Effect of cataract surgery on intraocular pressure control in glaucoma patients

Intraocular pressure rise after phacoemulsification surgery in glaucoma patients

PURPOSE

To examine the changes in intraocular pressure (IOP) and the incidence of substantial rises in IOP in the early period after cataract surgery in eyes with open-angle glaucoma (OAG).

SETTING

Hayashi Eye Hospital, Fukuoka, Japan.

METHODS

The study included 32 eyes of 32 patients with OAG and 31 control eyes of 31 age-matched patients scheduled for phacoemulsification surgery. The IOP was measured preoperatively and 1, 2, 3, 5, 7, 14, and 28 days postoperatively. The incidence of a substantial rise in IOP postoperatively was evaluated, with the criterion being an IOP higher than 30 mm Hg.

RESULTS

In the OAG group, the mean IOP increased 1, 2, and 3 days postsurgery and then decreased, whereas in the control group, it decreased from day 1 postsurgery. Although no significant differences were found between groups preoperatively, the mean IOP in the OAG group was significantly higher than in the control group postoperatively. Furthermore, the mean IOP decrease was also less in the OAG group than in the control group. A substantial increase in IOP occurred at day 1 postsurgery in 4 eyes (12.5%) in the OAG group, whereas no eyes in the control group showed such an increase; this difference was significant (P =.0419).

CONCLUSIONS

A substantial increase in IOP occurred in an approximately 13% of eyes with OAG 1 day after phacoemulsification surgery. The IOP shortly after surgery was significantly greater in the eyes with OAG than in nonglaucomatous eyes.

Cataract surgery in patients with nanophthalmos

PURPOSE

To evaluate the results and complications of cataract surgery in patients with nanophthalmos.

SETTING

University hospital practice.

METHODS

The records of consecutive patients with nanophthalmos who had cataract surgery from 1978 through 2002 were reviewed for ocular diagnoses, corneal diameter, keratometry, axial length, retinal-choroidal-scleral thickness determined by echography, ocular surgeries, visual acuity, and complications.

RESULTS

Eight patients (6 women, 2 men) with a mean age of 59 years were reviewed. Four patients were not previously diagnosed with nanophthalmos; increased retinal-choroidal-scleral thickness (mean 2.41 mm) confirmed the diagnosis. Twelve eyes had cataract extraction with posterior chamber intraocular lens (IOL) implantation, 11 by phacoemulsification and 1 by extracapsular cataract extraction, and 4 eyes had lamellar scleral resections. Additional surgeries included glaucoma laser treatment (8 eyes), cyclocryotherapy (2 eyes), trabeculectomy with scleral resection (1 eye), trabeculectomy combined with phacoemulsification (1 eye), and neodymium:YAG laser capsulotomy (4 eyes). No eye lost vision; however, complications included severe iritis, broken IOL haptic with vitreous loss, posterior capsule opacity, choroidal hemorrhage, phthisis, and aqueous misdirection.

CONCLUSIONS

Results indicate that echography should be used to assess retinal-choroidal-scleral thickness in eyes that are hyperopic and at risk for narrow-angle glaucoma. Thickening may confirm the diagnosis of nanophthalmos and allow careful preoperative assessment and appropriate operative procedures in these high-risk eyes. With advances in cataract, glaucoma, and uveal effusion treatments, surgical results in patients with nanophthalmos are improving.

Surgical strategies in patients with combined cataract and glaucoma

PURPOSE OF REVIEW

In the elderly population, the combined presence of cataract and glaucoma is a frequent condition. In this situation, several surgical options are possible: cataract surgery only and later maybe trabeculectomy, trabeculectomy only and later maybe cataract surgery, or combined cataract and glaucoma surgery. This review compares the different surgical options on the basis of their achievable postoperative intraocular pressure (IOP) level and success and complication rates.

RECENT FINDINGS

The impression of better IOP regulation with trabeculectomy than with phacotrabeculectomy has been recently confirmed by an evidence-based review. Contrary to this finding, the success of deep sclerectomy or trabeculotomy does not seem to be compromised by simultaneous phacoemulsification. In eyes with previous glaucoma-filtering surgery, cataract surgery with clear corneal incision has no effect on mean IOP but increases the 3-year failure probability. For phacotrabeculectomy, moderate evidence of a beneficial effect of MMC on IOP regulation and only weak evidence for separating the incisions has been recently reported by another evidence-based review.

SUMMARY

The choice of the preferred surgical method depends on the target pressure, the amount of glaucomatous damage, and the grade of visual disturbance caused by the cataract. Phacotrabeculectomy combined with mitomycin C achieves the best IOP lowering of all types of combined cataract and glaucoma surgery currently possible but is associated with potentially sight-threatening complications. In the absence of a low target pressure, phacotrabeculotomy or the combination of phacoemulsification with viscocanalostomy or deep sclerectomy may be the therapy of choice.

Ultrasound Biomicroscopic Changes after Laser Iridotomy or Trabeculectomy in Angle-closure Glaucoma

This study was performed to demonstrate the ultrasound, biomicroscopic and dimensional changes of angle structure after laser iridotomy (LI) and primary trabeculectomy (PT) in primary angle-closure glaucoma (PACG). Angle-opening distance at a point 500 m from the scleral spur (AOD500), trabecular-iris angle (theta1), trabecular ciliary process distance (TCPD), ciliary process-iris angle (CPI), iris thickness (ID1, ID3), length of iris-lens contact distance (ILCD) and anterior chamber depth (ACD) were assessed before and after each procedure. Thirteen patients with LI and 16 with PT were prospectively enrolled. There were statistically significant increases in AOD500, theta1, and ILCD in both groups. CPI was decreased in both groups. ACD, TCPD, and iris thickness were not changed significantly. The changes in angle configuration after LI or PT may result more from alterations in aqueous pressure gradients across the iris and the changes of configuration were greater in the iris roots without rotation of ciliary body. However, we didn't find any significant differences in the changes of parameters between the two procedures.

Interventions for angle-closure glaucoma

PURPOSE

To assess the interventions to treat acute angle closure (AAC) and primary angle closure (PAC) with or without glaucomatous optic neuropathy.

CLINICAL RELEVANCE

Primary angle closure is one of the leading causes of blindness in East Asia. At present, there are few clinical guidelines on the optimal treatment of AAC or PAC in the affected or contralateral eye.

METHODS

All randomized clinical trials, prospective controlled clinical trials, nonprospective controlled clinical trials, and retrospective case series with >50 cases that evaluated treatments for AAC or PAC were included. Studies published in the English language were identified from MEDLINE, PubMed, EMBASE, and the Cochrane Collaborations, as well as by a hand search of the reference lists of important articles.

RESULTS

Nine randomized clinical trials and 24 nonrandomized clinical trials and large case series were evaluated. Laser peripheral iridotomy (LPI) has been found to be as effective as surgical peripheral iridectomy in randomized clinical trials of the affected and contralateral eyes of AAC or PAC patients with or without evidence of glaucoma. In another randomized clinical trial, latanoprost was found to decrease intraocular pressure (IOP) more than timolol for PAC in patients for whom LPI alone failed.

CONCLUSIONS

This review suggests that LPI should be recommended for the treatment of affected and contralateral eyes of AAC patients. In patients with PAC and insufficient treatment with LPI, latanoprost eye drops may decrease IOP more than timolol. There is still insufficient evidence about other interventions for the treatment of AAC and PAC.

Results of phacoemulsification in eyes with preexisting glaucoma filters

PURPOSE

To evaluate the intraocular pressure (IOP), best corrected visual acuity (BCVA), and glaucoma medication requirements in patients having phacoemulsification after preexisting glaucoma filters.

SETTING

Ophthalmic Consultants of Boston, Boston, Massachusetts, USA.

METHODS

A retrospective analysis of 58 eyes that had temporal phacoemulsification via a clear corneal (32 eyes) or a scleral tunnel (26 eyes) approach after filtration surgery was performed with a minimum follow-up of 12 months. Two-tailed homoscedastic t tests were used for statistical analysis.

RESULTS

The mean preoperative IOP in all eyes was 11.8 mm Hg +/- 4.2 (SD), and the mean final postoperative IOP was 13.7 +/- 4.6 mm Hg (P<.022). The mean preoperative logMAR equivalent BCVA was 0.8 +/- 0.4, which improved to a mean of 0.4 +/- 0.4 postoperatively (P<.0000002). There was no statistically significant change in glaucoma medication requirements postoperatively. The differences in IOP, BCVA, and postoperative glaucoma medication requirements were not statistically significant between the clear corneal group and the scleral tunnel group or between patients who received mitomycin at the time of filtration surgery and those who did not. There were no intraoperative complications; 1 patient required additional glaucoma surgery.

CONCLUSION

Clear corneal or scleral tunnel phacoemulsification in the setting of a preexisting glaucoma filter was associated with improved BCVA, a small but statistically significant increase in IOP, and stability in the number of glaucoma medicines required for IOP control over a minimum follow-up of 1 year.

A pilot study of lens extraction in the management of acute primary angle-closure glaucoma

PURPOSE

To describe a pilot study of lens extraction in the management of acute primary angle-closure glaucoma (APACG) in Chinese patients.

DESIGN

Interventional case series.

METHODS

A prospective case series of patients presented with APACG at a tertiary eye hospital in Xiamen, China. All the patients had intensive medical treatment followed by immediate phacoemulsification and posterior chamber intraocular lens implantation under topical anesthesia.

RESULTS

There were 18 patients who were seen with APACG who had phacoemulsification and posterior chamber intraocular lens implantation under topical anesthesia. There was a 9.0-mm Hg drop in mean preoperative and first day postoperative intraocular pressure (22.8 vs 13.8 mm Hg, P =.012) and a 10.2-mm Hg drop in mean preoperative and seventh-day postoperative intraocular pressure (22.8 vs 13.2 mm Hg, P =.002).

CONCLUSIONS

This pilot study indicates that phacoemulsification and posterior chamber intraocular lens implantation may be useful in the treatment of primary acute angle-closure glaucoma in Chinese patients. Further study with longer follow-up is needed.

Angle-closure glaucoma: impact, etiology, diagnosis, and treatment

PURPOSE OF REVIEW

Recent studies underscore the importance of angle-closure glaucoma (ACG) as a cause of world blindness. A major contribution in assessing the true impact of this disease has been an article estimating the number of persons with occludable angles, angle closure, and blindness from ACG in China as 28.2 million, 9.1 million, and 1.7 million, respectively. Although these numbers are based on data from Singapore and Mongolia, which may be applied to China only with caution, they emphasize the blinding potential of ACG, which is three times as likely to be associated with blindness as open-angle glaucoma (OAG).

RECENT FINDINGS

Recent reports in the Chinese literature on ACG prevalence suffer from definitional problems that would appear to lead to systematic overestimates of ACG prevalence and underestimates of OAG prevalence. Nonetheless, data from studies by Chinese investigators further emphasize the strong association between ACG and blindness, with fully 16% of subjects with ACG blind in one report-a far higher proportion than for OAG in China and elsewhere. The importance of topiramate as a cause of secondary angle closure has recently been understood, in part, because of a series of 19 such cases reported by investigators at the Food and Drug Administration.

SUMMARY

Angle closure in this setting appears to be caused by uveal effusion and anterior rotation of the ciliary body with resultant closure of the angle. The condition is not always responsive to laser iridectomy, and elimination of the causative agent appears to be critical. Ultrasonic biomicroscopy is a potential new diagnostic modality for ACG, allowing the measurement of novel parameters, such as the angle opening distance (AOD) at 500 microm (AOD 500). The efficacy of such parameters in improving screening for ACG can only be established by prospective studies of potentially at-risk eyes. A number of novel treatments for AC and angle closure have recently been proposed, including cataract extraction, paracentesis, and argon laser iridoplasty. As with proposed new diagnostic modalities, the efficacy of these treatments remains to be demonstrated with prospective studies, ideally organized in a controlled, randomized fashion.

Avoiding complications in combined phacotrabeculectomy

Combined phacoemulsification and trabeculectomy offers the advantage of relieving both cataract and increased intraocular pressure in one surgical sitting. The procedure however entails greater risks than either alone. An approach to minimize these risks is described.