Ординатура / Офтальмология / Английские материалы / Clinical Pathways in Glaucoma_Zimmerman, Kooner_2001
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480 Surgical Therapy for Glaucoma
age. Conjunctiva is then reapproximated and closed. If there is insufficient conjunctival tissue for closure, a conjunctival graft will be needed.
What If the IOP Is Too High During the First Week?
If the anterior chamber is collapsed and the IOP is very high, then the patient may have malignant glaucoma (Fig. 19–3). These patients are treated with maximal dilation and cycloplegia, maximal medical therapy including mannitol, and often still require pars plana vitrectomy. If the anterior chamber is shallow but not collapsed, the patient may have extensive PAS from prolonged hypotony and will require an attempt at angle reconstruction with viscoelastic, as well as surgical reevaluation of the trabeculectomy site.
If the anterior chamber is deep (i.e., no malignant glaucoma) then the patient is underfiltering. Laser suture lysis should be attempted until the desired effect is achieved. If the pressure is very high, then it might be safer to reduce pressure prior to suture lysis. This is attempted medically first, but a 27-gauge needle can be used (bevel up) through the paracentesis site to slowly
Patient with elevated IOP after first week of surgery.
Yes
Tenon’s cyst
Consider “needling” and 5-FU
FML, fluorometholone IOP, intraocular pressure
Is there a large encapsulated bleb?
No
No Tenon’s cyst: remember it is common for IOP to rise temporarily about 3 weeks postop.
Taper steroids to FML and slowly taper off FML, if conjunctiva is quiet. If inflamed, continue FML and restart topical glaucoma meds, as needed, but use as little topical as possible. After six weeks postop, reevaluate the need for a “drug holiday” by coming off one topical at a time.
Figure 19–4. Management of a patient with elevated IOP after first week of filtration surgery.
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Table 19–5. Needling a Tenon’s Cyst
•Apply copious topical anesthesia. Prep and drape the eye, including topical Betadine 25% to rinse out the cul-de-sac. Apply wire rim speculum.
•Use 30-gauge needle to inject lidocaine 2% with epinephrine subconjunctivally.
•Enter subconjunctival space at least 12 mm away from bleb site and inject lidocaine as you advance the needle toward the bleb. This will balloon up the conjunctiva from the needle entrance to the bleb site. It will also provide adequate anesthesia. Then use a 21 to 23-gauge needle through the same track and advance it subconjunctivally and/or sub-Tenon’s well into the wall of the Tenon’s cyst and as close to the limbus as possible, but at least 4 mm posterior to the limbus. Extreme care must be used to be absolutely certain of not buttonholing through the conjunctiva, especially when working anterior near the limbus. Once the needle is in the Tenon’s cyst, rotate the needle or pivot it posteriorly, so that it strips part of its wall posteriorly. If too great a resistance is encountered, then simply poke the needle in and out through the Tenon’s cyst several times. Remove the needle and recheck pressure to document filtration. If aggressive aqueous leakage occurs through the needle track, a single 10.0 nylon suture may be required. Usually, however, leakage will stop within minutes on its own. Finally, use a 30-gauge needle to inject 0.5 to 1.0 mL of 5-FU (5 mg/mL). This is not done through the original needle track. Instead, this is usually done on the other side of the bleb. It is not injected into the bleb, but injected at least 20 degrees away from the bleb. After needling the Tenon’s cyst, Pred Forte 1% and Ocuflox is restarted. Repeated 5-FU injections every other day for 1 to 2 weeks is helpful.
“burp” aqueous from the anterior chamber if medical therapy is insufficient or too slow.
How Is Elevated IOP Managed After the First Week?
Consider that the patient may be a steroid responder, and begin tapering steroids (Fig. 19–4). Because most patients only need conjunctival treatment rather than intraocular treatment, it is reasonable to change from Pred Fort 1% to FML 0.1% rather early postoperatively. If a Tenon’s cyst is developing, and pressure is inadequately controlled with medication, then proceed with needling of the bleb and subconjunctival 5-FU injection near, but not into, the bleb (Table 19–5).
What About Cycloablative Procedures?
These procedures (Table 19–2) are only indicated if all other avenues fail. They reduce IOP by destroying the ciliary body and consequently decreasing the production of aqueous humor. Various types of laser therapies and a cryo procedure are available (Table 19–2). The former more commonly are associated with fewer complications than the latter (see Chapter 22).
In transpupillary (direct) laser cyclophotocoagulation, more controlled destruction of the ciliary epithelium is possible as compared to transscleral laser procedure.42 Most patients require retroor peribulbar anesthesia for comfort during this surgery. The 3 and 9 o’clock meridians are avoided to pre-
482 Surgical Therapy for Glaucoma
vent damage to the long posterior ciliary arteries. Laser energy parameters are variable and depend on the nature of the laser material. Complications may also be minimized by treating 270 degrees or less of the ciliary epithelium. The effect on IOP may be dramatic, though many patients require repeat treatments. Most (60 to 70%) end up with pressures of 22 mm Hg or lower.42–44 Complications include pain, hemorrhage, reduced visual acuity, uveitis, and phthisis bulbi.
Uram45 introduced endoscopic cyclophotocoagulation in the treatment of glaucoma. He reported a 57% decrease in IOP in patients undergoing combined cataract and glaucoma surgeries
Future Considerations
As previously mentioned, nonpenetrating trabeculectomies and adaptations of shunt devices will be important future considerations. The nonpenetrating trabeculectomies especially sound promising and may become a more common form of glaucoma surgery in the future.
Endoscopic laser cyclodestructive procedures may gain popularity, especially in combined cataract cases as technology advances. Even still the “traditional” guarded trabeculectomy should increase in frequency as the population ages. Planned postoperative suture lysis should also increase in frequency as the benefits of this modification become better known.
Acknowledgments
In that this chapter is mostly a compilation of what I have learned from others, I would like to thank all of those who came before. In particular, I thank my mentors: Dr. Thom Zimmerman, Dr. George Nardin, Dr. Bernard Schwartz, and Dr. M. Bruce Shields.
References
1.Hitchings RA: Primary surgery for primary open angle glaucoma—justified or not? Br J Ophthalmol 1993;77:445–448.
2.Migdal C: What is the appropriate treatment for patients with primary open angle glaucoma: medicine, laser or primary surgery? Ophthalmic Surg 1995;26:108–109.
3.Anderson DR: Glaucoma: the damage caused by pressure. Jackson Memorial Lecture. Am J Ophthalmol 1989;108:485–495.
4.Thomas R, Billings F: The place of trabeculectomy in the management of primary open angle glaucoma and factors favoring success. Aust NZ J Ophthalmol 1989;17:217–224.
5.Jay JL, Murray SB: Early trabeculectomy versus conventional management in primary open angle glaucoma. Br J Ophthalmol 1988;72:881–889.
6.Jay JL, Allan D: The benefit of early trabeculectomy versus conventional management in primary open angle glaucoma relative to the severity of the disease. Eye 1989;3:528–535.
7.Migdal C, Hitchings RA: Control of chronic simple glaucoma with primary medical, surgery and laser treatment. Trans Ophthalmol Soc UK 1986;105:653–656.
8.Migdal C, Gregory W, Hitchings R: Long term functional outcome of early surgery compared with laser and medicine in open angle glaucoma. Ophthalmology 1994;101:1651–1657.
9.Sherwood MB, Migdal C, Hitchings RA, et al.: Initial treatment of glaucoma: surgery or medications. Surv Ophthalmol 1993;37:293–305.
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10.Ainsworth JR, Jay JL: Cost analysis of early trabeculectomy versus conventional management in primary open angle glaucoma. Eye 1991;5:332–338.
11.Schwab L, Steinkuller PG: Surgical treatment of open angle glaucoma is preferable to medical management in Africa. Soc Sci Med 1983;17:1723–1727.
12.Wilson R, Richardson TM, Hertzmark E, et al.: Race as a risk factor for progressive glaucomatous damage. Ann Ophthalmol 1985;17:653–659.
13.Stegmann R, Pienaar A, Miller D: Viscocanalostomy for open-angle glaucoma in black African patients. J Cataract Refract Surg 1999;25:316–322.
14.Javitt JC, McBean AM, Nicholson GA, et al.: Undertreatment of glaucoma among black Americans. N Engl J Med 1991;325:1418–1422.
15.Glynn RJ, Gurwitz JH, Bohn RL, et al.: Old age and race as determinations of initiation of glaucoma therapy. Am J Epidermiol 1993;138:395–406.
16.Gaasterland DE, Ederer F, Sullivan EK, et al.: The Advanced Glaucoma Intervention Study (AGIS)–4—comparison of treatment outcomes within race: seven year results. Ophthalmology 1998;105:1146–1164.
17.Thomas JV, El-Mofty A, Hamdy EE, et al:. Argon laser trabeculoplasty as initial therapy for glaucoma. Arch Ophthalmol 1984;102:702–703.
18.Kalenak JW, Ripken DJ, Medendorp SV: Randomized controlled trial of the Molteno implant with and without mitomycin. Scientific Poster at American Academy of Ophthalmology annual meeting, Atlanta, 1995;136.
19.Tuulonen A: Laser trabeculoplasty as a primary therapy in chronic open angle glaucoma. Acta Ophthalmol 1984;62:150–155.
20.Juhas T, Corova M: Diode laser trabeculoplasty in the treatment of primary open-angle glaucoma [Slovak]. Cesk Oftalmol 1994;50:182–185.
21.Van Buskirk EM, Pond V, Rosenquist RC, et al.: Argon laser trabeculoplasty. Studies of mechanism of action. Ophthalmology 1984;91:1005–1010.
22.Wise JB, Witter SC: Argon laser therapy for open angle glaucoma. A pilot study. Arch Ophthalmol 1979;97:319–322.
23.Lewis R, Perkins TW, Gangnon R, et al.: The rarity of clinically significant rise in intraocular pressure after laser peripheral iridotomy with apraclonidine. Ophthalmology 1998;105: 2256–2259.
24.Schwartz AL, Kopelman J: Four year experience with argon laser trabecular surgery in uncontrolled open-angle glaucoma. Ophthalmology 1983;90:771–780.
25.Gandolf SA, Vechhi M: Effect of YAG laser iridotomy on intraocular pressure in pigment dispersion syndrome. Ophthalmology 1996;103:1693–1695.
26.Sherwood MB, Grierson I, Miller L, et al.: Long-term morphologic effects of anti-glaucoma drugs on the conjunctiva and Tenon’s capsule in glaucomatous patients. Ophthalmology 1989;96:327–335.
27.Lavin MJ, Wormald RPL, Migdal CS, et al.: The influence of prior therapy on the success of trabeculectomy. Arch Ophthalmol 1990;108:1543–1548.
28.Richter C, Shingleton B, Bellows AR: The development of encapsulated filtering blebs. Ophthalmology 1998;105:1163–1168.
29.Schwartz AL, Val Veldhuisen PC, Gaasterland DE, et al.: The Advanced Glaucoma Intervention Study (AGIS)–5—encapsulated bleb after initial trabeculectomy. Am J Ophthalmol 1999;127:8–19.
30.Chauvaud D, Clay-Fressinet C, Poulequen Y, et al.: [Opacification of the crystalline lens after trabeculectomy. Study of 95 cases.] [French] Arch Ophthalmol 1976;36:379–386.
31.Sugar HS: Experimental trabeculectomy in glaucoma. Am J Ophthalmol 1961;51:623–627.
32.Cairnes JE: Trabeculectomy. Preliminary report of a new method. Am J Ophthalmol 1968; 5:673–679.
33.Shields MB: Textbook of Glaucoma. Baltimore: Williams & Wilkins, 1987;466–471.
34.Zimmerman TJ, Kooner KS, Ford VJ, et al.: Effectiveness of nonpenetrating trabeculectomy in aphakic patients with glaucoma. Ophthalmic Surg 1984;15:44–50.
35.Zimmerman TJ, Kooner KS, Ford VJ, et al.: Trabeculectomy vs. nonpenetrating trabeculectomy: a retrospective study of two procedures in phakic patients with glaucoma. Ophthalmic Surg 1984;15:734–740.
36.Molteno AC: New implant for drainage in glaucoma. Clinical trial. Br J Ophthalmol 1969;53: 606–615.
37.Oh Y, Katz LJ, Spaeth GL, et al.: Risk factors for the development of encapsulating filtering blebs. The role of surgical glove powder and 5-fluorouracil. Ophthalmology 1994;101:629–634.
38.Robin AL, Ramakrishnan R, Krishnadas R, et al.: A long-term dose-response study of mitomycin in glaucoma filtration surgery. Arch Ophthalmol 1997;115:969–974.
39.Greenfield DS, Liebmann JM, Jee J, et al.: Late-onset bleb leaks after glaucoma filtering surgery. Arch Ophthalmol 1998;116:443–447.
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40.Khoury JM, Joos KM, Shen JH, et al.: Half corneal light shield as a delivery system for standardized application of mitomycin C. J Glaucoma 1998;7:8–11.
41.Vass C, Menapace R, Strenn K, Rainer G: Episcleral versus combined episcleral and intrascleral application of mitomycin-c in trabeculectomy. Ophthalmic Surg Lasers 1998;29:714–721.
42.Shields S, Stewart WC, Shields MB: Transpupillary argon laser cyclophotocoagulation in the treatment of glaucoma. Ophthalmic Surg 1988;19:171–175.
43.Crymes BM, Gross RL: Laser placement in noncontact Nd:YAG cyclophotocoagulation. Am J Ophthalmol 1990;110:670–673.
44.Schuman JS, Bellows AR, Shingleton BJ, et al.: Contact transscleral Nd:YAG laser cyclophotocoagulation. Ophthalmology 1992;99:1089–1095.
45.Uram M: Combined phacoemulsification, endoscopic ciliary process photocoagulation and intraocular lens implantation in glaucoma management. Ophthalmic Surg 1995;26:346–352.
20
Management of Cataract
and Glaucoma
Artemios S. Kandarakis
Definition
What Variables Need to be Considered in Management of Cataract and Glaucoma?
The management of a patient with visually significant cataract and glaucoma poses a clinical challenge for an ophthalmologist. The variables to consider are the patient’s age, stage of glaucomatous damage, status of the control of glaucoma, the patient’s general health, ability to pay for treatments, noncompliance, and family or social support.
Epidemiology and Importance
Has There Been an Increase or Decrease of Cataract and Glaucoma Over the Years?
Although there are no large studies on the rate of incidence of age-related cataract and glaucoma, it is reasonable to assume that with the increase in the world’s older population, there would be an increase in the number of cataract and glaucoma patients as well. Kahn et al,1 studying the Framingham population, found that among 2,477 subjects aged 52 to 85, the prevalence of senile cataract was 15.5% and that of open-angle glaucoma was 3.3%. More recently, Rahmani et al,2 studying the Baltimore Eye Survey population of 40 years of age or older, found that the prevalence of cataract was 35.3% and that of glaucoma 4.7%. Similarly, Singh et al,3 in a total of 903 persons above 50 years of age from Maharashtra, India, found the prevalence of cataract to be 40.4% and that of glaucoma to be 3.1%.
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The 5-year incidence of age-related cataract from the Framingham Eye Study ranged from 1% at the age of 55 to 15% at the age of 75.4 Klein et al5 estimated the incidence of cataract in the Beaver Dam Eye Study population by taking into account the prevalence of cataract at a baseline examination conducted between 1988 and 1990 and again at the follow-up examination held between 1993 and 1995. They found that incipient nuclear cataract occurred in 13.1%, cortical cataract in 8.0%, and posterior subcapsular cataract in 3.4%. The cumulative incidence of nuclear cataract increased from 2.9% in persons aged 43 to 54 years at baseline to 40.0% in those aged 75 years or older. For cortical cataract, the corresponding values were 1.9% and 21.8% and for posterior subcapsular cataract, 1.4% and 7.3%, respectively.
In Europe, Dielemans et al6 in the Rotterdam Study concluded that the overall prevalence of primary open-angle glaucoma (POAG) in 3,062 participants over 55 years of age was 1.1%.
What Are the Demographic Characteristics of Patients with Cataract and Glaucoma?
It has been confirmed that the older the individual, the greater the prevalence of cataract and glaucoma.7,8 Hiller et al,7 in the National Health and Nutrition Examination Survey (NHANES), found that the risk of cataract at age 70 is 13-fold higher than that at age 50. Klein et al8 noted in the Beaver Dam Eye Study that the prevalence of glaucoma increased from 0.9% at ages 43 to 54 to 4.7% at age 75 or more. In England, Das et al9 found that, under the age of 60, Asians had a 30% prevalence of age-related cataract compared to 3% in Europeans, and 78% compared to 54% at age 60 and over. In another detailed study, Mitchell et al10 examined the prevalence and demographics of age-related cataract in an urban population of Australia. They reported that nuclear cataract involved 51.7% of the population (53.5% of women and 49.7% of men) and was found in 17.6% of persons less than 55 years of age, 34.2% of persons aged 55 to 64 years, 61.8% of persons aged 65 to 74 years, 87.3% of persons aged 75 to 84 years, and 89.6% of persons aged 85 years or older. They also reported that cortical opacities were found in 23.8% of the population (25.9% of women and 21.1% of men) and specifically in 4.4% of individuals less than 55 years of age, 13.1% of those aged 55 to 64 years, 28.4% of those aged 65 to 74 years, 46.7% of those aged 75 to 84 years, and 55.8% of those aged 85 years or older. Finally posterior subcapsular cataracts were seen in 6.3% of the population (6.2% of women and 6.5% of men) and were found in 2.7% of persons less than 55 years of age, 3.8% of those aged 55 to 64 years of age, 6.5% of those aged 65 to 74 years, 11.7% of those aged 75 to 84 years, and 19.8% of people aged 85 year or older. Women are affected slightly more than men are, and this excess in prevalence is mainly due to a higher risk of cortical cataracts.7,10,11 Mitchell et al10 also found that the rates of cortical cataracts were higher in women than men in each age group and the age-adjusted prevalence of advanced cortical cataract was significantly higher in women compared with men—relative prevalence 1.21 [95% confidence interval (CI) 1.08 to 1.36]. In the Beaver Dam Eye Study, Klein et al11 found that women had more cortical opacities than men (p <.002).
Dielemans et al6 reported that age-specific prevalence figures of POAG in the Netherlands increased from 0.2% (95% CI : 0.16, 0.24) in the age group of 55 to
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59 years to 3.3% (95% CI : 2.57, 4.04) in the age group of 85 to 89 years. Men had a more than three times higher risk of having primary open-angle glaucoma than women (odds ratio, 3.6). Tuck and Crick,12 studying the age distribution of POAG in England, found that the prevalence for age 40 to 89 years was 1.2%, rising from 0.2% for those in their 40s to 4.3% for those in their 80s.
Using data from the NHANES, Hiller et al13 found that cortical and nuclear cataracts were more commonly associated with blacks than whites (relative risk of cortical cataracts 3.5 and of nuclear cataracts 1.8 for blacks versus whites). Blacks have a prevalence of POAG three or four times higher than that of whites.14,15 There is probably a wide variation of geographic distribution of agerelated cataract. In Punjab, India, the prevalence of senile cataract was found to be 15.3% among 1,269 persons aged 30 years and older with a prevalence of 1% for ages 30 to 49 and 67% for ages 70 and older.16 In the Tibet Eye Study (2,665 participants) the prevalence of senile cataract among persons aged 20 to 32 years was 0.2% and among persons aged 40 or more was 11.8%. The authors attributed these findings to the high altitude (4,000 meters) because this prevalence was 60% higher than the prevalence of a similar, previously conducted study in Shunyi County, China, with an altitude of only 50 meters.17 However, Brilliant et al18 also found that cataract prevalence was negatively correlated with altitude in 873 residents of Nepal, reporting a 2.7 times lower prevalence at sites over 1,000 meters than at sites of 185 meters or less (r = .0533, p <.0001).
Are There Any Social and Economic Factors Associated with Cataracts and Glaucoma?
Klein et al19 found that less education was significantly associated with nuclear and cortical cataract, whereas lower income was significantly associated with cortical and posterior subcapsular cataract (p <.05). Hiller et al13 found in the NHANES study that less education was associated only with cortical cataract [realtive risk (RR) = 1.8 for less than 9 years of schooling vs. college], whereas posterior subcapsular cataracts were associated with diabetes (RR = 6.6 for diabetes present vs. diabetes absent) and high systolic blood pressure (RR = 2.2 for 160 mm Hg vs. 120 mm Hg). Positive correlation between cataract prevalence and sunlight (p <.0001) was observed by Brilliant et al.18 Taylor et al20 examined 838 fishermen at Chesapeake Bay and found that high cumulative levels of ultraviolet B (UVB) exposure significantly increased the risk of cortical cataract (regression coefficient, 0.70; p = .04) and that fishermen with cortical lens opacities had a 21% higher average annual exposure to UVB (t- test, 2.23, p = .03). In a series of 351 cataract patients operated in Oulu, Finland, Lumme and Laatikainen21 found that 30% of them lived alone at home, 62% lived with some other person, and 8% were in institutions. Another study has found that anterior subcapsular cataract was significantly (p = .001) more prevalent (26%) in participants with schizophrenia than controls (0.2%). 22
Are There Any Personal Habits That Predispose Patients to Cataract and Glaucoma?
Evaluation of 4,926 participants in the Beaver Dam Eye Study revealed a relationship between cigarette smoking and lens opacities.23 Specifically, it was found that the frequency of nuclear sclerosis increased with cigarette smoking in
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both sexes. For men the odds ratio (OR) was 1.09 (CI = 1.05, 1.14) and for women, the OR was 1.09 (CI = 1.04, 1.16). It was also found that the frequencies of posterior subcapsular cataract (PSC) also increased in both sexes with smoking. The OR was 1.06 (CI = 0.98, 1.14) for women and 1.05 (CI = 1.00, 1.11) for men.
Recently there have been suggestions that good nutrition with antioxidant supplements may have protective association against cataract. Jacques et al24 investigated the antioxidant status of 112 individuals aged 40 to 70 years, and found that subjects with high levels of at least two of the three vitamins (vitamin E, vitamin C, and carotenoids), are at reduced risk of cataract (OR, 0.2). Similar findings of dietary intake of riboflavin, vitamins C and E, and carotene as well as intake of niacin, thiamin, and iron support a protective effect against cortical, nuclear, and mixed cataract (OR 0.40, 0.48, 0.56, respectively).25
Drug intake may also play a role in cataract formation. The association of steroid intake with the PSC is well established. In the Lens Opacities CaseControl Study of 1,380 participants, it was found that oral steroid therapy increased the risk of PSC (OR, 5.83).25 In the Blue Mountains Eye Study26 the hypothesis that aspirin protects against cataract formation was not supported because aspirin users for more than 10 years had higher prevalence of PSC than did 40 nonusers (p = .02). In the same study, antihypertensive medications, cholesterol-lowering drugs, and allopurinol were not associated with any type of cataract, whereas the use of antimalarial drug meracrine was associated with PSC (OR, 3.56; 95% CI = 1.56, 8.13) and the use of phenothiazines with nuclear cataract (OR, 2.18; CI = 1.01, 4.74). In a recent study, McCarty et al22 found that the distribution of the age-related cataract was similar across all users of psychotropic medications (diazepams, butyrophenols, tricyclic antidepressants, and monoamine oxidase inhibitors), with the exception of users of phenothiazines in whom cortical cataract was statistically lower (p = .047).
What Is the Magnitude of the Economic Cost
of Cataract and Glaucoma?
Cataract is a major health problem; it is the leading cause of blindness worldwide.27 It is estimated that more than 1 million cataract surgeries are performed annually in the United States.28 Steinberg et al29 analyzed a 5% sample of Medicare beneficiaries who underwent extracapsular cataract extraction (ECCE) between 1982 to 1987. The authors modified the costs by using the 1991 charges allowed by Medicare. It was found that the median charge allowed by Medicare for an uncomplicated routine cataract surgery was approximately $2,500 and that Medicare spent $3.4 billion on cataract-related surgery. In addition, Medicare also spent more than $39 million for preoperative evaluation of nonophthalmologic tests such as cardiac angiograms, and more than $18 million for perioperative medical services. Kobelt et al30 estimated the direct cost of glaucoma management in a study dealing with 200 glaucoma patients in Germany. They found that during the 2 years of follow-up, 54% of patients had their therapy changed at least once. Mean total charge and cost per patient were 815 and 1,274 deutsche marks, respectively. Mean intraocular pressure (IOP) at baseline was 31.2 mm Hg and after 2 years 18.8 mm Hg. IOP at baseline was positively correlated with costs (p <.01), whereas IOP reduction after treatment initiation was negatively correlated with costs (p <.01). The authors
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concluded that because frequent treatment change was associated with higher costs, new treatments that control the IOP effectively over time may reduce the cost of patient management.
What Is the Importance of the Management
of Cataract and Glaucoma?
There are quite a few options by which the problem can be solved. These options are based on general principles, surgical experience, and individualization of each case. Cataract and glaucoma are, in the majority of cases, diseases of aging. And as population life span increases, the frequency of both conditions in the same age group may increase as well. Also, the chronic use of glaucoma medications that cause miosis, apart from other side effects, may have a cataractogenic effect. Cataract formation is associated with the use of both directly acting miotics (pilocarpine) and indirectly acting anticholinesterase drugs (phospholine iodide).31 Therefore, glaucoma and cataract not only commonly coexist, but one can influence the management of the other.
On the other hand, the evolution of both cataract and glaucoma surgery of the past 5 to 10 years has been enormous. Modern cataract surgery is now characterized by the reduced incision size of phacoemulsification, the use of foldable intraocular lenses (IOLs),32 and improved techniques of management of the miotic pupil.33 Concerning glaucoma surgery, refinement of trabeculectomy by microsurgery, the possibility of less invasion of the conjunctiva, and the adjunctive use of antimetabolites,34 releasable sutures,35 and laser suture lysis36 have all improved the risk/benefit ratio for the glaucoma and cataract patient.
Therefore, ophthalmologists must be prepared to simultaneously manage cataract and glaucoma, taking advantage of all the latest advances for effectively solving this situation.
Diagnosis and Differential Diagnosis
What Factors Need to be Evaluated in a Patient Suffering from Cataract and Glaucoma?
To evaluate a cataract, pupillary dilation is necessary. One can then identify the types of cataracts (nuclear, cortical, subcapsular), the integrity of the zonules, the existence of pseudoexfoliation or posterior synechiae, the degree of pupillary dilation, and the health of macular area. In a case of axial (nuclear) cataract and miosis (either from miotics or from age), pupil dilation may improve a patient’s visual acuity to such a degree that a filtering operation may be sufficient. This approach may work better because the patient, after a successful filtering procedure, might be taken off miotics and not subjected to further miosis. In the case of a low-density cortical cataract, a patient may have 20/40 vision and yet experience severe disability and glare in driving under bright sunlight or facing oncoming vehicle headlights. In the case of a posterior subcapsular cataract, one needs to be extra vigilant because vigorous scraping or vacuuming of the calcified opacity may lead to rupture of the posterior capsule. Zonules become fragile with advanced aging and in the presence of pseudoexfoliation. It is important to identify zonular integrity preoperatively so that an appropriate