Shalini Mohan

Comparison of ultrasound biomicroscopic parameters after laser iridotomy in eyes with primary angle closure and primary angle closure glaucoma

PurposeTo study changes in anterior segment morphology after laser peripheral iridotomy (LPI) in primary angle closure (PAC) and primary angle closure glaucoma (PACG) using ultrasound biomicroscopy (UBM).MethodsNinety-three eyes of 93 patients underwent anterior segment evaluation including gonioscopy, disc evaluation with + 90D lens, applanation intraocular pressure, and standard achromatic perimetry. UBM was performed before and 2 weeks after Nd:YAG LPI to measure the trabecular-iris angle (TIA), the angle-opening distance (AOD 250/500), and the central anterior chamber depth (ACD).ResultsThe superior TIA widened from a mean of 7.54±3.15 to 15.66±6.69° (P=0.0001), the inferior TIA increased from a mean of 9.0±4.7 to 15.9±6.8° (P=0.0001) after LPI in PAC. In PACG, the mean superior angle changed from 4.55±2.5 to 6.12±3.8° (P=0.4) and the inferior angle increased from 4.75±2.0 to 7.9±3.7° (P=0.1). The mean ACD increased from 2.19±0.36 to 2.30±0.36 mm in PAC group (P=0.0003), with no significant change seen in the PACG group (1.79±0.32 vs1.82±0.33 mm, P=0.13).ConclusionLPI leads to a widening of the anterior chamber angle and a deepening of the anterior chamber in eyes with PAC. It does not significantly change any anterior segment parameters in eyes with PACG.

Study of biometric parameters in family members of primary angle closure glaucoma patients

ObjectivesTo measure ocular biometric parameters in all possible untreated family members of index primary angle closure glaucoma (PACG) patients and to correlate these values among affected, unaffected, and suspected family members.MethodsAnterior chamber depth (ACD), axial length (AL), lens thickness (LT), relative lens position, and central corneal thickness (CCT) were measured in first- and second-degree relatives of index patients. These biometric parameters were compared among the relatives and index patients as well as among affected, unaffected, and suspected family members.ResultsOf the 108 family members included in the study, 34 (31.6%) were affected with primary angle closure, 19 (17.6%) were suspect, and 55 (50.7%) were unaffected family members. In comparison to index cases, ACD was 14.56% more in affected, 21.7% more in primary angle closure suspects and 34.92% more in unaffected family members. LT was 10.73, 11.1, 16% less and AL was 0.11, 3.53 and 5.37% more in affected, suspected, and unaffected family members, respectively. Lens position and CCT were not statistically different in the various subgroups.ConclusionsACD is narrowest, lens thickest, and AL shortest in family members affected with PACG compared to suspected and unaffected members. Although LT and ACD could change with advancing age, AL appears to be a marker to identify members at risk of angle closure glaucoma.

Management of acute corneal hydrops secondary to keratoconus with intracameral injection of sulfur hexafluoride (SF6).

Purpose: To report the use of sulfur hexafluoride (SF6) gas in the management of corneal edema caused by acute corneal hydrops secondary to keratoconus. Methods: Nine eyes with acute hydrops secondary to keratoconus managed by SF6 gas injected into the anterior chamber (group 1) were compared to another 9 eyes that were managed conservatively with conventional medical therapy (group 2). Results: Of 9 eyes in group 1, 3 had 1 injection, 4 had 2 injections, and the remaining 2 had 3 injections into the anterior chamber. All the eyes in group 1 showed an early resolution of corneal edema at 4 weeks. The same was achieved in group 2 at 12 weeks. The central corneal thickness (CCT) in group 1 and group 2 was >1.0 mm at presentation. The CCT at 3 and 12 weeks in group 1 was 0.99 and 0.65 mm, respectively, whereas CCT in group 2 at 3 weeks was >1.0 mm and at 12 weeks was 0.991 mm (P = 0.001). The mean best spectacle-corrected visual acuity (BSCVA) at 12 weeks in group 1 and group 2 was 0.39 and 0.24, respectively (P = 0.016). The results were significant in favor of group 1 over group 2 both in CCT and BSCVA. Conclusion: Early intervention with intracameral SF6 injection is a safe and effective therapy for early reduction of corneal edema in eyes with keratoconus and acute hydrops.

An evaluation of the darkroom prone provocative test in family members of primary angle closure glaucoma patients

PurposeTo compare ocular biometric parameters with darkroom prone provocative test (DRPPT) in family members of primary angle closure glaucoma (PACG) patients.MethodsOne hundred and forty-nine family members of 46 PACG patients underwent ocular examination included slit lamp biomicroscopy, gonioscopy, fundus examination using +90 D lens, Goldmann applanation tonometry, darkroom prone provocative test, perimetry on Humphreys field analyzer II and optic disc evaluation using HRT II. Ultrasonic ocular biometry and the DRPPT were then performed. IOP⩾8 mmHg rise from baseline with iridocorneal touch was considered as a positive test.ResultsOf the 149 family members examined, 55 (36.9%) were found to have PACG. Forty (72.7%) of these had subacute PACG and 15 (27.3%) were found to have chronic PACG. Thirty-nine (70.3%) of the affected members showed a positive DRPPT. Mean anterior chamber depth (ACD) was 2.03±0.3, 2.3±0.4, 2.7±0.3 mm (P=0.0001) and mean lens thickness was 4.41±0.39, 3.99±0.5, 3.93±0.4 mm (P=0.0001) in DRPPT positives, borderlines and negatives respectively. ROC curve (ACD) plotted showed cutoff value of 2.07 mm (sensitivity 88.57%) for screening.ConclusionAnterior chamber is shallowest, lens is thickest and axial length is shortest in affected and DRPPT positive, family members of PACG patients.

Ultrasound biomicroscopic assessment of angle parameters in patients with primary angle closure glaucoma undergoing phacoemulsification.

Purpose To evaluate the effect of phacoemulsification and foldable intraocular lens (IOL) implantation on biometric determinants of the anterior chamber angle in primary angle closure glaucoma (PACG) using ultrasound biomicroscopy (UBM). Methods Forty-six eyes of 46 patients with chronic PACG and cataract having a patent laser iridotomy were included in this prospective, interventional case series. Angle parameters were measured using UBM before surgery and 3 months after phacoemulsification with IOL implantation. Intraocular pressure (IOP) was measured by applanation tonometer and records of glaucoma medication administered were maintained. Main outcome measures were IOP, central anterior chamber depth (ACD), trabecular iris angle (TIA), and angle opening distance at 250 and 500 μm from scleral spur (AOD250 and AOD500). Results The mean age of study participants was 56.5±9.9 years (range 44–75). The preoperative mean IOP was 25.0±5.4 mmHg on maximum antiglaucoma medication, which was reduced to 15.8±3.8 mmHg (p=0.0001) at 3 months. Number of antiglaucoma medications also decreased from 2.4±1.1 to 0.4±1.1 (p=0.0001). There was a significant widening of the anterior chamber angle with the TIA increasing significantly after phacoemulsification (p<0.001) with an associated increase in AOD250, AOD500, and ACD (p<0.001). Conclusions Phacoemulsification in eyes with PACG results in significant widening of the anterior chamber angle. This results in better IOP control after surgery and decreases the need for glaucoma medications. These findings are of clinical significance in obviating the need for simultaneous filtering surgery in eyes with PACG undergoing phacoemulsification cataract surgery.

Malignant glaucoma after intracameral isoexpansile perfluoropropane tamponade for the management of acute corneal hydrops.

To the Editor: We read with interest the case series on management of acute corneal hydrops with intracameral perfluoropropane tamponade and compression sutures. The conventional medical management for acute hydrops is giving way to newer interventional treatment modalities in both keratoconus and pellucid marginal corneal degeneration as evidenced by several recent reports. The use of intracameral air, isoexpansile perfluoropropane (C3F8), or sulfur hexafluoride (SF6) injections with or without tissue adhesive in the management of acute corneal hydrops in keratoconus had been described with encouraging results. We congratulate the authors on their excellent narration on use of intracameral C3F8 tamponade along with compression sutures in acute corneal hydrops and agree that it is a safe and useful therapy to shorten the duration of corneal edema in cases of corneal ectasias. Application of compression sutures to bridge the gaps of the stromal clefts along with intracameral gas injections, either as primary or as an adjunct procedure, is indeed a novel way to enhance rapid resolution of edema in such cases. The need of repeated injections in several cases is also to be noted. It, however, remains important to remember that, although intracameral injections of isoexpansile gases is an effective procedure for management of such cases, potential complications such as infection, raised intraocular pressure, and pupillary block may occur. Although intracameral gas injection treatment in cases of corneal ectasia with hydrops yields good results, we wish to highlight our experience in a case of keratoconus with acute corneal hydrops. A 16-year-old male patient who presented to us with keratoconus with acute hydrops in his left eye was managed with intracameral C3F8. The patient developed raised intraocular pressures in the first week after intracameral gas injection, which failed to respond to systemic antiglaucoma medical management. Slit-lamp biomicroscopic examination showed significant corneal edema and extremely shallow anterior chamber along with raised intraocular pressure of 58 mm Hg on Goldmann applanation tonometry (Figs. 1A, B). Nd:YAG peripheral iridotomy attempted was unsuccessful. The diagnosis of malignant glaucoma was confirmed by ultrasound biomicroscopic examination of the left eye that showed extremely shallow anterior chamber, peripheral iridocorneal touch, anteriorly placed iris lens diaphragm with stretched out anteriorly rotated ciliary body (Fig. 2). B-scan ultrasonography showed optically clear spaces in vitreous. Surgical intervention of automated lens aspiration with anterior vitrectomy in the left eye was done. The patient currently awaits his turn for keratoplasty with an unaided Snellen visual acuity of 6/60, normal intraocular pressures (Fig. 2), and keratometry of 48.75@15(/52.00@105(. From our experience, we would like to reiterate that intracameral gas injection is effective in treatment of acute hydrops in cases of corneal ectasia, but there is need to exercise adequate caution because

Trypan blue staining of filtering bleb in eyes with operated trabeculectomy

OBJECTIVE To report the use of trypan blue staining of the filtering bleb to assess its functional status in eyes undergoing phacoemulsification after trabeculectomy. SUBJECTS AND METHODS This retrospective study was conducted at a tertiary eye care centre in North India and studied 33 eyes of 33 patients ( with previously operated trabeculectomy), who underwent phacoemulsification. Trypan blue dye (0.06%) was used to stain the anterior capsule. After completion of phacoemulsification, the staining of the trabeculectomy bleb was noted as diffuse, patchy, minimal or no staining. RESULTS Of the 33 eyes, 13 had diffuse staining (39.4%, mean IOP = 9.3 ± 2.2 mm Hg), 7 (21.2%, mean IOP= 15.5 ± 1.8 mm Hg) had patchy staining, 4 had minimal staining (12.1%, mean IOP= 17.5 ± 0.5mm Hg) and nine (27.3%, mean IOP= 19.3 ± 1.6 mm Hg) had no staining. These staining patterns were labeled as groups 1 - 4 respectively. Statistical analysis showed that the difference between the IOPs in Group 1 - 2 and between Group 2 - 3 was not significant statistically (p=0.682 and 0.665 respectively). However the differences between the IOPs between Groups 1 - 3, 1 - 4, 2 - 4, and 3 - 4 were found to be highly significant statistically (p less than 0.0005). CONCLUSIONS Trypan blue dye can be used to test the amount of sub conjunctival filtration in eyes undergoing phacoemulsification cataract surgery.

Scanning laser ophthalmoscopy in an elderly Indian population

ABSTRACT Purpose: To study optic nerve head (ONH) characteristics using scanning laser ophthalmoscopy, Heidelberg retina tomograph (HRT), in an elderly population. Methods: A population-based, cross-sectional study included 1460 eyes of 1460 consecutive, subjects >60 years, in North India. All subjects underwent a detailed ophthalmic evaluation and imaged on HRT. Stereometric parameters, Moorfields regression analysis (MRA) and discriminant function analysis were analyzed. Correlation between ONH parameters and disc area, age, sex, and intraocular pressure was analyzed. Results: Disc size had a normal Gaussian distribution (2.22 ± 0.48 mm2), but all other stereometric parameters showed a wide variation. MRA found 1320 (90.4%) eyes within normal limits, 71 (4.86%), borderline limits, and 69 (4.73%) outside normal limits. Comparison of eyes meeting International Society of Geographical and Epidemiological Ophthalmology criteria for a glaucoma suspect, C:D > 0.7, with those that did not show a statistically significant difference in the cup area, rim area, rim disc ratio, and cup volume (p = 0.02, 0.02, 0.02, 0.03, respectively). An Intraocular pressure (IOP) ≥21 mmHg was seen in 3.01%, and only 12 eyes out of 1460, 0.82%, had an IOP ≥21 mmHg and a cup:disc ratio of more than 0.7. A van Herick estimation of < Grade 3 was seen in 19.4% Conclusions: Stereometric parameter data, MRA, and clinical examination in this population at high risk for glaucoma found that about 10% of individuals over 60 years of age could be classified as glaucoma suspects and would need further evaluation.

Scleral buckling-induced ocular parameter changes in different age group patients of rhegmatogenous retinal detachment

Purpose: This study was aimed to evaluate the difference in the ocular parameter changes following scleral buckling (SB) for rhegmatogenous retinal detachment (RRD) in different age group patients. Materials and Methods: This prospective study included 26 eyes of 26 patients who underwent SB for uncomplicated RRD. The patients were divided into three age groups: 16–30 years (Group I), 31–45 years (Group II), and 46–60 years (Group III). Axial length (AL), anterior chamber depth (ACD), and corneal curvatures were measured preoperatively and postoperatively at 1 week, 1 month, and 3-month. The postoperative change and progression of these parameters were evaluated and compared between three age groups using nonparametric Wilcoxon signed-rank test and Kruskal–Wallis test. Results: At 3-month follow-up, a statistically significant postoperative AL increase, ACD decrease, and surgically induced astigmatism (SIA) were observed in all groups (Group I - 0.75 ± 0.32 mm, 0.21 ± 0.21 mm, and 1.5 ± 0.48 D, respectively; Group II - 0.79 ± 0.41 mm, 0.14 ± 0.04 mm, and 2.07 ± 1.18 D, respectively; Group III - 0.86 ± 0.33 mm, 0.16 ± 0.05 mm, and 1.56 ± 1.19 D, respectively). However, surgery-induced change for any parameter was not significantly different between the groups (P for AL [0.7955]; ACD [0.8805]; and SIA [0.5485]). Progression in postoperative changes in AL and ACD was insignificant during three follow-up examinations in all the groups. However, SIA of Group I continued to change significantly up to 3 months but stopped to change at 1 month only in Group II and III. Conclusion: Age-related change in physical properties of ocular tissue does not have any major additional effect on the results of SB except that the postsurgical change in corneal curvature stops earlier in older patients compared to that in younger patients.

Clinical Objective Dry Eye Tests in a Population of Tannery Workers in North India

ABSTRACT Purpose: To analyze the correlation between subjective symptoms and clinical signs of dry eye among tannery workers. Methods: In this cross-sectional study, three classic clinical tests, namely the fluorescein tear film break-up time (FTBUT) test, the fluorescein staining (FS) test, and the Schirmer test (ST), were performed to assess the clinical signs of dry eye disease in 246 tanners who were found symptomatic for dry eye in a prior ocular surface disease index survey. Results: All workers were male with a mean age of 35 ± 9 years, and the mean duration of work at tanneries was 8 ± 5 years. Among 246 symptomatic subjects, the FTBUT test, the FS test and the ST were positive in 63.8%, 30.9% and 41.9% workers, respectively. Mean FTBUT and ST scores were 10.6 ± 4.2 seconds and 10.1 ± 7.7mm, respectively. Mean FTBUT for mild, moderate and severe symptom categories differed significantly. Mean ST scores for the mild symptom group were significantly higher than that of the moderate group (p < 0.0001). The FTBUT and ST score showed a strong negative correlation with severity of symptoms (p < 0.0001). A moderate positive correlation was observed between FS positivity and increasing symptom severity (p < 0.0001). The effect of age was insignificant for FTBUT (p = 0.10), while significant for ST score (p < 0.001). The effect of duration of tannery work was significant for both FTBUT and ST scores (p < 0.0001). Conclusion: Clinical tests correlated well with symptom severity among tanners, and a multifactorial etiology is suggested for dry eye diseases.