Kamal 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.

A comparative debate on the various anti-vascular endothelial growth factor drugs: Pegaptanib sodium (Macugen), ranibizumab (Lucentis) and bevacizumab (Avastin)

Wet age-related macular degeneration and diabetic retinopathy are pathological consequences of vascular endothelial growth factor (VEGF) release as a reaction to deficiency of oxygen and nutrients in the macular cells. Conventional treatment modalities have been constrained by limited success. Convincing evidence exists that targeting VEGF signaling is a significant approach for the therapy of these ocular angiogenesis-dependent disorders. We have come a long way since the approval of the first angiogenesis inhibitors in medicine. The clinical use of these drugs has provided enormous tempo to clinical and pharmacological research. It has also significantly altered patient outcome and expectations. In the following brief, we will discuss the development and emergence of these drugs as well as the anticipated future course based on evidence.

POSTCATARACT CYSTOID MACULAR EDEMA

Ocular tissues, like those of other organs, exhibit well-defined morphologic reactions to local trauma and insult in the form of hyperemia, vasodilation, increased permeability of blood vessels, and edema. Cystoid macular edema (CME) following cataract surgery is one such manifestation, and it can result in either temporary, or rarely, a permanent reduction of visual acuity. Although its cause remains obscure, the relationship of CME to the details of the surgical procedures and their complications are becoming clearer. Likewise more insight into the phenomenon is being imparted by the agents being used in the preventative or curative line of management in CME.

Endophthalmitis following cataract surgery.

This article is an attempt to review the latest advances in recognition, treatment, and prevention of postcataract extraction endophthalmitis.

Role of Early Radial Optic Neurotomy in Central Retinal Vein Occlusion

PURPOSE To determine safety, clinical and visual results, and potential complications of early radial optic neurotomy (RON) surgery in eyes with central retinal vein occlusion (CRVO), with relative afferent pupillary defect and visual acuity MATERIALS AND METHODS This prospective, interventional case-series included 24 patients of CRVO who underwent RON within 2 months of disease onset. The preoperative examination included slitlamp biomicroscopy, fundus photography and fluorescein angiography. Foveal thickness was measured using optical coherence tomography (OCT) in the last 6 eyes only. In each case, RON was performed after informed consent. Two radial incisions were placed in the nasal quadrant of the optic disc, using a micro-vitreoretinal blade. The postoperative change in vision, clinical picture, fundus photographs, angiograms and foveal thickness by OCT were the main outcome variables studied. The Wilcoxan signed test was used to assess the results. RESULTS Average symptom duration was 37.8 +/- 15.2 days (range 15-60 days, median: 34.5 days) and follow-up 7.7 +/- 2.1 months (range 1-12 months, median: 8 months). Visual outcome: 2 (8.33%) eyes each had fall and preservation of pre-RON visual acuity respectively. Twenty eyes (83.33%) showed increase in vision (of average 3 lines). Pre and postoperative vision ranged from 0.017-0.1 (average:0.061) and 0.017-0.667 (average: 0.17) respectively (P < 0.05). Clinical and angiographic outcome: decline in macular oedema, decreased or resolved intraretinal haemorrhages, resolution of venous dilatation and disc oedema could be appreciated in all cases. Foveal thickness: average pre and postoperative foveal thickness was 834.17 microm and 556.17 microm respectively (P < 0.05) in the 6 eyes where it was measured before and after RON. One eye developed retinal-detachment. CONCLUSION Radial optic neurotomy is better than the natural course in eyes with CRVO, with vision < 6/60.

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.

Pars Plana Vitrectomy With or Without Silicone Oil Endotamponade in Surgical Management of Endophthalmitis.

Purpose To compare outcomes of pars plana vitrectomy (PPV) with and without silicone oil injection (SOI) in surgical management of endophthalmitis. Design This was a prospective, randomized, interventional, comparative study. Methods This is a prospective, randomized, interventional, comparative study comprising 129 eyes with endophthalmitis (postsurgical and traumatic) that underwent PPV. Group 1 (n = 65) eyes, which underwent vitrectomy alone, were compared with group 2 (n = 64) eyes, in whom complete PPV with SOI was done for visual and anatomical outcomes and additional subsequent interventions. Results Mean best corrected visual acuity improvement was 0.867 ± 1.13 and 1.140 ± 0.88 in groups 1 and 2, respectively (P < 0.005). In the posttraumatic subgroup, difference between groups 1 and 2 in mean change in best corrected visual acuity was statistically significant (0.580 ± 1.10 and 1.132 ± 0.8 respectively, P < 0.05). Rate of retinal detachment was 6.2% in group 2 as compared with 25.5% in group 1. Groups 1 and 2 required additional subsequent procedures in 27 eyes (41.54%) and 5 eyes (7.8%), respectively (P < 0.0001). Conclusions Overall, complete vitrectomy with SOI resulted in significantly better anatomical outcomes and significantly less need for additional surgery as compared with PPV. In addition, in the posttraumatic subgroup, statistically better visual outcomes were noted in group 2 than in group 1.

Simultaneous presentation of branch retinal artery occlusion and vitreomacular traction.

PURPOSE To report a case of simultaneous presentation of branch retinal artery occlusion and vitreomacular traction and the auxiliary role of optical coherence tomography and fluorescein angiogram in the management of this case. METHODS A 42-year-old female patient presented with diminution of vision in the left eye. Visual acuity was 20/200. Ocular examination revealed the presence of whitening of the retina along the superotemporal arcade, suggestive of branch retinal artery occlusion. Fluorescein angiogram showed delayed filling of the superotemporal artery consistent with branch retinal artery occlusion along with uncharacterisitic leakage at the fovea. Optical coherence tomographic scan through the fovea revealed vitreomacular traction with distortion of foveal contour. The patient was diagnosed as a case of branch retinal artery occlusion with vitreomacular traction. The patient underwent vitrectomy for the hyaloidal traction on the macula. RESULTS Postoperatively, the visual acuity in the left eye improved to 20/20 with resolution of dye leakage on fluorescein angiogram with normal foveal contour on optical coherence tomography. CONCLUSION Branch retinal artery occlusion and vitreomacular traction can present simultaneously, and fluorescein angiogram with optical coherence tomography has a complementary role in the management of such cases.

Re: Surgical treatment of a juxtapapillary retinal hemangioma.

Dear Editor: The study by Soong et al1 was of engaging interest. The authors’ efforts need to be lauded for their diligence and ingenuity involved in culling data from archival records and putting it forth with such simplicity. Macular structure (heterotopia) and visual function (including contrast acuity and visual acuity) were correlated in patients with history of retinopathy of prematurity and age-matched controls. The study, however, had some nebulous aspects in its methodology. It was unclear what selection criteria were used to isolate the cases in the study, especially in people older than 60 years when retinopathy of prematurity would have been a relatively little known disease. Furthermore, the two groups of patients, 6 with macular heterotopia (Group 1) and 3 with normal vision (Group 2), did not seem to have been matched for their spherical equivalents (mean SEQ 6.15 DS in Group 1 vs. mean SEQ 1.8 DS in Group 2). It is well known that myopic refractive status may result in poor retinal sensitivity.2 Agerelated macular changes could have also contributed to the reduced macular function in at least 3 patients in Group 1. More importantly, prematurity and retinopathy of prematurity are often associated with foveal hypoplasia. This condition is often associated with micronystagmus, and poor microperimetry readings may have been due to such an association.3,4 Assiduous examination with high-plus spherical lenses or electronystagmography could have ruled out such an association. Instead of Stratus optical coherence tomography, topographic assessment of retinal thickness at the site of fixation would be better judged with optical coherence tomography-SLO in future studies, allowing reproducibility and accuracy of repeated readings.