintaining a physiological barrier between the anterior chamber and the sub-scleral space. This offers a lower complication profile than penetrating procedures, though with less intraocular pressure (IOP) reduction. Methods We retrospectively reviewed the electronic record for all DS undertaken at our hospital (a tertiary care center) over 14 years, collecting data on demographics, diagnosis, IOP, visual acuity, complications, medications, and further procedures required. Results Eighty eyes of 69 patients underwent DS, with a mean follow-up period of 53.5 months. The mean pre-operative IOP was 23.55 mmHg (range 11-52, standard deviation 8.46); the mean final IOP was 13.61 mmHg (range 5-35, SD 4.73), with a mean reduction of 42.21%. The mean change in glaucoma medications was -1.64. 78.40% experienced a reduction in glaucoma treatment. Post-operatively, 43.80% had no complications; this improved to 85.0% when numerical hypotony and raised IOP without visual sequelae were excluded. Further procedures required included Nd:YAG goniopuncture (10%), bleb needling (13.75%) or revision (7.5%), iridectomy (3.75%), goniosynechiolysis (1.25%), and autologous blood injection (1.25%). Two eyes were converted to trabeculectomy peri-operatively, with seven overall (8.75%) requiring trabeculectomy over the course of follow-up. 3.75% underwent glaucoma drainage device implantation, and 3.75% underwent cyclodiode laser. Conclusion We have found DS to be a safe, effective procedure for selected patients where trabeculectomy has a high likelihood of failure or where a higher IOP can be tolerated.

Cureus Journal of Medical Science

Methods
We retrospectively reviewed the electronic record for all DS undertaken at our hospital (a tertiary care center) over 14 years, collecting data on demographics, diagnosis, IOP, visual acuity, complications, medications, and further procedures required.

Results
Eighty eyes of 69 patients underwent DS, with a mean follow-up period of 53.5 months. The mean pre-operative IOP was 23.55 mmHg (range 11-52, standard deviation 8.46); the mean final IOP was 13.61 mmHg (range 5-35, SD 4.73), with a mean reduction of 42.21%. The mean change in glaucoma medications was -1.64. 78.40% experienced a reduction in glaucoma treatment. Post-operatively, 43.80% had no complications; this improved to 85.0% when numerical hypotony and raised IOP without visual sequelae were excluded. Further procedures required included Nd:YAG goniopuncture (10%), bleb needling (13.75%) or revision (7.5%), iridectomy (3.75%), goniosynechiolysis (1.25%), and autologous blood injection (1.25%). Two eyes were converted to trabeculectomy peri-operatively, with seven overall (8.75%) requiring trabeculectomy over the course of follow-up. 3.75% underwent glaucoma drainage device implantation, and 3.75% underwent cyclodiode laser.

Conclusion
We have found DS to be a safe, effective procedure for selected patients where trabeculectomy has a high likelihood of failure or where a higher IOP can be tolerated.

We conducted a genome-wide association study for primary open-angle glaucoma (POAG) in ,263 affec... more We conducted a genome-wide association study for primary open-angle glaucoma (POAG) in ,263 affected individuals (cases) and 34,877 controls from Iceland. We identified a common sequence variant at 7q3 (rs423660[A], odds ratio (OR) = .36, P = 5.0 × 0 −0 ). We then replicated the association in sample sets of 2,75 POAG cases and 2,064 controls from Sweden, the UK and Australia (combined OR = .8, P = 0.005) and in 299 POAG cases and 580 unaffected controls from Hong Kong and Shantou, China (combined OR = 5.42, P = 0.002). The risk variant identified here is located close to CAV1 and CAV2, both of which are expressed in the trabecular meshwork and retinal ganglion cells that are involved in the pathogenesis of POAG. Glaucoma is the leading cause of irreversible blindness worldwide, affecting approximately 70 million people 1 . It is a chronic degenerative optic neuropathy with progressive loss of retinal ganglion cells and axons resulting in a corresponding thinning of the neuroretinal...

Investigative Ophthalmology & Visual Science, 2014

Indian journal of ophthalmology, 1998

Glaucoma is fast emerging as a major cause of blindness in India. In order to estimate the preval... more Glaucoma is fast emerging as a major cause of blindness in India. In order to estimate the prevalence of primary open angle glaucoma (POAG) and primary angle closure glaucoma (PACG) in an urban South Indian population, we examined 972 individuals aged 30-60 years, chosen using a cluster sampling technique from 12 census blocks of Vellore town. They underwent a complete ocular examination, including applanation tonometry and gonioscopy, at the Medical College Hospital. Characteristic field defects on automated perimetry was a diagnostic requisite for POAG. Prevalence (95% CI) of POAG, PACG, and ocular hypertension were 4.1 (0.08-8.1), 43.2 (30.14-56.3), and 30.8 (19.8-41.9) per 1,000, respectively. All the PACG cases detected were of the chronic type. Hitherto unavailable community-based information on primary glaucoma in our study population indicates that PACG is about five times as common as POAG.

Ophthalmology, 2022

PURPOSE To develop and validate a deep learning (DL) system for predicting each point on visual f... more PURPOSE To develop and validate a deep learning (DL) system for predicting each point on visual fields (VF) from disc and optical coherence tomography (OCT) imaging and derive a structure-function mapping. DESIGN Retrospective, cross-sectional database study PARTICIPANTS: 6437 patients undergoing routine care for glaucoma in three clinical sites in the UK. METHODS OCT and infrared reflectance (IR) optic disc imaging was paired with the closest VF within 7 days. Efficient-Net B2 was used to train two single modality DL models to predict each of the 52 sensitivity points on the 24-2 VF pattern. A policy DL model was designed and trained to fuse the two model predictions. MAIN OUTCOME MEASURES Pointwise Mean Absolute Error (PMAE) RESULTS: A total of 5078 imaging to VF pairs were used as a held-out test set to measure the final performance. The improvement in PMAE with the policy model was 0.485 [0.438, 0.533] dB compared to the IR image of the disc alone and 0.060 [0.047, 0.073] dB compared to the OCT alone. The improvement with the policy fusion model was statistically significant (p < 0.0001). Occlusion masking shows that the DL models learned the correct structure function mapping in a data-driven, feature agnostic fashion. CONCLUSIONS The multimodal, policy DL model performed the best; it provided explainable maps of its confidence in fusing data from single modalities and provides a pathway for probing the structure-function relationship in glaucoma.

Eye

Aims To assess the efficacy of Xen in reducing intraocular pressure (IOP) in varying glaucoma sub... more Aims To assess the efficacy of Xen in reducing intraocular pressure (IOP) in varying glaucoma subtypes. To assess the effect of combined phacoemulsification. To determine the frequency of complications and explore further bleb management needed. Methods Retrospective case note review of all patients undergoing Xen implantation across four centres from August 2015 to May 2017. Results In total, 259 consecutive surgeries of 226 patients were reviewed. IOP reduced from 19.3 (SD ± 6.0) mmHg preoperatively to 14.2 (SD ± 4.4) at month 12 and 13.5 (SD ± 3.3) at month 18 (p < 0.0001). Medication usage reduced from 2.6 (±1.1) preoperatively to 0.8 (±1.0) at month 12 (p < 0.0001) and 1.1 (±1.3) medications at month 18 (p < 0.0001). Simultaneous phacoemulsification did not alter outcomes as Xen IOP was 14.3 (SD ± 4.7) mmHg and Phaco-Xen was 13.8 (SD ± 2.6) mmHg at month 12 (p = 0.5367). Xen appears to be effective in previous failed filtration surgery. Adverse events included: IOP spikes of ≥30 mmHg in 33 (12.7%) cases, secondary filtration surgery required in 24 (9.3%) cases; implant exposure in 6 (2.3%) cases; persistent hypotonous maculopathy in 5 (1.9%) cases; persistent choroidal effusions in 4 (1.5%) cases; a cyclodialysis cleft secondary to implant insertion in 1 (0.5%) case; and 1 (0.5%) case of endophthalmitis postimplant bleb resuturing. In all, 40.9% of cases required postoperative bleb needling or antimetabolite injection. Conclusions Xen reduces IOP and medications at 18 months. Adverse events are uncommon. Careful postoperative surveillance and low threshold for bleb management is needed. Xen is safe and effective in mild to moderate glaucoma.

Indian journal of ophthalmology, 1997

The increasing popularity of phacoemulsification in our country raises important training issues.... more The increasing popularity of phacoemulsification in our country raises important training issues. We prospectively analyzed the incidence of complications and visual outcomes in the initial 70 phacoemulsifications (70 patients) performed by the first two residents learning phacoemulsification in our training programme. Both were experienced in standard (manual) extracapsular cataract extraction. Postoperative follow up of 6 weeks or longer was available in 59 eyes. The 11 patients (11 eyes) lost to follow up did not have any intra-operative complications. The overall incidence of vitreous loss was 10%, similar to the frequency of this complication (determined retrospectively) in the first 70 standard extracapsular cataract extractions performed by the same residents. Intraocular lenses (IOL) were successfully implanted in 62 eyes, as planned. One IOL dislocated into the vitreous was successfully repositioned. Other complications encountered included superior corneal edema (3 eyes), ...

Molecular vision, 2012

Primary open angle glaucoma (POAG) is a characteristic optic neuropathy which progresses to irrev... more Primary open angle glaucoma (POAG) is a characteristic optic neuropathy which progresses to irreversible vision loss. Few genes have been detected that influence POAG susceptibility and other genes are therefore likely to be involved. We analyzed carefully characterized POAG cases in a genome-wide association study (GWAS). We performed a GWAS in 387 POAG cases using public control data (WTCCC2). We also investigated the quantitative phenotypes, cup:disc ratio (CDR), central corneal thickness (CCT), and intra-ocular pressure (IOP). Promising single nucleotide polymorphisms (SNPs), based on various prioritisation criteria, were genotyped in a cohort of 294 further POAG cases and controls. We found 2 GWAS significant results in the discovery stage for association, one of which which had multiple evidence in the gene 'neural precursor cell expressed, developmentally down-regulated 9' (NEDD9; rs11961171, p=8.55E-13) and the second on chromosome 16 with no supporting evidence. Tak...

Indian journal of ophthalmology, 1993

To investigate the incidence of complications reportedly caused by the use of 5-fluorouracil (5-F... more To investigate the incidence of complications reportedly caused by the use of 5-fluorouracil (5-FU) in glaucoma filtering surgery, we performed trabeculectomy with 5-FU on 57 eyes of 56 patients with advanced glaucoma. The mean preoperative intraocular pressure was 34.8 mm Hg. The most frequent complication encountered was superficial punctate keratopathy (26%), followed by shallowing of the anterior chamber (12%), choroidal detachment (9%), and flap retraction (7%). We, however, did not encounter any cases of confluent corneal epithelial defect, subepithelial scarring, or striate melanokeratosis which are usually described with the use of 5-FU. With a mean follow-up of 7.1 months, an intraocular pressure less than 16 mm Hg without hypotensive therapy were achieved in 73.7% of cases, and less than 21 mm Hg without hypotensive therapy in 86%. Considering the low incidence of complications and the high success rate, we recommend the use of 5-FU in routine glaucoma filtering surgery.

Nephrology Dialysis Transplantation, 2006

Human Molecular Genetics, 2011

British Journal of Ophthalmology, 2007