This prospective observational study was conducted at the Ophthalmology OPD of a tertiary care hospital, R.G. Kar Medical College, Kolkata, India over a period of two years, from April 2021 to March 2023, involving a total of 138 patients. All procedures performed in the current study were approved by the Institutional Ethics Committee in accordance with the 1964 Helsinki Declaration and its later amendments (ECR/322/Inst/WB/2013/RKC/292 dated 15.2.2021). Informed consent was obtained from each individual patient and, in the case of minors, from their parents.

Sample size calculation: The sample size was calculated using the formula: N=(Z1-α/2)²×p×q/L², where Z1-α/2 is 1.96, considering a 95% confidence level. L represents the precision in absolute terms, taken as 5 (considering a p-value of <0.05 as significant). From an extensive literature search, an average success rate of 50-95% for steroid injections was found without any recurrence [10]. For present study, the proportion of cases of chalazion showing a reduction in size was denoted as ‘p’, which was taken to be 90. Consequently, ‘q’ was calculated as 100-90, resulting in 10. Therefore, the sample size (N) was calculated as (1.96)²×90×10/25=138.2976 (rounded off to 138).

Inclusion criteria: The inclusion criteria were patients aged above 12 years, of either gender, with chalazia measuring ≥2 mm to <10 mm, and unresolved primary chalazia after one month of failed conservative management, which included maintenance of lid hygiene, hot compresses, systemic antibiotics, and local antibiotic-steroid ointment application three times per day.

Exclusion criteria: The exclusion criteria included patients allergic to corticosteroids, those with chalazia ≥10 mm in size, individuals under 12 years of age, infected chalazia in the acute stage of inflammation, pregnant women, chalazia with features suspicious of underlying malignancy, a history of steroid-induced elevated IOP, patients who defaulted on follow-up (4 patients), and patients who were unwilling to participate in the study.

Patient particulars, including presenting symptoms such as redness, pain, level of ocular discomfort, and any diminution of vision, as well as clinical signs including eyelid oedema, tenderness, any pus discharge, and general lid hygiene, were recorded. Ocular examination was conducted to assess the size, site, duration, number, recurrence, and proximity to the lacrimal punctum of the chalazion. Visual acuity and IOP were noted at the first visit. The IOP was measured in each case at the outset and was also monitored during the study period to prevent the complication of elevated IOP due to steroid use.

All patients underwent the same technique for TA injection. A 1 mL vial of TA containing 40 mg/mL of aqueous suspension was used for present procedure. The initial dose per injection site varied depending on the size of the lesion being treated. Generally, 0.1-0.2 mL was injected per square millimeter of the involved skin. The total volume should not normally exceed 1-2 mL per dose [11]. Under aseptic conditions, topical anaesthesia (proparacaine 0.5%) drops were instilled into the affected eye. About 0.05-0.15 mL of this suspension (containing 2-6 mg of TA) was drawn into a sterile tuberculin syringe fitted with a 26-gauge needle and injected into the center of the lesion via the transconjunctival or transcutaneous route in the outpatient treatment room. In the case of a large chalazion (>5 mm) or difficulty during lid eversion, the injection was given directly into the base of the lesion transcutaneously after cleansing the skin with 70% isopropyl alcohol wipes. Care was taken not to puncture the tarsal plate or the wall of the chalazion.

All patients were reviewed after two weeks. The chalazion was clinically measured in length and width using calipers at each subsequent visit. The TA injection was repeated at the same dosage if the chalazion did not reduce by half of its original size, with a maximum of three further injections at two-week intervals. Outcome parameters included reduction in size, resolution, recurrence of the lesion, no response, persistence of the lesion, and any complications that may arise during and after the procedure. The definitions of the outcome parameters were as follows:

A minimum of three follow-ups were conducted at two-week intervals to look for any complications such as scarring, depigmentation, lid fat atrophy, lid deformity, or tarsal plate injury. All patients were advised to maintain lid hygiene, reduce screen time exposure, and use prescribed glasses if required, without further surgical intervention. Patients showing persistence of the chalazion even after three TA injections, beyond six weeks after the last injection, were advised to consider I&C.

All the data were tabulated, and statistical analysis was conducted using SPSS (version 24.0; SPSS Inc., Chicago, IL, USA). Data were summarised as mean and standard deviation for numerical variables, and as counts and percentages for categorical variables. The Chi-square test was used to assess the size after TA injection and to evaluate the differences in means among unpaired samples. p-values less than 0.05 were considered significant.

At the time of presentation, the worst recorded visual acuity in the right eye was 6/36, which was noted in 12 (8.7%) patients, while in the left eye, it was also 6/36, noted in 9 (6.5%) patients of the study population. A total of 43 (31.2%) patients presented with chalazia that were in close proximity to the lacrimal punctum, and 98 (71.1%) patients had an underlying refractive error. 15 (10.9%) patients presented with chalazia in both eyes simultaneously, and 24 (17.4%) cases were treated for recurrent chalazia [Table/Fig-1].

The average size of the chalazia measured following TA injection was 2.61±1.95 mm at two weeks, 1.30±1.24 mm at four weeks, and 0.37±0.73 mm at six weeks, indicating a gradual decrease in the size of the chalazia in the study population at each follow-up. A total of 47 (34.05%) patients showed complete resolution in response to the intralesional TA injection, while 70 (50.7%) cases showed a reduction in the size of the lesion during the 2-4 weeks follow-up period. Lack of response was noted in 21 (15.2%) patients following the first dose. After six weeks and three doses of TA injection, a total of 111 (80.4%) patients showed complete resolution. Recurrence was noted in 9 (6.5%) cases, while 18 (13.04%) failed to resolve after six weeks following the intralesional injection of TA and ultimately underwent I&C [Table/Fig-2].

At four weeks, no major complications were noted in 130 (94.2%) cases of the study population. Depigmentation was observed in 4 (2.9%) patients, an uneven depigmented scar was noted in 1 (0.7%) patient, and local eyelid fat atrophy with skin thinning was seen in 3 (2.2%) patients [Table/Fig-3]. Only 2 (1.4%) patients experienced immediate complications of tarsal plate injury at the time of administering the injection, resulting in bleeding and haematoma, which were managed accordingly. 4 (2.9%) patients developed lid deformity due to a combined effect of scarring, uneven eyelid margin, and local fat atrophy during long-term follow-up. The resolution of chalazia cases between four and six weeks was greater than that between two and four weeks [Table/Fig-4].

Localised swelling of the eyelid is a common condition with which patients present to the Ophthalmology OPD. In the present study, most cases of chalazion presented with lid swelling without any other significant ocular complaints. The present study was designed to determine the effectiveness of intralesional triamcinolone injection in the treatment of uncomplicated chalazia of size between ≥2 mm and <10 mm. A total of 82.6% of cases had primary chalazia, while 17.4% had recurrent chalazia.

Of the 138 lesions studied, 125 (90.6%) cases were treated with intralesional TA injection for a single chalazion, while in 13 (9.4%) cases, both chalazia were treated with intralesional TA injections. Successful treatment was defined as a reduction in the size of the chalazion by atleast 95-100% from the baseline pretreatment size without any major complications, which is in concordance with the studies published by Wong MY et al., [8,9].

Out of a total of 138 patients, 62 (44.9%) were aged between 21-30 years, 48 (34.8%) were between 31-40 years, and the remaining 28 patients (20.3%) were aged between 13-20 years, with a male-to-female ratio of 0.75:1. Most of the lesions occurred in the right eyelid (76% of cases; upper eyelid: 39.9%), which corroborates the findings of a study by Jin KW et al., [1].

An 11.6% of cases had unstable refraction at the time of presentation, which may be attributed to the large size of the chalazion (>5 mm). The study conducted by Jin KW et al., found that large chalazia of the upper eyelid could induce significant corneal astigmatism, leading to unstable refractive errors in the affected eye [1]. Most patients-63% of the study population-had no associated symptoms and tended to present late for the management of chalazia. A trial of conservative management often failed in such cases, as observed in a clinical trial conducted by Wu AY et al., [12].

The treatment of chalazia includes frequent warm compresses, eyelid hygiene, and topical anti-inflammatory medications during the acute inflammatory phase. Most cases resolve within one month with these conservative measures [13]. Conservative management was carried out in 54.3% of cases prior to intralesional TA injection for controlling inflammation in recent onset chalazia or chalazia up to 2 mm in size. A response to conservative management was obtained in 52 (37.7%) cases, while 86 (62.3%) cases had no response to conservative management. Intralesional TA injection therapy is most effective when the chalazion has not become secondarily infected; if treatment is attempted and there is still no response, surgery is the method of choice, as stated by Jordan GA and Beier K, [13].

Intralesional steroid injection for the treatment of chalazia was first described by Leinfelder in 1964, and since then, many studies have established the efficacy of intralesional corticosteroid injections [1,3,14]. In the present study, 47 (34.1%) patients showed complete resolution of chalazia at four weeks following TA injection, while 70 (50.7%) cases showed a reduction in size. After six weeks of follow-up, 80.4% of patients demonstrated complete resolution of chalazia, with persistence of lesions in 13.1% of cases and recurrence in 6.5% of the study population. Additionally, 13.1% of cases failed to respond. These findings were corroborated by a study conducted by Goawalla A and Lee V, who found an 84% resolution rate after intralesional injection of TA, which was close to the 87% resolution rate achieved by I&C, concluding that the former is a successful mode of treatment [3]. A clinical trial conducted by Watson AP and Austin DJ, also showed that 77% of cases resolved completely by three weeks with a single injection of TA, with 54% requiring a second injection [15].

In another study conducted by Vidaurri LJ and Pe’er J, 71% of cases resolved after the first injection, while Wong MYY et al., observed a 50% reduction in size in 81.3% of chalazia at four weeks, with 83% achieving complete resolution at 6 weeks [16,17]. An even higher success rate of 94.1% was reported by Prasad S et al., [18]. Chung CF et al., concluded that the success rate of intralesional TA injection was 93.8% [14]. The average time to resolution after the intralesional injection of TA was found to be 2.16±1.46 weeks. This observation was similar to the findings of studies conducted by Pavicic-Astalos J et al., and Ben Simon GJ et al., [11,19].

A total of 47.2% of the present study population required a second dose of injection at two weeks, 44.44% required a second dose at four weeks, and 14.29% of cases required a third dose of injection for complete resolution by six weeks. This finding is corroborated by a study conducted by Huang L et al., which observed that 36.23% of the study population required two doses of injections, 33.3% required only a single injection, and 19.6% of cases required up to three injections for complete resolution. A greater number of injections were needed for patients with large primary chalazia, recurrent chalazia, multiple chalazia, those with poor lid hygiene, and those with associated blepharitis [19].

In 97.8% of cases, intralesional injections of TA were administered via the transcutaneous route, which was an easy and safe procedure for both small and large chalazia (>5 mm), as concluded by the study of Vidaurri LJ and Pe’er J., [16]. In the study by Sloas HA et al., intralesional TA injection was found to be a successful therapy, and its effect was not merely due to mechanical disruption of the lesion but also involved modification of the pathogenesis [20].

In the present study, 27.5% of cases presented with chalazia located close to the lacrimal punctum, creating a challenging situation for any I&C performed, as it could easily damage the lacrimal apparatus. In a study by Castren J and Stenborg T, perfect recovery was achieved in 88% of cases following steroid therapy when the chalazion had not become secondarily infected [21]. They found this treatment to be particularly suitable for chalazia located near the lacrimal punctum.

The most common complication found in the present study was lid depigmentation or an uneven scar occurring between two to six weeks following TA injection. At the four-week follow-up, it was noted that 130 (94.2%) patients had no complications. Complications observed at the injection site included depigmentation alone in 4 (2.9%) patients, an uneven scar in 1 (0.7%) patient, and local eyelid fat atrophy with skin thinning in 3 (2.2%) patients. These findings are corroborated by a study conducted by Ho SY and Lai SJ., which reported skin depigmentation at the site of injection in only two patients [22]. Sloas HA et al., observed pain and discomfort as common complaints following TA injection [20]. No significant complications were reported in the study conducted by Lee JW et al., [23].

At the six-week follow-up, localised depigmentation was noted in 7 (5.1%) patients, scarring was seen in 2 (1.4%) patients, and eyelid fat atrophy with local skin thinning was observed in 4 (2.9%) patients in the present study. Eun JK et al., noted that a higher concentration of TA was more frequently related to yellow deposition at the injection site [24]. This complication has also been reported in other case series [25] and is thought to be caused by inhibition of melanosome synthesis, impaired transfer of the melanosome to the keratinocyte, or melanocyte ischaemia [26].

Patients who failed to respond or showed persistence of lesions during follow-up, even after receiving up to two additional doses, underwent I&C. Steroid therapy is most effective when the chalazion has not become secondarily infected. If treatment is attempted and yet no response is obtained, then I&C surgery is the method of choice [8].

There was a limited time span (6 weeks) for follow-up, which could have affected the findings of the study, including the need for repeating injections for an effective response. Additionally, the long-term complications and the actual rate of recurrence following the procedure cannot be definitively concluded. A major limitation of this study was the lack of a control group.

Intralesional injection of TA is a simple, fast, and less painful procedure for uncomplicated chalazia measuring 2 mm to 10 mm. However, the true efficacy of present treatment can be determined only by conducting a long-term, multicentric randomised controlled trial.