Aphakic cystoid macular edema. Longterm clinical observations

Discrepancy between fluorescein angiography and optical coherence tomography in detection of macular disease

PURPOSE

To compare high-resolution optical coherence tomography (OCT) and fluorescein angiography (FA) in detection of macular edema (ME) of various etiologies.

METHODS

In a retrospective study over a 12-month period at one retina center, data for consecutive eyes that had undergone simultaneous conventional FA (HRA; Heidelberg Engineering, Vista, CA) and StratusOCT (Carl Zeiss Meditec, Dublin, CA) to rule out ME were reviewed. A subset of patients underwent additional examination with extremely high-resolution (6-microm)/ultrahigh-speed spectral OCT/scanning laser ophthalmoscopy (OTI, Inc., Toronto, Ontario, Canada).

RESULTS

Of 1,272 eyes, 1,208 (94.97%) had the finding of ME or subretinal fluid confirmed by both techniques. There were 49 eyes (3.86%) for which FA showed dye leakage in the macular area and OCT showed normal foveal contour. Of 10 eyes in this group that underwent imaging with ultrahigh-speed spectral OCT/scanning laser ophthalmoscopy, 8 had subtle diffuse lucencies in the retina. For 15 eyes (1.17%), OCT showed intraretinal and subretinal fluid, which was missed by FA.

CONCLUSIONS

Both FA and high-resolution OCT are highly sensitive techniques and correlate well in detection of ME. However, there is a small chance that when performed alone they might miss existing subtle ME.

Corticosteroids in posterior segment disease: an update on new delivery systems and new indications

PURPOSE OF REVIEW

Corticosteroids are traditionally used for inflammatory disorders because of their ability to diminish neutrophil transmigration, limit access to sites of inflammation, and decrease cytokine production. More recently, however, investigators have focused on the angiostatic and antipermeability properties of corticosteroids for posterior segment diseases such as age-related macular degeneration (AMD), diabetic retinopathy, and macular edema. Both new angiostatic and traditional corticosteroids are currently undergoing evaluation as new delivery techniques such as intravitreal injection and intraocular sustained-release devices facilitate high local angiostatic and antipermeability concentrations while minimizing extraocular toxicity. The purpose of this review is to discuss recent work concerning both the mechanism and effectiveness of these newer treatments.

RECENT FINDINGS

Steroids may exert a beneficial effect in AMD-related choroidal neovascular membranes (CNVM) through inhibition of CNVM-promoting macrophages and direct inhibition of angiogenic growth factors. They may also alter extracellular matrix turnover and inhibit matrix metalloproteinases involved in CNVM formation. Intravitreal steroid injections potently inhibit experimental CNVM in primates and rats and have shown promise in some early human pilot trials. In proliferative diabetic retinopathy, steroids may directly inhibit growth factors such as vascular endothelial derived growth factor and inhibit leukocytes that play an important role in early microvascular alterations. Intravitreal steroid injections inhibit experimental preretinal neovascularization in pigs and rats, and rubeosis in some early human studies. In addition, the effect of steroids on vascular permeability has led to their use for macular edema from many causes such as diabetes and venous occlusive disease.

SUMMARY

The use of steroids to treat a number of retinal diseases is gaining wide spread acceptance. The apparent short-term success must be balanced by the fact that the long-term safety and efficacy have yet to be determined for any of these approaches. A number of large randomized prospective clinical trials of steroid compounds and new delivery systems are currently under way for AMD, diabetic retinopathy, uveitis, and other retinovascular diseases, and hopefully these studies will provide guidance about the use of these new modalities.

Corneal edema after cataract surgery: incidence and etiology

Corneal edema from inadequate endothelial pump function is one of the most common complications of cataract surgery. Various causes for this endothelial dysfunction can be divided into four categories including (a). mechanical injury, (b). inflammation/infection, (c). chemical injury, and (d). concurrent eye disease. This review serves as a basis for the diagnosis and treatment of this complication.

Ischaemic heart disease may predispose to pseudophakic cystoid macular oedema

PURPOSE

Pseudophakic macular oedema (PMO) is uncommon following uncomplicated phacoemulsification and lens implantation and the cause of infrequent cases is rarely understood. This study was undertaken to determine whether a relationship exists between ischaemic heart disease (IHD) and PMO.

METHODS

Retrospective case note review was carried out of 177 (252 eyes) consecutive patients without pre-existing retinal disease who underwent phacoemulsification and intraocular lens implantation during a 12 month period. Patients with a post-operative best corrected visual acuity < 6/9 underwent slit-lamp biomicroscopy and fluorescein angiography to identify PMO. IHD was defined on clinical and electrocardiographic grounds. The incidence of IHD was compared in patients with and without PMO and statistical analysis performed using the Fisher's exact test.

RESULTS

PMO occurred in 4 patients (6 eyes), all of whom had IHD, whereas no PMO occurred in the remaining 173 patients (246 eyes) (p = 0.04).

CONCLUSIONS

Pseudophakic macular oedema represents an important complication following modern phacoemulsification and intraocular lens implantation and is associated significantly with ischaemic heart disease.

Intraocular lens complications requiring removal or exchange

Intraocular lens (IOL)-related complications are caused primarily by mechanical trauma, inflammatory or infectious complications, or optical problems. Complications may occur at the time of surgery or be the result of an ongoing postoperative process. Mechanical and inflammatory injury may produce corneal decompensation, cystoid macular edema, hyphema, uveitis, and glaucoma, causing reduced vision and in some cases chronic pain. Optical problems may be due to a wrong power of the IOL or to postoperative decentration or dislocation of the lens. Ophthalmologists should be aware of the indications for IOL removal or exchange in those patients who have ongoing IOL-induced injury or impairment. Removal or exchange of an IOL frequently involves a complex decision-making process and is often associated with immense technical challenge. Various medical and surgical treatments may be tried to correct IOL problems before the decision is made to remove or exchange the lens.

Simultaneous bilateral cataract extraction in the UK

AIMS/BACKGROUND

Simultaneous bilateral extracapsular cataract extraction (SBCE) is not routinely performed in the developed world. This study investigated the safety and efficacy of this procedure as performed in the UK.

METHODS

A review of 319 consecutive patients (638 eyes) who underwent SBCE with posterior chamber intraocular lens implantation is presented.

RESULTS

The incidence of intraoperative complications was 7.7%. These included posterior capsule rupture (0.8%) and vitreous loss (0.3%). Postoperative complications were seen in 8.7% of operated eyes and included iris prolapse (0.3%) and raised intraocular pressure (3.0%). Endophthalmitis occurred in one eye (0.15%). There were no major bilateral complications, and, in particular, no cases of bilateral endophthalmitis. Final visual acuities compared favourably with reports for unilateral surgery. Eighty two per cent achieved a final visual acuity of 6/12 or better, and 41% tested 6/6 or better.

CONCLUSION

This study illustrates that SBCE is not associated with an increased incidence of complications and that the visual results are good. Where indicated, and under strict surgical protocol, this procedure is safe.

Pars plana vitrectomy for chronic pseudophakic cystoid macular edema

PURPOSE

We determined the efficacy of pars plana vitrectomy in a series of patients with chronic pseudophakic cystoid macular edema.

METHODS

Clinical records were reviewed on 24 consecutive patients who underwent pars plana vitrectomy in one eye for chronic pseudophakic cystoid macular edema. All 24 patients had failed to improve on medical therapy and had preoperative evidence of either vitreous adhesions to anterior segment structures (23 eyes) or iris capture of the intraocular lens (one eye).

RESULTS

The mean, best-corrected Snellen visual acuity was 20/190 preoperatively (median, 20/200; range, 20/50 to 3/200) and 20/52 postoperatively (median, 20/40; range, 20/20 to 20/400 [P < .0001]). Visual acuity improved postoperatively in all 24 eyes, with a mean improvement of 4.7 Snellen lines (range, one to eight lines). There was no highly significant difference in preoperative visual acuity (P = .41) or postoperative visual improvement (P = .17) between patients with anterior as opposed to posterior chamber intraocular lenses. Longer time interval from cataract surgery to vitrectomy did not correlate with less postoperative visual improvement.

CONCLUSIONS

In pseudophakic eyes with chronic cystoid macular edema, vitreous adhesions to anterior segment structures, and visual loss that is unresponsive to medical therapy, pars plana vitrectomy with removal of these vitreous adhesions may lead to improved visual acuity.

Cystoid macular oedema after complicated cataract surgery and implantation of an anterior chamber lens

During the period January 1988 to August 1990, 48 anterior chamber intraocular lenses were implanted during primary cataract surgery. In 6 eyes an anterior chamber intraocular lens was implanted after intracapsular cataract extraction, in 42 eyes after extracapsular cataract extraction complicated by posterior capsular or zonular rupture. Of the 40 cases which had been followed for at least 6 months (mean 23 months), 5 eyes (12.5%) developed clinically significant cystoid macular oedema. All these eyes had an extracapsular cataract extraction with a posterior capsular tear and anterior vitrectomy and in addition all had some other surgical or postoperative complications. Thus, in this series of complicated cataract surgery, cystoid macular oedema was an important cause of visual impairment but cystoid macular oedema was hardly due to the presence of an anterior chamber intraocular lens.

Visual outcome and complications following intracapsular and extracapsular cataract extraction. A prospective, controlled follow-up study

We followed two comparable groups of patients operated on for cataract immediately before and after a transition from intracapsular extraction with an anterior chamber lens to extracapsular technique with a posterior chamber lens. Both groups consisting of 69 eyes of 69 patients were invited to follow-up examinations 4 months and 2 1/2 years after surgery. The visual acuity was similar in the two groups at the two follow-up examinations. Significantly more eyes in the intracapsular group showed either a rise in intraocular pressure or received anti-glaucomatous medications at the latest follow-up. YAG-laser capsulotomy had been performed in 14.5% of the 69 extracapsularly operated eyes. There was a trend towards more intra-operative and cumulative post-operative complications in the intracapsular group, but this difference was not statistically significant. We conclude, that both intracapsular and extracapsular cataract extraction are followed by such low incidences of post-operative complications, that it will require a very large number of eyes to confirm or reject a possible statistically significant difference in post-operative complication rate.

Pseudophakic cystoid macular edema with the Severin lens

Clinically significant cystoid macular edema confirmed by fluorescein angiography has been studied in a consecutive series of 285 eyes having intracapsular cataract extraction and Severin intraocular lens implantation. The incidence and natural course of the condition is described and associated factors are discussed.

A comparison of ciliary sulcus and capsular bag fixation of posterior chamber intraocular lenses

We compare indications, advantages, and disadvantages of ciliary sulcus and lens capsular bag (lens capsular sac) fixation of posterior chamber intraocular lenses (IOLs). Our findings suggest that, whenever possible, it is efficacious to implant the loops of posterior chamber IOLs within the capsular bag. This positions the lens optic and the supporting loops in the natural anatomical position, sequestered from highly vascular uveal tissue and the blood aqueous barrier. This should minimize the potential for complications that may be associated with iris-ciliary body contact. Considering the rapid increase in the number of implantations of IOLs now being performed (approximately 700,000 per year in the United States alone), a possible reduction of even 1% in clinically significant complications would make this effort worthwhile. Widespread application of in-the-bag implantation is predicated on the assumption that the surgeon is proficient with this procedure and that careful follow-up of patients does not reveal any significantly increased incidence of lens dislocation due to zonular rupture.

Complications of intraocular lenses. A historical and histopathological review

Recent improvements in intraocular lens (IOL) design, manufacturing techniques, and surgical techniques have greatly reduced the incidence of complications following implantation, and many authors now consider IOL implantation to be among the most safe and effective major surgical procedures. However, adverse reactions are still seen--some as late sequelae of earlier IOL designs and implantation techniques and some as sequelae of more recent implantations using "state-of-the-art" lenses and surgical techniques. Complications may be due to various factors, including surgical technique, IOL design, or the inability of some eyes with preexisting disease to tolerate an implant. The authors trace the evolution of IOLs since Ridley's first implant, summarizing the modifications in lenses and surgical techniques that were made as complications were recognized. They then review the clinical and histopathological features of selected cases from more than 200 IOLs and/or globes removed due to IOL-related complications and studied in the University of Utah Ocular Pathology Laboratory. It is hoped that this review will provide insights into the pathogenesis of IOL complications, enhancing the current success of implant procedures and stimulating further basic and clinical research in this area.