Jagat Ram

Surgical prevention of posterior capsule opacification. Part 1: Progress in eliminating this complication of cataract surgery.

PURPOSE To evaluate over almost 2 decades the success of a component of cataract surgery that represents a critical step in reducing the incidence of posterior capsule opacification (PCO); namely, the efficacy of cortical cleanup. SETTING Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS Accessioned from the early 1980s to 1997, 3320 eyes obtained postmortem with posterior chamber intraocular lenses were analyzed with respect to formation of a postoperative Soemmerings ring. This anatomic lesion, the precursor of clinical PCO, represents an important and measurable indication of the quality of cortical cleanup. Its formation was documented using Miyake-Apple posterior photographic analysis. RESULTS The quality and thoroughness of cortical cleanup and overall effectiveness in eliminating retained and/or regenerating cortical cells, as measured by scoring of Soemmerings rings, showed virtually no net change since the early 1980s. The intensity of Soemmerings ring was higher in the most recent specimens than in those in the early 1980s. CONCLUSION The results indicate that renewed attention to cortical cleanup in cataract surgery is warranted for significant reduction in incidence or the elimination of PCO. More attention to the hydrodissection (cortical cleaving hydrodissection) step of the procedure is likely a practical, immediately implementable, and inexpensive remedy.

Update on fixation of rigid and foldable posterior chamber intraocular lenses. part II: choosing the correct haptic fixation and intraocular lens design to help eradicate posterior capsule opacification

PURPOSE Posterior capsule opacification (PCO) is one of the most common complications of cataract surgery, and there is an urgent need to reduce its incidence. Its main treatment, neodymium:YAG (Nd:YAG) laser posterior capsulotomy, may be associated with significant morbidity and is expensive. In this study, the authors ascertain the effect of posterior chamber intraocular lens (PC-IOL) fixation and various IOL designs (rigid polymethyl methacrylate [PMMA] optic and small-incision foldable designs) on the pathogenesis of PCO. DESIGN Prospective analysis of pseudophakic eyes obtained postmortem. PARTICIPANTS A total of 3493 eyes with PC-IOLs obtained postmortem and received between 1984 and 1998. METHODS Miyake-Apple posterior photographic technique. MAIN OUTCOME MEASURES Peripheral Soemmerings ring, central PCO in the visual axis, and eyes that have had Nd:YAG laser posterior capsulotomy were analyzed and scored, and these findings were correlated with the type of fixation and IOL design. RESULTS The degree of formation of peripheral Soemmerings ring was not influenced by IOL fixation. The acrylic design revealed relatively low Soemmerings ring scores. In contrast, central PCO and Nd:YAG laser capsulotomy scores were consistently influenced by fixation. The scores were significantly lower in eyes with in-the-bag fixation. The bag-bag fixated acrylic-PMMA design and the three modern silicone IOL designs analyzed in this study had less central PCO and lower posterior capsulotomy scores than did the PMMA IOLs. CONCLUSIONS The formation of peripheral PCO (the Soemmerings ring), the precursor of clinically significant, vision-threatening PCO, is not significantly influenced by the haptic fixation pattern. It is much more dependent on the quality and thoroughness of surgical cortical cleanup. Reduction of Soemmerings ring is an important goal because the retained regenerative cortical cells within this lesion are the cells of origin of PCO. The acrylic IOL design was associated with a lessor amount of peripheral Soemmerings ring as compared with all other designs. In sharp contrast to peripheral PCO, fixation of the IOL was a highly significant factor affecting the formation and quantity of central PCO-the clinically significant opacity behind the IOL optic, measured in this series either by scoring an intact retro-optical membrane or by documenting the presence of a Nd:YAG laser posterior capsulotomy orifice. The quantity of central PCO was consistently much lower in eyes with in-the-bag fixated IOLs compared with lenses with one or both haptics out of the bag. This is best explained by the fact that secure in-the-bag fixation positions the IOL optic in the best possible position to create a barrier effect. The lowest PCO rates were generally noted with the acrylic and modern silicone IOL designs.

Fungal endophthalmitis following cataract surgery: clinical presentation, microbiological spectrum, and outcome.

PURPOSE To determine the clinical presentation, microbiological spectrum, and outcome in cases of fungal endophthalmitis following cataract surgery. DESIGN Observational case series. METHODS SETTING Tertiary referral hospital. PATIENTS Retrospective analysis of 27 cases of smear- and culture-proven fungal endophthalmitis. INTERVENTION Pars plana vitrectomy in 18 eyes, where the corneal condition did not preclude the same. All eyes received intravitreal amphotericin B and dexamethasone along with systemic antifungal agents. MAIN OUTCOME MEASURES Functional success: Final visual acuity of 3/60 or better with attached retina. Anatomical success: Final visual acuity of better than light perception with preserved anatomy of globe. RESULTS The majority of the eyes (22 of the 27) had early onset and diffuse presentation (that is, anterior segment as well as posterior vitreous exudates). Substantial corneal involvement was seen in 14 eyes (51.85%). Aspergillus sp. was the most common isolate. Multivariate analysis using forward stepwise logistic regression showed corneal involvement as the single most important risk factor in determining final visual outcome (P =.0429). CONCLUSIONS Early onset and diffuse presentation, which mimics bacterial endophthalmitis, stresses the importance of both bacterial and fungal cultures from intraocular fluids to reach a diagnosis apart from the clinical judgment. Corneal involvement was the most important predictor of outcome in cases of fungal endophthalmitis.

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.

Effect of in-the-bag intraocular lens fixation on the prevention of posterior capsule opacification

Purpose: To compare the incidence of posterior capsule opacification (PCO) after extracapsular cataract extraction (ECCE) and phacoemulsification and to evaluate the role of posterior chamber intraocular lens (PC IOL) haptic fixation and biomaterial/design in reducing the incidence. Setting: Postgraduate Institute of Medical Education and Research, Chandigarh, India; Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. Methods: This study comprised 278 eyes of 263 patients having ECCE and 318 eyes of 297 patients having phacoemulsification with PC IOL implantation. Posterior capsule opacification leading to a decrease in Snellen visual acuity of 2 or more lines was considered visually significant. The presence of PCO and IOL haptic fixation were evaluated postoperatively using slitlamp biomicroscopy. Haptic position was noted as in‐the‐bag (B‐B), 1 haptic in the bag and 1 in the sulcus (bag‐sulcus [B‐S]), or both haptics out of the bag (sulcus‐sulcus [S‐S]). In addition, the rate of visually significant PCO was compared among 3 IOL biomaterials: poly(methyl methacrylate), silicone, and hydrophobic acrylic. Results: Visually significant PCO occurred in 42.45% of eyes having ECCE and 19.18% of eyes having phacoemulsification (P < .001, chi‐square test) after a mean follow‐up of 2.4 years ± 0.7 (SD). In both groups, visually significant PCO was significantly less in eyes with B‐B fixation than in those with B‐S or S‐S fixation (P < .001). The rate of visually significant PCO in all eyes in the phacoemulsification group with B‐B fixation was low (11.90%) and was significantly lower in eyes with a hydrophobic acrylic IOL (2.22%; P < .05, chi‐square test). Conclusions: In‐the‐bag PC IOL fixation is required to consistently reduce the incidence of PCO. Thorough removal of lens substance, including hydrodissection‐assisted cortical cleanup, and in‐the‐bag PC IOL fixation seem to be the most important factors in reducing PCO, regardless of surgical procedure or IOL type used. Intraocular lens biomaterial and design also help prevent PCO.

Low-dose intraoperative mitomycin-C versus conjunctival autograft in primary pterygium surgery: long term follow-up.

PURPOSE To evaluate and compare the long term safety and efficacy of low-dose intraoperative application of mitomycin-C (0.02%) with conjunctival autograft in primary pterygium surgery. PATIENTS AND METHODS Of 37 consecutive patients 41 eyes with primary pterygium underwent pterygium excision with either intraoperative mitomycin-C (0.02%) (Group I) or conjunctival autografts (Group II) at random. Mitomycin-C (0.2 mg/mL) was applied for 2.5 minutes on the scleral bed under the conjunctiva. Conjunctival autograft was obtained from upper temporal limbus and secured with 10-0 monofilament nylon. The follow-up period ranged from 14 to 54 months (mean 36 months) for mitomycin-C group and 13 to 58 months (mean 38 months) for conjunctival autograft group. RESULTS Twenty-one eyes underwent pterygium excision with intraoperative mitomycin-C (0.02%) application (Group I) and 20 eyes were treated using conjunctival autograft (Group II). The mean size of the pterygium was 3.80 mm (range 2.6 to 4.8 mm) in the mitomycin-C group and 3.60 mm (range 2.5 to 4.5 mm) in the conjunctival autograft group. Two (9.52%) eyes treated with intraoperative mitomycin-C had delayed epithelial healing of corneoscleral wound and one (4.76%) eye developed pyogenic granuloma. Three (14.3%) of the 21 eyes in Group I and one (5%) of 20 eyes in Group II had recurrence of pterygium (P = 0.3174). All recurrences occurred in patients below 40 years of age (P = 0.0384). CONCLUSION We conclude that conjunctival autograft and intraoperative mitomycin-C are both equally effective adjuncts to primary pterygium surgery on long term follow-up. However, future prospective studies with larger numbers of subjects may be carried out to find out the optimum concentration and duration of intraoperative mitomycin-C application.

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.

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.

Update on fixation of rigid and foldable posterior chamber intraocular lenses. Part I: Elimination of fixation-induced decentration to achieve precise optical correction and visual rehabilitation.

PURPOSE Realizing that precise posterior chamber intraocular lens (PC-IOL) centration is needed to consistently achieve good optical results and visual rehabilitation after modern cataract surgery, the authors assessed the status and success rate of lens haptic fixation and its correlation with lens optic centration-decentration in a large series of eyes with PC-IOLs obtained postmortem. DESIGN Prospective analysis of pseudophakic eyes obtained postmortem. PARTICIPANTS A total of 3493 human eyes obtained postmortem, the largest database of such specimens available to date. METHODS Miyake-Apple posterior photographic technique. MAIN OUTCOME MEASURES The amount of decentration of rigid PC-IOLs and small-incision foldable PC-IOLs was analyzed, and the results were correlated with the type of fixation that had been achieved in each case. RESULTS Determination of mean values revealed that capsular bag fixation was achieved in 52.05% of eyes, asymmetric bag-sulcus fixation in 34.21 % of eyes, and sulcus-sulcus fixation in 13.74% of eyes. Asymmetrically fixed lenses consistently showed significant decentration. During the past 5 years (1993-98), the overall rate of in-the-bag fixation increased to 59.2%; by 1998 it had increased to 64%. Most significantly, success in achieving bag-bag fixation of foldable IOLs implanted in association with modern capsular surgery with small incisions has surged to 90% over the past 4 years. CONCLUSIONS The authors found a direct correlation of decentration in eyes with asymmetric fixation, and the results underscore the need for careful in-the-bag haptic placement. Although few surgeons today would dispute the goal to implanting haptics in the capsular bag, these findings show that the overall success rate over the years has, while improving, remained surprisingly low. The overall success rate of about 60% seen with all lens designs is probably as good as can be expected with classic large-incision extracapsular techniques. However, and most important and encouraging, the success rate of haptic fixation in cases with foldable lenses has improved dramatically during the past 4 years (up to the 90% range). This coincides with the present emphasis on modern capsular surgery and small-incision techniques used to insert these lenses.

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.