Sushmita Kaushik

Neuroprotection in glaucoma.

Currently, glaucoma is recognised as an optic neuropathy. Selective death of retinal ganglion cells (RGC) is the hallmark of glaucoma, which is also associated with structural changes in the optic nerve head. The process of RGC death is thought to be biphasic: a primary injury responsible for initiation of damage that is followed by a slower secondary degeneration related to noxious environment surrounding the degenerating cells. For example, retinal ishaemia may establish a cascade of changes that ultimately result in cell death: hypoxia leads to excitotoxic levels of glutamate, which cause a rise in intra-cellular calcium, which in turn, leads to neuronal death due to apoptosis or necrosis. Neuroprotection is a process that attempts to preserve the cells that were spared during the initial insult, but are still vulnerable to damage. Although not yet available, a neuroprotective agent would be of great use in arresting the progression of glaucoma. There is evidence that neuroprotection can be achieved both pharmacologically and immunologically. Pharmacological intervention aims at neutralising some of the effects of the nerve-derived toxic factors, thereby increasing the ability of the spared neurons to cope with stressful conditions. On the other hand, immunological interventions boost the bodys own repair mechanisms for counteracting the toxic effects of various chemicals generated during the cascade. This review, based on a literature search using MEDLINE, focuses on diverse cellular events associated with glaucomatous neurodegeneration, and discusses some pharmacological agents believed to have a neuroprotective role in glaucoma.

Role of posterior capsulotomy with vitrectomy and intraocular lens design and material in reducing posterior capsule opacification after pediatric cataract surgery

Purpose: To study the effect of primary posterior capsulotomy with anterior vitrectomy (PPC + AV) and intraocular lens (IOL) design and material on the development of posterior capsule opacification (PCO) after pediatric cataract surgery. Setting: Tertiary care institution in India. Patients: Sixty‐four eyes of 52 children ranging in age from 3 months to 12 years who had cataract extraction with IOL implantation were prospectively evaluated for a minimum postoperative period of 2 years. Methods: Thirty‐two eyes received a hydrophobic acrylic lens with a truncated, square edge and 32, a single‐piece poly(methyl methacrylate) (PMMA) lens that was not heparin surface modified. Sixteen eyes in each IOL group had PPC + AV; in the remaining 16 eyes in each group, the posterior capsule was left intact. Results: Postoperatively, 25 eyes in the intact capsule group and 5 in the PPC + AV group developed PCO; the difference between groups was significant (P<.05). Of eyes with an intact capsule, 12 with an acrylic IOL and 13 with a PMMA IOL developed PCO (P>.05). In the PPC + AV group, 2 eyes with an acrylic IOL and 3 with a PMMA IOL developed PCO (P>.05). Overall, 14 eyes with an acrylic lens and 16 eyes with a PMMA lens developed PCO (P>.05). After surgery, there was a significant short‐term delay in the development of PCO in the acrylic group (14 eyes; mean 6.66 months ± 1.57 [SD]) compared to the PMMA group (16 eyes; mean 3.16 ± 0.83 months) (P<.05). Conclusions: It is the management of the posterior capsule rather than IOL design and material that influences the incidence of PCO after cataract surgery in children. Development of PCO in the postoperative period was delayed with a hydrophobic acrylic IOL with square edges compared with a PMMA lens without square edges.

Contrast sensitivity and depth of focus with aspheric multifocal versus conventional monofocal intraocular lens

BACKGROUND Laboratoires Domilens, Lyon, France, has introduced a new aspheric multifocal intraocular lens (IOL), the Progress 3. The central portion, measuring 4.7 mm in diameter, has an anterior surface of progressively increasing power, such that there is a central add of +5.00 dioptres. We compared contrast sensitivity and depth of focus in patients who received the Progress 3 and in those who received a conventional monofocal IOL. METHODS Prospective study. Forty patients with age-related cataract were randomly divided into two groups: 20 patients received the Progress 3 aspheric multifocal IOL, and 20 patients received a conventional monofocal IOL of similar design. Contrast sensitivity was measured with the Pelli-Robson letter-based chart. Depth of focus was determined by dialling a series of overcorrections over the patients manifest refraction until the patient read 6/12 clearly. The depth of focus was defined as the range over which 6/12 or better acuity was achieved. Quality of vision was evaluated by patient questionnaire. RESULTS Mean contrast sensitivity was significantly lower in the patients with a multifocal IOL than in those with a monofocal IOL (1.38 vs. 1.56 log units) (p < 0.001). The mean depth of focus values for the two groups were 3.10 D and 1.65 D respectively (p < 0.001). The prevalence of subjective problems was similar in the two groups. INTERPRETATION In our opinion, aspheric multifocal IOLs should be reserved for patients who are willing to trade increased depth of focus for reduced contrast sensitivity postoperatively.

Outcomes of phacoemulsification in patients with dry eye

Purpose: To evaluate the outcomes of phacoemulsification in patients with dry eye. Setting: Department of Ophthalmology, Post Graduate Institute of Medical Education and Research, Chandigarh, India. Methods: This study included 25 eyes of 23 patients with dry eye having phacoemulsification. Dry eye was defined as Schirmer I with lidocaine hydrochloride (Xylocaine®) score of 5.0 mm after 5 minutes, a tear‐film breakup time (TFBUT) of less than 5 seconds, or both. Data were retrospectively analyzed for preoperative and postoperative tear function, postoperative complications, and final visual outcomes. Results: Of the 23 patients, 18 had age‐related dry eye and 5 had secondary Sjögrens syndrome. Twenty‐two eyes had predominant aqueous deficiency (Schirmer I with Xylocaine score of 5.0 mm or less), and 3 had a Schirmer score between 6.0 mm and 9.0 mm. The TFBUT was 5 seconds or less in 17 eyes and between 6 seconds and 9 seconds in 8 eyes. The mean preoperative Schirmer score was 4.80 mm ± 2.01 (SD) (range 2.0 to 9.0 mm) and the mean postoperative score, 3.80 ± 2.40 mm (range 0 to 7.0 mm). The mean preoperative TFBUT was 4.00 ± 1.87 seconds (range 0 to 9 seconds) and the mean score at the last follow‐up, 3.40 ± 1.60 seconds (range 0 to 8 seconds). Postoperatively, 8 eyes had superficial punctate keratopathy and 8 had an epithelial defect. The final visual acuity was 6/6 in 13 eyes, 6/9 to 6/12 in 8 eyes, and 6/18 to 6/60 in 4 eyes. Conclusion: Phacoemulsification was safe and led to minimal complications in patients with age‐related dry eye with or without associated systemic disorders.

Intracameral amphotericin B: initial experience in severe keratomycosis.

Purpose. Fungal keratitis is a significant cause of ocular morbidity in India. The most commonly implicated fungi are Aspergillus spp. Patients often present with hypopyon, which usually contains fungal elements. The treatment is difficult owing to poor intraocular penetration of most available antifungal agents. This study evaluated the results of intracameral injection of amphotericin B in natamycin resistant cases of severe keratomycosis. Methods. Three patients of culture proven Aspergillus flavus corneal ulcer with hypopyon not responding to topical natamycin 5%, amphotericin B 0.15%, and oral itraconazole were administered intracameral amphotericin B. The first case received 7.5 &mgr;g in 0.1 mL followed by two subsequent injections of 10 &mgr;g in 0.1 mL each, the second case received two injections of 10 &mgr;g in 0.1 mL, and the third patient received a single dose of 10 &mgr;g in 0.1 mL. Culture of the aqueous sample also grew A. flavus in all three cases. Results. All three cases responded favorably, with the ulcer and hypopyon clearing completely. There was no clinical evidence of corneal or lenticular toxicity in any patient. Conclusions. Intracameral amphotericin B may be a useful modality in the treatment of severe keratomycosis not responding to topical natamycin. It ensures adequate drug delivery into the anterior chamber and may be especially useful to avoid surgical intervention in the acute stage of the disease.

Phacoemulsification with intraocular lens implantation in patients with uveitis

PURPOSE: To evaluate the outcomes of phacoemulsification with intraocular lens (IOL) implantation in eyes with uveitis. SETTING: Tertiary care center, Chandigarh, India. METHODS: Consecutive patients with uveitis and visually significant cataract were retrospectively studied for outcomes after phacoemulsification and implantation of a poly(methyl methacrylate) (PMMA) or a hydrophobic acrylic IOL. RESULTS: The study comprised 108 eyes of 81 patients (50 women, 31 men) with a mean age of 42.3 years ± 13.98 (SD) (range 18 to 75 years) and a mean follow‐up of 21.95 months (range 12 to 66 months). Etiology of uveitis was presumed tuberculosis (n = 24), Vogt–Koyanagi–Harada syndrome (n = 9), Behçet disease (n = 8), sarcoidosis (n = 5), ankylosing spondylitis (n = 4), serpiginous choroiditis (n = 2), and idiopathic (n = 29). The mean corrected distance visual acuity (CDVA) was 1.08 ± 0.85 logMAR preoperatively and 0.42 ± 0.78 D logMAR postoperatively; the improvement was statistically significant (P<.001, paired t test); Seventy‐seven eyes (71.30%) achieved a CDVA between 0.00 logMAR and 0.30 logMAR (20/20 to 20/40 Snellen). Posterior capsule opacification (PCO) requiring neodymium:YAG capsulotomy occurred in 31 eyes (28.70%); posterior synechias in 27 eyes (25.00%); cystoid macular edema (CME) in 23 eyes (21.30%); recurrent uveitis in 6 eyes (5.55%); and epiretinal membrane formation, glaucoma, and iris bombe in 5 eyes (4.63%) each. CONCLUSIONS: Phacoemulsification with IOL implantation improved vision in most patients with coexisting cataract and uveitis. The main complications affecting visual outcomes were macular involvement, CME, PCO, and glaucoma. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Retinal nerve fiber layer thickness in normal, ocular hypertensive, and glaucomatous Indian eyes: an optical coherence tomography study.

PurposeTo determine retinal nerve fiber layer (RNFL) thickness measurements in normal, ocular hypertensive (OHT), and glaucomatous Asian Indian eyes. MethodsThis prospective observational cross-sectional study included patients with OHT, primary open angle glaucoma (POAG), and age-matched normal controls. The global and 4-quadrant average RNFL thickness was measured using the Stratus OCT. The main outcome measures were differences in RNFL thickness measurements between the 3 groups. The discriminating power of each parameter was evaluated by calculating areas under receiver operating characteristic curves (AROCs). ResultsTwenty-three eyes of 23 POAG patients, 24 eyes of 24 OHT, and 48 eyes of 48 normal controls were analyzed. The superior, inferior, and global RNFL measurements were significantly thinner in OHTs compared with normals (P=0.031, 0.019, and 0.022, respectively). All 5 RNFL parameters were significantly thinner in the POAG group compared with OHT group (P<0.001). Parameters with largest AROCs for distinguishing glaucoma from OHT were average and inferior average RNFL measurements (0.989 and 0.979, respectively). Inferior and superior RNFL measurements had largest AROCs (0.717 and 0.700, respectively) to distinguish OHT from normal eyes. ConclusionsStratus OCT detected significant quantitative differences in RNFL thickness between normal, OHT, and glaucomatous Asian Indian eyes.

Neodymium:YAG capsulotomy rates following phacoemulsification with implantation of PMMA, silicone, and acrylic intraocular lenses

BACKGROUND AND OBJECTIVE Posterior capsular opacification (PCO) is the most common visually disabling sequela of modern cataract surgery. Methods of reducing its incidence include the development of newer surgical techniques and intraocular lens (IOL) materials and designs. The aim of this study was to compare the incidence and time interval of development of PCO, and the requirement of laser capsulotomy in patients implanted with a polymethylmethacrylate (PMMA), silicone, or acrylic IOL. PATIENTS AND METHODS The data of 340 consecutive patients who underwent phacoemulsification and implantation ofa PMMA, silicone, or acrylic intraocular lens were analyzed. The aim of this study was to compare the incidence and time interval of development of PCO, and the requirement of laser capsulotomy in patients implanted with a PMMA, silicone, or acrylic IOL. RESULTS The incidence of PCO was found to be significantly less in the acrylic group (6.5% as compared to 21.74% and 26.6% in the PMMA and silicone groups, respectively; P = 0.01297 and 0.0039). Most patients (65%) exhibiting PCO in the PMMA group developed it within the first six months. In the silicone group, development of PCO was delayed. In 60% of patients, it appeared 18 months after surgery. Neodymium:YAG capsulotomy was required in 45% and 60% of patients developing PCO in the PMMA and silicone groups, respectively, while it was required in only 1 of the 4 patients developing PCO in the acrylic group. CONCLUSION This study indicates that implantation of an acrylic IOL helps reduce the incidence of PCO as well as the need for Nd:YAG capsulotomy. PMMA IOLs require Nd:YAG capsulotomy earlier in the postoperative period as compared to silicone IOLs.

Subtenon Block Compared to Intravenous Fentanyl for Perioperative Analgesia in Pediatric Cataract Surgery

BACKGROUND: General anesthesia with opioids provides good operative conditions for ocular surgery in children; however, postoperative pain management remains a significant problem. Regional anesthesia is commonly used as an adjunct to general anesthesia in children. We compared the efficacy and safety of subtenon block (SB) versus IV fentanyl for perioperative analgesia in pediatric cataract surgery. We hypothesized that perioperative analgesia using SB may reduce the requirement of postoperative rescue analgesia compared with fentanyl. METHODS: This was a prospective, randomized, controlled, double-blind trial. One hundred fourteen ASA I and II children (6 mo–6 yr) undergoing elective cataract surgery in one eye under general anesthesia were studied. Children were randomly allocated to one of the two groups, i.e., Group SB (n = 58) or Group F (n = 56) after securing the airway. Children in Group SB received SB with 0.06–0.08 mL/kg of 2% lidocaine and 0.5% bupivacaine (50:50) mixture and simultaneous 0.2 mL/kg normal saline IV, whereas children in Group F received 1 &mgr;g/kg (0.2 mL/kg of 5 &mgr;g/kg) of fentanyl IV and simultaneous subtenon injection with normal saline (0.06–0.08 mL/kg). Surgery started after 5 min of study drug administration. Postoperative assessment for pain, sedation, and nausea/vomiting was done at 0.5, 1, 2, 3, 4, and 24 h. The primary outcome was number of patients requiring rescue analgesia during the 24-h study period. Secondary outcomes assessed were pain and sedation scores, time to first rescue analgesia, incidence of occulocardiac reflex, and nausea/vomiting. RESULTS: The number of patients requiring rescue analgesia during the 24 h was significantly less in Group SB (n = 17/58, 29.3%) compared with Group F (n = 39/56, 69.6%, P < 0.001). The postoperative pain scores were statistically lower in Group SB at all time intervals. The median (range) time to first analgesic requirement was significantly prolonged in Group SB (16 [2–13] vs 4 [0.5–8.5] h in Group F) (P < 0.001). Sedation scores at ½ h were comparable, after which significantly more children were anxious or crying in Group F compared with Group SB in which more children were calm, sitting, or lying with eyes open and relaxed (P < 0.05). A significantly higher incidence of oculocardiac reflex was recorded in Group F versus Group SB (P = 0.019). No complication related to SB was noticed. CONCLUSIONS: SB is a safe and superior alternative to IV fentanyl for perioperative analgesia in pediatric cataract surgery.

Primary intraocular lens implantation in the first two years of life: Safety profile and visual results

PURPOSE To study the safety profile of primary intraocular lens (IOL) implantation in the first two years of life. MATERIALS AND METHODS A prospective nonrandomized, interventional study was done at the tertiary care center. Forty-five eyes of 27 children (aged three weeks to two years) with congenital cataract who underwent phacoaspiration with continuous curvilinear capsulorrhexis combined with primary posterior capsulotomy and anterior vitrectomy with in the bag placement of IOL at primary surgery were included. Outcome measures were clarity of visual axis, postoperative inflammation, fixation pattern and retinoscopy. RESULTS The mean IOL power was 23.95 +/- 0.87 diopter (D) (range 22D to 27D). Follow-up ranged from 12 months to 48 months (mean 18 +/- 9.13 months). In infants, hypermetropia decreased from 6.60D +/- 2.64D at one week postoperatively to 3.03D +/- 2.53D at one year following surgery and 4.78D +/- 1.93D to 2.56D +/- 1.5D in children older than one year at the time of surgery. Re-opacification of the central visual axis was observed in six eyes (13.3%). Significant posterior synechiae due to irido-capsular adhesion was seen in seven eyes (15.6%). Five of these seven eyes also had significant posterior capsular opacification. CONCLUSIONS Meticulously performed primary IOL implantation and primary posterior capsulorrhexis with anterior vitrectomy in the first two years of life is a safe and effective method of aphakic correction.