Manish Nagpal

Comparison of laser photocoagulation for diabetic retinopathy using 532-nm standard laser versus multispot pattern scan laser.

Purpose: The purpose of this study was to compare the efficacy, collateral damage, and convenience of panretinal photocoagulation for proliferative diabetic retinopathy or severe nonproliferative diabetic retinopathy using a 532-nm solid-state green laser (GLX) versus a multispot 532-nm pattern scan laser (PASCAL). Methods: This study was a prospective randomized clinical trial. Sixty patients with bilaterally symmetrical proliferative diabetic retinopathy or severe nonproliferative diabetic retinopathy participated. Each patient underwent panretinal photocoagulation: one eye with GLX and the other with PASCAL, two sittings per eye. Grade 3 burns with a 200-&mgr;m spot size were placed with both modalities. The fluence, pain using the visual analog scale, time, laser spot spread with infrared images, and retinal sensitivity were compared. Results: Pattern scan laser and GLX required an average fluence of 40.33 vs 191 J/cm2, respectively. Average time required per sitting was 1.43 minutes with PASCAL and 4.53 minutes with GLX. Average visual analog scale reading for GLX was 4.6, whereas that for PASCAL was 0.33. Heidelberg retinal angiography images showed the spot spread as being 430 versus 310 &mgr;m at 3 months with GLX and PASCAL. The eyes treated with PASCAL showed higher average retinal sensitivity in the central 15° and 15° to 30° zones (25.08 and 22.08 dB, respectively) than the eyes treated with GLX (23.16 and 17.14 dB), respectively. Conclusion: Pattern scan laser showed lesser collateral damage and similar regression of retinopathy compared with GLX. Pattern scan laser treatment was less time consuming and less painful for the patient compared with GLX.

Comparison of clinical outcomes and wound dynamics of sclerotomy ports of 20, 25, and 23 gauge vitrectomy.

Purpose: To compare the benefits, the risks and the dynamics of port closure in different gauge vitrectomy systems. Methods: Prospective, randomized, comparative study of 90 eyes undergoing 20, 23 and 25 gauge (G) vitrectomy for uncomplicated vitreous hemorrhage due to proliferative diabetic retinopathy, vasculitis, trauma, venous occlusions and others. An endoscope was used in five cases of each group to visualize the inside of sclerotomy ports. Results: Vision improved from 0.048 (3/60) to 0.206 (6/24) (p = 0.0021), from 0.069 (4/60) to 0.389 (6/18) (p < 0.0001) and from 0.055 (3/60) to 0.286 (6/24) (p = 0.0010) with 20, 23, and 25-G systems, respectively. Re-bleeds occurred in 4, 1 and 4 eyes of 20, 23 and 25-G systems respectively and post-operative retinal detachment was seen in 2 cases of 20-G system. There were no cases of post-operative hypotony or endophthalmitis seen. With 23 and 25 gauge systems, significant amount of vitreous was seen blocking the inner lip of the sclerotomy ports. Conclusion: The small gauge systems are safe and equally effective than the 20-G system for non-complicated vitreous hemorrhage cases with faster recovery and more comfort for the patient. Increased vitreous clogging with small gauge systems does not extrapolate to an increased risk of complications.

Recent developments in retinal lasers and delivery systems

Photocoagulation is the standard of care for several ocular disorders and in particular retinal conditions. Technology has offered us newer lasing mediums, wavelengths and delivery systems. Pattern scan laser in proliferative diabetic retinopathy and diabetic macular edema allows laser treatment that is less time consuming and less painful. Now, it is possible to deliver a subthreshold micropulse laser that is above the threshold of biochemical effect but below the threshold of a visible, destructive lesion thereby preventing collateral damage. The advent of solid-state diode yellow laser allows us to treat closer to the fovea, is more effective for vascular structures and offers a more uniform effect in patients with light or irregular fundus pigmentation. Newer retinal photocoagulation options along with their advantages is discussed in this review.

Silicone oil removal

Silicone oil is an important postoperative tamponading tool used during vitreoretinal surgery, the most common indication being retinal detachment with proliferative vitreoretinopathy. However, once it has served its purpose its removal is mandatory. Various approaches have been used for this, and many factors play a role in reducing the risk of complications following oil removal. The most important complication is recurrent retinal detachment. However, there are no clear guidelines about how one could reduce this incidence. In this article we discuss the various approaches for the procedure and also consider variables that may play a role in reducing the complications following oil removal, and which have prognostic value for the final outcomes.

LEUKEMIC OPTIC NERVE INFILTRATION IN A PATIENT WITH ACUTE LYMPHOBLASTIC LEUKEMIA.

PURPOSE To describe the clinical presentation and imaging features of a patient with acute lymphoblastic leukemia that was complicated by optic nerve leukemic infiltration. METHODS A 36-year-old man with history of acute lymphoblastic leukemia on treatment presented with decreased vision and optic nerve leukemic infiltrates. RESULTS At presentation, ocular examination revealed decreased visual acuity at hand movement close to face in his right eye and 20/120 in his left eye. Fundus examination showed a pale optic disk with blurred margins and multiple flame-shaped and dot and blot retinal hemorrhages in his right eye and disk edema with whitish leukemic infiltrates over it with few dot and blot retinal hemorrhages in his left eye. The patient was referred to the treating oncologist, and curative orbital radiotherapy was administered. Vision improved dramatically to 20/40 in the right eye and to 20/20 in the left eye. He again reported with complaints of blurring of vision in the left eye after 1 month. Visual acuity was 20/20, but fundus revealed severe disk edema with whitish leukemic infiltrates. We diagnosed as relapse of leukemic optic nerve infiltration and referred to the treating oncologist for further management. CONCLUSION Isolated optic nerve relapse of leukemic infiltration is of paramount importance to early diagnosis, as vision can be saved if treatment is initiated promptly.

Topical nepafenac 0.1% alone versus prednisolone acetate 1% as postoperative anti-inflammatory agents in small gauge vitrectomy

Aim: To compare the efficacy of postoperative topical nepafenac (0.1%) with prednisolone acetate (1%) as anti-inflammatory agents in eyes undergoing Transscleral Sutureless Vitrectomy (TSV). Settings and Design: Prospective, double-blind, randomized, single center clinical study. Materials and Methods: Eighty eyes of 76 subjects, who underwent small gauge vitrectomy, were included in the study. The subjects who fulfilled the inclusion criteria were randomized to either topical nepafenac only (Group 1) or prednisolone acetate only (Group 2), to be used as postoperative anti-inflammatory agents. The subjects were reviewed on days 1, 30, and 90. Ocular and adnexal inflammation was appropriately graded using the standardized classification. Grading of ocular pain was done on the Visual Analog Scale (VAS). Statistical Analysis: The Wilcoxon rank-sum test, using two-sided analysis, was used. Results: During the follow-up, both Group 1 and Group 2 did not have a significant difference related to the grade of the anterior chamber inflammation (P > 0.05) or adnexal inflammation (P > 0.05). Pain perception was less in the subjects in Group 1 as compared to subjects in Group 2, but was not statistically significant (P > 0.05). Conclusion: Postoperative topical nepafenac was non-inferior to prednisolone acetate in reducing postoperative ocular inflammation in eyes undergoing TSV.

Scleral Buckling for Rhegmatogenous Retinal Detachment Using Vitrectomy-Based Visualization Systems and Chandelier Illumination.

PurposeThe objective of this study was to evaluate an alternative approach to scleral buckling surgery using vitrectomy-based chandelier visualization systems instead of the indirect ophthalmoscope. DesignThis was a prospective case series. MethodsTen eyes underwent scleral buckling under microscope using contact wide-angle lens with 25-gauge chandelier illumination and were followed up for 6 months. ResultsAn encirclage was done in 8 eyes, and segmental buckle used in 2 eyes. Excellent intraoperative visualization was achieved, and all routine buckling steps were easily replicated with this approach. ConclusionsUsing contact wide-angle lens along with chandelier illumination under microscope allows good visualization for scleral buckling procedure. This approach may allow excellent visibility with zooming capabilities for each step of the procedure as well as allows transmission to a monitor in the theater for teaching purposes apart from allowing better ergonomics for the surgeon.

Factors having implications on re-retinal detachments after silicone oil removal

Aim: To investigate factors having implications on re-retinal detachments (reRD) after silicone oil removal (SOR). Materials and Methods: A retroprospective study of 412 eyes (with attached retina after vitrectomy with silicone oil for rhegmatogenous RD) which underwent SOR was conducted and were followed up for six months after SOR. They were studied for various factors like encirclage, 360° retinopexy, oil emulsification at the time of SOR, duration of oil tamponade and previous retinal surgeries prior to SOR with their implications on reRD after SOR. Results: Encirclage, 360 laser barrage, both, emulsification of oil ( P =0.021, P =0.001, P =0.001, P =0.001, respectively) were associated with lower risks of reRD after SOR whereas duration of tamponade ( P =0.980) was not. Conclusion: Factors like encirclage, 360 retinopexy, their combination, oil emulsification reduced the incidence of re RD after SOR whereas duration of tamponade does not have statistical significant correlation with re RD after SOR.

In Vivo Assessment of Choroid in Diabetic Retinopathy by Enhanced Depth Imaging in Spectral Domain Optical Coherence Tomography.

PurposeThe aim of this study was to measure the largest hyporeflective (LHR) lumen in the choroid and subfoveal choroidal thickness (SFCT) in patients with diabetic retinopathy (DR) and in control subjects using enhanced depth imaging (EDI) spectral domain optical coherence tomography (SD-OCT). DesignThis was a prospective, cross-sectional study. MethodsThis was a study of 240 eyes of DR patients (n = 120) and control subjects (n = 120) matched for age, sex, and refractive error. The LHR lumens of the choroidal vessels and SFCT were measured by EDI SD-OCT. Further intergroup classification into nonproliferative and proliferative DR, with or without macular edema, was done. ResultsThe mean diameter of the LHR lumen in DR patients (139.24 ± 35.53 &mgr;m) was significantly smaller (P < 0.01) than in control subjects (186.37 ± 26.43 &mgr;m). The mean SFCT was also significantly less (P < 0.01) in patients with diabetes (277.15 ± 32.24 &mgr;m) as compared with control subjects (313.68 ± 25.13 &mgr;m). There was no significant intergroup variation. ConclusionsPatients with DR showed smaller LHR lumen and SFCT as compared with control eyes. In vivo assessment of the choroid in DR is possible using EDI SD-OCT.

Dropped Lens Fragment, Dislocated Intraocular Lens

Management of posteriorly dislocated crystalline lens has traditionally been performed with a standard 20-gauge vitrectomy system. The latest surgical platforms integrate multiple devices into single systems and feature advanced fluidics, vitreous cutting technology, and intraocular pressure control along with continued improvements in small-gauge instrumentation and wide-angle viewing systems. This allows truly robust removal of core vitreous and outstanding control of the surgical field on par with its 20-gauge predecessor, resulting in an expanded spectrum of complex vitreoretinal maneuvers feasible with 23- or 25-gauge systems. Posteriorly dislocated crystalline lens/intraocular lens is one such indication which can be safely and effectively managed by a 23- or 25-gauge vitrectomy system alone or combined with the 20-gauge fragmatome/forceps with lesser complications and early recovery.