A cataract is an opacification of the crystalline lens of the eye that causes vision loss. As the leading cause of blindness,¹ cataracts impose a public health burden on over 2 billion people worldwide.² They are a major cause of visual disability in Africa,^3,4,5,6 creating a serious socio-economic problem.

The current method of cataract treatment is surgery.^7,8 While phacoemulsification is the most advanced and technically superior method of cataract surgery, in developing countries, manual small incision cataract surgery (MSICS) is the most popular surgical management option for cataracts.^9,10,11 Manual small incision cataract surgery is the method of choice at Evangelical Church Winning All (ECWA) Eye Hospital, Kano, a tertiary eye care centre, because of its affordability, shorter surgical time and comparable visual outcome to phacoemulsification.

The location, size and shape of incisions used in MSICS have been shown to influence postoperative surgically induced astigmatism (SIA).^12,13 The superior approach produces a smaller SIA than the temporal approach.¹² To the best of the authors’ knowledge, no retrospective review of temporal approach MSICS for cataract surgery has been performed at their centre since its inception. Following the standard temporal approach MSICS, the authors present their centre’s experiences. This is a 2-year retrospective review (January 2019 – December 2020) to determine the indications of temporal approach MSICS, as well as SIA and visual outcome.

There were 63 eyes from 44 patients who had temporal approach MSICS. Thirty (68.2%) of the patients were male, while 14 (31.8%) were female (Table 1). They ranged in age from 20 to 80 years, with a mean age of 62.32 ± 11.62 years. Previous glaucoma surgery was the reason for the temporal approach in 61 (96.8%) of the eyes. The remaining two (3.2%) had anterior staphyloma in the superior part of the eye. As shown in Table 1, cataract was more common in people aged between 61 and 80 years. The age group of 20 to 30 years had the fewest cataract cases (1.58%).

Figure 1 depicts pre- and postoperative astigmatism in the 63 eyes. Astigmatism was present in 34 of the eyes prior to surgery, while it was absent in 29. Astigmatism was present in 53 eyes after surgery, with only 10 having no astigmatism. Intra-operative hyphaema occurred in one eye, accounting for 1.6%, while uveitis occurred postoperatively in three eyes (4.7%), as shown in Table 2.

In Table 3, the majority of the eyes (54.0%, 34 eyes) had borderline visual impairment (< 6/18 – 6/60) prior to surgery. Furthermore, 27 eyes scored < 6/60 – 3/60, indicating a poor visual outcome. Postoperatively, 9 eyes had a poor visual outcome, while 52 eyes had a borderline visual outcome.

The goal of this study was to determine the indications for temporal approach MSICS and the effects of surgically induced astigmatism on temporal approach in cataract surgeries at ECWA Eye Hospital Kano, through a retrospective review of cases. The goal of modern cataract surgery is to minimise postoperative corneal astigmatism for the best visual outcome.^14,15 A temporal approach to cataract surgery has the potential to achieve this goal.^15,16 Precision in the evaluation of corneal curvature before and after surgery is required to minimise postoperative corneal astigmatism, because incisions may induce a variable amount of corneal astigmatism.¹⁵

Cataracts were more prevalent in patients between the ages of 61 and 80 years (Table 1). This finding is consistent with Lou et al.’s report¹⁷ that old age is a risk factor for developing cataracts.

According to the astigmatism results shown in Figure 1, pre-operative astigmatism was present in 34 eyes (53.96%), while postoperative astigmatism occurred in 53 eyes (84.12%). Nikose et al.¹⁵ made a similar observation, reporting that 18.2% (25/138) of patients who underwent temporal cataract surgery had pre-operative astigmatism. Although the temporal approach has the potential to reduce postoperative corneal astigmatism when compared with superior corneal incision,¹⁵ it is not without the risk of SIA. This is evident in 30.15% (n = 19) of the eyes with postoperative astigmatism (Figure 1). These findings are consistent with those of other studies.^15,18,19

One of the difficulties that cataract surgeons face is cataract surgery in uveitic eyes,²⁰ which can result in intra-operative and postoperative complications. Uveitis occurred postoperatively in three eyes (4.7%) in this study, as shown in Table 2. However, better and more efficient management of the complication resulted in a better outcome in terms of vision quality. Only one eye (1.6%) experienced intra-operative hyphaema as a complication.

In a parallel comparison of the visual acuity outcomes shown in Table 3, 34 eyes had borderline visual acuity of pre-operatively, while this increased to 52 eyes postoperatively. This indicated that the number of patients with improved vision had increased. Pre-operative visual acuity was poor in 27 eyes and postoperatively in 9 eyes (Table 3). Two of the operated eyes had good postoperative visual outcomes, with visual acuities of 6/18. According to a similar study by Zawar et al.,²¹ best-corrected visual acuity (BCVA) better than 6/18 was achieved in 1868 (93.4%) eyes, with 46 (2.3%) having BCVA < 6/60. The indication for temporal MSICS in the majority of the patients was previous glaucoma surgery; nonetheless, the majority of the operated eyes had moderate visual impairment postoperatively (Table 3). The findings of this study support previous reports in the literature that performing cataract surgery using a temporal approach improves vision quality and reduces postoperative astigmatism.^15,22,23

In the patients, post-trabeculectomy cataract was the most common reason for temporal approach cataract surgery. The procedure was both safe and effective, resulting in better visual outcomes.