Modifications to Combined Trabeculectomy and Manual Small Incision Cataract Surgery: Outcomes and Adaptability in Resource-constrained Areas.

PRECIS: We describe standardization and simplification of classic trabeculectomy combined with manual small incision cataract surgery (MSICS) to effectively manage the 2 leading and often coexisting causes of blindness and vision impairment in resource-constrained areas. PURPOSE: The purpose of this study was to describe modifications to trabeculectomy combined with MSICS and report on the outcomes of this technique. The modifications consist of standardization and simplification of the surgical steps. METHODS: Data obtained from adult patients who underwent described surgical technique at rural eye care centers across 3 Indian states between January 2018 and May 2019 were analyzed retrospectively. Complete success was intraocular pressure between 6 and 18 mm Hg without supplementary medication. Qualified success allowed up to 3 topical medication(s). Data are presented as median (first and third quartiles). RESULTS: We analyzed data of 70 eyes of 70 patients. Ophthalmology fellows performed 27 (38.5%) surgeries, whereas an experienced glaucoma specialist performed 43 (61.4%) surgeries. Patients were 63 (56, 67) years old. The preoperative intraocular pressure was 20 (16, 26) mm Hg on treatment with 3 (2, 3) antiglaucoma medications. Glaucoma was advanced by optic disc structural criteria in 58 (82.8%) eyes. Intraoperative mitomycin C was used in 5 (7.1%) eyes. Follow-up was 12.5 (6, 18) months. At 1 year, complete success (95% confidence interval) achieved was 55% (41-67), whereas qualified success was 83% (68-92) with 0 (0, 1) topical medications. The complete and qualified success rates did not differ between ophthalmology fellows and the glaucoma specialist (P=0.75 and 0.44, respectively). CONCLUSIONS: We present a straightforward, yet effective technique of combined cataract and glaucoma surgery. The technique has a potential for wider applicability, especially in the underserved regions of the world.

Comparison of Saccadic Eye Movements Among the High-tension Glaucoma, Primary Angle-closure Glaucoma, and Normal-tension Glaucoma.

PRCIS: Saccadic eye movements were compared between high-tension glaucoma (HTG), normal-tension glaucoma (NTG), and primary angle-closure glaucoma (PACG). Saccades were differently affected between the subtypes of primary glaucoma. AIM: The aim of the study was to compare saccadic eye movements in eyes with HTG, PACG, and NTG. METHODS: Saccadic eye movements were recorded using the eye tracker Eyelink-1000 in 52 participants: 15 HTG, 14 PACG, 8 NTG, and 15 normal controls. All participants underwent a complete ophthalmic and visual field examination. Prosaccades were measured using the gap paradigm. Prosaccades were measured at 3 target eccentricities (5-, 7-, and 10-degree eccentricity). All prosaccade targets were projected outside the area of visual field defect. Saccade latency, average and peak velocity, and amplitude difference of the saccades were compared between glaucoma subtypes. RESULTS: The mean±SD age was lesser in controls compared with glaucoma (P=0.02). The mean age in all the glaucoma subtypes was comparable (P=0.92). The average mean deviation in PACG (-16.66±6.69 dB) was worse (P=0.01) than in HTG (-11.56±6.08 dB) and NTG (-9.55±3.96 dB). The latencies were delayed, average and peak velocities were reduced, and saccades were hypometric in glaucoma compared with controls (P<0.01). Between subtypes, the differences in latency (P<0.01), peak velocity (P=0.02), and amplitude (P=0.02) were significant. Saccadic eye movements were significantly different in NTG compared with other glaucoma subtypes (post hoc analysis; latency (HTG vs. NTG; P<0.01, HTG vs. PACG; P=0.01), peak velocity (HTG vs. NTG; P=0.02) and amplitude difference (HTG vs. NTG; P=0.02). CONCLUSIONS: Saccadic eye movement parameters were differently affected among the glaucoma subtypes. Saccadic parameters were more affected in NTG.

Visual impairment in pseudoexfoliation from four tertiary centres in India.

PURPOSE: To analyse the disease burden of pseudoexfoliation (PXF) disease stages from East and South India. DESIGN: Prospective hospital based study of patients seen at 4 tertiary centres. SUBJECTS, PARTICIPANTS, AND/OR CONTROLS: Consecutive old and new patients of pseudoexfoliation with normal intraocular pressure (IOP), raised IOP (PXF with Ocular hypertension, OHT) and irreversible disc/field changes (pseudoexfoliation glaucoma, PXG) seen from April 2016-March 2017 at a tertiary centre in Odisha, East India and 3 centres in Andhra Pradesh and Telangana, South India, recruited into the prospective study were screened for baseline characteristics. METHODS: The clinical and demographic details including visual acuity, laterality, intraocular pressure (IOP) with details of medical/surgical therapy at presentation were collected from the hospital database at all 4 centres. INTERVENTION OR EXPOSURE: The World Health Organization WHO visual criteria were used for defining visual impairment/absolute blindness in different disease stages. OUTCOME MEASURES: The visual impairment/blindness rates with comorbidities in the anterior/posterior segment in PXF, OHT and PXG at baseline were compared and the influence of age, IOP fluctuations and laterality was analysed using multivariate logistic regression. RESULTS: Of 6284 PXF eyes (of 3142 patients) included from all centres, OHT and PXG was seen in 2.1% and 29% respectively which included 3676 (>50%) bilateral PXF eyes. Reversible visual impairment rates caused by PXF associated co-morbidities in PXF and OHT were 33% and 26% respectively with cataract being the major cause (67% in PXF and 74% in OHT). Irreversible blindness rate was higher in bilateral PXG eyes (30.5%) compared to bilateral PXF (23.2%) or bilateral OHT (21.6%) with overall absolute blindness rates of 28.2% at presentation. Older age (p<0.001), bilaterality and higher baseline IOP were significantly associated with higher rates of blindness in PXF eyes. CONCLUSION AND RELEVANCE: Pseudoexfoliation is associated with ≥30% visual impairment across all stages and 28% absolute blindness rate which is a huge hidden burden of glaucoma. Adequate disease staging and assessment of comorbidities is required for accurate prognostication at baseline and reducing avoidable pseudoexfoliation blindness.

Comparison of peripapillary and subfoveal choroidal thickness in normal versus primary open-angle glaucoma (POAG) subjects using spectral domain optical coherence tomography (SD-OCT) and swept source optical coherence tomography (SS-OCT).

OBJECTIVE: To elucidate the difference between choroidal thickness (CT) in primary open-angle glaucoma (POAG) and normal subjects and to compare the CT measured using spectral domain optical coherence tomography (SD-OCT) and swept source optical coherence tomography (SS-OCT). METHODS AND ANALYSIS: This cross-sectional observational study included 25 eyes of 17 POAG subjects (cases) and 31 eyes of 20 normal subjects (controls). All the patients underwent complete ophthalmologic examination, enhanced depth imaging, SD-OCT and SS-OCT. In both controls and cases, the CT was measured in seven predetermined points in macular and peripapillary area and were compared. RESULTS: Choroid was significantly thicker on SS-OCT compared with SD-OCT in peripapillary and macular area in both cases and controls, except for inferior peripapillary in controls. The CT was not different from glaucoma and controls in peripapillary or macular area on SD-OCT (p>0.05), however, the CT was significantly thicker in glaucoma compared with controls in peripapillary area on SS-OCT (p<0.05) except inferior peripapillary (p=0.13). There was good intraobserver (±20 µm) and interobserver (±55 µm and ±45 µm) agreement on both SD-OCT and SS-OCT respectively.On SD-OCT, choroid was thinnest at the temporal peripapillary and thickest at subfoveal location in controls. In POAG, choroid was thinnest at inferior peripapillary region and thickest (500 µm) nasal to the fovea. On SS-OCT, choroid was thinnest at inferior peripapillary and thickest at the temporal peripapillary area in both cases and controls. CONCLUSION: CT measurements on SS-OCT were higher than the SD-OCT measurements possibly due to better delineation of the sclerochoroidal junction on SS-OCT. CT was significantly thicker in glaucoma subjects compared with controls in peripapillary area on SS-OCT but not in macular area.

Outcomes of Silicone Ahmed Glaucoma Valve Implantation in Refractory Pediatric Glaucoma.

PURPOSE: The purpose of this study was to report the outcomes of Silicone Ahmed Glaucoma Valve (AGV) implantation in the management of refractory pediatric glaucoma. METHODS: Between 2007 and 2015, 76 eyes of 64 children aged 16 years or younger underwent AGV implantation. We included 65 eyes of 53 children with follow up ≥6 months; 24 eyes had primary congenital glaucoma (PCG) and 41 eyes had secondary pediatric glaucoma (SPG). Success was defined as IOP>5 and ≤21 mm Hg with or without topical antiglaucoma medications; considered failure, when repeat glaucoma surgery was need or loss of light perception. Primary outcome measure was success of AGV in refractory pediatric glaucomas and secondary outcome measure was comparison of outcomes in PCG and SPG. RESULTS: The median age at AGV implantation was 3 years (interquartile range, 2, 12), and median follow up was 27 months (15, 39). The overall cumulative success probability was 88% [95% confidence interval (CI), 76%-94%] at 1 year and was maintained up to 4 years. The success probability in PCG was 91% (80.8%-100%), and SPG was 83% (72%-96%) at 1 year and 4 years (P=0.49). Among the preoperative factors, number of previous intraocular surgeries (hazard ratio of 2.24; 95% CI, 1.14-4.37, was significantly associated with failure; P=0.01). Tube-related complications (16%) were similar in both the groups. One eye in each group had sight-threatening complication. CONCLUSIONS: AGV implantation had good success rate in refractory pediatric glaucoma. The success rates were similar in PCG and SPG as were the complications. Number of prior intraocular surgeries was a risk factor for failure.

Comparison of the New Low-Cost Nonvalved Glaucoma Drainage Device with Ahmed Glaucoma Valve in Refractory Pediatric Glaucoma in Indian Eyes.

PURPOSE: To compare outcomes of a nonvalved glaucoma drainage device (the Aurolab aqueous drainage device [AADI] with a valved glaucoma drainage device (the Ahmed glaucoma valve [AGV]) in refractory pediatric glaucoma. DESIGN: Retrospective interventional case series. PARTICIPANTS: One hundred sixteen eyes of 97 children with refractory pediatric glaucoma. METHODS: Children (≤16 years) treated with drainage implants from January 2007 through December 2016 with a minimum follow-up of 6 months (operated by a single surgeon) were included. Success was defined as intraocular pressure (IOP) ≥6 mmHg or ≤21 mmHg (complete without antiglaucoma medications [AGMs] and qualified with AGM); repeat glaucoma surgery or loss of light perception was failure. MAIN OUTCOME MEASURES: Comparison of success rates and complications with AADI (350 mm2) and silicone AGV (models FP7 [182-mm2 surface area] and FP8 [102-mm2 surface area]) implantation. RESULTS: Outcomes of 116 eyes of 97 children (AADI, 36 eyes; AGV, 85 eyes; FP7, n = 14; FP8, n = 72) were analyzed. Median follow-up for AADI was 16.8 months (interquartile range [IQR], 11.7-24.5 months) and for AGV was 27 months (IQR, 15.3-52.3 months). Preoperative parameters (age, IOP, number of AGMs) were similar in both groups except number of previous nonglaucoma surgeries, which were significantly more in AADI (P = 0.05). Qualified success was similar (P = 0.81) in both groups, 91% and 88% at 1 year and 81% and 84% at 3 years with AADI and AGV, respectively. With AADI, the complete success was significantly more (41.8% vs.13.7%; P < 0.005). The postoperative mean IOP (12.6±5.5 mmHg vs. 17.6±6.8 mmHg; P = 0.001), median number of AGMs (1 [IQR, 0-2] vs. 2 [IQR, 1-3]; P < 0.001), and hypertensive phase (16.5% [n = 7] vs. 40% [n = 34]; P = 0.02) were significantly less in AADI compared with AGV. Transient complications (AADI, 30.5% [n = 11/36] vs. AGV, 21.1% [n = 18/85]; P = 0.26), sight-threatening complications (AADI, 13.9% [n = 5/36) vs. AGV, 7% [n = 6/85]; P = 0.22), and complications needing intervention (AADI, 19.4% [n = 7/36] vs. AGV, 14.1% [n = 12/85]; P = 0.46) were similar in both groups. CONCLUSIONS: In refractory pediatric glaucoma, both AGV and AADI showed similar qualified success and complication rates at 1 and 3 years. However, the AADI showed greater complete success, better IOP control, less need for AGM, and lesser incidence of an hypertensive phase.

Intermediate Term Outcomes of Early Posttrabeculectomy Bleb Leaks Managed by Large Diameter Soft Bandage Contact Lens.

PURPOSE: To study the outcomes of large diameter soft bandage contact lens (BCL) in managing early trabeculectomy bleb leak. MATERIALS AND METHODS: Of 972 eyes that underwent fornix-based trabeculectomy between 2011 and 2015, 19 eyes with bleb leak with at least 1 year follow-up were eligible. Bleb leak was conservatively managed using large diameter BCL (≥15.5 mm in diameter). Success was defined as complete, if bleb leak resolved and the intraocular pressure (IOP) was ≥5 and ≤18 mm Hg with no additional antiglaucoma medication and failure if surgical intervention was needed. RESULTS: Mean age (±SD) of subjects was 43.5±11.9 years. Mitomycin C was used in 15/19 eyes. Median time (interquartile range) from trabeculectomy to bleb leak was 9 days (interquartile range: 8 to 19 d). Bleb leak was treated with 15.5 mm BCL in 16 eyes and 17 mm lens in 3 eyes. Bleb leak resolved with BCL in 17 [89.5%; 95% confidence interval (95% CI), 68.6-97] and 2 eyes (10.5%; 95% CI, 2-31) required bleb resuturing. Mean duration of BCL wear for bleb leak resolution was 23.7±8.9 days. Mean IOP increased from 5.8±2.7 to 12.5±3.1 mm Hg after resolution of bleb leak (P<0.05). At 16 months, complete success probability of trabeculectomy was 89.4% (95% CI, 75.6%-100%). CONCLUSIONS: Large diameter BCL was effective in the management of early bleb leak with good intermediate term success for IOP control. We suggest a trial of soft contact lens of appropriate diameter to manage early bleb leaks, before planning any invasive intervention.

Glaucoma associated with iridocorneal endothelial syndrome in 203 Indian subjects.

PURPOSE: To report the demographic profile, clinical features, and prevalence of glaucoma and its management in patients with Iridocorneal endothelial (ICE) syndrome. METHODS: Retrospective review of 203 consecutive subjects with ICE syndrome at a tertiary eye care centre between January 1988 and June 2013. RESULTS: ICE syndrome was present in 223 eyes of 203 subjects, 124 (61%) were female and 79 (39%) were male. The median age at presentation was 43 years (1st (Q1) and 3rd (Q3) quartile; 34, 51 years). ICE syndrome was unilateral in 183 (90%) subjects, and bilateral in 20 (10%) subjects. The most common clinical variant was progressive iris atrophy (PIA, 115; 52% eyes), followed by Chandler syndrome (CS, 87; 39% eyes) and Cogan-Reese syndrome (CRS, 21; 9% eyes). Glaucoma was found in 156 eyes (70%) at presentation and the median (Q1, Q3) intraocular pressure in eyes with glaucoma was 24 (16, 38) mm Hg. Seven eyes developed glaucoma during the follow-up period, increasing the percentage of eyes with glaucoma to 73%. Intraocular pressure was managed medically in 81 eyes (50%) and the other 82 eyes (50%) required surgical intervention. Corneal edema was present in 124 eyes (56%) of which, 32 eyes (14%) required keratoplasty. CONCLUSIONS: In our study on ICE syndrome in Indian population, the presentation was predominantly uniocular and more common in middle aged women. Progressive iris atrophy was the most common clinical variant. ICE syndrome was associated with glaucoma in over 70% of the eyes and half of the eyes had corneal edema.

Correction: Etiology and Management of Raised Intraocular Pressure following Posterior Chamber Phakic Intraocular Lens Implantation in Myopic Eyes.

[This corrects the article DOI: 10.1371/journal.pone.0165469.].

Etiology and Management of Raised Intraocular Pressure following Posterior Chamber Phakic Intraocular Lens Implantation in Myopic Eyes.

AIM: To evaluate the etiology and management of elevated intraocular pressure (IOP) following posterior chamber phakic implantable collamer lens (ICL) surgery. METHODS: Between 2009 and 2015, 638 eyes of 359 subjects with refractive myopia, underwent V4b and V4c (CentraFLOW) model ICL implantation. Ocular hypertension (OHT) was defined as IOP of ≥ 22 mm Hg on two separate occasions and elevated IOP with corresponding optic disc or visual field damage was defined as glaucoma. RESULTS: Elevated IOP ≥ 22 mm Hg was noted in 33 eyes of 30 subjects (33/638; 5.17%). Median age of subjects with raised IOP was 26 years (Inter quartile range (IQR):22, 29) and median refarctive error was -16 diopters (-19.5, -13). The median follow up was 7.8 months (IQR:0.3, 17.6) and median time for postoperative IOP rise was 12 days, (IQR:2, 24). The various etiologies for elevated IOP were steroid response in 21 eyes (64%; 10 eyes with V4b, 11 eyes with V4c), retained viscoelastic in 5 eyes (15%) (3 with V4b, 2 with V4c), pupillary block in four eyes (12%; 3 with V4b, 1 with V4c), malignant glaucoma in one eye (3%, V4b), and missed pre-existing Juvenile open angle glaucoma (JOAG) in two eyes (6% with V4b). Elevated IOP in 31 eyes resolved with conservative management. One eye (centraFLOW design) with central aquaport block by viscoelastic, needed AC wash and one eye with malignant glaucoma needed parsplana vitrectomy and hyaloidotomy. Ten eyes required longterm (>2 months) antiglaucoma medications (AGM) for IOP control. Except the two eyes with JOAG, none had disc and field damage. CONCLUSION: In our series, OHT was seen in 4.85% and glaucoma in 0.3% eyes that underwent V4b and V4c model ICL implantation. Multiple etiologies were noted and steroid induced ocular hypertension was the most common cause of elevated IOP followed by retained viscoelastic and pupillary block. One third of these eyes required longterm AGM for IOP control.

How Often the Goldmann Applanation Tonometer Should be Checked for Calibration Error?

PURPOSE: To evaluate the frequency of Goldmann applanation tonometer (GAT) calibration error (CE) check. METHODS: One observer at each of the 3 tertiary care ophthalmic centers was involved. The tonometers were checked at baseline for CE. A tonometer was defined as faulty when CE exceeded 2 mm Hg at any testing level. Faulty GATs were repaired in-house. Subsequent CE check was done once per month for 6 months. GATs were divided into 3 groups: group 1 (G1)≤1 year, group 2 (G2)>1 to 10 years, and group 3 (G3)>10 years of usage. RESULTS: In total, 76 slit-lamp mounted GATs were included. The number of GATs in groups 1 to 3 was 19, 36, and 21, respectively. Seven (9.2%) tonometers were faulty at the baseline. None in G1, 5 in G2, and 16 in G3 demonstrated unacceptable CE over the study course (P<0.01). The survival function of G1 tonometers was 1.0 throughout, whereas that (95% confidence interval) of the G2 and G3 tonometers were 0.97 (0.81-0.99) and 0.76 (0.51-0.89) at 1 month, and 0.86 (0.69-0.93) and 0.23 (0.08-0.43) at 6 months, respectively. The probability of CE development increased with increasing age of the tonometer. The frequency of use of the tonometer was not associated with the development of CE (odds ratio=1.00). CONCLUSIONS: CE occurs more frequently in older tonometers. Although newer GATs (<1 y old) can be checked twice yearly, GATs older than a year should be checked at least monthly.

Comparison of Cataract Surgery Alone Versus Cataract Surgery Combined With Trabeculectomy in the Management of Phacomorphic Glaucoma.

PURPOSE: To compare the outcomes of cataract surgery alone versus combined cataract surgery with trabeculectomy in eyes with phacomorphic glaucoma. MATERIALS AND METHODS: In a retrospective comparative case series, 126 eyes of phacomorphic glaucoma presenting within 4 weeks of onset between 1993 and 2012, with at least 6 months of postoperative follow-up were included. Group 1 included 63 eyes with cataract surgery only and group 2 included 63 eyes with combined cataract surgery and trabeculectomy. Primary outcome measure was intraocular pressure (IOP) ≤21 mm Hg (without antiglaucoma medication) 6 months after surgery. RESULTS: The median (interquartile range) preoperative IOP in group 1 was 36 mm Hg (30 to 50 mm Hg) and group 2 was 40 mm Hg (32 to 48 mm Hg) (P=0.34). The median duration of phacomorphic attack was 7 days (3 to 12 d) in group 1 and 7 days (3 to 15 d) in group 2 (P=0.39). The median duration of postoperative follow-up was 23 months in group 1 and 30 months in group 2 (P=0.89). Six months after surgery, 97% of the eyes in group 1 and 100% in group 2 achieved IOP≤21 mm Hg without antiglaucoma medications with a median postoperative IOP of 12 mm Hg in both the groups (P=0.09). The median Log MAR visual acuity was significantly better in group 1 compared with group 2 (0.2 vs. 0.3, P<0.001). The percentage of eyes that achieved visual acuity better than 20/40 at 3 months was 62% in group 1 versus 19% in group 2 and at 6 months it was 75% in group 1 versus 38% in group 2 (P<0.001). CONCLUSIONS: In our cohort of phacomorphic glaucoma presenting within 4 weeks of onset, cataract surgery and combined surgery resulted in similar IOP control at 6 months. However, cataract surgery alone resulted in better and faster visual recovery.

Diagnostic Abilities of Variable and Enhanced Corneal Compensation Algorithms of GDx in Different Severities of Glaucoma.

PURPOSE: To compare the abilities of retinal nerve fiber layer (RNFL) parameters of variable corneal compensation (VCC) and enhanced corneal compensation (ECC) algorithms of scanning laser polarimetry (GDx) in detecting various severities of glaucoma. METHODS: Two hundred and eighty-five eyes of 194 subjects from the Longitudinal Glaucoma Evaluation Study who underwent GDx VCC and ECC imaging were evaluated. Abilities of RNFL parameters of GDx VCC and ECC to diagnose glaucoma were compared using area under receiver operating characteristic curves (AUC), sensitivities at fixed specificities, and likelihood ratios. RESULTS: After excluding 5 eyes that failed to satisfy manufacturer-recommended quality parameters with ECC and 68 with VCC, 56 eyes of 41 normal subjects and 161 eyes of 121 glaucoma patients [36 eyes with preperimetric glaucoma, 52 eyes with early (MD>-6 dB), 34 with moderate (MD between -6 and -12 dB), and 39 with severe glaucoma (MD<-12 dB)] were included for the analysis. Inferior RNFL, average RNFL, and nerve fiber indicator parameters showed the best AUCs and sensitivities both with GDx VCC and ECC in diagnosing all severities of glaucoma. AUCs and sensitivities of all RNFL parameters were comparable between the VCC and ECC algorithms (P>0.20 for all comparisons). Likelihood ratios associated with the diagnostic categorization of RNFL parameters were comparable between the VCC and ECC algorithms. CONCLUSION: In scans satisfying the manufacturer-recommended quality parameters, which were significantly greater with ECC than VCC algorithm, diagnostic abilities of GDx ECC and VCC in glaucoma were similar.

Outcomes of Primary Trabeculectomy With Mitomycin-C in Glaucoma Secondary to Iridocorneal Endothelial Syndrome.

PURPOSE: To report the outcomes of primary trabeculectomy with mitomycin-C (MMC) in eyes with glaucoma secondary to iridocorneal endothelial (ICE) syndrome. METHODS: We included 16 eyes of 15 subjects with ICE syndrome who underwent primary trabeculectomy with MMC between 1991 and 2013. Surgical success was defined as complete when the intraocular pressure (IOP) was ≥5 and ≤21 mm Hg with no additional antiglaucoma medication (AGM) or surgery and as qualified if IOP was controlled with AGM. RESULTS: The median age (interquartile range) of subjects at the time of trabeculectomy was 41 years (37, 44 y) and the median follow-up period was 23 months (7, 79 mo). Postoperatively, the median IOP significantly reduced from 36 (26, 43) to 14 mm Hg (12, 17 mm Hg) (P<0.001) and median number of AGMs reduced from 3 (2, 4) to 0 (0, 0) (P<0.001). The percentage of complete success was 75% at 6 months, 64% at 12 months, 57% at 36 months, and 33% at 60 months. The percentage of qualified success was 94% at 6 months, 82% at 12 months, 71% at 36 months, and 60% at 60 months. Five eyes failed during the follow-up period. The mean (±SD) number of glaucoma surgeries per eye was 1.3±0.5. Eight eyes developed corneal edema at a median follow-up of 78.5 months and 4 eyes underwent keratoplasty. CONCLUSIONS: Primary trabeculectomy with MMC offers moderate surgical success in patients with ICE syndrome. Maintaining long-term IOP control and corneal clarity in these eyes is a big challenge.

Structure-Function Relationship in Glaucoma Using Ganglion Cell-Inner Plexiform Layer Thickness Measurements.

PURPOSE: To evaluate the structure-function relationship between ganglion cell-inner plexiform layer (GCIPL) thickness at the macula and 10-2 standard automated perimetry (SAP) in glaucoma and to evaluate the relationship using a recently proposed linear model. METHODS: In a cross-sectional analysis, structure-function relationship was determined in 50 glaucomatous eyes (40 patients, mean deviation: -15.4 ± 7.5 dB) and 21 control eyes (13 subjects, mean deviation: -3.4 ± 3.0 dB), which had undergone 10-2 SAP and GCIPL imaging on the same day. Functional loss was derived from total deviation numerical values on 10-2 SAP and calculated on both a linear (reciprocal of Lambert) and a decibel scale after accounting for the retinal ganglion cell displacement at the macula. Strength of relationship was reported as coefficient of determination (R2) of the linear regression models fitted to the data separately for different sectors. The relationship was also evaluated using a linear model. RESULTS: The R2 for the associations between GCIPL thickness sectors and the corresponding sector SAP total deviation values ranged from 0.19 (for superonasal GCIPL sector) to 0.60 (for average GCIPL thickness) when functional loss was calculated on the decibel scale and 0.16 (for superonasal sector) to 0.54 (for inferior sector) on the linear scale. All associations were statistically significant (P < 0.05). The linear model fitted the data reasonably well. CONCLUSIONS: Significant structure-function associations were found between GCIPL thickness measurements at the macula and the functional loss measured on 10-2 SAP in glaucoma. Best fit was found for the inferior and average GCIPL sector thickness. The linear model was useful to study the structure-function relationship.